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000
FXUS61 KRNK 191149
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
749 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN
ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW
AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT
CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT SUNDAY...

WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY
AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC
SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA.
LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL
RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST
LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE
RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER
06Z/2AM.

TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE
INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY.
LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES
AND DEW POINTS REMAINING MAINLY IN THE 50S.

THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY
VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW
CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT
CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...

THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS
TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL
DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR
SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS
OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE
INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING.
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.

A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 745 AM EDT SUNDAY...

RAIN HAD ADVANCED INTO SOUTHWEST VIRGINIA AND WESTERN NORTH
CAROLINA THIS MORNING WITH CEILINGS LOWERING IN ADVANCE OF THE
RAIN. RAIN WILL BEGIN AT KBLF AROUND THE 12Z START OF THE TAF TIME
AND BY 16Z/NOON AT THE OTHER TAF SITES.

A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE TODAY
AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS TODAY.
WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE
RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH
THE SURFACE. HAVE LLWS IN THE KDAN...KLWB AND KBCB TAFS AFTER
00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR BY THIS AFTERNOON AND WILL REMAIN LOW OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 430 AM EDT SUNDAY...

HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE
AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF
ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE
THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT
WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED
INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL
AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY
RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME.

TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.

PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032.
     FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR VAZ022>024-033>035.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...AMS




000
FXUS61 KRNK 191149
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
749 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN
ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW
AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT
CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT SUNDAY...

WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY
AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC
SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA.
LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL
RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST
LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE
RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER
06Z/2AM.

TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE
INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY.
LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES
AND DEW POINTS REMAINING MAINLY IN THE 50S.

THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY
VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW
CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT
CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...

THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS
TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL
DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR
SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS
OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE
INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING.
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.

A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 745 AM EDT SUNDAY...

RAIN HAD ADVANCED INTO SOUTHWEST VIRGINIA AND WESTERN NORTH
CAROLINA THIS MORNING WITH CEILINGS LOWERING IN ADVANCE OF THE
RAIN. RAIN WILL BEGIN AT KBLF AROUND THE 12Z START OF THE TAF TIME
AND BY 16Z/NOON AT THE OTHER TAF SITES.

A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE TODAY
AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS TODAY.
WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE
RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH
THE SURFACE. HAVE LLWS IN THE KDAN...KLWB AND KBCB TAFS AFTER
00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR BY THIS AFTERNOON AND WILL REMAIN LOW OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 430 AM EDT SUNDAY...

HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE
AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF
ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE
THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT
WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED
INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL
AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY
RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME.

TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.

PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032.
     FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR VAZ022>024-033>035.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...AMS




000
FXUS61 KRNK 191149
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
749 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN
ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW
AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT
CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT SUNDAY...

WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY
AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC
SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA.
LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL
RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST
LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE
RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER
06Z/2AM.

TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE
INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY.
LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES
AND DEW POINTS REMAINING MAINLY IN THE 50S.

THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY
VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW
CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT
CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...

THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS
TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL
DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR
SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS
OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE
INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING.
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.

A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 745 AM EDT SUNDAY...

RAIN HAD ADVANCED INTO SOUTHWEST VIRGINIA AND WESTERN NORTH
CAROLINA THIS MORNING WITH CEILINGS LOWERING IN ADVANCE OF THE
RAIN. RAIN WILL BEGIN AT KBLF AROUND THE 12Z START OF THE TAF TIME
AND BY 16Z/NOON AT THE OTHER TAF SITES.

A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE TODAY
AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS TODAY.
WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE
RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH
THE SURFACE. HAVE LLWS IN THE KDAN...KLWB AND KBCB TAFS AFTER
00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR BY THIS AFTERNOON AND WILL REMAIN LOW OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 430 AM EDT SUNDAY...

HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE
AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF
ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE
THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT
WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED
INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL
AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY
RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME.

TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.

PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032.
     FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR VAZ022>024-033>035.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...AMS





000
FXUS61 KRNK 190905
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
505 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN
ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW
AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT
CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT SUNDAY...

WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY
AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC
SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA.
LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL
RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST
LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE
RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER
06Z/2AM.

TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE
INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY.
LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES
AND DEW POINTS REMAINING MAINLY IN THE 50S.

THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY
VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW
CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT
CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...

THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS
TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL
DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR
SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS
OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE
INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING.
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.

A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.


&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH
PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE
STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN
THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW
OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 430 AM EDT SUNDAY...

HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE
AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF
ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE
THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT
WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED
INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL
AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY
RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME.

TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.

PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032.
     FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR VAZ022>024-033>035.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...AMS





000
FXUS61 KRNK 190905
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
505 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN
ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW
AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT
CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT SUNDAY...

WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY
AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC
SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA.
LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL
RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST
LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE
RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER
06Z/2AM.

TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE
INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY.
LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES
AND DEW POINTS REMAINING MAINLY IN THE 50S.

THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY
VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW
CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT
CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...

THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS
TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL
DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR
SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS
OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE
INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING.
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.

A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.


&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH
PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE
STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN
THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW
OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 430 AM EDT SUNDAY...

HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE
AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF
ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE
THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT
WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED
INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL
AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY
RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME.

TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.

PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032.
     FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR VAZ022>024-033>035.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...AMS




000
FXUS61 KRNK 190547
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
147 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 912 PM EDT SATURDAY

STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH
PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE
STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN
THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW
OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ015>017-032.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...PH




000
FXUS61 KRNK 190547
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
147 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 912 PM EDT SATURDAY

STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH
PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE
STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN
THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW
OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ015>017-032.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...PH





000
FXUS61 KRNK 190547
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
147 AM EDT SUN APR 19 2015

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 912 PM EDT SATURDAY

STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH
PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE
STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN
THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM.

A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW
OVERNIGHT.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.

&&

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ015>017-032.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...PH




000
FXUS61 KRNK 190132
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
932 PM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 912 PM EDT SATURDAY

STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AS OF 735 PM EDT SATURDAY...

ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY
WITH LOSS OF HEATING.

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND
CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG
AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED
TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE
POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL
BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND
SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS
IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL
THE FRONT CLEARS THE REGION MONDAY EVENING

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PC/PH
HYDROLOGY...PH




000
FXUS61 KRNK 190132
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
932 PM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 912 PM EDT SATURDAY

STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AS OF 735 PM EDT SATURDAY...

ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY
WITH LOSS OF HEATING.

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND
CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG
AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED
TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE
POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL
BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND
SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS
IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL
THE FRONT CLEARS THE REGION MONDAY EVENING

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PC/PH
HYDROLOGY...PH





000
FXUS61 KRNK 182342
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
742 PM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 712 PM EDT SATURDAY

A FEW ISOLATED SHOWERS AND THUNDERSTORMS POPPED UP THIS
AFTERNOON...MAINLY SOUTH OF HIGHWAY 460 IN THE WEST AND SOUTH OF
THE VA-NC BORDER EAST. THIS CONVECTION WILL FADE WITH LOSE OF
HEATING THIS EVENING. RAIN CHANCES WILL INCREASE OVERNIGHT AS A
STRONG AREA OF LOW PRESSURE APPROACHES THE REGION.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 735 PM EDT SATURDAY...

ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY
WITH LOSS OF HEATING.

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND
CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG
AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED
TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE
POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL
BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND
SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS
IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL
THE FRONT CLEARS THE REGION MONDAY EVENING

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PC/PH
HYDROLOGY...PH




000
FXUS61 KRNK 182342
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
742 PM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 712 PM EDT SATURDAY

A FEW ISOLATED SHOWERS AND THUNDERSTORMS POPPED UP THIS
AFTERNOON...MAINLY SOUTH OF HIGHWAY 460 IN THE WEST AND SOUTH OF
THE VA-NC BORDER EAST. THIS CONVECTION WILL FADE WITH LOSE OF
HEATING THIS EVENING. RAIN CHANCES WILL INCREASE OVERNIGHT AS A
STRONG AREA OF LOW PRESSURE APPROACHES THE REGION.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 735 PM EDT SATURDAY...

ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY
WITH LOSS OF HEATING.

MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND
CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG
AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED
TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE
POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL
BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND
SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES.

EXTENDED AVIATION...

A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS
IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL
THE FRONT CLEARS THE REGION MONDAY EVENING

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PC/PH
HYDROLOGY...PH





000
FXUS61 KRNK 182312
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
712 PM EDT SAT APR 18 2015

.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING
A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT
TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON
MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF
NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 712 PM EDT SATURDAY

A FEW ISOLATED SHOWERS AND THUNDERSTORMS POPPED UP THIS
AFTERNOON...MAINLY SOUTH OF HIGHWAY 460 IN THE WEST AND SOUTH OF
THE VA-NC BORDER EAST. THIS CONVECTION WILL FADE WITH LOSE OF
HEATING THIS EVENING. RAIN CHANCES WILL INCREASE OVERNIGHT AS A
STRONG AREA OF LOW PRESSURE APPROACHES THE REGION.

PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...

VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.

FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PH




000
FXUS61 KRNK 182001
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
401 PM EDT SAT APR 18 2015

.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING
A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT
TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON
MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF
NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...

VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.

FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PH





000
FXUS61 KRNK 182001
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
401 PM EDT SAT APR 18 2015

.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING
A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT
TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON
MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF
NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...

VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.

FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PH




000
FXUS61 KRNK 182001
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
401 PM EDT SAT APR 18 2015

.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING
A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT
TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON
MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF
NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...

VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.

FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PH





000
FXUS61 KRNK 182001
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
401 PM EDT SAT APR 18 2015

.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING
A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT
TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON
MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF
NEXT WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 300 PM EDT SATURDAY

WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.

ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.

PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.

CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...

HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...

MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...

VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.

FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...

ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     VAZ015>017-032.
NC...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
     NCZ001>003-018>020.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PH




000
FXUS61 KRNK 181721
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
121 PM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM EDT SATURDAY...

TEMPERATURES ARE RAPIDLY CLIMBING UNDER ABUNDANT SUNSHINE THIS
MORNING AND 13Z TEMPS ARE ALREADY RUNNING A FEW DEGREES HIGHER
THAN FORECAST. AS A RESULT...CONTINUED THE TREND OF INCREASING
TEMPS TODAY AND NUDGED HIGHS UP A COUPLE OF DEGREES.

MODELS ARE IN GOOD AGREEMENT THAT THE AXIS OF SFC HIGH PRESSURE
SHIFTS EAST...ALLOWING LOW LEVEL WINDS TO VEER TO THE EAST LATER
TODAY. ALOFT...WEAK AREAS OF SHEARED VORTICITY WILL DRIFT ACROSS
NC OVER A BUILDING RIDGE. WEAK LOW LEVEL CONVERGENCE...INCREASING
PWATS...FORECAST CAPES OF 100-500 J/KG AND THESE SUBTLE UPPER
DISTURBANCES...SHOULD GENERATE SOME ISOLATED
SHOWERS/STORMS...ESPECIALLY ALONG THE EAST SLOPES OF THE SOUTHERN
BLUE RIDGE.

FOR TONIGHT...WINDS CONTINUE TO VEER TO THE SOUTHEAST WIT BUFKIT
SHOWING A LOW LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40
KNOT RANGE AFTER 06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER
MOISTURE...RAIN WILL ALSO SPREAD INTO THE COUNTY WARNING AREA FROM
THE SOUTHWEST AFTER MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION
WILL MEAN LOW TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...

VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.

FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PH




000
FXUS61 KRNK 181721
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
121 PM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM EDT SATURDAY...

TEMPERATURES ARE RAPIDLY CLIMBING UNDER ABUNDANT SUNSHINE THIS
MORNING AND 13Z TEMPS ARE ALREADY RUNNING A FEW DEGREES HIGHER
THAN FORECAST. AS A RESULT...CONTINUED THE TREND OF INCREASING
TEMPS TODAY AND NUDGED HIGHS UP A COUPLE OF DEGREES.

MODELS ARE IN GOOD AGREEMENT THAT THE AXIS OF SFC HIGH PRESSURE
SHIFTS EAST...ALLOWING LOW LEVEL WINDS TO VEER TO THE EAST LATER
TODAY. ALOFT...WEAK AREAS OF SHEARED VORTICITY WILL DRIFT ACROSS
NC OVER A BUILDING RIDGE. WEAK LOW LEVEL CONVERGENCE...INCREASING
PWATS...FORECAST CAPES OF 100-500 J/KG AND THESE SUBTLE UPPER
DISTURBANCES...SHOULD GENERATE SOME ISOLATED
SHOWERS/STORMS...ESPECIALLY ALONG THE EAST SLOPES OF THE SOUTHERN
BLUE RIDGE.

FOR TONIGHT...WINDS CONTINUE TO VEER TO THE SOUTHEAST WIT BUFKIT
SHOWING A LOW LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40
KNOT RANGE AFTER 06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER
MOISTURE...RAIN WILL ALSO SPREAD INTO THE COUNTY WARNING AREA FROM
THE SOUTHWEST AFTER MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION
WILL MEAN LOW TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...

VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.

FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.

CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PH





000
FXUS61 KRNK 181335
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
935 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM EDT SATURDAY...

TEMPERATURES ARE RAPIDLY CLIMBING UNDER ABUNDANT SUNSHINE THIS
MORNING AND 13Z TEMPS ARE ALREADY RUNNING A FEW DEGREES HIGHER
THAN FORECAST. AS A RESULT...CONTINUED THE TREND OF INCREASING
TEMPS TODAY AND NUDGED HIGHS UP A COUPLE OF DEGREES.

MODELS ARE IN GOOD AGREEMENT THAT THE AXIS OF SFC HIGH PRESSURE
SHIFTS EAST...ALLOWING LOW LEVEL WINDS TO VEER TO THE EAST LATER
TODAY. ALOFT...WEAK AREAS OF SHEARED VORTICITY WILL DRIFT ACROSS
NC OVER A BUILDING RIDGE. WEAK LOW LEVEL CONVERGENCE...INCREASING
PWATS...FORECAST CAPES OF 100-500 J/KG AND THESE SUBTLE UPPER
DISTURBANCES...SHOULD GENERATE SOME ISOLATED
SHOWERS/STORMS...ESPECIALLY ALONG THE EAST SLOPES OF THE SOUTHERN
BLUE RIDGE.

FOR TONIGHT...WINDS CONTINUE TO VEER TO THE SOUTHEAST WIT BUFKIT
SHOWING A LOW LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40
KNOT RANGE AFTER 06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER
MOISTURE...RAIN WILL ALSO SPREAD INTO THE COUNTY WARNING AREA FROM
THE SOUTHWEST AFTER MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION
WILL MEAN LOW TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. LOCATIONS THAT HAVE SOME MVFR FOG
WILL BECOME VFR BY 14Z/10AM THIS MORNING...THEN VFR CONDITIONS ARE
EXPECTED FOR THE REST OF THE DAY.

THERE MAY BE ENOUGH WEAK CONVERGENCE AND UPSLOPE TO TRIGGER A FEW
ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR BLUE
RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO LOW
TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER MIDNIGHT/04Z. HIGHEST CONFIDENCE IN MVFR
CEILINGS IS AT KBCB AFTER 06Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT.
WIND GUSTS UP TO 30 KNOTS ARE POSSIBLE AT KBLF BY 12Z. BUFKIT
SOUNDINGS WERE SUGGESTING THAT STRONGER WINDS WOULD REMAIN JUST
ABOVE THE SURFACE AT KBCB...RESULTING IN LOW LEVEL WIND SHEAR.
CONFIDENCE IS LOW FOR HOW MUCH WIND WILL MIX DOWN TO THE SURFACE.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/SK





000
FXUS61 KRNK 181335
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
935 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM EDT SATURDAY...

TEMPERATURES ARE RAPIDLY CLIMBING UNDER ABUNDANT SUNSHINE THIS
MORNING AND 13Z TEMPS ARE ALREADY RUNNING A FEW DEGREES HIGHER
THAN FORECAST. AS A RESULT...CONTINUED THE TREND OF INCREASING
TEMPS TODAY AND NUDGED HIGHS UP A COUPLE OF DEGREES.

MODELS ARE IN GOOD AGREEMENT THAT THE AXIS OF SFC HIGH PRESSURE
SHIFTS EAST...ALLOWING LOW LEVEL WINDS TO VEER TO THE EAST LATER
TODAY. ALOFT...WEAK AREAS OF SHEARED VORTICITY WILL DRIFT ACROSS
NC OVER A BUILDING RIDGE. WEAK LOW LEVEL CONVERGENCE...INCREASING
PWATS...FORECAST CAPES OF 100-500 J/KG AND THESE SUBTLE UPPER
DISTURBANCES...SHOULD GENERATE SOME ISOLATED
SHOWERS/STORMS...ESPECIALLY ALONG THE EAST SLOPES OF THE SOUTHERN
BLUE RIDGE.

FOR TONIGHT...WINDS CONTINUE TO VEER TO THE SOUTHEAST WIT BUFKIT
SHOWING A LOW LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40
KNOT RANGE AFTER 06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER
MOISTURE...RAIN WILL ALSO SPREAD INTO THE COUNTY WARNING AREA FROM
THE SOUTHWEST AFTER MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION
WILL MEAN LOW TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. LOCATIONS THAT HAVE SOME MVFR FOG
WILL BECOME VFR BY 14Z/10AM THIS MORNING...THEN VFR CONDITIONS ARE
EXPECTED FOR THE REST OF THE DAY.

THERE MAY BE ENOUGH WEAK CONVERGENCE AND UPSLOPE TO TRIGGER A FEW
ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR BLUE
RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO LOW
TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER MIDNIGHT/04Z. HIGHEST CONFIDENCE IN MVFR
CEILINGS IS AT KBCB AFTER 06Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT.
WIND GUSTS UP TO 30 KNOTS ARE POSSIBLE AT KBLF BY 12Z. BUFKIT
SOUNDINGS WERE SUGGESTING THAT STRONGER WINDS WOULD REMAIN JUST
ABOVE THE SURFACE AT KBCB...RESULTING IN LOW LEVEL WIND SHEAR.
CONFIDENCE IS LOW FOR HOW MUCH WIND WILL MIX DOWN TO THE SURFACE.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/SK




000
FXUS61 KRNK 181123
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
723 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 425 AM EDT SATURDAY...

ISOLATED THUNDERSTORMS NEAR FARMVILLE HAS DISSIPATED. GENERAL
TREND SHOWN ON SATELLITE WAS DIMINISHING COVERAGE OF MID AND HIGH
CLOUDS. STRATUS AND FOG WERE FORMING ALONG THE SOUTHERN BLUE RIDGE
AND FOOTHILLS AND IN THE GREENBRIER VALLEY. FOG WILL CONTINUE TO
DEVELOP IN THE WESTERN VALLEYS EARLY THIS MORNING...ESPECIALLY IN
AREAS THAT CLEAR OUT OF THE HIGH CLOUDS.

TREND IN MODELS WAS FOR DRIER AIR TO COME IN AT MID AND UPPER
LEVELS TODAY. SOME DIFFERENCES IN HOW MUCH LOW LEVEL MOISTURE WILL
BE AVAILABLE AS WELL AS THE AMOUNT OF UPSLOPE BEING ENOUGH
GENERATE ANY SHOWERS. HAVE HELD PROBABILITY OF RAIN TO THIS
AFTERNOON WHEN THE PREVAILING SURFACE AND LOW LEVEL WINDS WILL BE
OUT OF THE NORTHEAST TO EAST.

TEMPERATURES WILL BE STARTING VERY MILD THIS MORNING. EXPECT
ENOUGH SUNSHINE FOR AT LEAST A 20 TO 25 DEGREE RISE WHICH WOULD
PUT MAXIMUM TEMPERATURES TODAY CLOSE TO THE WARMER GUIDANCE.

WINDS CONTINUE TO VEER TO THE SOUTHEAST TONIGHT. BUFKIT SHOWED LOW
LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40 KNOT RANGE AFTER
06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER MOISTURE...RAIN WILL
ALSO SPREAD INTO THE COUNTY WARNING AREA FROM THE SOUTHWEST AFTER
MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION WILL MEAN LOW
TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. LOCATIONS THAT HAVE SOME MVFR FOG
WILL BECOME VFR BY 14Z/10AM THIS MORNING...THEN VFR CONDITIONS ARE
EXPECTED FOR THE REST OF THE DAY.

THERE MAY BE ENOUGH WEAK CONVERGENCE AND UPSLOPE TO TRIGGER A FEW
ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR BLUE
RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO LOW
TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER MIDNIGHT/04Z. HIGHEST CONFIDENCE IN MVFR
CEILINGS IS AT KBCB AFTER 06Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT.
WIND GUSTS UP TO 30 KNOTS ARE POSSIBLE AT KBLF BY 12Z. BUFKIT
SOUNDINGS WERE SUGGESTING THAT STRONGER WINDS WOULD REMAIN JUST
ABOVE THE SURFACE AT KBCB...RESULTING IN LOW LEVEL WIND SHEAR.
CONFIDENCE IS LOW FOR HOW MUCH WIND WILL MIX DOWN TO THE SURFACE.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/SK




000
FXUS61 KRNK 181123
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
723 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 425 AM EDT SATURDAY...

ISOLATED THUNDERSTORMS NEAR FARMVILLE HAS DISSIPATED. GENERAL
TREND SHOWN ON SATELLITE WAS DIMINISHING COVERAGE OF MID AND HIGH
CLOUDS. STRATUS AND FOG WERE FORMING ALONG THE SOUTHERN BLUE RIDGE
AND FOOTHILLS AND IN THE GREENBRIER VALLEY. FOG WILL CONTINUE TO
DEVELOP IN THE WESTERN VALLEYS EARLY THIS MORNING...ESPECIALLY IN
AREAS THAT CLEAR OUT OF THE HIGH CLOUDS.

TREND IN MODELS WAS FOR DRIER AIR TO COME IN AT MID AND UPPER
LEVELS TODAY. SOME DIFFERENCES IN HOW MUCH LOW LEVEL MOISTURE WILL
BE AVAILABLE AS WELL AS THE AMOUNT OF UPSLOPE BEING ENOUGH
GENERATE ANY SHOWERS. HAVE HELD PROBABILITY OF RAIN TO THIS
AFTERNOON WHEN THE PREVAILING SURFACE AND LOW LEVEL WINDS WILL BE
OUT OF THE NORTHEAST TO EAST.

TEMPERATURES WILL BE STARTING VERY MILD THIS MORNING. EXPECT
ENOUGH SUNSHINE FOR AT LEAST A 20 TO 25 DEGREE RISE WHICH WOULD
PUT MAXIMUM TEMPERATURES TODAY CLOSE TO THE WARMER GUIDANCE.

WINDS CONTINUE TO VEER TO THE SOUTHEAST TONIGHT. BUFKIT SHOWED LOW
LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40 KNOT RANGE AFTER
06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER MOISTURE...RAIN WILL
ALSO SPREAD INTO THE COUNTY WARNING AREA FROM THE SOUTHWEST AFTER
MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION WILL MEAN LOW
TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. LOCATIONS THAT HAVE SOME MVFR FOG
WILL BECOME VFR BY 14Z/10AM THIS MORNING...THEN VFR CONDITIONS ARE
EXPECTED FOR THE REST OF THE DAY.

THERE MAY BE ENOUGH WEAK CONVERGENCE AND UPSLOPE TO TRIGGER A FEW
ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR BLUE
RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO LOW
TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.

MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER MIDNIGHT/04Z. HIGHEST CONFIDENCE IN MVFR
CEILINGS IS AT KBCB AFTER 06Z/2AM.

A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT.
WIND GUSTS UP TO 30 KNOTS ARE POSSIBLE AT KBLF BY 12Z. BUFKIT
SOUNDINGS WERE SUGGESTING THAT STRONGER WINDS WOULD REMAIN JUST
ABOVE THE SURFACE AT KBCB...RESULTING IN LOW LEVEL WIND SHEAR.
CONFIDENCE IS LOW FOR HOW MUCH WIND WILL MIX DOWN TO THE SURFACE.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/SK




000
FXUS61 KRNK 180844
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
444 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 425 AM EDT SATURDAY...

ISOLATED THUNDERSTORMS NEAR FARMVILLE HAS DISSIPATED. GENERAL
TREND SHOWN ON SATELLITE WAS DIMINISHING COVERAGE OF MID AND HIGH
CLOUDS. STRATUS AND FOG WERE FORMING ALONG THE SOUTHERN BLUE RIDGE
AND FOOTHILLS AND IN THE GREENBRIER VALLEY. FOG WILL CONTINUE TO
DEVELOP IN THE WESTERN VALLEYS EARLY THIS MORNING...ESPECIALLY IN
AREAS THAT CLEAR OUT OF THE HIGH CLOUDS.

TREND IN MODELS WAS FOR DRIER AIR TO COME IN AT MID AND UPPER
LEVELS TODAY. SOME DIFFERENCES IN HOW MUCH LOW LEVEL MOISTURE WILLBE
AVAILABLE AS WELL AS THE AMOUNT OF UPSLOPE BEING ENOUGH GENERATE
ANY SHOWERS. HAVE HELD PROBABILITY OF RAIN TO THIS AFTERNOON WHEN
THE PREVAILING SURFACE AND LOW LEVEL WINDS WILL BE OUT OF THE
NORTHEAST TO EAST.

TEMPERATURES WILL BE STARTING VERY MILD THIS MORNING. EXPECT
ENOUGH SUNSHINE FOR AT LEAST A 20 TO 25 DEGREE RISE WHICH WOULD
PUT MAXIMUM TEMPERATURES TODAY CLOSE TO THE WARMER GUIDANCE.

WINDS CONTINUE TO VEER TO THE SOUTHEAST TONIGHT. BUFKIT SHOWED LOW
LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40 KNOT RANGE AFTER
06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER MOISTURE...RAIN WILL
ALSO SPREAD INTO THE COUNTY WARNING AREA FROM THE SOUTHWEST AFTER
MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION WILL MEAN LOW
TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. SOME FOG HAD DEVELOPED IN THE
VALLEYS IN AREAS WHERE THE HIGH CLOUDS HAD CLEARED OUT. ISOLATED
THUNDERSTORMS EAST OF LYNCHBURG WILL NOT IMPACT TAF SITES.
LOCATIONS THAT HAVE SOME CLEARING EARLY THIS MORNING MAY HAVE FOG
DEVELOPMENT...ESPECIALLY IN THE VALLEYS WEST OF THE BLUE RIDGE.
HIGHEST CONFIDENCE OF FOG FORMING IS AT KBCB WERE THE DEW POINT
DEPRESSION WAS ALREADY SMALL. FOG WILL BRING THE VISIBILITY DOWN
TO IFR VALUES...POSSIBLY LIFR AT KLWB AFTER 10Z/6AM.

ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/SK





000
FXUS61 KRNK 180844
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
444 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT...BEFORE A COLD FRONT CROSSES THE REGION WITH A
CHANCE OF SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS ON MONDAY.
HIGH PRESSURE...ALONG WITH DRY AND COOLER WEATHER...RETURNS FOR
TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 425 AM EDT SATURDAY...

ISOLATED THUNDERSTORMS NEAR FARMVILLE HAS DISSIPATED. GENERAL
TREND SHOWN ON SATELLITE WAS DIMINISHING COVERAGE OF MID AND HIGH
CLOUDS. STRATUS AND FOG WERE FORMING ALONG THE SOUTHERN BLUE RIDGE
AND FOOTHILLS AND IN THE GREENBRIER VALLEY. FOG WILL CONTINUE TO
DEVELOP IN THE WESTERN VALLEYS EARLY THIS MORNING...ESPECIALLY IN
AREAS THAT CLEAR OUT OF THE HIGH CLOUDS.

TREND IN MODELS WAS FOR DRIER AIR TO COME IN AT MID AND UPPER
LEVELS TODAY. SOME DIFFERENCES IN HOW MUCH LOW LEVEL MOISTURE WILLBE
AVAILABLE AS WELL AS THE AMOUNT OF UPSLOPE BEING ENOUGH GENERATE
ANY SHOWERS. HAVE HELD PROBABILITY OF RAIN TO THIS AFTERNOON WHEN
THE PREVAILING SURFACE AND LOW LEVEL WINDS WILL BE OUT OF THE
NORTHEAST TO EAST.

TEMPERATURES WILL BE STARTING VERY MILD THIS MORNING. EXPECT
ENOUGH SUNSHINE FOR AT LEAST A 20 TO 25 DEGREE RISE WHICH WOULD
PUT MAXIMUM TEMPERATURES TODAY CLOSE TO THE WARMER GUIDANCE.

WINDS CONTINUE TO VEER TO THE SOUTHEAST TONIGHT. BUFKIT SHOWED LOW
LEVEL SOUTHEAST JET INCREASING INTO THE 35 TO 40 KNOT RANGE AFTER
06Z/2AM. WITH INCREASING UPSLOPE AND DEEPER MOISTURE...RAIN WILL
ALSO SPREAD INTO THE COUNTY WARNING AREA FROM THE SOUTHWEST AFTER
MIDNIGHT. CLOUDS AND THE LACK OF ANY ADVECTION WILL MEAN LOW
TEMPERATURES WILL AGAIN BE MILD OVERNIGHT.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM EDT SATURDAY...

MODELS ARE FAIRLY CONSISTENT WITH HANDLING THE UPCOMING RAIN EVENT WITH
THE MAIN DIFFERENCES BEING TIMING AS THE GFS IS A FEW HOURS FASTER THAN
OTHER SOLUTIONS. HIGH PRESSURE WILL WEDGE DOWN THE EASTERN SEABOARD ON
SUNDAY AS DEEPENING LOW PRESSURE MOVES UP THE MISSISSIPPI VALLEY AND
PUSHES A WARM FRONT INTO THE REGION. SIGNIFICANT ISENTROPIC LIFT WILL
DEVELOP AS THE WARM AIR RUNS OVER THE WEDGE AND DEEP MOISTURE TRANSPORT
CONTINUES TO BRING ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES INTO THE
REGION. THE LOW LEVEL WIND FIELD WILL ALSO STRENGTHEN MARKEDLY FROM THE
SOUTHEAST SUNDAY AFTERNOON...ALLOWING FOR ENHANCED OROGRAPHIC LIFT
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE. ALL OF THESE FACTORS WILL
COMBINE TO BRING A SOAKING RAIN TO THE REGION SUNDAY INTO SUNDAY NIGHT.
DOWNSLOPING WILL HELP LIMIT RAINFALL AMOUNTS ACROSS THE FAR WEST TO
JUST UNDER ONE INCH...WITH MOST LOCATIONS EAST OF THE BLUE RIDGE
PICKING UP 1.0 TO 1.5 INCHES. THE HIGHEST TOTALS WILL LIKELY BE FOUND
ALONG THE EAST SLOPES OF THE BLUE RIDGE FROM NORTHWEST NC AND EXTENDING
ACROSS THE BORDER INTO VA WHERE AMOUNTS MAY APPROACH 2.0 INCHES. THE
LATEST ENSEMBLE HYDRO GUIDANCE INDICATES FORECAST POINTS IN THE ROANOKE
RIVER BASIN WILL LIKELY EXCEED ACTIONS STAGE AND APPROACH FLOOD
STAGE...AND SMALLER STREAMS AND CREEKS WILL ALSO EXPERIENCE SHARP
RISES. THIS SITUATION WILL CONTINUE TO BE MONITORED FOR THE THREAT
OF FLOODING AND FLOOD WATCHES MAY BE ISSUED LATER TODAY.

INDICATIONS ARE THAT THE CORE OF THE SOUTHEASTERLY LOW LEVEL JET WILL
MOVE JUST TO OUR WEST. THIS COMBINED WITH INEFFICIENT DOWNWARD MOMENTUM
TRANSFER ONCE PRECIPITATION BEGINS SHOULD MITIGATE THE THREAT FOR
ADVISORY LEVEL WINDS IN DOWNSLOPING AREAS WEST OF THE BLUE RIDGE ON
SUNDAY. HOWEVER...IT WILL STILL BE QUITE GUSTY ESPECIALLY ALONG THE
RIDGE.

LATER SUNDAY NIGHT AND INTO MONDAY THERE WILL BE A BREAK IN THE ACTION
AS WE GET SOLIDLY INTO THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THERE WILL BE ENOUGH INSTABILITY FOR THUNDERSTORMS TO DEVELOP
AHEAD OF THE FRONT ON MONDAY. THERE WILL BE ENOUGH SHEAR FOR A MARGINAL
SEVERE THREAT ACROSS MOST OF THE AREA BUT CONDITIONS LOOK MORE
FAVORABLE FROM THE PIEDMONT EASTWARD.

WE WILL THEN REMAIN UNDER THE INFLUENCE OF COOL CYCLONIC FLOW ON
TUESDAY AND CONDITIONS WILL BE UNSETTLED ENOUGH FOR A SLIGHT CHANCE OF
SHOWERS WEST OF THE BLUE RIDGE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. SOME FOG HAD DEVELOPED IN THE
VALLEYS IN AREAS WHERE THE HIGH CLOUDS HAD CLEARED OUT. ISOLATED
THUNDERSTORMS EAST OF LYNCHBURG WILL NOT IMPACT TAF SITES.
LOCATIONS THAT HAVE SOME CLEARING EARLY THIS MORNING MAY HAVE FOG
DEVELOPMENT...ESPECIALLY IN THE VALLEYS WEST OF THE BLUE RIDGE.
HIGHEST CONFIDENCE OF FOG FORMING IS AT KBCB WERE THE DEW POINT
DEPRESSION WAS ALREADY SMALL. FOG WILL BRING THE VISIBILITY DOWN
TO IFR VALUES...POSSIBLY LIFR AT KLWB AFTER 10Z/6AM.

ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/SK




000
FXUS61 KRNK 180554
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
154 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1012 PM EDT FRIDAY...

ISOLD SHOWERS HAVE DISSIPATED AND SEE NO REASON FOR ANY NEW ONES
TO FIRE UP OVERNIGHT...OTHER THAN ONE OR TWO ACROSS NORTHERN NC
GIVEN MUCAPE VALUES STILL AROUND 300-500 J/KG. ALSO KEEPING AN EYE
ON THE NORTHERN EDGE OF AREA OF SHOWERS INTO SW NC...WHICH IS
AHEAD OF A SHORT WAVE NEAR CHATTANOOGA...AS SOMETHING COULD SNEAK
INTO OUR NW NC MTNS AFTER MIDNIGHT...BUT MOST GUIDANCE AGREES
THIS WILL STAY JUST TO OUR SOUTH. LEFT SLIGHT CHC POP ACROSS
SOUTHERN EDGE OF FCST AREA THROUGH MUCH OF THE NIGHT...BUT REMOVED
MENTION EVERYWHERE ELSE. TRENDS LOOK BETTER FOR MORE CLEARING FROM
WEST LATE...AND THUS POSSIBILITY OF SOME PATCHY VALLEY FOG WITH
WET GROUND SO ADDED THAT AS WELL...MAINLY TO MTN VALLEYS.
OVERNIGHT TEMPS LOOK ON TRACK AT THIS POINT.

PREV DISC AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOLD LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE
EASTERN OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER
OF MOISTURE NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN
POCKETS OF FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH.
LEANED TOWARD THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. SOME FOG HAD DEVELOPED IN THE
VALLEYS IN AREAS WHERE THE HIGH CLOUDS HAD CLEARED OUT. ISOLATED
THUNDERSTORMS EAST OF LYNCHBURG WILL NOT IMPACT TAF SITES.
LOCATIONS THAT HAVE SOME CLEARING EARLY THIS MORNING MAY HAVE FOG
DEVELOPMENT...ESPECIALLY IN THE VALLEYS WEST OF THE BLUE RIDGE.
HIGHEST CONFIDENCE OF FOG FORMING IS AT KBCB WERE THE DEW POINT
DEPRESSION WAS ALREADY SMALL. FOG WILL BRING THE VISIBILITY DOWN
TO IFR VALUES...POSSIBLY LIFR AT KLWB AFTER 10Z/6AM.

ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/SK





000
FXUS61 KRNK 180554
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
154 AM EDT SAT APR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1012 PM EDT FRIDAY...

ISOLD SHOWERS HAVE DISSIPATED AND SEE NO REASON FOR ANY NEW ONES
TO FIRE UP OVERNIGHT...OTHER THAN ONE OR TWO ACROSS NORTHERN NC
GIVEN MUCAPE VALUES STILL AROUND 300-500 J/KG. ALSO KEEPING AN EYE
ON THE NORTHERN EDGE OF AREA OF SHOWERS INTO SW NC...WHICH IS
AHEAD OF A SHORT WAVE NEAR CHATTANOOGA...AS SOMETHING COULD SNEAK
INTO OUR NW NC MTNS AFTER MIDNIGHT...BUT MOST GUIDANCE AGREES
THIS WILL STAY JUST TO OUR SOUTH. LEFT SLIGHT CHC POP ACROSS
SOUTHERN EDGE OF FCST AREA THROUGH MUCH OF THE NIGHT...BUT REMOVED
MENTION EVERYWHERE ELSE. TRENDS LOOK BETTER FOR MORE CLEARING FROM
WEST LATE...AND THUS POSSIBILITY OF SOME PATCHY VALLEY FOG WITH
WET GROUND SO ADDED THAT AS WELL...MAINLY TO MTN VALLEYS.
OVERNIGHT TEMPS LOOK ON TRACK AT THIS POINT.

PREV DISC AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOLD LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE
EASTERN OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER
OF MOISTURE NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN
POCKETS OF FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH.
LEANED TOWARD THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...

STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. SOME FOG HAD DEVELOPED IN THE
VALLEYS IN AREAS WHERE THE HIGH CLOUDS HAD CLEARED OUT. ISOLATED
THUNDERSTORMS EAST OF LYNCHBURG WILL NOT IMPACT TAF SITES.
LOCATIONS THAT HAVE SOME CLEARING EARLY THIS MORNING MAY HAVE FOG
DEVELOPMENT...ESPECIALLY IN THE VALLEYS WEST OF THE BLUE RIDGE.
HIGHEST CONFIDENCE OF FOG FORMING IS AT KBCB WERE THE DEW POINT
DEPRESSION WAS ALREADY SMALL. FOG WILL BRING THE VISIBILITY DOWN
TO IFR VALUES...POSSIBLY LIFR AT KLWB AFTER 10Z/6AM.

ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.

THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.

VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.

THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/SK




000
FXUS61 KRNK 180212
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1012 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 1012 PM EDT FRIDAY...

ISOLD SHOWERS HAVE DISSIPATED AND SEE NO REASON FOR ANY NEW ONES
TO FIRE UP OVERNIGHT...OTHER THAN ONE OR TWO ACROSS NORTHERN NC
GIVEN MUCAPE VALUES STILL AROUND 300-500 J/KG. ALSO KEEPING AN EYE
ON THE NORTHERN EDGE OF AREA OF SHOWERS INTO SW NC...WHICH IS
AHEAD OF A SHORT WAVE NEAR CHATTANOOGA...AS SOMETHING COULD SNEAK
INTO OUR NW NC MTNS AFTER MIDNIGHT...BUT MOST GUIDANCE AGREES
THIS WILL STAY JUST TO OUR SOUTH. LEFT SLIGHT CHC POP ACROSS
SOUTHERN EDGE OF FCST AREA THROUGH MUCH OF THE NIGHT...BUT REMOVED
MENTION EVERYWHERE ELSE. TRENDS LOOK BETTER FOR MORE CLEARING FROM
WEST LATE...AND THUS POSSIBILITY OF SOME PATCHY VALLEY FOG WITH
WET GROUND SO ADDED THAT AS WELL...MAINLY TO MTN VALLEYS.
OVERNIGHT TEMPS LOOK ON TRACK AT THIS POINT.

PREV DISC AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 750 PM EDT FRIDAY...

ISOLD SHOWERS NOT EXPECTED TO IMPACT ANY AIRPORTS THIS
EVENING...AND FOR MOST OF THE OVERNIGHT EXPECTING VFR CONDITIONS
AND LIGHT TO CALM WINDS WITH HIGH PRESSURE IN CONTROL. SOME
MOISTURE OFF TO SOUTH SHOULD REMAIN THERE WITH WEAK SHORT WAVE
MOVING IN FROM THE WEST ACROSS TENNESSEE AND SHUNTING AN AREA OF
SHOWERS EASTWARD. THIS WAVE WILL ALSO EVENTUALLY TAKE MID TO HIGH CLOUDS
EAST AND WITH CLEARING THERE IS LIKELY TO BE SOME RADIATION FOG
FORMING...LOWERED CONDITIONS TO IFR AT BLF...LWB...BCB...AND LYH
BY 08-09Z...BUT MOST CONFIDENT IN IFR CONDITIONS AT LWB AND BCB.
ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN DURING THE DAY SUNDAY INTO SUNDAY NIGHT...
FOLLOWED BY ANOTHER COLD FRONTAL PASSAGE MONDAY. THIS LIKELY TO
KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS THE
REGION LATER MONDAY. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY
WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH GOOD DRYING
EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH/SK




000
FXUS61 KRNK 180212
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1012 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 1012 PM EDT FRIDAY...

ISOLD SHOWERS HAVE DISSIPATED AND SEE NO REASON FOR ANY NEW ONES
TO FIRE UP OVERNIGHT...OTHER THAN ONE OR TWO ACROSS NORTHERN NC
GIVEN MUCAPE VALUES STILL AROUND 300-500 J/KG. ALSO KEEPING AN EYE
ON THE NORTHERN EDGE OF AREA OF SHOWERS INTO SW NC...WHICH IS
AHEAD OF A SHORT WAVE NEAR CHATTANOOGA...AS SOMETHING COULD SNEAK
INTO OUR NW NC MTNS AFTER MIDNIGHT...BUT MOST GUIDANCE AGREES
THIS WILL STAY JUST TO OUR SOUTH. LEFT SLIGHT CHC POP ACROSS
SOUTHERN EDGE OF FCST AREA THROUGH MUCH OF THE NIGHT...BUT REMOVED
MENTION EVERYWHERE ELSE. TRENDS LOOK BETTER FOR MORE CLEARING FROM
WEST LATE...AND THUS POSSIBILITY OF SOME PATCHY VALLEY FOG WITH
WET GROUND SO ADDED THAT AS WELL...MAINLY TO MTN VALLEYS.
OVERNIGHT TEMPS LOOK ON TRACK AT THIS POINT.

PREV DISC AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 750 PM EDT FRIDAY...

ISOLD SHOWERS NOT EXPECTED TO IMPACT ANY AIRPORTS THIS
EVENING...AND FOR MOST OF THE OVERNIGHT EXPECTING VFR CONDITIONS
AND LIGHT TO CALM WINDS WITH HIGH PRESSURE IN CONTROL. SOME
MOISTURE OFF TO SOUTH SHOULD REMAIN THERE WITH WEAK SHORT WAVE
MOVING IN FROM THE WEST ACROSS TENNESSEE AND SHUNTING AN AREA OF
SHOWERS EASTWARD. THIS WAVE WILL ALSO EVENTUALLY TAKE MID TO HIGH CLOUDS
EAST AND WITH CLEARING THERE IS LIKELY TO BE SOME RADIATION FOG
FORMING...LOWERED CONDITIONS TO IFR AT BLF...LWB...BCB...AND LYH
BY 08-09Z...BUT MOST CONFIDENT IN IFR CONDITIONS AT LWB AND BCB.
ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN DURING THE DAY SUNDAY INTO SUNDAY NIGHT...
FOLLOWED BY ANOTHER COLD FRONTAL PASSAGE MONDAY. THIS LIKELY TO
KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS THE
REGION LATER MONDAY. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY
WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH GOOD DRYING
EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH/SK





000
FXUS61 KRNK 172353
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
753 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 750 PM EDT FRIDAY...

ISOLD SHOWERS NOT EXPECTED TO IMPACT ANY AIRPORTS THIS
EVENING...AND FOR MOST OF THE OVERNIGHT EXPECTING VFR CONDITIONS
AND LIGHT TO CALM WINDS WITH HIGH PRESSURE IN CONTROL. SOME
MOISTURE OFF TO SOUTH SHOULD REMAIN THERE WITH WEAK SHORT WAVE
MOVING IN FROM THE WEST ACROSS TENNESSEE AND SHUNTING AN AREA OF
SHOWERS EASTWARD. THIS WAVE WILL ALSO EVENTUALLY TAKE MID TO HIGH CLOUDS
EAST AND WITH CLEARING THERE IS LIKELY TO BE SOME RADIATION FOG
FORMING...LOWERED CONDITIONS TO IFR AT BLF...LWB...BCB...AND LYH
BY 08-09Z...BUT MOST CONFIDENT IN IFR CONDITIONS AT LWB AND BCB.
ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN DURING THE DAY SUNDAY INTO SUNDAY NIGHT...
FOLLOWED BY ANOTHER COLD FRONTAL PASSAGE MONDAY. THIS LIKELY TO
KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS THE
REGION LATER MONDAY. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY
WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH GOOD DRYING
EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH/SK




000
FXUS61 KRNK 172353
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
753 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 750 PM EDT FRIDAY...

ISOLD SHOWERS NOT EXPECTED TO IMPACT ANY AIRPORTS THIS
EVENING...AND FOR MOST OF THE OVERNIGHT EXPECTING VFR CONDITIONS
AND LIGHT TO CALM WINDS WITH HIGH PRESSURE IN CONTROL. SOME
MOISTURE OFF TO SOUTH SHOULD REMAIN THERE WITH WEAK SHORT WAVE
MOVING IN FROM THE WEST ACROSS TENNESSEE AND SHUNTING AN AREA OF
SHOWERS EASTWARD. THIS WAVE WILL ALSO EVENTUALLY TAKE MID TO HIGH CLOUDS
EAST AND WITH CLEARING THERE IS LIKELY TO BE SOME RADIATION FOG
FORMING...LOWERED CONDITIONS TO IFR AT BLF...LWB...BCB...AND LYH
BY 08-09Z...BUT MOST CONFIDENT IN IFR CONDITIONS AT LWB AND BCB.
ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN DURING THE DAY SUNDAY INTO SUNDAY NIGHT...
FOLLOWED BY ANOTHER COLD FRONTAL PASSAGE MONDAY. THIS LIKELY TO
KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS THE
REGION LATER MONDAY. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY
WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH GOOD DRYING
EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH/SK




000
FXUS61 KRNK 172353
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
753 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 750 PM EDT FRIDAY...

ISOLD SHOWERS NOT EXPECTED TO IMPACT ANY AIRPORTS THIS
EVENING...AND FOR MOST OF THE OVERNIGHT EXPECTING VFR CONDITIONS
AND LIGHT TO CALM WINDS WITH HIGH PRESSURE IN CONTROL. SOME
MOISTURE OFF TO SOUTH SHOULD REMAIN THERE WITH WEAK SHORT WAVE
MOVING IN FROM THE WEST ACROSS TENNESSEE AND SHUNTING AN AREA OF
SHOWERS EASTWARD. THIS WAVE WILL ALSO EVENTUALLY TAKE MID TO HIGH CLOUDS
EAST AND WITH CLEARING THERE IS LIKELY TO BE SOME RADIATION FOG
FORMING...LOWERED CONDITIONS TO IFR AT BLF...LWB...BCB...AND LYH
BY 08-09Z...BUT MOST CONFIDENT IN IFR CONDITIONS AT LWB AND BCB.
ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN DURING THE DAY SUNDAY INTO SUNDAY NIGHT...
FOLLOWED BY ANOTHER COLD FRONTAL PASSAGE MONDAY. THIS LIKELY TO
KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS THE
REGION LATER MONDAY. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY
WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH GOOD DRYING
EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH/SK





000
FXUS61 KRNK 172236
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
636 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 635 PM EDT FRIDAY...

UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.

SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.

PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 120 PM EDT FRIDAY...

VFR WITH A FEW MVFR CIGS WERE NOTED ACROSS THE REGION EARLY THIS
AFTERNOON. CLOUDS SHOULD GRADUALLY SCATTERED THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING HOURS WITH LIGHT WINDS.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS
AFTERNOON...BUT COVERAGE WILL BE VERY LIMITED AND THE CHANCES OF
ONE OF THESE STRAY SHOWERS/STORMS IMPACTING A TAF SITE IS SMALL.

A SHALLOW LAYER OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE
TONIGHT...AND WITH LIGHT WINDS...POCKETS FOG REDUCING VISIBILITIES
TO IFR TO MVFR CATEGORIES WILL BE POSSIBLE LATE TONIGHT.

HIGH PRESSURE BUILDS NOSING DOWN INTO OUR REGION
SATURDAY...WILL USHER IN SLIGHTLY DRIER AIR ALLOWING MORNING
FOG/STRATUS TO QUICKLY ERODE...BRINGING VFR CONDITIONS TO ALL
AREAS BY MID-MORNING SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH





000
FXUS61 KRNK 171959
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
359 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 235 PM EDT MONDAY

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 120 PM EDT FRIDAY...

VFR WITH A FEW MVFR CIGS WERE NOTED ACROSS THE REGION EARLY THIS
AFTERNOON. CLOUDS SHOULD GRADUALLY SCATTERED THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING HOURS WITH LIGHT WINDS.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS
AFTERNOON...BUT COVERAGE WILL BE VERY LIMITED AND THE CHANCES OF
ONE OF THESE STRAY SHOWERS/STORMS IMPACTING A TAF SITE IS SMALL.

A SHALLOW LAYER OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE
TONIGHT...AND WITH LIGHT WINDS...POCKETS FOG REDUCING VISIBILITIES
TO IFR TO MVFR CATEGORIES WILL BE POSSIBLE LATE TONIGHT.

HIGH PRESSURE BUILDS NOSING DOWN INTO OUR REGION
SATURDAY...WILL USHER IN SLIGHTLY DRIER AIR ALLOWING MORNING
FOG/STRATUS TO QUICKLY ERODE...BRINGING VFR CONDITIONS TO ALL
AREAS BY MID-MORNING SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH




000
FXUS61 KRNK 171959
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
359 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 235 PM EDT MONDAY

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 120 PM EDT FRIDAY...

VFR WITH A FEW MVFR CIGS WERE NOTED ACROSS THE REGION EARLY THIS
AFTERNOON. CLOUDS SHOULD GRADUALLY SCATTERED THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING HOURS WITH LIGHT WINDS.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS
AFTERNOON...BUT COVERAGE WILL BE VERY LIMITED AND THE CHANCES OF
ONE OF THESE STRAY SHOWERS/STORMS IMPACTING A TAF SITE IS SMALL.

A SHALLOW LAYER OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE
TONIGHT...AND WITH LIGHT WINDS...POCKETS FOG REDUCING VISIBILITIES
TO IFR TO MVFR CATEGORIES WILL BE POSSIBLE LATE TONIGHT.

HIGH PRESSURE BUILDS NOSING DOWN INTO OUR REGION
SATURDAY...WILL USHER IN SLIGHTLY DRIER AIR ALLOWING MORNING
FOG/STRATUS TO QUICKLY ERODE...BRINGING VFR CONDITIONS TO ALL
AREAS BY MID-MORNING SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH





000
FXUS61 KRNK 171959
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
359 PM EDT FRI APR 17 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 235 PM EDT MONDAY

AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.

MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.

ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.

AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.

FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.

A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...

FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.

MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.

BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 120 PM EDT FRIDAY...

VFR WITH A FEW MVFR CIGS WERE NOTED ACROSS THE REGION EARLY THIS
AFTERNOON. CLOUDS SHOULD GRADUALLY SCATTERED THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING HOURS WITH LIGHT WINDS.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS
AFTERNOON...BUT COVERAGE WILL BE VERY LIMITED AND THE CHANCES OF
ONE OF THESE STRAY SHOWERS/STORMS IMPACTING A TAF SITE IS SMALL.

A SHALLOW LAYER OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE
TONIGHT...AND WITH LIGHT WINDS...POCKETS FOG REDUCING VISIBILITIES
TO IFR TO MVFR CATEGORIES WILL BE POSSIBLE LATE TONIGHT.

HIGH PRESSURE BUILDS NOSING DOWN INTO OUR REGION
SATURDAY...WILL USHER IN SLIGHTLY DRIER AIR ALLOWING MORNING
FOG/STRATUS TO QUICKLY ERODE...BRINGING VFR CONDITIONS TO ALL
AREAS BY MID-MORNING SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PH
NEAR TERM...JH/PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH





000
FXUS61 KRNK 171721
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
121 PM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT FRIDAY...

A MOIST AIRMASS REMAINS IN PLACE THIS MORNING WITH PW VALUES
AT 0.80 AT RNK AND 1.23 IN AT GSO. VISIBLE SATELLITE PHOTOS
SHOW PLENTY OF BREAKS IN THE CLOUD COVER AND TEMPS HAVE JUMPED
ABOVE GUIDANCE VALUES IN SOME AREAS IN RESPONSE TO THIS
CLEARING.

AS A RESULT...REDUCED THE CLOUD COVER THE FORECAST AND PUSHED UP
HIGHS A DEGREE OR TWO.

A SUBTLE UPPER LEVEL DISTURBANCE ACROSS OHIO THIS MORNING WILL
MOVE ACROSS THE NORTHEAST PORTION OF OUR FORECAST AREA AND SPARK A
FEW PASSING SHOWERS OR ISOLATED STORMS AS DCAPES ARE FORECAST TO
REACH AROUND 500 J/KG. ISOLATED STORMS ALSO POSSIBLE LATER THIS
AFTERNOON ALONG THE EDGE OF THE CLOUDINESS SOUTH OF HIGHWAY 460.
HOWEVER...KEPT HIGHEST POPS CLOSER TO THE WEAK UPPER LEVEL SUPPORT
IN THE NORTHEAST.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 120 PM EDT FRIDAY...

VFR WITH A FEW MVFR CIGS WERE NOTED ACROSS THE REGION EARLY THIS
AFTERNOON. CLOUDS SHOULD GRADUALLY SCATTERED THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING HOURS WITH LIGHT WINDS.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS
AFTERNOON...BUT COVERAGE WILL BE VERY LIMITED AND THE CHANCES OF
ONE OF THESE STRAY SHOWERS/STORMS IMPACTING A TAF SITE IS SMALL.

A SHALLOW LAYER OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE
TONIGHT...AND WITH LIGHT WINDS...POCKETS FOG REDUCING VISIBILITIES
TO IFR TO MVFR CATEGORIES WILL BE POSSIBLE LATE TONIGHT.

HIGH PRESSURE BUILDS NOSING DOWN INTO OUR REGION
SATURDAY...WILL USHER IN SLIGHTLY DRIER AIR ALLOWING MORNING
FOG/STRATUS TO QUICKLY ERODE...BRINGING VFR CONDITIONS TO ALL
AREAS BY MID-MORNING SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PH




000
FXUS61 KRNK 171408
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1008 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT FRIDAY...

A MOIST AIRMASS REMAINS IN PLACE THIS MORNING WITH PW VALUES
AT 0.80 AT RNK AND 1.23 IN AT GSO. VISIBLE SATELLITE PHOTOS
SHOW PLENTY OF BREAKS IN THE CLOUD COVER AND TEMPS HAVE JUMPED
ABOVE GUIDANCE VALUES IN SOME AREAS IN RESPONSE TO THIS
CLEARING.

AS A RESULT...REDUCED THE CLOUD COVER THE FORECAST AND PUSHED UP
HIGHS A DEGREE OR TWO.

A SUBTLE UPPER LEVEL DISTURBANCE ACROSS OHIO THIS MORNING WILL
MOVE ACROSS THE NORTHEAST PORTION OF OUR FORECAST AREA AND SPARK A
FEW PASSING SHOWERS OR ISOLATED STORMS AS DCAPES ARE FORECAST TO
REACH AROUND 500 J/KG. ISOLATED STORMS ALSO POSSIBLE LATER THIS
AFTERNOON ALONG THE EDGE OF THE CLOUDINESS SOUTH OF HIGHWAY 460.
HOWEVER...KEPT HIGHEST POPS CLOSER TO THE WEAK UPPER LEVEL SUPPORT
IN THE NORTHEAST.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR/LIFR CIGS CONTINUE ACROSS THE REGION EARLY THIS
MORNING WITH AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO
IFR/LIFR VSBYS AS WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS.
INCREASING WARM ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD
POOL SHOULD CONTINUE TO MAKE FOR POOR FLYING CONDITIONS THROUGH
MID MORNING.

LOW LEVEL FLOW TURNS TO THE SOUTHWEST THIS AFTERNOON IN ADVANCE
OF A TROUGH OF LOW PRESSURE APPROACHING FROM THE NW. THIS SHOULD
ALLOW CEILINGS TO RISE AND EVEN BRING SOME CLEARING TO VFR...ESPECIALLY
BY AFTERNOON. HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE
EXITS STILL IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A
BIT SLOWER EROSION LATER TODAY. THUS DELAYED THE RETURN TO VFR A
COUPLE HOURS ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS




000
FXUS61 KRNK 171408
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1008 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT FRIDAY...

A MOIST AIRMASS REMAINS IN PLACE THIS MORNING WITH PW VALUES
AT 0.80 AT RNK AND 1.23 IN AT GSO. VISIBLE SATELLITE PHOTOS
SHOW PLENTY OF BREAKS IN THE CLOUD COVER AND TEMPS HAVE JUMPED
ABOVE GUIDANCE VALUES IN SOME AREAS IN RESPONSE TO THIS
CLEARING.

AS A RESULT...REDUCED THE CLOUD COVER THE FORECAST AND PUSHED UP
HIGHS A DEGREE OR TWO.

A SUBTLE UPPER LEVEL DISTURBANCE ACROSS OHIO THIS MORNING WILL
MOVE ACROSS THE NORTHEAST PORTION OF OUR FORECAST AREA AND SPARK A
FEW PASSING SHOWERS OR ISOLATED STORMS AS DCAPES ARE FORECAST TO
REACH AROUND 500 J/KG. ISOLATED STORMS ALSO POSSIBLE LATER THIS
AFTERNOON ALONG THE EDGE OF THE CLOUDINESS SOUTH OF HIGHWAY 460.
HOWEVER...KEPT HIGHEST POPS CLOSER TO THE WEAK UPPER LEVEL SUPPORT
IN THE NORTHEAST.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR/LIFR CIGS CONTINUE ACROSS THE REGION EARLY THIS
MORNING WITH AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO
IFR/LIFR VSBYS AS WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS.
INCREASING WARM ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD
POOL SHOULD CONTINUE TO MAKE FOR POOR FLYING CONDITIONS THROUGH
MID MORNING.

LOW LEVEL FLOW TURNS TO THE SOUTHWEST THIS AFTERNOON IN ADVANCE
OF A TROUGH OF LOW PRESSURE APPROACHING FROM THE NW. THIS SHOULD
ALLOW CEILINGS TO RISE AND EVEN BRING SOME CLEARING TO VFR...ESPECIALLY
BY AFTERNOON. HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE
EXITS STILL IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A
BIT SLOWER EROSION LATER TODAY. THUS DELAYED THE RETURN TO VFR A
COUPLE HOURS ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS





000
FXUS61 KRNK 171408
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1008 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT FRIDAY...

A MOIST AIRMASS REMAINS IN PLACE THIS MORNING WITH PW VALUES
AT 0.80 AT RNK AND 1.23 IN AT GSO. VISIBLE SATELLITE PHOTOS
SHOW PLENTY OF BREAKS IN THE CLOUD COVER AND TEMPS HAVE JUMPED
ABOVE GUIDANCE VALUES IN SOME AREAS IN RESPONSE TO THIS
CLEARING.

AS A RESULT...REDUCED THE CLOUD COVER THE FORECAST AND PUSHED UP
HIGHS A DEGREE OR TWO.

A SUBTLE UPPER LEVEL DISTURBANCE ACROSS OHIO THIS MORNING WILL
MOVE ACROSS THE NORTHEAST PORTION OF OUR FORECAST AREA AND SPARK A
FEW PASSING SHOWERS OR ISOLATED STORMS AS DCAPES ARE FORECAST TO
REACH AROUND 500 J/KG. ISOLATED STORMS ALSO POSSIBLE LATER THIS
AFTERNOON ALONG THE EDGE OF THE CLOUDINESS SOUTH OF HIGHWAY 460.
HOWEVER...KEPT HIGHEST POPS CLOSER TO THE WEAK UPPER LEVEL SUPPORT
IN THE NORTHEAST.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR/LIFR CIGS CONTINUE ACROSS THE REGION EARLY THIS
MORNING WITH AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO
IFR/LIFR VSBYS AS WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS.
INCREASING WARM ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD
POOL SHOULD CONTINUE TO MAKE FOR POOR FLYING CONDITIONS THROUGH
MID MORNING.

LOW LEVEL FLOW TURNS TO THE SOUTHWEST THIS AFTERNOON IN ADVANCE
OF A TROUGH OF LOW PRESSURE APPROACHING FROM THE NW. THIS SHOULD
ALLOW CEILINGS TO RISE AND EVEN BRING SOME CLEARING TO VFR...ESPECIALLY
BY AFTERNOON. HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE
EXITS STILL IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A
BIT SLOWER EROSION LATER TODAY. THUS DELAYED THE RETURN TO VFR A
COUPLE HOURS ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS




000
FXUS61 KRNK 171408
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1008 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT FRIDAY...

A MOIST AIRMASS REMAINS IN PLACE THIS MORNING WITH PW VALUES
AT 0.80 AT RNK AND 1.23 IN AT GSO. VISIBLE SATELLITE PHOTOS
SHOW PLENTY OF BREAKS IN THE CLOUD COVER AND TEMPS HAVE JUMPED
ABOVE GUIDANCE VALUES IN SOME AREAS IN RESPONSE TO THIS
CLEARING.

AS A RESULT...REDUCED THE CLOUD COVER THE FORECAST AND PUSHED UP
HIGHS A DEGREE OR TWO.

A SUBTLE UPPER LEVEL DISTURBANCE ACROSS OHIO THIS MORNING WILL
MOVE ACROSS THE NORTHEAST PORTION OF OUR FORECAST AREA AND SPARK A
FEW PASSING SHOWERS OR ISOLATED STORMS AS DCAPES ARE FORECAST TO
REACH AROUND 500 J/KG. ISOLATED STORMS ALSO POSSIBLE LATER THIS
AFTERNOON ALONG THE EDGE OF THE CLOUDINESS SOUTH OF HIGHWAY 460.
HOWEVER...KEPT HIGHEST POPS CLOSER TO THE WEAK UPPER LEVEL SUPPORT
IN THE NORTHEAST.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR/LIFR CIGS CONTINUE ACROSS THE REGION EARLY THIS
MORNING WITH AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO
IFR/LIFR VSBYS AS WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS.
INCREASING WARM ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD
POOL SHOULD CONTINUE TO MAKE FOR POOR FLYING CONDITIONS THROUGH
MID MORNING.

LOW LEVEL FLOW TURNS TO THE SOUTHWEST THIS AFTERNOON IN ADVANCE
OF A TROUGH OF LOW PRESSURE APPROACHING FROM THE NW. THIS SHOULD
ALLOW CEILINGS TO RISE AND EVEN BRING SOME CLEARING TO VFR...ESPECIALLY
BY AFTERNOON. HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE
EXITS STILL IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A
BIT SLOWER EROSION LATER TODAY. THUS DELAYED THE RETURN TO VFR A
COUPLE HOURS ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/PH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS





000
FXUS61 KRNK 171119
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
719 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT FRIDAY...

SHOULD FINALLY SEE SOME IMPROVEMENT TODAY AS THE WEEK LONG COOL WEDGE
ERODES IN RESPONSE TO WARMING ALOFT AND CONTINUED PRESSURE FALLS
THAT WILL SCOUR OUT THE BUBBLE SURFACE HIGH ALONG THE BLUE RIDGE.
HOWEVER JUST HOW FAST THAT HAPPENS GIVEN WEAK FLOW STILL IFFY AS
APPEARS SOUTHERN/EASTERN SECTIONS MAY TAKE UNTIL AFTERNOON TO
DISSIPATE THE CAD WHEN A WEAK SURFACE TROUGH CROSSES HELPING TURN
THE FLOW MORE WESTERLY ALOFT. ONCE THIS HAPPENS AND SOME SUN
EMERGES...GUIDANCE QUICKLY DEVELOPS SOME WEAK INSTABILITY IN
RESPONSE TO A SURGE IN WARMING AND LOW LEVEL SW FLOW ALONG/EAST OF
THE BLUE RIDGE. LATEST FORECAST CAPES OF 500-1K J/KG WOULD SUPPORT
SOME ISOLATED CONVECTION AS A FAINT DISTURBANCE ALOFT
CROSSES...WITH BEST CHANCES APPEARING CLOSER TO THE BLUE
RIDGE...AND ESPCLY ON THE EDGE OF WHERE THE LOW CLOUDS FADE LATER
ON PROVIDING FOCUS VIA DIFFERENTIAL HEATING. GUIDANCE REMAINS
UNCLEAR ON COVERAGE/LOCATION BUT APPEARS SOME CONSENSUS BLUE RIDGE
WEST INITIALLY PER MORE INSOLATION EARLIER AHEAD OF THE WEAK
SHORTWAVE...THEN ACROSS THE NE ALONG THE TRAILING RIGHT REAR OF
A PASSING SPEED MAX. COVERAGE FARTHER SOUTH PERHAPS DELAYED UNTIL
LATE IF AT ALL GIVEN POTENTIAL FOR THE WEDGE TO LINGER LONGER.

OTRW WENT MORE OPTIMISTIC IN REGARDS TO SEEING A BIT MORE SUN AS WELL
AS HIGH TEMPS...WITH THICKNESS AND A LIGHT WESTERLY FLOW
SUPPORTING 70-77 EAST AND 65-72 WEST TODAY. HOWEVER IN SPOTS OVER
THE SOUTH AND EAST HIGHS MAY BE OF THE LATE DAY VARIETY PENDING
JUST HOW FAST THE WEDGE EXITS. OVERALL POPS CHANCE/LOW
CHANCE...MAINLY THIS AFTERNOON AFTER EARLY FOG AND -DZ FINALLY
FADE BY MIDDAY OR SO.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR/LIFR CIGS CONTINUE ACROSS THE REGION EARLY THIS
MORNING WITH AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO
IFR/LIFR VSBYS AS WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS.
INCREASING WARM ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD
POOL SHOULD CONTINUE TO MAKE FOR POOR FLYING CONDITIONS THROUGH
MID MORNING.

LOW LEVEL FLOW TURNS TO THE SOUTHWEST THIS AFTERNOON IN ADVANCE
OF A TROUGH OF LOW PRESSURE APPROACHING FROM THE NW. THIS SHOULD
ALLOW CEILINGS TO RISE AND EVEN BRING SOME CLEARING TO VFR...ESPECIALLY
BY AFTERNOON. HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE
EXITS STILL IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A
BIT SLOWER EROSION LATER TODAY. THUS DELAYED THE RETURN TO VFR A
COUPLE HOURS ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS




000
FXUS61 KRNK 171119
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
719 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT FRIDAY...

SHOULD FINALLY SEE SOME IMPROVEMENT TODAY AS THE WEEK LONG COOL WEDGE
ERODES IN RESPONSE TO WARMING ALOFT AND CONTINUED PRESSURE FALLS
THAT WILL SCOUR OUT THE BUBBLE SURFACE HIGH ALONG THE BLUE RIDGE.
HOWEVER JUST HOW FAST THAT HAPPENS GIVEN WEAK FLOW STILL IFFY AS
APPEARS SOUTHERN/EASTERN SECTIONS MAY TAKE UNTIL AFTERNOON TO
DISSIPATE THE CAD WHEN A WEAK SURFACE TROUGH CROSSES HELPING TURN
THE FLOW MORE WESTERLY ALOFT. ONCE THIS HAPPENS AND SOME SUN
EMERGES...GUIDANCE QUICKLY DEVELOPS SOME WEAK INSTABILITY IN
RESPONSE TO A SURGE IN WARMING AND LOW LEVEL SW FLOW ALONG/EAST OF
THE BLUE RIDGE. LATEST FORECAST CAPES OF 500-1K J/KG WOULD SUPPORT
SOME ISOLATED CONVECTION AS A FAINT DISTURBANCE ALOFT
CROSSES...WITH BEST CHANCES APPEARING CLOSER TO THE BLUE
RIDGE...AND ESPCLY ON THE EDGE OF WHERE THE LOW CLOUDS FADE LATER
ON PROVIDING FOCUS VIA DIFFERENTIAL HEATING. GUIDANCE REMAINS
UNCLEAR ON COVERAGE/LOCATION BUT APPEARS SOME CONSENSUS BLUE RIDGE
WEST INITIALLY PER MORE INSOLATION EARLIER AHEAD OF THE WEAK
SHORTWAVE...THEN ACROSS THE NE ALONG THE TRAILING RIGHT REAR OF
A PASSING SPEED MAX. COVERAGE FARTHER SOUTH PERHAPS DELAYED UNTIL
LATE IF AT ALL GIVEN POTENTIAL FOR THE WEDGE TO LINGER LONGER.

OTRW WENT MORE OPTIMISTIC IN REGARDS TO SEEING A BIT MORE SUN AS WELL
AS HIGH TEMPS...WITH THICKNESS AND A LIGHT WESTERLY FLOW
SUPPORTING 70-77 EAST AND 65-72 WEST TODAY. HOWEVER IN SPOTS OVER
THE SOUTH AND EAST HIGHS MAY BE OF THE LATE DAY VARIETY PENDING
JUST HOW FAST THE WEDGE EXITS. OVERALL POPS CHANCE/LOW
CHANCE...MAINLY THIS AFTERNOON AFTER EARLY FOG AND -DZ FINALLY
FADE BY MIDDAY OR SO.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR/LIFR CIGS CONTINUE ACROSS THE REGION EARLY THIS
MORNING WITH AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO
IFR/LIFR VSBYS AS WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS.
INCREASING WARM ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD
POOL SHOULD CONTINUE TO MAKE FOR POOR FLYING CONDITIONS THROUGH
MID MORNING.

LOW LEVEL FLOW TURNS TO THE SOUTHWEST THIS AFTERNOON IN ADVANCE
OF A TROUGH OF LOW PRESSURE APPROACHING FROM THE NW. THIS SHOULD
ALLOW CEILINGS TO RISE AND EVEN BRING SOME CLEARING TO VFR...ESPECIALLY
BY AFTERNOON. HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE
EXITS STILL IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A
BIT SLOWER EROSION LATER TODAY. THUS DELAYED THE RETURN TO VFR A
COUPLE HOURS ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS





000
FXUS61 KRNK 170750
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
350 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT FRIDAY...

SHOULD FINALLY SEE SOME IMPROVEMENT TODAY AS THE WEEK LONG COOL WEDGE
ERODES IN RESPONSE TO WARMING ALOFT AND CONTINUED PRESSURE FALLS
THAT WILL SCOUR OUT THE BUBBLE SURFACE HIGH ALONG THE BLUE RIDGE.
HOWEVER JUST HOW FAST THAT HAPPENS GIVEN WEAK FLOW STILL IFFY AS
APPEARS SOUTHERN/EASTERN SECTIONS MAY TAKE UNTIL AFTERNOON TO
DISSIPATE THE CAD WHEN A WEAK SURFACE TROUGH CROSSES HELPING TURN
THE FLOW MORE WESTERLY ALOFT. ONCE THIS HAPPENS AND SOME SUN
EMERGES...GUIDANCE QUICKLY DEVELOPS SOME WEAK INSTABILITY IN
RESPONSE TO A SURGE IN WARMING AND LOW LEVEL SW FLOW ALONG/EAST OF
THE BLUE RIDGE. LATEST FORECAST CAPES OF 500-1K J/KG WOULD SUPPORT
SOME ISOLATED CONVECTION AS A FAINT DISTURBANCE ALOFT
CROSSES...WITH BEST CHANCES APPEARING CLOSER TO THE BLUE
RIDGE...AND ESPCLY ON THE EDGE OF WHERE THE LOW CLOUDS FADE LATER
ON PROVIDING FOCUS VIA DIFFERENTIAL HEATING. GUIDANCE REMAINS
UNCLEAR ON COVERAGE/LOCATION BUT APPEARS SOME CONSENSUS BLUE RIDGE
WEST INITIALLY PER MORE INSOLATION EARLIER AHEAD OF THE WEAK
SHORTWAVE...THEN ACROSS THE NE ALONG THE TRAILING RIGHT REAR OF
A PASSING SPEED MAX. COVERAGE FARTHER SOUTH PERHAPS DELAYED UNTIL
LATE IF AT ALL GIVEN POTENTIAL FOR THE WEDGE TO LINGER LONGER.

OTRW WENT MORE OPTIMISTIC IN REGARDS TO SEEING A BIT MORE SUN AS WELL
AS HIGH TEMPS...WITH THICKNESS AND A LIGHT WESTERLY FLOW
SUPPORTING 70-77 EAST AND 65-72 WEST TODAY. HOWEVER IN SPOTS OVER
THE SOUTH AND EAST HIGHS MAY BE OF THE LATE DAY VARIETY PENDING
JUST HOW FAST THE WEDGE EXITS. OVERALL POPS CHANCE/LOW
CHANCE...MAINLY THIS AFTERNOON AFTER EARLY FOG AND -DZ FINALLY
FADE BY MIDDAY OR SO.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.
&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.
&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.
&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR CIGS CONTINUE ACROSS THE REGION TONIGHT WITH
SPOTTY AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO IFR VSBYS AS
WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS. INCREASING WARM
ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD POOL SHOULD
CONTINUE TO MAKE FOR POOR FLYING CONDITIONS OVERNIGHT INTO EARLY
FRIDAY WITH CONDITIONS DETERIORATING TO MORE WIDESPREAD IFR/LIFR
IN STRATUS/FOG AND DRIZZLE BY DAYBREAK.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE EXITS STILL
IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A BIT SLOWER
EROSION ON FRIDAY. THUS DELAYED THE RETURN TO VFR A COUPLE HOURS
ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS




000
FXUS61 KRNK 170750
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
350 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT FRIDAY...

SHOULD FINALLY SEE SOME IMPROVEMENT TODAY AS THE WEEK LONG COOL WEDGE
ERODES IN RESPONSE TO WARMING ALOFT AND CONTINUED PRESSURE FALLS
THAT WILL SCOUR OUT THE BUBBLE SURFACE HIGH ALONG THE BLUE RIDGE.
HOWEVER JUST HOW FAST THAT HAPPENS GIVEN WEAK FLOW STILL IFFY AS
APPEARS SOUTHERN/EASTERN SECTIONS MAY TAKE UNTIL AFTERNOON TO
DISSIPATE THE CAD WHEN A WEAK SURFACE TROUGH CROSSES HELPING TURN
THE FLOW MORE WESTERLY ALOFT. ONCE THIS HAPPENS AND SOME SUN
EMERGES...GUIDANCE QUICKLY DEVELOPS SOME WEAK INSTABILITY IN
RESPONSE TO A SURGE IN WARMING AND LOW LEVEL SW FLOW ALONG/EAST OF
THE BLUE RIDGE. LATEST FORECAST CAPES OF 500-1K J/KG WOULD SUPPORT
SOME ISOLATED CONVECTION AS A FAINT DISTURBANCE ALOFT
CROSSES...WITH BEST CHANCES APPEARING CLOSER TO THE BLUE
RIDGE...AND ESPCLY ON THE EDGE OF WHERE THE LOW CLOUDS FADE LATER
ON PROVIDING FOCUS VIA DIFFERENTIAL HEATING. GUIDANCE REMAINS
UNCLEAR ON COVERAGE/LOCATION BUT APPEARS SOME CONSENSUS BLUE RIDGE
WEST INITIALLY PER MORE INSOLATION EARLIER AHEAD OF THE WEAK
SHORTWAVE...THEN ACROSS THE NE ALONG THE TRAILING RIGHT REAR OF
A PASSING SPEED MAX. COVERAGE FARTHER SOUTH PERHAPS DELAYED UNTIL
LATE IF AT ALL GIVEN POTENTIAL FOR THE WEDGE TO LINGER LONGER.

OTRW WENT MORE OPTIMISTIC IN REGARDS TO SEEING A BIT MORE SUN AS WELL
AS HIGH TEMPS...WITH THICKNESS AND A LIGHT WESTERLY FLOW
SUPPORTING 70-77 EAST AND 65-72 WEST TODAY. HOWEVER IN SPOTS OVER
THE SOUTH AND EAST HIGHS MAY BE OF THE LATE DAY VARIETY PENDING
JUST HOW FAST THE WEDGE EXITS. OVERALL POPS CHANCE/LOW
CHANCE...MAINLY THIS AFTERNOON AFTER EARLY FOG AND -DZ FINALLY
FADE BY MIDDAY OR SO.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.
&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.
&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.
&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR CIGS CONTINUE ACROSS THE REGION TONIGHT WITH
SPOTTY AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO IFR VSBYS AS
WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS. INCREASING WARM
ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD POOL SHOULD
CONTINUE TO MAKE FOR POOR FLYING CONDITIONS OVERNIGHT INTO EARLY
FRIDAY WITH CONDITIONS DETERIORATING TO MORE WIDESPREAD IFR/LIFR
IN STRATUS/FOG AND DRIZZLE BY DAYBREAK.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE EXITS STILL
IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A BIT SLOWER
EROSION ON FRIDAY. THUS DELAYED THE RETURN TO VFR A COUPLE HOURS
ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS





000
FXUS61 KRNK 170750
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
350 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT FRIDAY...

SHOULD FINALLY SEE SOME IMPROVEMENT TODAY AS THE WEEK LONG COOL WEDGE
ERODES IN RESPONSE TO WARMING ALOFT AND CONTINUED PRESSURE FALLS
THAT WILL SCOUR OUT THE BUBBLE SURFACE HIGH ALONG THE BLUE RIDGE.
HOWEVER JUST HOW FAST THAT HAPPENS GIVEN WEAK FLOW STILL IFFY AS
APPEARS SOUTHERN/EASTERN SECTIONS MAY TAKE UNTIL AFTERNOON TO
DISSIPATE THE CAD WHEN A WEAK SURFACE TROUGH CROSSES HELPING TURN
THE FLOW MORE WESTERLY ALOFT. ONCE THIS HAPPENS AND SOME SUN
EMERGES...GUIDANCE QUICKLY DEVELOPS SOME WEAK INSTABILITY IN
RESPONSE TO A SURGE IN WARMING AND LOW LEVEL SW FLOW ALONG/EAST OF
THE BLUE RIDGE. LATEST FORECAST CAPES OF 500-1K J/KG WOULD SUPPORT
SOME ISOLATED CONVECTION AS A FAINT DISTURBANCE ALOFT
CROSSES...WITH BEST CHANCES APPEARING CLOSER TO THE BLUE
RIDGE...AND ESPCLY ON THE EDGE OF WHERE THE LOW CLOUDS FADE LATER
ON PROVIDING FOCUS VIA DIFFERENTIAL HEATING. GUIDANCE REMAINS
UNCLEAR ON COVERAGE/LOCATION BUT APPEARS SOME CONSENSUS BLUE RIDGE
WEST INITIALLY PER MORE INSOLATION EARLIER AHEAD OF THE WEAK
SHORTWAVE...THEN ACROSS THE NE ALONG THE TRAILING RIGHT REAR OF
A PASSING SPEED MAX. COVERAGE FARTHER SOUTH PERHAPS DELAYED UNTIL
LATE IF AT ALL GIVEN POTENTIAL FOR THE WEDGE TO LINGER LONGER.

OTRW WENT MORE OPTIMISTIC IN REGARDS TO SEEING A BIT MORE SUN AS WELL
AS HIGH TEMPS...WITH THICKNESS AND A LIGHT WESTERLY FLOW
SUPPORTING 70-77 EAST AND 65-72 WEST TODAY. HOWEVER IN SPOTS OVER
THE SOUTH AND EAST HIGHS MAY BE OF THE LATE DAY VARIETY PENDING
JUST HOW FAST THE WEDGE EXITS. OVERALL POPS CHANCE/LOW
CHANCE...MAINLY THIS AFTERNOON AFTER EARLY FOG AND -DZ FINALLY
FADE BY MIDDAY OR SO.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.
&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.
&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.
&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR CIGS CONTINUE ACROSS THE REGION TONIGHT WITH
SPOTTY AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO IFR VSBYS AS
WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS. INCREASING WARM
ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD POOL SHOULD
CONTINUE TO MAKE FOR POOR FLYING CONDITIONS OVERNIGHT INTO EARLY
FRIDAY WITH CONDITIONS DETERIORATING TO MORE WIDESPREAD IFR/LIFR
IN STRATUS/FOG AND DRIZZLE BY DAYBREAK.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE EXITS STILL
IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A BIT SLOWER
EROSION ON FRIDAY. THUS DELAYED THE RETURN TO VFR A COUPLE HOURS
ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS





000
FXUS61 KRNK 170750
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
350 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM TONIGHT INTO SATURDAY BRINGING DRIER
AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY
INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT FRIDAY...

SHOULD FINALLY SEE SOME IMPROVEMENT TODAY AS THE WEEK LONG COOL WEDGE
ERODES IN RESPONSE TO WARMING ALOFT AND CONTINUED PRESSURE FALLS
THAT WILL SCOUR OUT THE BUBBLE SURFACE HIGH ALONG THE BLUE RIDGE.
HOWEVER JUST HOW FAST THAT HAPPENS GIVEN WEAK FLOW STILL IFFY AS
APPEARS SOUTHERN/EASTERN SECTIONS MAY TAKE UNTIL AFTERNOON TO
DISSIPATE THE CAD WHEN A WEAK SURFACE TROUGH CROSSES HELPING TURN
THE FLOW MORE WESTERLY ALOFT. ONCE THIS HAPPENS AND SOME SUN
EMERGES...GUIDANCE QUICKLY DEVELOPS SOME WEAK INSTABILITY IN
RESPONSE TO A SURGE IN WARMING AND LOW LEVEL SW FLOW ALONG/EAST OF
THE BLUE RIDGE. LATEST FORECAST CAPES OF 500-1K J/KG WOULD SUPPORT
SOME ISOLATED CONVECTION AS A FAINT DISTURBANCE ALOFT
CROSSES...WITH BEST CHANCES APPEARING CLOSER TO THE BLUE
RIDGE...AND ESPCLY ON THE EDGE OF WHERE THE LOW CLOUDS FADE LATER
ON PROVIDING FOCUS VIA DIFFERENTIAL HEATING. GUIDANCE REMAINS
UNCLEAR ON COVERAGE/LOCATION BUT APPEARS SOME CONSENSUS BLUE RIDGE
WEST INITIALLY PER MORE INSOLATION EARLIER AHEAD OF THE WEAK
SHORTWAVE...THEN ACROSS THE NE ALONG THE TRAILING RIGHT REAR OF
A PASSING SPEED MAX. COVERAGE FARTHER SOUTH PERHAPS DELAYED UNTIL
LATE IF AT ALL GIVEN POTENTIAL FOR THE WEDGE TO LINGER LONGER.

OTRW WENT MORE OPTIMISTIC IN REGARDS TO SEEING A BIT MORE SUN AS WELL
AS HIGH TEMPS...WITH THICKNESS AND A LIGHT WESTERLY FLOW
SUPPORTING 70-77 EAST AND 65-72 WEST TODAY. HOWEVER IN SPOTS OVER
THE SOUTH AND EAST HIGHS MAY BE OF THE LATE DAY VARIETY PENDING
JUST HOW FAST THE WEDGE EXITS. OVERALL POPS CHANCE/LOW
CHANCE...MAINLY THIS AFTERNOON AFTER EARLY FOG AND -DZ FINALLY
FADE BY MIDDAY OR SO.

WEAK SURFACE HIGH SLIDES IN FROM THE WEST OVERNIGHT AS 5H HEIGHTS BUILD
AND LEFTOVER DEEP MOISTURE HEADS TO THE SE. THIS SHOULD ALLOW CLEARING
AFTER ANY EARLY EVENING SHOWERS EXIT THE EAST MAKING FOR A TRANQUIL
OVERNIGHT. HOWEVER RESIDUAL WET GROUND AND LIGHT WINDS UNDER STILL
RATHER MOIST DEWPOINTS SUPPORT SOME FOG FORMATION VALLEYS AND ESPCLY
SOUTH/EAST WHERE MOISTURE WILL BE HIGHER AND WINDS LIGHTER. OTRW MILD
LOWS IN THE 50S OVERALL WITH A FEW 40S IN THE VALLEYS.
&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 330 AM EDT FRIDAY...

A LARGE AREA OF HIGH PRESSURE MOVING THROUGH SOUTHERN CANADA AND INTO
NEW ENGLAND WILL BUILD SOUTHWARD INTO THE REGION AND BRING A PLEASANT
SPRING DAY TO THE REGION AS WE START THE WEEKEND ON SATURDAY.
HOWEVER...THIS RESPITE OF TRANQUIL WEATHER WILL BE SHORT LIVED AS THE
HIGH WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS AND COMBINES WITH A
LOW MOVING UP THE MISSISSIPPI VALLEY TO BRING A SIGNIFICANT INFLUX OF
MOISTURE ALONG WITH ENHANCED LIFT TO THE REGION WITH A WARM FRONT ON
SUNDAY. THIS WILL PRODUCE COPIOUS AMOUNTS OF RAINFALL. PRECIPITATION
WILL ARRIVE IN THE WEST AS EARLY AS DAYBREAK SUNDAY BUT THE HEAVIEST
RAIN WILL BE LATER ON SUNDAY AND INTO SUNDAY NIGHT. DEEP SOUTHEASTERLY
FLOW WILL BE FAVORABLE FOR OROGRAPHIC ENHANCEMENT ALONG THE EAST FACE
OF THE BLUE RIDGE WHERE RAINFALL TOTALS THROUGH MONDAY MAY TOP THE TWO
INCH MARK. IF MODEL GUIDANCE CONTINUES TO INDICATE SUCH PROLIFIC
RAINFALL AMOUNTS IN LATER RUNS A FLOOD WATCH WILL BE NEEDED FOR
PORTIONS OF THE AREA FOR LATE SUNDAY AND SUNDAY NIGHT. LOW LEVEL WINDS
WILL ALSO BECOME SQUEEZED BETWEEN THE LOW PRESSURE TO THE EAST AND HIGH
PRESSURE TO THE WEST WHICH WILL ACCELERATE THE SOUTHEASTERLY FLOW.
HIGHER ELEVATIONS FROM THE BLUE RIDGE WEST MAY SEE GUSTY CONDITIONS BY
SUNDAY AFTERNOON... ESPECIALLY ACROSS THE MOUNTAIN EMPIRE REGION WHERE
SOUTHEAST FLOW FAVORS DOWNSLOPING AND ENHANCED WINDS.

WE WILL BE IN THE WARM SECTOR ON MONDAY AS A COLD FRONT APPROACHES FROM
THE WEST. UNSTABLE CONDITIONS WILL FAVOR THE DEVELOPMENT OF
THUNDERSTORMS AHEAD OF THE FRONT. PARAMETERS INDICATE THE POSSIBILITY
FOR SOME STORMS TO APPROACH SEVERE LEVELS SO THIS SITUATION WILL BE
WATCHED CLOSELY AS IT DEVELOPS.

TEMPERATURES THROUGHOUT THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR SUNDAY
WHEN THE WEDGE OF HIGH PRESSURE AND COOLING AFFECTS OF RAINFALL WILL
KEEP TEMPERATURES ON THE COOL SIDE.
&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE STRONG
UPPER SHORT WAVE ON SATURDAY. BY TUESDAY...500MB HEIGHTS DROP INTO THE
560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH
BY MIDWEEK. ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND
POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS
AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE MOUNTAINS
THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL
TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER
AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES ROTATING THROUGH THE UPPER
TROUGH MAY ENHANCE CLOUD AND RAIN SHOWERS AT TIMES...ESPECIALLY ACROSS
THE MOUNTAINS...BUT NO SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS
PERIOD WITH DEEP CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.
&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR CIGS CONTINUE ACROSS THE REGION TONIGHT WITH
SPOTTY AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO IFR VSBYS AS
WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS. INCREASING WARM
ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD POOL SHOULD
CONTINUE TO MAKE FOR POOR FLYING CONDITIONS OVERNIGHT INTO EARLY
FRIDAY WITH CONDITIONS DETERIORATING TO MORE WIDESPREAD IFR/LIFR
IN STRATUS/FOG AND DRIZZLE BY DAYBREAK.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE EXITS STILL
IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A BIT SLOWER
EROSION ON FRIDAY. THUS DELAYED THE RETURN TO VFR A COUPLE HOURS
ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...JH/PM/RCS




000
FXUS61 KRNK 170521
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
121 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM FRIDAY NIGHT INTO SATURDAY BRINGING
DRIER AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION
WITH CHANCES OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT THURSDAY...

COOL DAMP CONDITIONS LIKELY THROUGH FRIDAY MORNING AS SHALLOW
WEDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE ALONG EASTERN
SLOPES OF THE APPALACHIANS. OCCASIONAL DRIZZLE AND FOG WILL BE
MOST PRONOUNCED ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WHERE
SHALLOW ISENTROPIC LIFT WILL BE THE GREATEST.

VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED OVERNIGHT WITH
TEMPERATURES REMAINING IN THE U40S-M50S. FRIDAYS HIGH TEMPERATURES
HOWEVER...WILL BE A LITTLE TRICKY...ESPECIALLY IN AREAS WHERE THE
WEDGE HANGS ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE
COULD SEE HIGH TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS
REMAINING IN THE WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE
LOW TO MID 60S WITH A LATE DAY SURGE IF THE WEDGE BREAKS.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR CIGS CONTINUE ACROSS THE REGION TONIGHT WITH
SPOTTY AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO IFR VSBYS AS
WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS. INCREASING WARM
ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD POOL SHOULD
CONTINUE TO MAKE FOR POOR FLYING CONDITIONS OVERNIGHT INTO EARLY
FRIDAY WITH CONDITIONS DETERIORATING TO MORE WIDESPREAD IFR/LIFR
IN STRATUS/FOG AND DRIZZLE BY DAYBREAK.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE EXITS STILL
IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A BIT SLOWER
EROSION ON FRIDAY. THUS DELAYED THE RETURN TO VFR A COUPLE HOURS
ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...PM/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PM/RCS




000
FXUS61 KRNK 170521
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
121 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM FRIDAY NIGHT INTO SATURDAY BRINGING
DRIER AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION
WITH CHANCES OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT THURSDAY...

COOL DAMP CONDITIONS LIKELY THROUGH FRIDAY MORNING AS SHALLOW
WEDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE ALONG EASTERN
SLOPES OF THE APPALACHIANS. OCCASIONAL DRIZZLE AND FOG WILL BE
MOST PRONOUNCED ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WHERE
SHALLOW ISENTROPIC LIFT WILL BE THE GREATEST.

VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED OVERNIGHT WITH
TEMPERATURES REMAINING IN THE U40S-M50S. FRIDAYS HIGH TEMPERATURES
HOWEVER...WILL BE A LITTLE TRICKY...ESPECIALLY IN AREAS WHERE THE
WEDGE HANGS ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE
COULD SEE HIGH TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS
REMAINING IN THE WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE
LOW TO MID 60S WITH A LATE DAY SURGE IF THE WEDGE BREAKS.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR CIGS CONTINUE ACROSS THE REGION TONIGHT WITH
SPOTTY AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO IFR VSBYS AS
WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS. INCREASING WARM
ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD POOL SHOULD
CONTINUE TO MAKE FOR POOR FLYING CONDITIONS OVERNIGHT INTO EARLY
FRIDAY WITH CONDITIONS DETERIORATING TO MORE WIDESPREAD IFR/LIFR
IN STRATUS/FOG AND DRIZZLE BY DAYBREAK.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE EXITS STILL
IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A BIT SLOWER
EROSION ON FRIDAY. THUS DELAYED THE RETURN TO VFR A COUPLE HOURS
ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...PM/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PM/RCS




000
FXUS61 KRNK 170521
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
121 AM EDT FRI APR 17 2015

.SYNOPSIS...
A WEDGE OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THIS MORNING BEFORE WEAKENING AS A WEAK TROUGH OF LOW PRESSURE
CROSSES THE AREA FROM THE WEST DURING THE AFTERNOON. HIGH
PRESSURE FOLLOWS THIS SYSTEM FRIDAY NIGHT INTO SATURDAY BRINGING
DRIER AND WARMER WEATHER TO START THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION
WITH CHANCES OF SHOWERS AND STORMS ON MONDAY.
&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT THURSDAY...

COOL DAMP CONDITIONS LIKELY THROUGH FRIDAY MORNING AS SHALLOW
WEDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE ALONG EASTERN
SLOPES OF THE APPALACHIANS. OCCASIONAL DRIZZLE AND FOG WILL BE
MOST PRONOUNCED ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WHERE
SHALLOW ISENTROPIC LIFT WILL BE THE GREATEST.

VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED OVERNIGHT WITH
TEMPERATURES REMAINING IN THE U40S-M50S. FRIDAYS HIGH TEMPERATURES
HOWEVER...WILL BE A LITTLE TRICKY...ESPECIALLY IN AREAS WHERE THE
WEDGE HANGS ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE
COULD SEE HIGH TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS
REMAINING IN THE WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE
LOW TO MID 60S WITH A LATE DAY SURGE IF THE WEDGE BREAKS.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1253 AM EDT FRIDAY...

MVFR TO OCNL IFR CIGS CONTINUE ACROSS THE REGION TONIGHT WITH
SPOTTY AREAS OF -DZ/FOG MAKING FOR PERIODS OF MVFR TO IFR VSBYS AS
WELL ESPCLY ACROSS THE MOUNTAIN LOCATIONS. INCREASING WARM
ADVECTION OVER THE SLOWLY ERODING LOW LEVEL COLD POOL SHOULD
CONTINUE TO MAKE FOR POOR FLYING CONDITIONS OVERNIGHT INTO EARLY
FRIDAY WITH CONDITIONS DETERIORATING TO MORE WIDESPREAD IFR/LIFR
IN STRATUS/FOG AND DRIZZLE BY DAYBREAK.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
HOWEVER TIMING OF WHEN THIS STUCK LOW LEVEL MOISTURE EXITS STILL
IN QUESTION GIVEN LATEST BUFKIT SOUNDINGS SHOWING A BIT SLOWER
EROSION ON FRIDAY. THUS DELAYED THE RETURN TO VFR A COUPLE HOURS
ESPCLY BLUE RIDGE SITES AND POINTS EAST. ONCE MORE
CLEARING/HEATING DEVELOPS...A MORE UNSTABLE AIRMASS WILL SPAWN
WIDELY SCATTERED SHOWERS AND STORMS. HOWEVER THE COVERAGE IS NOT
EXPECTED TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES WITH
MAINLY A PERIOD OF BKN VFR CIGS AS A WEAK TROUGH CROSSES THE
REGION LATER IN THE DAY.

DRIER HIGH PRESSURE WILL BUILD IN BEHIND THIS FEATURE FRIDAY NIGHT
AND SATURDAY WITH A RETURN TO VFR EXPECTED TO START THE WEEKEND.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...PM/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PM/RCS





000
FXUS61 KRNK 170245
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1045 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1030 PM EDT THURSDAY...

COOL DAMP CONDITIONS LIKELY THROUGH FRIDAY MORNING AS SHALLOW
WEDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE ALONG EASTERN
SLOPES OF THE APPALACHIANS. OCCASIONAL DRIZZLE AND FOG WILL BE
MOST PRONOUNCED ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WHERE
SHALLOW ISENTROPIC LIFT WILL BE THE GREATEST.

VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED OVERNIGHT WITH
TEMPERATURES REMAINING IN THE U40S-M50S. FRIDAYS HIGH TEMPERATURES
HOWEVER...WILL BE A LITTLE TRICKY...ESPECIALLY IN AREAS WHERE THE
WEDGE HANGS ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE
COULD SEE HIGH TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS
REMAINING IN THE WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE
LOW TO MID 60S WITH A LATE DAY SURGE IF THE WEDGE BREAKS.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 720 PM EDT THURSDAY...

IFR TO MVFR CEILINGS WERE NOTED ACROSS THE MOUNTAIN TAF
SITES...INCLUDING KBCB...KLWB AND KBLF...AND EVEN AT KROA CIGS
WERE MVFR. AS LOW LEVEL WINDS TURN TO A MORE SOUTHERLY
DIRECTION...MOISTURE WILL ADVECT INTO THE REGION DURING THIS
EVENING AND OVERNIGHT HOURS. THIS MOISTURE ADVECTION IN
COMBINATION WITH A WEAK UPPER LEVEL DISTURBANCE MOVING OVER THE
AREA TONIGHT WILL KEEP LOW CLOUDS AND LIGHT PRECIP IN PLACE.
EXPECT FLYING CONDITIONS TO CONTINUE TO WORSEN TONIGHT WITH ALL
TAF SITES FALLING INTO IFR OR LIFR FLIGHT CATEGORIES THROUGH EARLY
FRIDAY.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
THIS MORE UNSTABLE AIRMASS WILL SPAWN WIDELY SCATTERED TO
SCATTERED SHOWERS AND STORMS...BUT THE COVERAGE IS NOT EXPECTED
TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES.

A COLD FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER
HIGH PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...PM/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PH/RCS




000
FXUS61 KRNK 170245
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1045 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1030 PM EDT THURSDAY...

COOL DAMP CONDITIONS LIKELY THROUGH FRIDAY MORNING AS SHALLOW
WEDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE ALONG EASTERN
SLOPES OF THE APPALACHIANS. OCCASIONAL DRIZZLE AND FOG WILL BE
MOST PRONOUNCED ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WHERE
SHALLOW ISENTROPIC LIFT WILL BE THE GREATEST.

VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED OVERNIGHT WITH
TEMPERATURES REMAINING IN THE U40S-M50S. FRIDAYS HIGH TEMPERATURES
HOWEVER...WILL BE A LITTLE TRICKY...ESPECIALLY IN AREAS WHERE THE
WEDGE HANGS ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE
COULD SEE HIGH TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS
REMAINING IN THE WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE
LOW TO MID 60S WITH A LATE DAY SURGE IF THE WEDGE BREAKS.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 720 PM EDT THURSDAY...

IFR TO MVFR CEILINGS WERE NOTED ACROSS THE MOUNTAIN TAF
SITES...INCLUDING KBCB...KLWB AND KBLF...AND EVEN AT KROA CIGS
WERE MVFR. AS LOW LEVEL WINDS TURN TO A MORE SOUTHERLY
DIRECTION...MOISTURE WILL ADVECT INTO THE REGION DURING THIS
EVENING AND OVERNIGHT HOURS. THIS MOISTURE ADVECTION IN
COMBINATION WITH A WEAK UPPER LEVEL DISTURBANCE MOVING OVER THE
AREA TONIGHT WILL KEEP LOW CLOUDS AND LIGHT PRECIP IN PLACE.
EXPECT FLYING CONDITIONS TO CONTINUE TO WORSEN TONIGHT WITH ALL
TAF SITES FALLING INTO IFR OR LIFR FLIGHT CATEGORIES THROUGH EARLY
FRIDAY.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
THIS MORE UNSTABLE AIRMASS WILL SPAWN WIDELY SCATTERED TO
SCATTERED SHOWERS AND STORMS...BUT THE COVERAGE IS NOT EXPECTED
TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES.

A COLD FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER
HIGH PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...PM/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PH/RCS





000
FXUS61 KRNK 170245
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1045 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1030 PM EDT THURSDAY...

COOL DAMP CONDITIONS LIKELY THROUGH FRIDAY MORNING AS SHALLOW
WEDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE ALONG EASTERN
SLOPES OF THE APPALACHIANS. OCCASIONAL DRIZZLE AND FOG WILL BE
MOST PRONOUNCED ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WHERE
SHALLOW ISENTROPIC LIFT WILL BE THE GREATEST.

VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED OVERNIGHT WITH
TEMPERATURES REMAINING IN THE U40S-M50S. FRIDAYS HIGH TEMPERATURES
HOWEVER...WILL BE A LITTLE TRICKY...ESPECIALLY IN AREAS WHERE THE
WEDGE HANGS ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE
COULD SEE HIGH TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS
REMAINING IN THE WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE
LOW TO MID 60S WITH A LATE DAY SURGE IF THE WEDGE BREAKS.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 720 PM EDT THURSDAY...

IFR TO MVFR CEILINGS WERE NOTED ACROSS THE MOUNTAIN TAF
SITES...INCLUDING KBCB...KLWB AND KBLF...AND EVEN AT KROA CIGS
WERE MVFR. AS LOW LEVEL WINDS TURN TO A MORE SOUTHERLY
DIRECTION...MOISTURE WILL ADVECT INTO THE REGION DURING THIS
EVENING AND OVERNIGHT HOURS. THIS MOISTURE ADVECTION IN
COMBINATION WITH A WEAK UPPER LEVEL DISTURBANCE MOVING OVER THE
AREA TONIGHT WILL KEEP LOW CLOUDS AND LIGHT PRECIP IN PLACE.
EXPECT FLYING CONDITIONS TO CONTINUE TO WORSEN TONIGHT WITH ALL
TAF SITES FALLING INTO IFR OR LIFR FLIGHT CATEGORIES THROUGH EARLY
FRIDAY.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
THIS MORE UNSTABLE AIRMASS WILL SPAWN WIDELY SCATTERED TO
SCATTERED SHOWERS AND STORMS...BUT THE COVERAGE IS NOT EXPECTED
TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES.

A COLD FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER
HIGH PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...PM/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PH/RCS




000
FXUS61 KRNK 170245
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1045 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1030 PM EDT THURSDAY...

COOL DAMP CONDITIONS LIKELY THROUGH FRIDAY MORNING AS SHALLOW
WEDGE OF HIGH PRESSURE REMAINS LOCKED IN PLACE ALONG EASTERN
SLOPES OF THE APPALACHIANS. OCCASIONAL DRIZZLE AND FOG WILL BE
MOST PRONOUNCED ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WHERE
SHALLOW ISENTROPIC LIFT WILL BE THE GREATEST.

VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED OVERNIGHT WITH
TEMPERATURES REMAINING IN THE U40S-M50S. FRIDAYS HIGH TEMPERATURES
HOWEVER...WILL BE A LITTLE TRICKY...ESPECIALLY IN AREAS WHERE THE
WEDGE HANGS ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE
COULD SEE HIGH TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS
REMAINING IN THE WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE
LOW TO MID 60S WITH A LATE DAY SURGE IF THE WEDGE BREAKS.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 720 PM EDT THURSDAY...

IFR TO MVFR CEILINGS WERE NOTED ACROSS THE MOUNTAIN TAF
SITES...INCLUDING KBCB...KLWB AND KBLF...AND EVEN AT KROA CIGS
WERE MVFR. AS LOW LEVEL WINDS TURN TO A MORE SOUTHERLY
DIRECTION...MOISTURE WILL ADVECT INTO THE REGION DURING THIS
EVENING AND OVERNIGHT HOURS. THIS MOISTURE ADVECTION IN
COMBINATION WITH A WEAK UPPER LEVEL DISTURBANCE MOVING OVER THE
AREA TONIGHT WILL KEEP LOW CLOUDS AND LIGHT PRECIP IN PLACE.
EXPECT FLYING CONDITIONS TO CONTINUE TO WORSEN TONIGHT WITH ALL
TAF SITES FALLING INTO IFR OR LIFR FLIGHT CATEGORIES THROUGH EARLY
FRIDAY.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
THIS MORE UNSTABLE AIRMASS WILL SPAWN WIDELY SCATTERED TO
SCATTERED SHOWERS AND STORMS...BUT THE COVERAGE IS NOT EXPECTED
TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES.

A COLD FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER
HIGH PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...PM/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PH/RCS





000
FXUS61 KRNK 162322
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
722 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
AS OF 720 PM EDT THURSDAY...

IFR TO MVFR CEILINGS WERE NOTED ACROSS THE MOUNTAIN TAF
SITES...INCLUDING KBCB...KLWB AND KBLF...AND EVEN AT KROA CIGS
WERE MVFR. AS LOW LEVEL WINDS TURN TO A MORE SOUTHERLY
DIRECTION...MOISTURE WILL ADVECT INTO THE REGION DURING THIS
EVENING AND OVERNIGHT HOURS. THIS MOISTURE ADVECTION IN
COMBINATION WITH A WEAK UPPER LEVEL DISTURBANCE MOVING OVER THE
AREA TONIGHT WILL KEEP LOW CLOUDS AND LIGHT PRECIP IN PLACE.
EXPECT FLYING CONDITIONS TO CONTINUE TO WORSEN TONIGHT WITH ALL
TAF SITES FALLING INTO IFR OR LIFR FLIGHT CATEGORIES THROUGH EARLY
FRIDAY.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
THIS MORE UNSTABLE AIRMASS WILL SPAWN WIDELY SCATTERED TO
SCATTERED SHOWERS AND STORMS...BUT THE COVERAGE IS NOT EXPECTED
TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES.

A COLD FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER
HIGH PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PH/RCS




000
FXUS61 KRNK 162322
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
722 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
AS OF 720 PM EDT THURSDAY...

IFR TO MVFR CEILINGS WERE NOTED ACROSS THE MOUNTAIN TAF
SITES...INCLUDING KBCB...KLWB AND KBLF...AND EVEN AT KROA CIGS
WERE MVFR. AS LOW LEVEL WINDS TURN TO A MORE SOUTHERLY
DIRECTION...MOISTURE WILL ADVECT INTO THE REGION DURING THIS
EVENING AND OVERNIGHT HOURS. THIS MOISTURE ADVECTION IN
COMBINATION WITH A WEAK UPPER LEVEL DISTURBANCE MOVING OVER THE
AREA TONIGHT WILL KEEP LOW CLOUDS AND LIGHT PRECIP IN PLACE.
EXPECT FLYING CONDITIONS TO CONTINUE TO WORSEN TONIGHT WITH ALL
TAF SITES FALLING INTO IFR OR LIFR FLIGHT CATEGORIES THROUGH EARLY
FRIDAY.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN
ADVANCE OF A COLD FRONT. THIS SHOULD ALLOW CEILINGS TO RISE AND
EVEN BRING SOME CLEARING TOMORROW...ESPECIALLY BY AFTERNOON.
THIS MORE UNSTABLE AIRMASS WILL SPAWN WIDELY SCATTERED TO
SCATTERED SHOWERS AND STORMS...BUT THE COVERAGE IS NOT EXPECTED
TO BE GREAT ENOUGH TO ADD PRECIP AT ANY TAF SITES.

A COLD FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER
HIGH PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PH/RCS





000
FXUS61 KRNK 161957
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
357 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...RCS





000
FXUS61 KRNK 161957
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
357 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...RCS




000
FXUS61 KRNK 161957
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
357 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...RCS





000
FXUS61 KRNK 161957
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
357 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

SOUTHWEST FLOW ALOFT WILL TRANSITION TO NORTHWEST FLOW ALOFT AT
THE BEGINNING OF THE SHORT TERM AS AN UPPER SHORT WAVE MOVES OFF
THE MID-ATLANTIC COAST. ANY LINGER SHOWERS ACROSS THE BLUE RIDGE
SHOULD MOVE OUT OF THE REGION QUICKLY AFT 00Z SAT. UPPER-LEVEL
SHORT WAVE RIDGING WILL EVOLVE ACROSS THE OH/TN VALLEY SUNDAY AS
THE FLOW AMPLIFIES IN RESPONSE TO A DEEP UPPER TROUGH SHIFTING
SLOWLY EAST FROM THE CENTRAL/SOUTHERN PLAINS. THIS PATTERN WILL
BRING DRY/SEASONABLE CONDITIONS TO THE REGION SATURDAY.

BY SUNDAY...THE AFOREMENTIONED UPPER TROUGH BEGINS TO LIFT OUT OF
THE MID-SOUTH INTO THE MID-ATLANTIC REGION...WHILE TAKING ON A
STRONG NEGATIVE TILT. ANTECEDENT SURFACE HIGH PRESSURE WILL MOVE
OFF THE MID-ATLANTIC COAST INTO YET AGAIN ANOTHER FAVORABLE WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT WILL ENSUE QUICKLY OVER THE
SHALLOW WEDGE SUNDAY BRINGING WIDESPREAD RAIN...SOME HEAVY DURING
THE AFTERNOON/EVENING...INTO THE WEDGE AIR MASS. THE WEDGE WILL BE
REINFORCED WITH THE PRECIPITATION...HOLDING HIGH TEMPERATURES
SUN AFTERNOON POTENTIALLY IN THE 50S. RAINFALL IN EXCESS OF 1 INCH
ACROSS MUCH OF THE CWA APPEARS LIKELY WITH THIS EVENT. THE GOOD
NEWS IS THAT THE SYSTEM IS MOVING VERY QUICKLY AS A NORTHERN
STREAM UPPER LOW QUICKLY DIGS INTO THE NORTHERN PLAINS HELPING TO
PUSH THE SOUTHERN STREAM UPPER TROUGH NORTHEAST OF THE REGION BY
SUN NIGHT/EARLY MON. THIS SHOULD CONFINE THE PERIOD OF HEAVY RAIN
TO ABOUT 12 HOURS OR LESS...WHICH SHOULD HELP LIMIT ANY POTENTIAL
FLOOD ISSUES. WILL CONTINUE TO HIGHLIGHT IN THE HWO AS THE GROUND
IS WELL SATURATED NOW FROM ALL OF THE RECENT RAINFALL. IT STILL
APPEARS THAT THE HEAVIEST RAINFALL WILL FALL ALONG THE EAST FACING
SLOPES OF THE BLUE RIDGE WITH PRONOUNCED SOUTHEAST FLOW IN THE
WEDGE AIR MASS AS THE STRONG NEGATIVELY TILTED UPPER SHORT WAVE
TRAVERSES THE REGION LATE SUN/SUN NIGHT. CANNOT RULE OUT A FLOOD
WATCH AS WE GET CLOSER TO THAT PERIOD. WE WILL NEED TO ALSO
WATCH...AS NOTED BEFORE...STRONG SOUTHEAST WINDS ARRIVING ACROSS
THE USUAL AREAS OF SOUTHEAST WV/SOUTHWEST VA...EARLY SUN PRIOR TO
THE HEAVIER RAIN MOVING INTO THE REGION. BOTTOMLINE...THIS WILL BE
A SIGNIFICANT RAIN EVENT...BUT TIME DURATION SHOULD LIMIT
PROBLEMS. THE SEVERE THREAT APPEARS TO BE NIL WITH MUCH OF THE CWA
IN A STRONG WEDGE AND VERY STABLE. HAVE OPTED NOT TO INTRODUCED
THUNDER AT THIS POINT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...

A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER APPEARS TO
EVOLVE THROUGH THE MID AND LATER PART OF NEXT WEEK AS A DEEP UPPER
TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. IN THE WAKE OF THE
STRONG UPPER SHORT WAVE ON SATURDAY. PRIOR TO THE ARRIVAL OF THE
COLDER AIR MON NIGHT/TUE...A WARM SECTOR WEDGE SURGES INTO THE
REGION DURING PEAK HEATING MON AFTERNOON. CAPE VALUES EXCEED 1000
J/KG ACROSS AREAS EAST OF THE BLUE RIDGE AND ARE NOTABLE IN MOST
OF THE CWA MON AFTERNOON. THE SIGNIFICANT SVR PARM RISES TOWARD
20000 ACROSS THE PIEDMONT WITH LIS DROPPING INTO THE -4C RANGE ON
SOME MODELS. THUS...MON AFTERNOON APPEARS TO BE THE BEST CHANCE
FOR THUNDERSTORM ACTIVITY...AND POTENTIALLY EVEN A FEW
STRONG/APPROACHING SEVERE LIMITS ACROSS EAST OF THE BLUE RIDGE.

BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB
TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S ACROSS THE
MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S
TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. EMBEDDED SHORT WAVES
ROTATING THROUGH THE UPPER TROUGH MAY ENHANCE CLOUD AND RAIN
SHOWERS AT TIMES...ESPECIALLY ACROSS THE MOUNTAINS...BUT NO
SIGNIFICANT RAINFALL EVENTS APPEAR THROUGH THIS PERIOD WITH DEEP
CYCLONIC NORTHWEST FLOW IN PLACE.

BY THE END OF THE WEEK...THE UPPER FLOW DEAMPLIFIES AND BECOMES
MORE ZONAL. AN EMBEDDED SHORT WAVE MAY BRING A MORE SIGNIFICANT
THREAT OF RAIN TO THE REGION THU NIGHT/FRI...SO HAVE RETAINED CHC
POPS TOWARD DAY 8 AS A RESULT. INSTABILITY MAY SUPPORT ISOLD
THUNDER...BUT HAVE NOT INTRODUCED JUST YET.

TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL THROUGH MOST OF THE
PERIOD...WITH THE EXCEPTION OF MONDAY...WHEN SOME LOWER 80S ARE
POSSIBLE ACROSS THE PIEDMONT. CLOUDS AND WIND SHOULD PREVENT ANY
FROST/FREEZE CONCERN THROUGH THIS TIME FRAME.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...RCS




000
FXUS61 KRNK 161828
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
228 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS





000
FXUS61 KRNK 161828
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
228 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS




000
FXUS61 KRNK 161828
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
228 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS




000
FXUS61 KRNK 161828
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
228 PM EDT THU APR 16 2015

.SYNOPSIS...
AN AREA OF COOL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
FRIDAY MORNING. ONCE THIS WEDGE BREAKS...TEMPERATURES WILL WARM
BACK INTO THE 70S. TEMPERATURES WILL DROP AS RAIN CHANCES
INCREASE WITH THE PASSING OF A COLD FRONT ON SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 130 PM EDT THURSDAY...

THE HIGH PRESSURE CENTER OF THE COOL WEDGE WILL DRIFT OUT TO SEA
THROUGH THE PERIOD. HOWEVER...BAGGY HIGH LEFT BEHIND WILL KEEP
COOL...CLOUDY AND DAMP CONDITIONS INTO FRIDAY MORNING. FROM THE
MORNING RNK/GSO SOUNDINGS...THE WEDGE WAS 4-5KFT THICK OVER THE
FORECAST AREA AND STRETCHED SOUTH INTO THE PANHANDLE OF FLORIDA.
WITH NO SIGNIFICANT FORCING OR PRESSURE RISES NEAR THE IMMEDIATE
AREA...THE WEDGE WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY
FRIDAY...ESPECIALLY ACROSS THE FOOTHILLS AND PIEDMONT COUNTIES.

A WARM FRONT...ASSOCIATED WITH A WEAK DISTURBANCE IN THE OHIO
VALLEY...WILL OVERRUN THE WEDGE LATE THIS AFTERNOON AND EVENING.
ISENTROPIC LIFT WILL SPREAD ANOTHER ROUND OF LIGHT RAIN ACROSS THE
FORECAST AREA THROUGH MIDNIGHT. THIS LIFT TRACKS NORTHWARD AND THE
FORECAST AREA WILL THEN BE IN A LULL OF MEASURABLE PRECIPITATION
INTO FRIDAY MORNING. HOWEVER...WITH SATURATED CONDITIONS AND
EASTERLY FLOW...LOW CLOUDS...FOG AND DRIZZLE HIGHLY POSSIBLE ALONG
EASTERN SLOPES...PARTICULARLY ALONG THE BLUE RIDGE.

VERY LITTLE CHANGE IN TEMPERATURES OVERNIGHT FROM THIS AFTERNOON
WITH LOWS ONLY IN THE MID 40S TO LOWER 50S. FRIDAY AFTERNOONS
TEMPERATURES TRICKY...ESPECIALLY IN AREAS WHERE THE WEDGE HANGS
ON. TEMPERATURES FOR LOCATIONS OUTSIDE OF THE WEDGE COULD SEE HIGH
TEMPERATURES IN THE LOW TO MID 70S. THOSE AREAS REMAINING IN THE
WEDGE MAY ONLY SEE TEMPERATURES WARMING INTO THE LOW TO MID 60S
WITH A LATE SURGE TOWARDS 70F.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS





000
FXUS61 KRNK 161719
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
119 PM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS




000
FXUS61 KRNK 161719
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
119 PM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS





000
FXUS61 KRNK 161719
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
119 PM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS




000
FXUS61 KRNK 161719
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
119 PM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
AS OF 130 PM EDT THURSDAY...

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS INTO
TONIGHT...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE IN
THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER AS EARLIER RAINFALL ADDS MOISTURE TO THE LOW
LEVELS OF THE ATMOSPHERE. CONFIDENCE IN TIMING OF LOWER CIGS
THOUGH REMAINS LOW GIVEN UNCERTAINTY IN THE DEGREE OF RAINFALL
GIVEN SUCH WEAK FEATURES PASSING THROUGH THE WEDGE. THUS TRENDING
TOWARD WIDESPREAD MVFR FROM MID AFTERNOON ONWARD BUT WITH ONLY
SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

EXTENDED AVIATION...

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS





000
FXUS61 KRNK 161405
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1005 AM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 630 AM EDT THURSDAY...

RAIN/DRIZZLE CONTINUES TO INCREASE FROM SOUTH TO NORTH THIS
MORNING...AIDED BY SE UPSLOPE FLOW AND DIFFLUENCE ALOFT. AT THE
SAME TIME...HAVE SEEN HIGH PRESSURE WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE BLUE RIDGE...PROVIDING A SURGE OF DRIER AIR INTO THE
LOW LEVELS OF THE ATMOSPHERE FROM KROA TO KLYH WHERE SEEING MORE
IN THE WAY OF MID DECK CIGS EARLY THIS MORNING. HOWEVER WITH
MOISTURE/PRECIP AGAIN INCREASING...EXPECTING CIGS TO AGAIN DROP
FROM CURRENT OVERALL VFR LEVELS BACK INTO MVFR FROM SOUTH TO NORTH
THIS MORNING-EARLY AFTERNOON WITH LOCAL IFR CONDITIONS ALSO
POSSIBLE ALONG THE BLUE RIDGE. PATCHY RAIN/DRIZZLE/FOG MAY ALSO BE
ENOUGH TO LOWER VSBYS INTO MVFR LEVELS...BUT MOSTLY FROM
KBCB/KROA SE TO KDAN AND DOWN ALONG THE BLUE RIDGE TO NEAR TNB.

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS THIS
AFTERNOON...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE
IN THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER FURTHER DURING MID AFTERNOON AS EARLIER
RAINFALL ADDS MOISTURE TO THE LOW LEVELS OF THE ATMOSPHERE.
CONFIDENCE IN TIMING OF LOWER CIGS THOUGH REMAINS LOW GIVEN
UNCERTAINTY IN THE DEGREE OF RAINFALL GIVEN SUCH WEAK FEATURES
PASSING THROUGH THE WEDGE. THUS TRENDING TOWARD WIDESPREAD MVFR
FROM MID AFTERNOON ONWARD BUT WITH ONLY SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

EXTENDED AVIATION...

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...JH/NF





000
FXUS61 KRNK 161405
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1005 AM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 630 AM EDT THURSDAY...

RAIN/DRIZZLE CONTINUES TO INCREASE FROM SOUTH TO NORTH THIS
MORNING...AIDED BY SE UPSLOPE FLOW AND DIFFLUENCE ALOFT. AT THE
SAME TIME...HAVE SEEN HIGH PRESSURE WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE BLUE RIDGE...PROVIDING A SURGE OF DRIER AIR INTO THE
LOW LEVELS OF THE ATMOSPHERE FROM KROA TO KLYH WHERE SEEING MORE
IN THE WAY OF MID DECK CIGS EARLY THIS MORNING. HOWEVER WITH
MOISTURE/PRECIP AGAIN INCREASING...EXPECTING CIGS TO AGAIN DROP
FROM CURRENT OVERALL VFR LEVELS BACK INTO MVFR FROM SOUTH TO NORTH
THIS MORNING-EARLY AFTERNOON WITH LOCAL IFR CONDITIONS ALSO
POSSIBLE ALONG THE BLUE RIDGE. PATCHY RAIN/DRIZZLE/FOG MAY ALSO BE
ENOUGH TO LOWER VSBYS INTO MVFR LEVELS...BUT MOSTLY FROM
KBCB/KROA SE TO KDAN AND DOWN ALONG THE BLUE RIDGE TO NEAR TNB.

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS THIS
AFTERNOON...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE
IN THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER FURTHER DURING MID AFTERNOON AS EARLIER
RAINFALL ADDS MOISTURE TO THE LOW LEVELS OF THE ATMOSPHERE.
CONFIDENCE IN TIMING OF LOWER CIGS THOUGH REMAINS LOW GIVEN
UNCERTAINTY IN THE DEGREE OF RAINFALL GIVEN SUCH WEAK FEATURES
PASSING THROUGH THE WEDGE. THUS TRENDING TOWARD WIDESPREAD MVFR
FROM MID AFTERNOON ONWARD BUT WITH ONLY SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

EXTENDED AVIATION...

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...JH/NF




000
FXUS61 KRNK 161405
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1005 AM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 630 AM EDT THURSDAY...

RAIN/DRIZZLE CONTINUES TO INCREASE FROM SOUTH TO NORTH THIS
MORNING...AIDED BY SE UPSLOPE FLOW AND DIFFLUENCE ALOFT. AT THE
SAME TIME...HAVE SEEN HIGH PRESSURE WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE BLUE RIDGE...PROVIDING A SURGE OF DRIER AIR INTO THE
LOW LEVELS OF THE ATMOSPHERE FROM KROA TO KLYH WHERE SEEING MORE
IN THE WAY OF MID DECK CIGS EARLY THIS MORNING. HOWEVER WITH
MOISTURE/PRECIP AGAIN INCREASING...EXPECTING CIGS TO AGAIN DROP
FROM CURRENT OVERALL VFR LEVELS BACK INTO MVFR FROM SOUTH TO NORTH
THIS MORNING-EARLY AFTERNOON WITH LOCAL IFR CONDITIONS ALSO
POSSIBLE ALONG THE BLUE RIDGE. PATCHY RAIN/DRIZZLE/FOG MAY ALSO BE
ENOUGH TO LOWER VSBYS INTO MVFR LEVELS...BUT MOSTLY FROM
KBCB/KROA SE TO KDAN AND DOWN ALONG THE BLUE RIDGE TO NEAR TNB.

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS THIS
AFTERNOON...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE
IN THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER FURTHER DURING MID AFTERNOON AS EARLIER
RAINFALL ADDS MOISTURE TO THE LOW LEVELS OF THE ATMOSPHERE.
CONFIDENCE IN TIMING OF LOWER CIGS THOUGH REMAINS LOW GIVEN
UNCERTAINTY IN THE DEGREE OF RAINFALL GIVEN SUCH WEAK FEATURES
PASSING THROUGH THE WEDGE. THUS TRENDING TOWARD WIDESPREAD MVFR
FROM MID AFTERNOON ONWARD BUT WITH ONLY SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

EXTENDED AVIATION...

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...JH/NF





000
FXUS61 KRNK 161405
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1005 AM EDT THU APR 16 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS THE CAROLINAS INTO
TONIGHT. WEAK WAVES OF LOW PRESSURE RIDING NORTHEAST ALONG THE
FRONT WILL COMBINE WITH A STRONG WEDGE OF HIGH PRESSURE TO KEEP
COOL AND DAMP CONDITIONS IN PLACE INTO EARLY FRIDAY. SLIGHTLY
WARMER AIR RETURNS BY WEEKS END AHEAD OF ANOTHER COLD FRONT THAT
WILL CROSS THE AREA EARLY IN THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT THURSDAY...

WEDGE SOLIDLY IN PLACE ACROSS THE HEART OF THE FCST AREA AND IN
FACT EXTENDS ALL THE WAY INTO NORTHEAST ALABAMA. SOME BREAKS
SHOWING UP IN SKY COVER ACROSS SW VA IN VCNTY OF RICHLANDS AND
MARION...AND THIS EDGE SHOULD WARM UP SOME BY THIS
AFTERNOON...ALTHOUGH MORE CLOUDS AND PERHAPS SHOWERS WILL MOVE IN
AS CONVECTION TO THE WEST DIES AT IT MOVES IN. STILL SEEING NO
NOTABLE INSTABILITY FOR ANY THUNDER...BUT WILL HAVE TO KEEP AN EYE
IN CASE SOEMTHING SNEAKS IN. EXTREME EAST THE WEDGE MAY THIN
ENOUGH FOR ENOUGH INSOLATION TO WARM UP INTO THE LOWER 60S BUT
THAT SHOULD BE CONFINED TO THE EXTREME EASTERN EDGE. FROM THE
FOOTHILLS WESTWARD THE WEDGE SHOULD HOLD STRONG...AND GIVEN
MORNING TEMPS AND BROADER AREA OF PRECIP THIS MORNING THAN EARLIER
EXPECTED...LOWERED HIGHS FOR MOST AREAS. MAY NOT GET OUT OF UPPER
40S IN A FEW SPOTS...INCLUDING NW NC...AND NOT TOO FAR ABOVE 50 IN
NRV AND ROANOKE VALLEYS.

LOWERED POPS MUCH OF THE MIDDAY IN WEST BEHIND THE AREA OF
PRECIP...EXCEPT ALONG BLUE RDG WITH UPSLOPE DRIZZLE...LIGHT
RAIN...AND THEN BROUGHT SOME LOW CHC POPS BACK IN TO SOUTHWEST
WITH THE POSSIBILITY OF A FEW SHOWERS SNEAKING BACK IN LATE.

PREV DISC AS OF 255 AM EDT THURSDAY...

CONTINUED PERSISTENCE FORECAST OVER THE NEXT 24 HOURS WITH THE LOW
LEVEL WEDGE LOCKED IN PLACE AND ENHANCED BY PERIODIC ROUNDS OF LIGHT
RAIN AS IMPULSES SLIDE ACROSS FROM THE RESIDUAL SYSTEM TO THE WEST.
THIS SHOULD KEEP CLOUDS ACROSS MUCH OF THE REGION INTO TONIGHT WITH
PERHAPS SOME BREAKS DEVELOPING OVER THE FAR WEST ALONG THE PERIPHERY OF
THE COOL POOL TODAY...AND EAST OF HIGHWAY 29 WHERE DRIER AIR HAS
ADVECTED IN FROM THE NE. SOME BREAKS COULD ALSO DEVELOP AT TIMES
ELSEWHERE ESPCLY IF RAINFALL IS LESS GIVEN MORE MID DECK ATTM BUT
IFFY. RAIN CHANCES ALSO TRICKY UNDER GRADUAL VEERING FLOW ALOFT
OVER THE CAD AND WEAK ISENTROPIC LIFT INTO TONIGHT. LATEST
GUIDANCE RATHER SPREAD OUT WITH SOME CONSENSUS TO FOCUS MORE ALONG
A CORRIDOR FROM DAN-BCB-LWB THIS MORNING PER ONGOING UPPER
DIFFLUENCE NORTH OF A PASSING JET MAX...AND ALONG THE SOUTHERN
BLUE RIDGE GIVEN WEAK UPSLOPE INTO THE AFTERNOON. HOWEVER
UNDERCUTTING BY DRY AIR TO THE NE LOOKS TO MAKE MOST RAIN/DRIZZLE
SPOTTY...WITH LOW LEVEL CONVERGENCE PERHAPS SHIFTING BACK ACROSS
THE FAR WEST LATER TODAY. THIS IN LINE WITH WHERE BETTER 85H WARM
ADVECTION WILL EXIST ON THE WESTERN FLANK OF THE WEDGE AHEAD OF
ANOTHER UPSTREAM IMPULSE.

OVERALL THIS SPELLS MOSTLY CHANCE TO LOW LIKELY POPS AT TIMES
ESPCLY CENTRAL SECTIONS FOR MAINLY LIGHT QPF TODAY WITH TEMPS
ONLY RISING A CAT OR TWO NEAR THE BLUE RIDGE. HOWEVER COULD
POSSIBLY TOP 60 EAST OF LYH-DAN...AND NEAR BLF WHERE GUSTY
DOWNSLOPE SE FLOW WILL LINGER AND PRECIP MAY BECOME MORE SHOWERY
LATER ON.

WEDGE STARTS TO SLOWLY BREAK DOWN OVERNIGHT AS THE HIGH SWINGS FARTHER
OFFSHORE BUT AGAIN THINK GUIDANCE TOO FAST TO ERODE WITH A TYPICAL
INDUCED BUBBLE HIGH LIKELY STUCK NEAR THE BLUE RIDGE. THIS SHOULD AGAIN
WITH LACK OF MUCH UPPER SUPPORT KEEP POPS MOSTLY IN THE LOW CHANCE
RANGE EXCEPT PERHAPS FAR WEST/NW AHEAD OF PASSING SHORTWAVE ENERGY
LIFTING BY TO THE NW LATE. OTRW APPEARS MORE CLOUDS/FOG AND SOME SPOTTY
-DZ LIKELY AS WARMING ALOFT INCREASES WHICH SHOULD HOLD TEMPS UP CLOSER
TO THE 45-53 RANGE FOR THE MOST PART.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 335 AM EDT THURSDAY...

HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE ATLANTIC OCEAN
FRIDAY INTO SATURDAY. MEANWHILE...LOW PRESSURE LOCATED OFF THE SOUTH
CAROLINA COAST FRIDAY MORNING WILL LIFT NORTHEAST ALONG THE EAST
COAST. A COLD FRONT CROSSES THROUGH THE FORECAST AREA FRIDAY INTO
FRIDAY NIGHT. WEDGE SHOULD BREAK DOWN/ERODE ON FRIDAY WITH SURFACE
WINDS BECOME SOUTHWEST AHEAD OF THE FRONT DURING THE DAY. HIGH
TEMPERATURES ON FRIDAY ARE A CHALLENGE...BECAUSE THEY ARE DEPENDENT
ON WHEN...WHERE AND HOW FAST THE WEDGE ERODES. HIGH TEMPERATURES
WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHERN MOUNTAINS TO THE
MID 70S IN THE SOUTHEAST. POPS ARE ALSO PROBLEMATIC ON FRIDAY. FIRST
START FRIDAY MORNING WITH CHANCE OF RAIN...THEN CHANGE TO CONVECTIVE
WITH FRONTAL BOUNDARY ROLLING THROUGH AREA. BELIEVE THERE IS ENOUGH
INSTABILITY ON FRIDAY TO ADD MENTION OF THUNDERSTORMS. WEAK HIGH
PRESSURE WILL BUILD EAST INTO OUR REGION FRIDAY NIGHT. LOW
TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE MID 40S IN THE
MOUNTAINS TO THE MID 50S IN THE PIEDMONT.

SURFACE HIGH PRESSURE BUILDS EAST INTO THE REGION SATURDAY. ALLOWED
FOR FOR SOME SLIGHT TO CHANCE POPS SATURDAY AFTERNOON.  HIGH
TEMPERATURES SATURDAY WILL WARM INTO THE MID 60S IN THE MOUNTAINS
THE UPPER 70S IN THE PIEDMONT. RAIN WILL SPREAD NORTHEAST INTO OUR
REGION SATURDAY NIGHT INTO SUNDAY. LOW TEMPERATURES SATURDAY NIGHT
WILL AVERAGE FROM AROUND 50 TO THE UPPER 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT THURSDAY...

00Z GFS AND ECMWF AND THEIR ENSEMBLES HAD DECENT CONSENSUS FOR
THE EXTENDED PERIOD. CENTRAL ROCKIES LOW OPENS AND LIFTS INTO THE
UPPER MISSISSIPPI VALLEY SATURDAY NIGHT THROUGH MONDAY. THEN
CLOSED LOW IN THE NORTHERN STREAM REMAINS OVER THE GREAT LAKES
THROUGH WEDNESDAY.

LOW PRESSURE OVER THE MISSISSIPPI VALLEY WILL BRING A WARM FRONT
ACROSS THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. SURFACE
PATTERN WILL BE MORE COMPLICATED. MODELS WERE SHOWING SOME
INDICATIONS OF SURFACE BASED COLD AIR DAMMING. A TRIPLE POINT LOW
DEVELOPS ON MONDAY OVER VIRGINIA THEN TRACKS TOWARD NEW JERSEY
COAST. A SURGE OF COLDER AIR COMES IN ON WEDNESDAY.

LIFT FROM THE SURFACE LOW CROSSING THE MID ATLANTIC STATES AND A
PROLONGED PERIOD OF INFLOW OFF THE ATLANTIC WILL RESULT IN A HIGH
PROBABILITY OF PRECIPITATION SUNDAY AND SUNDAY NIGHT. GIVEN
CONSISTENCY OFF MODELS IN SHOWING THE THREAT FOR HEAVY RAIN
ESPCLY ALONG THE BLUE RIDGE WILL MENTION IN THE HWO FOR LATE IN
THE WEEKEND.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 630 AM EDT THURSDAY...

RAIN/DRIZZLE CONTINUES TO INCREASE FROM SOUTH TO NORTH THIS
MORNING...AIDED BY SE UPSLOPE FLOW AND DIFFLUENCE ALOFT. AT THE
SAME TIME...HAVE SEEN HIGH PRESSURE WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE BLUE RIDGE...PROVIDING A SURGE OF DRIER AIR INTO THE
LOW LEVELS OF THE ATMOSPHERE FROM KROA TO KLYH WHERE SEEING MORE
IN THE WAY OF MID DECK CIGS EARLY THIS MORNING. HOWEVER WITH
MOISTURE/PRECIP AGAIN INCREASING...EXPECTING CIGS TO AGAIN DROP
FROM CURRENT OVERALL VFR LEVELS BACK INTO MVFR FROM SOUTH TO NORTH
THIS MORNING-EARLY AFTERNOON WITH LOCAL IFR CONDITIONS ALSO
POSSIBLE ALONG THE BLUE RIDGE. PATCHY RAIN/DRIZZLE/FOG MAY ALSO BE
ENOUGH TO LOWER VSBYS INTO MVFR LEVELS...BUT MOSTLY FROM
KBCB/KROA SE TO KDAN AND DOWN ALONG THE BLUE RIDGE TO NEAR TNB.

HIGH PRESSURE WILL REMAIN BANKED AGAINST THE APPALACHIANS THIS
AFTERNOON...WITH WINDS BECOMING MORE SOUTHEASTERLY ALOFT BY LATE
IN THE DAY. ADDED FAINT UPPER LEVEL ENERGY PASSING ACROSS THE AREA
WILL SUPPORT CONTINUED PATCHY RAINFALL...AS WELL AS CAUSE CEILINGS
TO GRADUALLY LOWER FURTHER DURING MID AFTERNOON AS EARLIER
RAINFALL ADDS MOISTURE TO THE LOW LEVELS OF THE ATMOSPHERE.
CONFIDENCE IN TIMING OF LOWER CIGS THOUGH REMAINS LOW GIVEN
UNCERTAINTY IN THE DEGREE OF RAINFALL GIVEN SUCH WEAK FEATURES
PASSING THROUGH THE WEDGE. THUS TRENDING TOWARD WIDESPREAD MVFR
FROM MID AFTERNOON ONWARD BUT WITH ONLY SPOTTY PRECIP FOR NOW.

LOW LEVEL WEDGE STARTS TO BREAK DOWN TONIGHT AS THE FLOW VEERS
FROM SOUTHEAST TO MORE SOUTHERLY OVERNIGHT. THIS MAY ACTUALLY HELP
MOISTEN THINGS FURTHER PROVIDING FOR OVERALL SUB-VFR AND RESIDUAL
SPOTTY SHOWERS WITH POTENTIAL FOR MORE IN THE WAY OF LOW END
IFR/LIFR IN STRATUS/FOG/DZ OVERNIGHT.

EXTENDED AVIATION...

ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS MOVES AWAY. A COLD
FRONT WILL PASS ACROSS THE AREA FRIDAY NIGHT...WITH DRIER HIGH
PRESSURE BUILDING IN BEHIND FOR SATURDAY.

A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/SK
SHORT TERM...KK
LONG TERM...AMS
AVIATION...JH/NF




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