000
FXUS62 KRAH 190044
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
840 PM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTH THROUGH THE REGION OVERNIGHT. HIGH
PRESSURE WILL BUILD IN FROM THE NORTH WEDNESDAY THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 840 PM TUESDAY...

MCV THAT TRACKED EAST ACROSS NORTHERN NORTH CAROLINA WAS LOCATED
OVER EASTERN HALIFAX COUNTY AS OF 840 PM. IT APPEARS THAT THERE WAS
JUST ENOUGH SHEAR ASSOCIATED ON THE LEADING FLANK OF THIS MESO-SCALE
FEATURE TO GEN UP SEVERAL ROTATING STORMS AND AT LEAST ONE TORNADO
TOUCHDOWN IN FRANKLIN COUNTY. THE LEADING CONVECTIVE LINE EXTENDED
FROM THE MCV WSW ACROSS WILSON... RALEIGH... SOUTHERN PINES TO NEAR
ALBEMARLE AT 840 PM. CURRENT SEVERE STORMS WERE LOCATED OVER WILSON
INTO NORTHERN WAYNE COUNTY WHERE DOPPLER RADAR INDICATED 50KT AT
3000 FEET WITH THE BOWING SEGMENT OVER THAT REGION. SOME OF THE
THESE WINDS MAY REACH THE GROUND. AREAS ALONG AND AHEAD OF THE
CONVECTIVE OUTFLOW BOUNDARY WILL BE MONITORED FOR ADDITIONAL SEVERE
WARNINGS. THE MAIN THREATS NOW APPEAR TO BE LOCALLY DAMAGING WIND
AND HEAVY RAINFALL. -BADGETT

OVERNIGHT...SFC COLD FRONT WILL PROGRESS SEWD AND SHOULD LIE WSW-ENE
ACROSS OUR FAR SOUTHERN-SE COUNTIES AT DAYBREAK. THIS FEATURE
SHOULD INTERACT WITH AVAILABLE MOISTURE TO TRIGGER SCATTERED SHOWERS
OVERNIGHT. STILL MUGGY OVERNIGHT THOUGH THE FAR N-NW SECTIONS MAY
START TO FEEL A LITTLE LESS HUMID BY DAYBREAK. MIN TEMPS MID 60S TO
NEAR 70.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 250 PM TUESDAY...

STRONGER S/W IN THE NORTHERN STREAM WILL CROSS THE NORTHERN
MID ATLANTIC WHILE THE TAIL END OF THE SHEAR AXIS APPROACHES OUR
NORTHERN COUNTIES BY EARLY EVENING. NLY FLOW BEHIND THE INITIAL MID
LEVEL TROUGH WILL ADVECT DRIER AND SLIGHTLY MORE STABLE AIR INTO
CENTRAL NC. WHILE CLOUDS WILL LIKELY STICK AROUND DUE TO RESIDUAL
MOISTURE AND CYCLONIC CURVATURE IN THE MID LEVEL FLOW...CONVECTIVE
COVERAGE SHOULD BE LESS NUMEROUS WEDNESDAY AFTERNOON AND NOT AS
ROBUST. EXPECT TWO MAIN AREAS OF PRECIP...ONE OVER THE FAR SOUTH IN
VICINITY OF THE NEARLY STATIONARY SFC FRONT...AND THE OTHER OVER THE
FAR NORTH AHEAD OF THE SWD ADVANCING MID LEVEL SHEAR AXIS. PLAN TO
CAP POPS NO HIGHER THAN 50 PERCENT (NEAR SC BORDER) WITH A 1-IN-3
CHANCE ACROSS THE NORTH. AS ATMOSPHERE STABILIZES IN THE EARLY
EVENING...EXPECT MAJORITY OF THE CONVECTION TO DISSIPATE THOUGH A
STRAY SHOWER MAY STILL OCCUR IN VICINITY OF THE SHEAR AXIS ACROSS
THE NORTH. THIS SHEAR AXIS WILL CONTINUE TO PROGRESS SE OVERNIGHT
AND EXIT THE REGION BY DAYBREAK THU. SUBSIDENCE BEHIND THIS FEATURE
WILL AID TO DISSIPATE THE CLOUD COVERAGE AFTER MIDNIGHT.

EXPECT A FAIRLY UNIFORM TEMP FIELD WEDNESDAY DUE TO CLOUD COVERAGE
AND LOW LEVEL COLD AIR ADVECTION. MAX TEMPS NEAR 80 NORTH TO LOWER
80S SOUTH. MIN TEMPS WEDNESDAY NIGHT IN THE MID 60S.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 215 PM TUESDAY...

THURSDAY THROUGH FRIDAY...HEIGHTS ALOFT RISE OVER CENTRAL NORTH
CAROLINA...WITH A SUBSIDENT AIR MASS IN PLACE OVER THE AREA.
PRECIPITABLE WATER VALUES REMAIN HIGHER THURSDAY RELATIVE TO
FRIDAY...BETWEEN AN INCH AND 1.5 INCHES ON THE FORMER COMPARED TO A
DECREASE FROM THE NORTHEAST TO AT OR BELOW AN INCH FRIDAY. BOTH THE
GFS AND NAM BUFR SOUNDINGS...AND PARTICULARLY THE LATTER...FORECAST
ENOUGH MOISTURE AROUND 850MB THURSDAY FOR AREAS OF CU TO FORM...MORE
LIKELY TOWARD THE WESTERN PIEDMONT WHERE THE 850MB MOISTURE IS
HIGHEST. K INDICES FALL FROM THE NORTHEAST AS WELL THURSDAY
AFTERNOON CONTINUING INTO FRIDAY...WITH K INDICES WELL INTO NEGATIVE
VALUES BY FRIDAY AFTERNOON. IN TERMS OF DEEP CONVECTION...AMPLE
OVERALL CIN AND GRADUAL WARMING ALOFT WITH CONVERGENCE ALOFT SHOULD
PRECLUDE THAT. THERE SHOULD BE A FEW MORNING GUSTS WITH INITIAL
MIXING THURSDAY IN THE LOWER TO MID TEENS KTS IN THE MODESTLY TIGHT
GRADIENT BETWEEN AN INVERTED TROUGH OFF OF THE COAST AND SURFACE
HIGH PRESSURE BUILDING IN FROM THE NORTHWEST...BUT OVERALL 925MB
WINDS ARE MAINLY AROUND 10KT. 1000-850MB THICKNESSES SUGGEST HIGHS
IN THE LOWER TO MID 80S BOTH DAYS...CLOSE TO OR ON THE LOWER SIDE OF
MOS GUIDANCE. OVERNIGHT LOWS THURSDAY NIGHT AROUND 60 TO THE MID
60S...MINS POSSIBLY TEMPERED A LITTLE OVER THE SOUTHWEST PIEDMONT BY
SLIGHTLY GREATER UPPER-LEVEL MOISTURE FORECAST BY BOTH THE NAM AND
THE GFS.

FRIDAY NIGHT THROUGH TUESDAY...UPPER RIDGING CONTINUES TO BUILD IN.
AROUND THE RIDGE...THERE COULD BE A WEAK MID-LEVEL SHORTWAVE OR TWO
THAT ATTEMPTS TO MOVE...OR HAS SOME SUCCESS MOVING...INTO CENTRAL
NORTH CAROLINA ESPECIALLY LATE IN THE WEEKEND AND EARLY NEXT WEEK.
THE MOISTURE OF THE MEAN AIR MASS...AND MOISTURE AT THE
SURFACE...INCREASE SUNDAY INTO MONDAY...WITH SURFACE DEW POINTS
EXPECTED TO INCREASE TO AROUND 70F BY MONDAY...CONTINUING INTO
TUESDAY. WITH SURFACE RIDGING OVER THE GULF CURRENTLY FORECAST...IT
SHOULD BE A GRADUAL MOISTURE INCREASE ESPECIALLY AT THE
SURFACE...AND COARSE MODEL SOUNDINGS AT LEAST INTO SUNDAY AFTERNOON
HAVE A GOOD CONSENSUS OF AT LEAST BEING WEAKLY CAPPED ALOFT. WILL
MAINTAIN THE DRY FORECAST FRIDAY NIGHT THROUGH THE WEEKEND...BUT
WITH INCREASING MOISTURE...SOME GUIDANCE SUGGESTING A WEAKNESS IN
THE MID-LEVEL HEIGHTS TRANSLATING INTO COOLING ALOFT...AT LEAST SOME
QPF BY MUCH OF THE CURRENT LONG-TERM GUIDANCE...AND MEX MOS POPS
NEAR OR ABOVE CLIMATOLOGY...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS AT THE END OF THE PERIOD MONDAY AND
TUESDAY. FORCING SHOULD BE LIMITED TO WEAK SURFACE TROUGHINESS...SEA
BREEZE...AND/OR WEAK MID-LEVEL PVA AT TIMES...WHICH MAY BE ENOUGH
FOR ISOLATED SHOWERS AND THUNDERSTORMS IN A RELATIVELY MOIST AIR
MASS. 1000-850MB THICKNESSES GRADUALLY RISE...WHICH...ALONG WITH MOS
GUIDANCE...WOULD SUGGEST HIGHS RISING TO AT OR ABOVE NORMAL BY
SUNDAY. IF THE SURFACE DEW POINT IS A LITTLE HIGHER THAN FORECAST
PRIMARILY DUE TO SLIGHTLY LESS MIXING...MAXIMUM AFTERNOON HEAT
INDICES COULD RISE TO AROUND 100 BY MONDAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 840 PM TUESDAY...

24 HOUR TAF PERIOD: A LINE OF HEAVY SHOWERS AND THUNDERSTORMS AHEAD
OF A COLD FRONT HAS JUST ABOUT MADE ITS WAY THROUGH KRDU...AND KRWI
BUT WILL CONTINUE TO IMPACT KFAY DURING THE NEXT SEVERAL HOURS.
WHILE THE THUNDER WILL LINGER NEAR KRWI...THE ACTIVITY SHOULD WANE
ENOUGH BY THE TIME THE LINE REACHES KFAY THAT THE MAIN CONCERN WILL
BE HEAVY RAIN AND REDUCED VISBYS. THE HEAVY SHOWERS WILL BE
ACCOMPANIED BY MVFR/IFR CIGS AND VISBYS...BUT SHOULD BE RELATIVELY
SHORT LIVED. THE EFFECTIVE FRONT...AS NOTED BY A VEERING OF THE
WINDS FROM SW TO NNW...HAS CROSSED THE TRIAD TERMINALS AS OF 8 PM
AND SHOULD MOVE THROUGH THE KRDU/KRWI TERMINALS BETWEEN 8 PM AND 10
PM...AND THE KFAY VICINITY BETWEEN 10 PM AND 1 AM. THE ACTUAL COLD
FRONT...ACCOMPANIED BY DROP IN DEWPOINTS...LINGERS A FEW HOURS
BEHIND. A BRIEF PERIOD OF MVFR/IFR CIGS IS POSSIBLE BEHIND THE
SHOWERS BUT AHEAD OF THE FRONT. -KC

AVIATION CONDITIONS WILL BEGIN TO IMPROVE WEDNESDAY MORNING AS DRIER
MORE STABLE AIR FLOWS INTO THE REGION BEHIND THE EXITING FRONT.
EXPECT A RETURN TO VFR CONDITIONS THOUGH A STRATOCU DECK WILL LIKELY
DEVELOP WEDNESDAY AFTERNOON WITH BASES 3000-4000FT.

LOOKING AHEAD: HIGH PRESSURE WILL BUILD INTO AND LINGER OVER CENTRAL
NC WEDNESDAY NIGHT THROUGH THE WEEKEND. THIS WEATHER SYSTEM WILL
BRING DRY AND STABLE CONDITIONS LEADING TO VFR PARAMETERS. THE
EXCEPTION WILL BE A BRIEF PERIOD OF MVFR VISIBILITY DUE TO
FOG...MAINLY IN THE COASTAL PLAIN. -WSS


&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BADGETT
NEAR TERM...BADGETT/WSS
SHORT TERM...WSS
LONG TERM...DJF
AVIATION...KC

000
FXUS62 KRAH 190040
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
840 PM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. HIGH PRESSURE WILL BUILD
INTO CENTRAL NC FROM THE NORTH WEDNESDAY THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 PM TUESDAY...

SLIGHT TO MODERATELY UNSTABLE AIR MASS RESIDES OVER CENTRAL NC AT
MID-AFTERNOON THANKS TO PEAKS OF SUN HEATING UP AN AIR MASS WITH SFC
DEWPOINTS IN THE UPPER 60S TO LOWER 70S. UPSTAIRS...A VORT MAXIMUM
OVER THE CENTRAL APPALACHIANS CONTINUES TO ROTATE EASTWARD WITH
ATTENDANT SHEAR AXIS EXTENDING SWWD ALONG THE SPINE OF THE SOUTHERN
APPALACHIANS. THIS MID LEVEL FEATURE AIDING TO ENHANCE THE 925-850MB
FLOW WHICH IS ADVECTING ADDITIONAL MOISTURE INTO THE COLUMN. LATEST
SATELLITE TOTAL BLEND PRECIP WATER PRODUCT DEPICTS VALUES BETWEEN
1.8-2 INCHES OVER OUR FORECAST AREA. THOUGH MID LEVEL LAPSE RATES
ARE MEAGER...ENOUGH JUICE EXISTS IN THE ATMOSPHERE TO SUPPORT THE
DEVELOPMENT OF NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS LATE
THIS AFTERNOON THROUGH EARLY EVENING AS THE MID LEVEL SHEAR AXIS
CROSSES THE REGION. CURRENT 0-6KM SHEAR VALUES IN THE 30-40KT RANGE
OVER THE NW PIEDMONT SUPPORT THE IDEA OF CONVECTION FORMING INTO A
LINE AS IT MARCHES EAST-SE. CANNOT RULE OUT THE POSSIBILITY OF AN
ISOLATED STRONG-SEVERE STORM WITH WIND GUSTS 40-50 MPH. STILL
BELIEVE MAIN WEATHER HAZARD WILL BE TORRENTIAL DOWNPOURS WITH
RAINFALL RATES 2-3 INCHES PER HOUR POSSIBLE IN A FEW OF THE STORMS.
FORTUNATELY STEERING WINDS CLOSE TO 25KTS SO STORMS WITH THIS
MAGNITUDE OF RAIN SHOULD NOT SETTLE OVER ONE SPOT VERY LONG. BULK OF
CONVECTIVE ALLOWING MODELS AS WELL AS THE 11Z HRRR SUGGEST THE
BROKEN LINE OF CONVECTION CROSSING THE PIEDMONT BETWEEN
21Z-00Z...AND INTO THE SANDHILLS AND COASTAL PLAIN 23Z-02Z.

PLAN TO MAINTAIN CATEGORICAL POPS IN THE NW PIEDMONT LATE THIS
AFTERNOON THEN SPREAD THESE HIGHER POPS SEWD WITH TIME. WILL
INTRODUCE DECREASING POPS BY EARLY EVENING IN THE NW PIEDMONT...THEN
TREND POPS LOWER OVER THE REMAINDER OF THE FORECAST BETWEEN 02Z-06Z.

OVERNIGHT...SFC COLD FRONT WILL PROGRESS SEWD AND SHOULD LIE WSW-ENE
ACROSS OUR FAR SOUTHERN-SE COUNTIES AT DAYBREAK. THIS FEATURE
SHOULD INTERACT WITH AVAILABLE MOISTURE TO TRIGGER SCATTERED SHOWERS
OVERNIGHT. STILL MUGGY OVERNIGHT THOUGH THE FAR N-NW SECTIONS MAY
START TO FEEL A LITTLE LESS HUMID BY DAYBREAK. MIN TEMPS MID 60S TO
NEAR 70.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 250 PM TUESDAY...

STRONGER S/W IN THE NORTHERN STREAM WILL CROSS THE NORTHERN
MID ATLANTIC WHILE THE TAIL END OF THE SHEAR AXIS APPROACHES OUR
NORTHERN COUNTIES BY EARLY EVENING. NLY FLOW BEHIND THE INITIAL MID
LEVEL TROUGH WILL ADVECT DRIER AND SLIGHTLY MORE STABLE AIR INTO
CENTRAL NC. WHILE CLOUDS WILL LIKELY STICK AROUND DUE TO RESIDUAL
MOISTURE AND CYCLONIC CURVATURE IN THE MID LEVEL FLOW...CONVECTIVE
COVERAGE SHOULD BE LESS NUMEROUS WEDNESDAY AFTERNOON AND NOT AS
ROBUST. EXPECT TWO MAIN AREAS OF PRECIP...ONE OVER THE FAR SOUTH IN
VICINITY OF THE NEARLY STATIONARY SFC FRONT...AND THE OTHER OVER THE
FAR NORTH AHEAD OF THE SWD ADVANCING MID LEVEL SHEAR AXIS. PLAN TO
CAP POPS NO HIGHER THAN 50 PERCENT (NEAR SC BORDER) WITH A 1-IN-3
CHANCE ACROSS THE NORTH. AS ATMOSPHERE STABILIZES IN THE EARLY
EVENING...EXPECT MAJORITY OF THE CONVECTION TO DISSIPATE THOUGH A
STRAY SHOWER MAY STILL OCCUR IN VICINITY OF THE SHEAR AXIS ACROSS
THE NORTH. THIS SHEAR AXIS WILL CONTINUE TO PROGRESS SE OVERNIGHT
AND EXIT THE REGION BY DAYBREAK THU. SUBSIDENCE BEHIND THIS FEATURE
WILL AID TO DISSIPATE THE CLOUD COVERAGE AFTER MIDNIGHT.

EXPECT A FAIRLY UNIFORM TEMP FIELD WEDNESDAY DUE TO CLOUD COVERAGE
AND LOW LEVEL COLD AIR ADVECTION. MAX TEMPS NEAR 80 NORTH TO LOWER
80S SOUTH. MIN TEMPS WEDNESDAY NIGHT IN THE MID 60S.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 215 PM TUESDAY...

THURSDAY THROUGH FRIDAY...HEIGHTS ALOFT RISE OVER CENTRAL NORTH
CAROLINA...WITH A SUBSIDENT AIR MASS IN PLACE OVER THE AREA.
PRECIPITABLE WATER VALUES REMAIN HIGHER THURSDAY RELATIVE TO
FRIDAY...BETWEEN AN INCH AND 1.5 INCHES ON THE FORMER COMPARED TO A
DECREASE FROM THE NORTHEAST TO AT OR BELOW AN INCH FRIDAY. BOTH THE
GFS AND NAM BUFR SOUNDINGS...AND PARTICULARLY THE LATTER...FORECAST
ENOUGH MOISTURE AROUND 850MB THURSDAY FOR AREAS OF CU TO FORM...MORE
LIKELY TOWARD THE WESTERN PIEDMONT WHERE THE 850MB MOISTURE IS
HIGHEST. K INDICES FALL FROM THE NORTHEAST AS WELL THURSDAY
AFTERNOON CONTINUING INTO FRIDAY...WITH K INDICES WELL INTO NEGATIVE
VALUES BY FRIDAY AFTERNOON. IN TERMS OF DEEP CONVECTION...AMPLE
OVERALL CIN AND GRADUAL WARMING ALOFT WITH CONVERGENCE ALOFT SHOULD
PRECLUDE THAT. THERE SHOULD BE A FEW MORNING GUSTS WITH INITIAL
MIXING THURSDAY IN THE LOWER TO MID TEENS KTS IN THE MODESTLY TIGHT
GRADIENT BETWEEN AN INVERTED TROUGH OFF OF THE COAST AND SURFACE
HIGH PRESSURE BUILDING IN FROM THE NORTHWEST...BUT OVERALL 925MB
WINDS ARE MAINLY AROUND 10KT. 1000-850MB THICKNESSES SUGGEST HIGHS
IN THE LOWER TO MID 80S BOTH DAYS...CLOSE TO OR ON THE LOWER SIDE OF
MOS GUIDANCE. OVERNIGHT LOWS THURSDAY NIGHT AROUND 60 TO THE MID
60S...MINS POSSIBLY TEMPERED A LITTLE OVER THE SOUTHWEST PIEDMONT BY
SLIGHTLY GREATER UPPER-LEVEL MOISTURE FORECAST BY BOTH THE NAM AND
THE GFS.

FRIDAY NIGHT THROUGH TUESDAY...UPPER RIDGING CONTINUES TO BUILD IN.
AROUND THE RIDGE...THERE COULD BE A WEAK MID-LEVEL SHORTWAVE OR TWO
THAT ATTEMPTS TO MOVE...OR HAS SOME SUCCESS MOVING...INTO CENTRAL
NORTH CAROLINA ESPECIALLY LATE IN THE WEEKEND AND EARLY NEXT WEEK.
THE MOISTURE OF THE MEAN AIR MASS...AND MOISTURE AT THE
SURFACE...INCREASE SUNDAY INTO MONDAY...WITH SURFACE DEW POINTS
EXPECTED TO INCREASE TO AROUND 70F BY MONDAY...CONTINUING INTO
TUESDAY. WITH SURFACE RIDGING OVER THE GULF CURRENTLY FORECAST...IT
SHOULD BE A GRADUAL MOISTURE INCREASE ESPECIALLY AT THE
SURFACE...AND COARSE MODEL SOUNDINGS AT LEAST INTO SUNDAY AFTERNOON
HAVE A GOOD CONSENSUS OF AT LEAST BEING WEAKLY CAPPED ALOFT. WILL
MAINTAIN THE DRY FORECAST FRIDAY NIGHT THROUGH THE WEEKEND...BUT
WITH INCREASING MOISTURE...SOME GUIDANCE SUGGESTING A WEAKNESS IN
THE MID-LEVEL HEIGHTS TRANSLATING INTO COOLING ALOFT...AT LEAST SOME
QPF BY MUCH OF THE CURRENT LONG-TERM GUIDANCE...AND MEX MOS POPS
NEAR OR ABOVE CLIMATOLOGY...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS AT THE END OF THE PERIOD MONDAY AND
TUESDAY. FORCING SHOULD BE LIMITED TO WEAK SURFACE TROUGHINESS...SEA
BREEZE...AND/OR WEAK MID-LEVEL PVA AT TIMES...WHICH MAY BE ENOUGH
FOR ISOLATED SHOWERS AND THUNDERSTORMS IN A RELATIVELY MOIST AIR
MASS. 1000-850MB THICKNESSES GRADUALLY RISE...WHICH...ALONG WITH MOS
GUIDANCE...WOULD SUGGEST HIGHS RISING TO AT OR ABOVE NORMAL BY
SUNDAY. IF THE SURFACE DEW POINT IS A LITTLE HIGHER THAN FORECAST
PRIMARILY DUE TO SLIGHTLY LESS MIXING...MAXIMUM AFTERNOON HEAT
INDICES COULD RISE TO AROUND 100 BY MONDAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 840 PM TUESDAY...

24 HOUR TAF PERIOD: A LINE OF HEAVY SHOWERS AND THUNDERSTORMS AHEAD
OF A COLD FRONT HAS JUST ABOUT MADE ITS WAY THROUGH KRDU...AND KRWI
BUT WILL CONTINUE TO IMPACT KFAY DURING THE NEXT SEVERAL HOURS.
WHILE THE THUNDER WILL LINGER NEAR KRWI...THE ACTIVITY SHOULD WANE
ENOUGH BY THE TIME THE LINE REACHES KFAY THAT THE MAIN CONCERN WILL
BE HEAVY RAIN AND REDUCED VISBYS. THE HEAVY SHOWERS WILL BE
ACCOMPANIED BY MVFR/IFR CIGS AND VISBYS...BUT SHOULD BE RELATIVELY
SHORT LIVED. THE EFFECTIVE FRONT...AS NOTED BY A VEERING OF THE
WINDS FROM SW TO NNW...HAS CROSSED THE TRIAD TERMINALS AS OF 8 PM
AND SHOULD MOVE THROUGH THE KRDU/KRWI TERMINALS BETWEEN 8 PM AND 10
PM...AND THE KFAY VICINITY BETWEEN 10 PM AND 1 AM. THE ACTUAL COLD
FRONT...ACCOMPANIED BY DROP IN DEWPOINTS...LINGERS A FEW HOURS
BEHIND. A BRIEF PERIOD OF MVFR/IFR CIGS IS POSSIBLE BEHIND THE
SHOWERS BUT AHEAD OF THE FRONT. -KC

AVIATION CONDITIONS WILL BEGIN TO IMPROVE WEDNESDAY MORNING AS DRIER
MORE STABLE AIR FLOWS INTO THE REGION BEHIND THE EXITING FRONT.
EXPECT A RETURN TO VFR CONDITIONS THOUGH A STRATOCU DECK WILL LIKELY
DEVELOP WEDNESDAY AFTERNOON WITH BASES 3000-4000FT.

LOOKING AHEAD: HIGH PRESSURE WILL BUILD INTO AND LINGER OVER CENTRAL
NC WEDNESDAY NIGHT THROUGH THE WEEKEND. THIS WEATHER SYSTEM WILL
BRING DRY AND STABLE CONDITIONS LEADING TO VFR PARAMETERS. THE
EXCEPTION WILL BE A BRIEF PERIOD OF MVFR VISIBILITY DUE TO
FOG...MAINLY IN THE COASTAL PLAIN. -WSS

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...DJF
AVIATION...KC/WSS

000
FXUS62 KRAH 181849
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
250 PM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE TODAY...AND CROSS
THE REGION TONIGHT. HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM
THE NORTH WEDNESDAY THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 PM TUESDAY...

SLIGHT TO MODERATELY UNSTABLE AIR MASS RESIDES OVER CENTRAL NC AT
MID-AFTERNOON THANKS TO PEAKS OF SUN HEATING UP AN AIR MASS WITH SFC
DEWPOINTS IN THE UPPER 60S TO LOWER 70S. UPSTAIRS...A VORT MAXIMUM
OVER THE CENTRAL APPALACHIANS CONTINUES TO ROTATE EASTWARD WITH
ATTENDANT SHEAR AXIS EXTENDING SWWD ALONG THE SPINE OF THE SOUTHERN
APPALACHIANS. THIS MID LEVEL FEATURE AIDING TO ENHANCE THE 925-850MB
FLOW WHICH IS ADVECTING ADDITIONAL MOISTURE INTO THE COLUMN. LATEST
SATELLITE TOTAL BLEND PRECIP WATER PRODUCT DEPICTS VALUES BETWEEN
1.8-2 INCHES OVER OUR FORECAST AREA. THOUGH MID LEVEL LAPSE RATES
ARE MEAGER...ENOUGH JUICE EXISTS IN THE ATMOSPHERE TO SUPPORT THE
DEVELOPMENT OF NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS LATE
THIS AFTERNOON THROUGH EARLY EVENING AS THE MID LEVEL SHEAR AXIS
CROSSES THE REGION. CURRENT 0-6KM SHEAR VALUES IN THE 30-40KT RANGE
OVER THE NW PIEDMONT SUPPORT THE IDEA OF CONVECTION FORMING INTO A
LINE AS IT MARCHES EAST-SE. CANNOT RULE OUT THE POSSIBILITY OF AN
ISOLATED STRONG-SEVERE STORM WITH WIND GUSTS 40-50 MPH. STILL
BELIEVE MAIN WEATHER HAZARD WILL BE TORRENTIAL DOWNPOURS WITH
RAINFALL RATES 2-3 INCHES PER HOUR POSSIBLE IN A FEW OF THE STORMS.
FORTUNATELY STEERING WINDS CLOSE TO 25KTS SO STORMS WITH THIS
MAGNITUDE OF RAIN SHOULD NOT SETTLE OVER ONE SPOT VERY LONG. BULK OF
CONVECTIVE ALLOWING MODELS AS WELL AS THE 11Z HRRR SUGGEST THE
BROKEN LINE OF CONVECTION CROSSING THE PIEDMONT BETWEEN
21Z-00Z...AND INTO THE SANDHILLS AND COASTAL PLAIN 23Z-02Z.

PLAN TO MAINTAIN CATEGORICAL POPS IN THE NW PIEDMONT LATE THIS
AFTERNOON THEN SPREAD THESE HIGHER POPS SEWD WITH TIME. WILL
INTRODUCE DECREASING POPS BY EARLY EVENING IN THE NW PIEDMONT...THEN
TREND POPS LOWER OVER THE REMAINDER OF THE FORECAST BETWEEN 02Z-06Z.

OVERNIGHT...SFC COLD FRONT WILL PROGRESS SEWD AND SHOULD LIE WSW-ENE
ACROSS OUR FAR SOUTHERN-SE COUNTIES AT DAYBREAK. THIS FEATURE
SHOULD INTERACT WITH AVAILABLE MOISTURE TO TRIGGER SCATTERED SHOWERS
OVERNIGHT. STILL MUGGY OVERNIGHT THOUGH THE FAR N-NW SECTIONS MAY
START TO FEEL A LITTLE LESS HUMID BY DAYBREAK. MIN TEMPS MID 60S TO
NEAR 70.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 250 PM TUESDAY...

STRONGER S/W IN THE NORTHERN STREAM WILL CROSS THE NORTHERN
MID ATLANTIC WHILE THE TAIL END OF THE SHEAR AXIS APPROACHES OUR
NORTHERN COUNTIES BY EARLY EVENING. NLY FLOW BEHIND THE INITIAL MID
LEVEL TROUGH WILL ADVECT DRIER AND SLIGHTLY MORE STABLE AIR INTO
CENTRAL NC. WHILE CLOUDS WILL LIKELY STICK AROUND DUE TO RESIDUAL
MOISTURE AND CYCLONIC CURVATURE IN THE MID LEVEL FLOW...CONVECTIVE
COVERAGE SHOULD BE LESS NUMEROUS WEDNESDAY AFTERNOON AND NOT AS
ROBUST. EXPECT TWO MAIN AREAS OF PRECIP...ONE OVER THE FAR SOUTH IN
VICINITY OF THE NEARLY STATIONARY SFC FRONT...AND THE OTHER OVER THE
FAR NORTH AHEAD OF THE SWD ADVANCING MID LEVEL SHEAR AXIS. PLAN TO
CAP POPS NO HIGHER THAN 50 PERCENT (NEAR SC BORDER) WITH A 1-IN-3
CHANCE ACROSS THE NORTH. AS ATMOSPHERE STABILIZES IN THE EARLY
EVENING...EXPECT MAJORITY OF THE CONVECTION TO DISSIPATE THOUGH A
STRAY SHOWER MAY STILL OCCUR IN VICINITY OF THE SHEAR AXIS ACROSS
THE NORTH. THIS SHEAR AXIS WILL CONTINUE TO PROGRESS SE OVERNIGHT
AND EXIT THE REGION BY DAYBREAK THU. SUBSIDENCE BEHIND THIS FEATURE
WILL AID TO DISSIPATE THE CLOUD COVERAGE AFTER MIDNIGHT.

EXPECT A FAIRLY UNIFORM TEMP FIELD WEDNESDAY DUE TO CLOUD COVERAGE
AND LOW LEVEL COLD AIR ADVECTION. MAX TEMPS NEAR 80 NORTH TO LOWER
80S SOUTH. MIN TEMPS WEDNESDAY NIGHT IN THE MID 60S.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 215 PM TUESDAY...

THURSDAY THROUGH FRIDAY...HEIGHTS ALOFT RISE OVER CENTRAL NORTH
CAROLINA...WITH A SUBSIDENT AIR MASS IN PLACE OVER THE AREA.
PRECIPITABLE WATER VALUES REMAIN HIGHER THURSDAY RELATIVE TO
FRIDAY...BETWEEN AN INCH AND 1.5 INCHES ON THE FORMER COMPARED TO A
DECREASE FROM THE NORTHEAST TO AT OR BELOW AN INCH FRIDAY. BOTH THE
GFS AND NAM BUFR SOUNDINGS...AND PARTICULARLY THE LATTER...FORECAST
ENOUGH MOISTURE AROUND 850MB THURSDAY FOR AREAS OF CU TO FORM...MORE
LIKELY TOWARD THE WESTERN PIEDMONT WHERE THE 850MB MOISTURE IS
HIGHEST. K INDICES FALL FROM THE NORTHEAST AS WELL THURSDAY
AFTERNOON CONTINUING INTO FRIDAY...WITH K INDICES WELL INTO NEGATIVE
VALUES BY FRIDAY AFTERNOON. IN TERMS OF DEEP CONVECTION...AMPLE
OVERALL CIN AND GRADUAL WARMING ALOFT WITH CONVERGENCE ALOFT SHOULD
PRECLUDE THAT. THERE SHOULD BE A FEW MORNING GUSTS WITH INITIAL
MIXING THURSDAY IN THE LOWER TO MID TEENS KTS IN THE MODESTLY TIGHT
GRADIENT BETWEEN AN INVERTED TROUGH OFF OF THE COAST AND SURFACE
HIGH PRESSURE BUILDING IN FROM THE NORTHWEST...BUT OVERALL 925MB
WINDS ARE MAINLY AROUND 10KT. 1000-850MB THICKNESSES SUGGEST HIGHS
IN THE LOWER TO MID 80S BOTH DAYS...CLOSE TO OR ON THE LOWER SIDE OF
MOS GUIDANCE. OVERNIGHT LOWS THURSDAY NIGHT AROUND 60 TO THE MID
60S...MINS POSSIBLY TEMPERED A LITTLE OVER THE SOUTHWEST PIEDMONT BY
SLIGHTLY GREATER UPPER-LEVEL MOISTURE FORECAST BY BOTH THE NAM AND
THE GFS.

FRIDAY NIGHT THROUGH TUESDAY...UPPER RIDGING CONTINUES TO BUILD IN.
AROUND THE RIDGE...THERE COULD BE A WEAK MID-LEVEL SHORTWAVE OR TWO
THAT ATTEMPTS TO MOVE...OR HAS SOME SUCCESS MOVING...INTO CENTRAL
NORTH CAROLINA ESPECIALLY LATE IN THE WEEKEND AND EARLY NEXT WEEK.
THE MOISTURE OF THE MEAN AIR MASS...AND MOISTURE AT THE
SURFACE...INCREASE SUNDAY INTO MONDAY...WITH SURFACE DEW POINTS
EXPECTED TO INCREASE TO AROUND 70F BY MONDAY...CONTINUING INTO
TUESDAY. WITH SURFACE RIDGING OVER THE GULF CURRENTLY FORECAST...IT
SHOULD BE A GRADUAL MOISTURE INCREASE ESPECIALLY AT THE
SURFACE...AND COARSE MODEL SOUNDINGS AT LEAST INTO SUNDAY AFTERNOON
HAVE A GOOD CONSENSUS OF AT LEAST BEING WEAKLY CAPPED ALOFT. WILL
MAINTAIN THE DRY FORECAST FRIDAY NIGHT THROUGH THE WEEKEND...BUT
WITH INCREASING MOISTURE...SOME GUIDANCE SUGGESTING A WEAKNESS IN
THE MID-LEVEL HEIGHTS TRANSLATING INTO COOLING ALOFT...AT LEAST SOME
QPF BY MUCH OF THE CURRENT LONG-TERM GUIDANCE...AND MEX MOS POPS
NEAR OR ABOVE CLIMATOLOGY...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS AT THE END OF THE PERIOD MONDAY AND
TUESDAY. FORCING SHOULD BE LIMITED TO WEAK SURFACE TROUGHINESS...SEA
BREEZE...AND/OR WEAK MID-LEVEL PVA AT TIMES...WHICH MAY BE ENOUGH
FOR ISOLATED SHOWERS AND THUNDERSTORMS IN A RELATIVELY MOIST AIR
MASS. 1000-850MB THICKNESSES GRADUALLY RISE...WHICH...ALONG WITH MOS
GUIDANCE...WOULD SUGGEST HIGHS RISING TO AT OR ABOVE NORMAL BY
SUNDAY. IF THE SURFACE DEW POINT IS A LITTLE HIGHER THAN FORECAST
PRIMARILY DUE TO SLIGHTLY LESS MIXING...MAXIMUM AFTERNOON HEAT
INDICES COULD RISE TO AROUND 100 BY MONDAY.

&&

.AVIATION /17Z TUESDAY THROUGH SUNDAY/...
AS OF 1210 PM TUESDAY...

A SURFACE COLD FRONT SLOWLY ADVANCING SOUTHEASTWARD WILL INTERACT
WITH THE MOIST AND SLIGHTLY UNSTABLE AIR MASS TO TRIGGER NUMEROUS
SHOWERS AND SCATTERED THUNDERSTORMS ACROSS CENTRAL NC LATER THIS
AFTERNOON THROUGH TONIGHT. THE SHOWER AND THUNDERSTORM COVERAGE IS
EXPECTED TO BE GREATEST BETWEEN 4 PM AND 10 PM. THE CONVECTIVE
ACTIVITY WILL CREATE WIDESPREAD MVFR CEILINGS/VISIBILITY WITH
POCKETS OF IFR CEILING/VISIBILITY IN THE HEAVIER SHOWERS.

THE COLD FRONT SHOULD CROSS THE TRIAD TERMINALS AROUND 10 PM...THE
KRDU/KRWI TERMINALS BETWEEN 1 AM AND 3 AM...AND THE KFAY VICINITY
BETWEEN 3-5 AM. AHEAD THE BOUNDARY EXPECT IFR CEILINGS ALONG WITH A
FEW SHOWERS. THE PASSAGE OF THE FRONT WILL BE NOTED BY SURFACE WINDS
VEERING FROM THE SW TO THE NORTH-NORTHWEST.

AVIATION CONDITIONS WILL BEGIN TO IMPROVE WEDNESDAY MORNING AS DRIER
MORE STABLE AIR FLOWS INTO THE REGION BEHIND THE EXITING FRONT.
EXPECT A RETURN TO VFR CONDITIONS THOUGH A STRATOCU DECK WILL LIKELY
DEVELOP WEDNESDAY AFTERNOON WITH BASES 3000-4000FT.

HIGH PRESSURE WILL BUILD INTO AND LINGER OVER CENTRAL NC WEDNESDAY
NIGHT THROUGH THE WEEKEND. THIS WEATHER SYSTEM WILL BRING DRY AND
STABLE CONDITIONS LEADING TO VFR PARAMETERS. THE EXCEPTION WILL BE A
BRIEF PERIOD OF MVFR VISIBILITY DUE TO FOG...MAINLY IN THE COASTAL
PLAIN.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...DJF
AVIATION...WSS

000
FXUS62 KRAH 181814
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
215 PM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST...AND CROSSES THE REGION
TONIGHT. HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA FROM
THE NORTH WEDNESDAY THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM TUESDAY...

VERY MOIST AIR MASS RESIDES OVER CENTRAL NC THIS MORNING AS AREA
SOUNDINGS AND SATELLITE BLENDED TOTAL PRECIP PRODUCT DEPICT PRECIP
WATER VALUES BETWEEN 1.75-2 INCHES. ALSO...WATER VAPOR IMAGERY
DEPICT A PAIR OF MID LEVEL VORTICES LIFTING E-NE ACROSS EASTERN TN
AND NORTHERN GA. THE LATER VORTEX PROJECTED TO LIFT NE INTO CENTRAL
NC LATE THIS AFTERNOON. PERIODS OF PARTIAL SUN WILL AID TO BOOST
SBCAPE AND ML CAPE INTO THE 1000-1500 J/KG RANGE...MAINLY OVER
SECTIONS OF THE SANDHILLS AND COASTAL PLAIN. IN THE PIEDMONT...THE
CLOUD COVER WILL LIKELY REMAIN TOO EXTENSIVE TO PERMIT MUCH
SUN...LEADING TO A SLIGHTLY MORE STABLE AIR MASS. THUS EXPECT SHOWER
AND THUNDERSTORM COVERAGE TO INCREASE FROM THE WEST-SW LATER THIS
AFTERNOON AND CONTINUE INTO THE EARLY EVENING HOURS.

DUE TO THE MOIST AIR MASS...THE SHOWERS AND STORMS WILL BE EFFICIENT
RAIN PRODUCERS. WILL NEED TO MONITOR SECTIONS OF THE SOUTHERN AND
WESTERN PIEDMONT WHERE LOCALLY HEAVY RAIN HAS OCCURRED SINCE EARLY
MONDAY AFTERNOON. NOT ANTICIPATING THE NEED FOR A FLASH FLOOD WATCH
AT THIS TIME BUT MAY NEED TO ISSUE A FEW URBAN/SMALL STREAM
ADVISORIES WITH THE STRONGER CELLS.

WHILE STORM PREDICTION CENTER HAS HIGHLIGHTED OUR REGION IN A
SLIGHT RISK THIS AFTERNOON FOR DAMAGING WINDS...I DO HAVE SOME
DOUBTS. BULK SHEAR PROJECTED TO BE 30KTS OR LESS WITH THE LOWER
VALUES EXPECTED ACROSS THE SOUTH. LACK OF DECENT LAPSE RATES AND A
VERY MOIST AIR THROUGH THE COLUMN WILL ALSO HINDER DAMAGING WIND
GUST POTENTIAL. WHILE AN ISOLATED WET MICROBURSTS A DEFINITE
PROBABILITY...SCATTERED-NUMEROUS OCCURRENCES OF STRONG-GUSTY WINDS
LOOKS UNLIKELY.

AFTERNOON TEMPS DEPENDENT ON AMOUNT (IF ANY) OF ANY PARTIAL SUN AND
EXTENT OF CONVECTION. PREVIOUS FORECAST OF LOWER 80S NW TO MID 80S
SE APPEAR ON TARGET. -WSS

TONIGHT: WHILE THERE MAY BE A LULL THIS EVENING AFTER THE AFTERNOON
AND EARLY EVENING CONVECTION...THE LEAD SURFACE BOUNDARY IS FORECAST
TO SETTLE SOUTHEASTWARD INTO CENTRAL NC ABOUT THE TIME THE SURFACE
WAVE OVER THE MID SOUTH TRACKS TOWARD INTO OUR REGION. THE PASSAGE
OF THE SURFACE WAVE - ONE SUPPORTED FROM ALOFT BY THE APPROACH OF A
NORTHERN STREAM SHORTWAVE TROUGH FROM THE UPPER MIDWEST THIS
MORNING - WILL ENCOURAGE RENEWED DEVELOPMENT OF AN AREA OF SHOWERS
AND ISOLATED STORMS OVER CENTRAL NC OVERNIGHT. LOWS...WITH MOSTLY
CLOUDY SKIES...IN THE MIDDLE 60S TO AROUND 70 DEGREES. TOTAL
RAINFALL AMOUNTS IN THE ONE TO TWO INCH RANGE WILL BE COMMON...
HIGHEST NORTH AND NORTHWEST...THOUGH AS WITH ANY CONVECTIVE
PRECIPITATION THERE WILL BE SOME AREAS THAT LIKELY RECEIVE
CONSIDERABLY LESS. -MWS

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...

THE NORTHERN STREAM FRONT REFERENCED IN THE NEAR TERM DISCUSSION - A
FRONT LIKELY ENHANCED BY NE MARITIME FLOW FROM CHESAPEAKE BAY
REGION - WILL NOT DRIFT SOUTHWARD THROUGH CENTRAL NC UNTIL THE
AFTERNOON WEDNESDAY. HOWEVER...THE MAIN CONVERGENCE AXIS WITH THE
LEAD FRONT TRAILING THE SURFACE WAVE TRACKING FROM THE MID-SOUTH TO
NC COAST WILL HAVE DRIFTED INTO SOUTHERN OR SOUTHEASTERN NC BY WED
MORNING. AS SUCH...HAVE TRENDED POPS DOWNWARD INTO THE CHANCE
RANGE...RANGING FROM AROUND 30 PERCENT NW...TO 50 PERCENT IN CLOSEST
PROXIMITY TO THE LEAD FRONT/CONVERGENCE AXIS AND WHERE BOUNDARY
LAYER MOISTURE IN THE UPPER 60S IS LIKELY TO LINGER...OVER THE SE.
HIGHS...WITH A MIX OF SUN AND CLOUDS...AGAIN IN THE LOWER TO MIDDLE
80S. CLEARING AND COOLER WITH LOWS IN THE LOWER TO MIDDLE 60S
OVERNIGHT...THOUGH A FEW PATCHES OF STRATUS IN NE LOW LEVEL FLOW
WILL BE POSSIBLE LATE.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 215 PM TUESDAY...

THURSDAY THROUGH FRIDAY...HEIGHTS ALOFT RISE OVER CENTRAL NORTH
CAROLINA...WITH A SUBSIDENT AIR MASS IN PLACE OVER THE AREA.
PRECIPITABLE WATER VALUES REMAIN HIGHER THURSDAY RELATIVE TO
FRIDAY...BETWEEN AN INCH AND 1.5 INCHES ON THE FORMER COMPARED TO A
DECREASE FROM THE NORTHEAST TO AT OR BELOW AN INCH FRIDAY. BOTH THE
GFS AND NAM BUFR SOUNDINGS...AND PARTICULARLY THE LATTER...FORECAST
ENOUGH MOISTURE AROUND 850MB THURSDAY FOR AREAS OF CU TO FORM...MORE
LIKELY TOWARD THE WESTERN PIEDMONT WHERE THE 850MB MOISTURE IS
HIGHEST. K INDICES FALL FROM THE NORTHEAST AS WELL THURSDAY
AFTERNOON CONTINUING INTO FRIDAY...WITH K INDICES WELL INTO NEGATIVE
VALUES BY FRIDAY AFTERNOON. IN TERMS OF DEEP CONVECTION...AMPLE
OVERALL CIN AND GRADUAL WARMING ALOFT WITH CONVERGENCE ALOFT SHOULD
PRECLUDE THAT. THERE SHOULD BE A FEW MORNING GUSTS WITH INITIAL
MIXING THURSDAY IN THE LOWER TO MID TEENS KTS IN THE MODESTLY TIGHT
GRADIENT BETWEEN AN INVERTED TROUGH OFF OF THE COAST AND SURFACE
HIGH PRESSURE BUILDING IN FROM THE NORTHWEST...BUT OVERALL 925MB
WINDS ARE MAINLY AROUND 10KT. 1000-850MB THICKNESSES SUGGEST HIGHS
IN THE LOWER TO MID 80S BOTH DAYS...CLOSE TO OR ON THE LOWER SIDE OF
MOS GUIDANCE. OVERNIGHT LOWS THURSDAY NIGHT AROUND 60 TO THE MID
60S...MINS POSSIBLY TEMPERED A LITTLE OVER THE SOUTHWEST PIEDMONT BY
SLIGHTLY GREATER UPPER-LEVEL MOISTURE FORECAST BY BOTH THE NAM AND
THE GFS.

FRIDAY NIGHT THROUGH TUESDAY...UPPER RIDGING CONTINUES TO BUILD IN.
AROUND THE RIDGE...THERE COULD BE A WEAK MID-LEVEL SHORTWAVE OR TWO
THAT ATTEMPTS TO MOVE...OR HAS SOME SUCCESS MOVING...INTO CENTRAL
NORTH CAROLINA ESPECIALLY LATE IN THE WEEKEND AND EARLY NEXT WEEK.
THE MOISTURE OF THE MEAN AIR MASS...AND MOISTURE AT THE
SURFACE...INCREASE SUNDAY INTO MONDAY...WITH SURFACE DEW POINTS
EXPECTED TO INCREASE TO AROUND 70F BY MONDAY...CONTINUING INTO
TUESDAY. WITH SURFACE RIDGING OVER THE GULF CURRENTLY FORECAST...IT
SHOULD BE A GRADUAL MOISTURE INCREASE ESPECIALLY AT THE
SURFACE...AND COARSE MODEL SOUNDINGS AT LEAST INTO SUNDAY AFTERNOON
HAVE A GOOD CONSENSUS OF AT LEAST BEING WEAKLY CAPPED ALOFT. WILL
MAINTAIN THE DRY FORECAST FRIDAY NIGHT THROUGH THE WEEKEND...BUT
WITH INCREASING MOISTURE...SOME GUIDANCE SUGGESTING A WEAKNESS IN
THE MID-LEVEL HEIGHTS TRANSLATING INTO COOLING ALOFT...AT LEAST SOME
QPF BY MUCH OF THE CURRENT LONG-TERM GUIDANCE...AND MEX MOS POPS
NEAR OR ABOVE CLIMATOLOGY...WILL INTRODUCE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS AT THE END OF THE PERIOD MONDAY AND
TUESDAY. FORCING SHOULD BE LIMITED TO WEAK SURFACE TROUGHINESS...SEA
BREEZE...AND/OR WEAK MID-LEVEL PVA AT TIMES...WHICH MAY BE ENOUGH
FOR ISOLATED SHOWERS AND THUNDERSTORMS IN A RELATIVELY MOIST AIR
MASS. 1000-850MB THICKNESSES GRADUALLY RISE...WHICH...ALONG WITH MOS
GUIDANCE...WOULD SUGGEST HIGHS RISING TO AT OR ABOVE NORMAL BY
SUNDAY. IF THE SURFACE DEW POINT IS A LITTLE HIGHER THAN FORECAST
PRIMARILY DUE TO SLIGHTLY LESS MIXING...MAXIMUM AFTERNOON HEAT
INDICES COULD RISE TO AROUND 100 BY MONDAY.

&&

.AVIATION /17Z TUESDAY THROUGH SUNDAY/...
AS OF 1210 PM TUESDAY...

A SURFACE COLD FRONT SLOWLY ADVANCING SOUTHEASTWARD WILL INTERACT
WITH THE MOIST AND SLIGHTLY UNSTABLE AIR MASS TO TRIGGER NUMEROUS
SHOWERS AND SCATTERED THUNDERSTORMS ACROSS CENTRAL NC LATER THIS
AFTERNOON THROUGH TONIGHT. THE SHOWER AND THUNDERSTORM COVERAGE IS
EXPECTED TO BE GREATEST BETWEEN 4 PM AND 10 PM. THE CONVECTIVE
ACTIVITY WILL CREATE WIDESPREAD MVFR CEILINGS/VISIBILITY WITH
POCKETS OF IFR CEILING/VISIBILITY IN THE HEAVIER SHOWERS.

THE COLD FRONT SHOULD CROSS THE TRIAD TERMINALS AROUND 10 PM...THE
KRDU/KRWI TERMINALS BETWEEN 1 AM AND 3 AM...AND THE KFAY VICINITY
BETWEEN 3-5 AM. AHEAD THE BOUNDARY EXPECT IFR CEILINGS ALONG WITH A
FEW SHOWERS. THE PASSAGE OF THE FRONT WILL BE NOTED BY SURFACE WINDS
VEERING FROM THE SW TO THE NORTH-NORTHWEST.

AVIATION CONDITIONS WILL BEGIN TO IMPROVE WEDNESDAY MORNING AS DRIER
MORE STABLE AIR FLOWS INTO THE REGION BEHIND THE EXITING FRONT.
EXPECT A RETURN TO VFR CONDITIONS THOUGH A STRATOCU DECK WILL LIKELY
DEVELOP WEDNESDAY AFTERNOON WITH BASES 3000-4000FT.

HIGH PRESSURE WILL BUILD INTO AND LINGER OVER CENTRAL NC WEDNESDAY
NIGHT THROUGH THE WEEKEND. THIS WEATHER SYSTEM WILL BRING DRY AND
STABLE CONDITIONS LEADING TO VFR PARAMETERS. THE EXCEPTION WILL BE A
BRIEF PERIOD OF MVFR VISIBILITY DUE TO FOG...MAINLY IN THE COASTAL
PLAIN.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS/MWS
SHORT TERM...MWS
LONG TERM...DJF
AVIATION...WSS

000
FXUS62 KRAH 181609
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1210 PM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE TODAY...AND CROSS
THE REGION TONIGHT. HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM
THE NORTH WEDNESDAY THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM TUESDAY...

VERY MOIST AIR MASS RESIDES OVER CENTRAL NC THIS MORNING AS AREA
SOUNDINGS AND SATELLITE BLENDED TOTAL PRECIP PRODUCT DEPICT PRECIP
WATER VALUES BETWEEN 1.75-2 INCHES. ALSO...WATER VAPOR IMAGERY
DEPICT A PAIR OF MID LEVEL VORTICES LIFTING E-NE ACROSS EASTERN TN
AND NORTHERN GA. THE LATER VORTEX PROJECTED TO LIFT NE INTO CENTRAL
NC LATE THIS AFTERNOON. PERIODS OF PARTIAL SUN WILL AID TO BOOST
SBCAPE AND ML CAPE INTO THE 1000-1500 J/KG RANGE...MAINLY OVER
SECTIONS OF THE SANDHILLS AND COASTAL PLAIN. IN THE PIEDMONT...THE
CLOUD COVER WILL LIKELY REMAIN TOO EXTENSIVE TO PERMIT MUCH
SUN...LEADING TO A SLIGHTLY MORE STABLE AIR MASS. THUS EXPECT SHOWER
AND THUNDERSTORM COVERAGE TO INCREASE FROM THE WEST-SW LATER THIS
AFTERNOON AND CONTINUE INTO THE EARLY EVENING HOURS.

DUE TO THE MOIST AIR MASS...THE SHOWERS AND STORMS WILL BE EFFICIENT
RAIN PRODUCERS. WILL NEED TO MONITOR SECTIONS OF THE SOUTHERN AND
WESTERN PIEDMONT WHERE LOCALLY HEAVY RAIN HAS OCCURRED SINCE EARLY
MONDAY AFTERNOON. NOT ANTICIPATING THE NEED FOR A FLASH FLOOD WATCH
AT THIS TIME BUT MAY NEED TO ISSUE A FEW URBAN/SMALL STREAM
ADVISORIES WITH THE STRONGER CELLS.

WHILE STORM PREDICTION CENTER HAS HIGHLIGHTED OUR REGION IN A
SLIGHT RISK THIS AFTERNOON FOR DAMAGING WINDS...I DO HAVE SOME
DOUBTS. BULK SHEAR PROJECTED TO BE 30KTS OR LESS WITH THE LOWER
VALUES EXPECTED ACROSS THE SOUTH. LACK OF DECENT LAPSE RATES AND A
VERY MOIST AIR THROUGH THE COLUMN WILL ALSO HINDER DAMAGING WIND
GUST POTENTIAL. WHILE AN ISOLATED WET MICROBURSTS A DEFINITE
PROBABILITY...SCATTERED-NUMEROUS OCCURRENCES OF STRONG-GUSTY WINDS
LOOKS UNLIKELY.

AFTERNOON TEMPS DEPENDENT ON AMOUNT (IF ANY) OF ANY PARTIAL SUN AND
EXTENT OF CONVECTION. PREVIOUS FORECAST OF LOWER 80S NW TO MID 80S
SE APPEAR ON TARGET. -WSS

TONIGHT: WHILE THERE MAY BE A LULL THIS EVENING AFTER THE AFTERNOON
AND EARLY EVENING CONVECTION...THE LEAD SURFACE BOUNDARY IS FORECAST
TO SETTLE SOUTHEASTWARD INTO CENTRAL NC ABOUT THE TIME THE SURFACE
WAVE OVER THE MID SOUTH TRACKS TOWARD INTO OUR REGION. THE PASSAGE
OF THE SURFACE WAVE - ONE SUPPORTED FROM ALOFT BY THE APPROACH OF A
NORTHERN STREAM SHORTWAVE TROUGH FROM THE UPPER MIDWEST THIS
MORNING - WILL ENCOURAGE RENEWED DEVELOPMENT OF AN AREA OF SHOWERS
AND ISOLATED STORMS OVER CENTRAL NC OVERNIGHT. LOWS...WITH MOSTLY
CLOUDY SKIES...IN THE MIDDLE 60S TO AROUND 70 DEGREES. TOTAL
RAINFALL AMOUNTS IN THE ONE TO TWO INCH RANGE WILL BE COMMON...
HIGHEST NORTH AND NORTHWEST...THOUGH AS WITH ANY CONVECTIVE
PRECIPITATION THERE WILL BE SOME AREAS THAT LIKELY RECEIVE
CONSIDERABLY LESS. -MWS

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...

THE NORTHERN STREAM FRONT REFERENCED IN THE NEAR TERM DISCUSSION - A
FRONT LIKELY ENHANCED BY NE MARITIME FLOW FROM CHESAPEAKE BAY
REGION - WILL NOT DRIFT SOUTHWARD THROUGH CENTRAL NC UNTIL THE
AFTERNOON WEDNESDAY. HOWEVER...THE MAIN CONVERGENCE AXIS WITH THE
LEAD FRONT TRAILING THE SURFACE WAVE TRACKING FROM THE MID-SOUTH TO
NC COAST WILL HAVE DRIFTED INTO SOUTHERN OR SOUTHEASTERN NC BY WED
MORNING. AS SUCH...HAVE TRENDED POPS DOWNWARD INTO THE CHANCE
RANGE...RANGING FROM AROUND 30 PERCENT NW...TO 50 PERCENT IN CLOSEST
PROXIMITY TO THE LEAD FRONT/CONVERGENCE AXIS AND WHERE BOUNDARY
LAYER MOISTURE IN THE UPPER 60S IS LIKELY TO LINGER...OVER THE SE.
HIGHS...WITH A MIX OF SUN AND CLOUDS...AGAIN IN THE LOWER TO MIDDLE
80S. CLEARING AND COOLER WITH LOWS IN THE LOWER TO MIDDLE 60S
OVERNIGHT...THOUGH A FEW PATCHES OF STRATUS IN NE LOW LEVEL FLOW
WILL BE POSSIBLE LATE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...

THURSDAY THROUGH FRIDAY NIGHT...HIGH PRESSURE BUILDS ACROSS SOUTHERN
NEW ENGLAND SHORE...EXTENDING DOWN THE MID ATLANTIC COAST WITH DRY
NORTHEAST TO EAST FLOW. THE PLEASANT ENSUING COOL DAMMING SCENARIO
WILL LINGER INTO THE WEEKEND...WITH THICKNESSES INDICATIVE OF TEMPS
A GOOD CATEGORY BELOW NORMAL...LOW-MID 80S. WILL MAKE SOME GRID
ADJUSTMENTS ON THURSDAY AND FRIDAY TO FAVOR COOLER TEMPS IN THE
NORTHEAST WHERE MARITIME FLOW WILL BE STRONGEST/COOLEST. MINS WILL
BE GENERALLY LOW AND MID 60S.

SATURDAY THROUGH MONDAY...THE COOL SURFACE HIGH WILL WEAKEN AND
DRIFT EAST WITH A GRADUAL RETURN OF MORE SOUTHERLY FLOW BY LATE
WEEKEND. MEANWHILE...UPPER RIDGING WILL BUILD EAST OUT OF THE
MIDWEST INTO THE EASTERN CONUS SATURDAY THROUGH MONDAY. SOUTHERLY
FLOW WILL RESULT IN INCREASING HUMIDITY SUNDAY INTO MONDAY. WITH THE
CAPPING MID LEVEL RIDGE OVERHEAD...CONVECTION WILL BE ISOLATED
OUTSIDE OF PERHAPS SOME DIFFERENTIAL HEATING ON THE EASTERN SLOPES
AND POTENTIAL FOR SOME SEA BREEZE CONVECTION TO MIGRATE INLAND INTO
THE COASTAL PLAIN. AT THIS POINT...THE CHANCES ARE TOO SMALL TO
MENTION IN THE FORECAST. THE AIRMASS WILL GRADUALLY WARM UP WITH THE
SOUTHERLY FLOW AND PERSISTENCE OF THE UPPER RIDGE INTO MONDAY...
HIGHS WILL WARM FROM THE MID 80S SATURDAY TO THE UPPER 80S...PERHAPS
LOWER 90S ON MONDAY. MINS WILL BE IN THE 60S.

&&

.AVIATION /17Z TUESDAY THROUGH SUNDAY/...
AS OF 1210 PM TUESDAY...

A SURFACE COLD FRONT SLOWLY ADVANCING SOUTHEASTWARD WILL INTERACT
WITH THE MOIST AND SLIGHTLY UNSTABLE AIR MASS TO TRIGGER NUMEROUS
SHOWERS AND SCATTERED THUNDERSTORMS ACROSS CENTRAL NC LATER THIS
AFTERNOON THROUGH TONIGHT. THE SHOWER AND THUNDERSTORM COVERAGE IS
EXPECTED TO BE GREATEST BETWEEN 4 PM AND 10 PM. THE CONVECTIVE
ACTIVITY WILL CREATE WIDESPREAD MVFR CEILINGS/VISIBILITY WITH
POCKETS OF IFR CEILING/VISIBILITY IN THE HEAVIER SHOWERS.

THE COLD FRONT SHOULD CROSS THE TRIAD TERMINALS AROUND 10 PM...THE
KRDU/KRWI TERMINALS BETWEEN 1 AM AND 3 AM...AND THE KFAY VICINITY
BETWEEN 3-5 AM. AHEAD THE BOUNDARY EXPECT IFR CEILINGS ALONG WITH A
FEW SHOWERS. THE PASSAGE OF THE FRONT WILL BE NOTED BY SURFACE WINDS
VEERING FROM THE SW TO THE NORTH-NORTHWEST.

AVIATION CONDITIONS WILL BEGIN TO IMPROVE WEDNESDAY MORNING AS DRIER
MORE STABLE AIR FLOWS INTO THE REGION BEHIND THE EXITING FRONT.
EXPECT A RETURN TO VFR CONDITIONS THOUGH A STRATOCU DECK WILL LIKELY
DEVELOP WEDNESDAY AFTERNOON WITH BASES 3000-4000FT.

HIGH PRESSURE WILL BUILD INTO AND LINGER OVER CENTRAL NC WEDNESDAY
NIGHT THROUGH THE WEEKEND. THIS WEATHER SYSTEM WILL BRING DRY AND
STABLE CONDITIONS LEADING TO VFR PARAMETERS. THE EXCEPTION WILL BE A
BRIEF PERIOD OF MVFR VISIBILITY DUE TO FOG...MAINLY IN THE COASTAL
PLAIN.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS/MWS
SHORT TERM...MWS
LONG TERM...MLM
AVIATION...WSS

000
FXUS62 KRAH 181446
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1045 AM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE TODAY...AND CROSS
THE REGION TONIGHT. HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM
THE NORTH WEDNESDAY THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM TUESDAY...

VERY MOIST AIR MASS RESIDES OVER CENTRAL NC THIS MORNING AS AREA
SOUNDINGS AND SATELLITE BLENDED TOTAL PRECIP PRODUCT DEPICT PRECIP
WATER VALUES BETWEEN 1.75-2 INCHES. ALSO...WATER VAPOR IMAGERY
DEPICT A PAIR OF MID LEVEL VORTICES LIFTING E-NE ACROSS EASTERN TN
AND NORTHERN GA. THE LATER VORTEX PROJECTED TO LIFT NE INTO CENTRAL
NC LATE THIS AFTERNOON. PERIODS OF PARTIAL SUN WILL AID TO BOOST
SBCAPE AND ML CAPE INTO THE 1000-1500 J/KG RANGE...MAINLY OVER
SECTIONS OF THE SANDHILLS AND COASTAL PLAIN. IN THE PIEDMONT...THE
CLOUD COVER WILL LIKELY REMAIN TOO EXTENSIVE TO PERMIT MUCH
SUN...LEADING TO A SLIGHTLY MORE STABLE AIR MASS. THUS EXPECT SHOWER
AND THUNDERSTORM COVERAGE TO INCREASE FROM THE WEST-SW LATER THIS
AFTERNOON AND CONTINUE INTO THE EARLY EVENING HOURS.

DUE TO THE MOIST AIR MASS...THE SHOWERS AND STORMS WILL BE EFFICIENT
RAIN PRODUCERS. WILL NEED TO MONITOR SECTIONS OF THE SOUTHERN AND
WESTERN PIEDMONT WHERE LOCALLY HEAVY RAIN HAS OCCURRED SINCE EARLY
MONDAY AFTERNOON. NOT ANTICIPATING THE NEED FOR A FLASH FLOOD WATCH
AT THIS TIME BUT MAY NEED TO ISSUE A FEW URBAN/SMALL STREAM
ADVISORIES WITH THE STRONGER CELLS.

WHILE STORM PREDICTION CENTER HAS HIGHLIGHTED OUR REGION IN A
SLIGHT RISK THIS AFTERNOON FOR DAMAGING WINDS...I DO HAVE SOME
DOUBTS. BULK SHEAR PROJECTED TO BE 30KTS OR LESS WITH THE LOWER
VALUES EXPECTED ACROSS THE SOUTH. LACK OF DECENT LAPSE RATES AND A
VERY MOIST AIR THROUGH THE COLUMN WILL ALSO HINDER DAMAGING WIND
GUST POTENTIAL. WHILE AN ISOLATED WET MICROBURSTS A DEFINITE
PROBABILITY...SCATTERED-NUMEROUS OCCURRENCES OF STRONG-GUSTY WINDS
LOOKS UNLIKELY.

AFTERNOON TEMPS DEPENDENT ON AMOUNT (IF ANY) OF ANY PARTIAL SUN AND
EXTENT OF CONVECTION. PREVIOUS FORECAST OF LOWER 80S NW TO MID 80S
SE APPEAR ON TARGET. -WSS

TONIGHT: WHILE THERE MAY BE A LULL THIS EVENING AFTER THE AFTERNOON
AND EARLY EVENING CONVECTION...THE LEAD SURFACE BOUNDARY IS FORECAST
TO SETTLE SOUTHEASTWARD INTO CENTRAL NC ABOUT THE TIME THE SURFACE
WAVE OVER THE MID SOUTH TRACKS TOWARD INTO OUR REGION. THE PASSAGE
OF THE SURFACE WAVE - ONE SUPPORTED FROM ALOFT BY THE APPROACH OF A
NORTHERN STREAM SHORTWAVE TROUGH FROM THE UPPER MIDWEST THIS
MORNING - WILL ENCOURAGE RENEWED DEVELOPMENT OF AN AREA OF SHOWERS
AND ISOLATED STORMS OVER CENTRAL NC OVERNIGHT. LOWS...WITH MOSTLY
CLOUDY SKIES...IN THE MIDDLE 60S TO AROUND 70 DEGREES. TOTAL
RAINFALL AMOUNTS IN THE ONE TO TWO INCH RANGE WILL BE COMMON...
HIGHEST NORTH AND NORTHWEST...THOUGH AS WITH ANY CONVECTIVE
PRECIPITATION THERE WILL BE SOME AREAS THAT LIKELY RECEIVE
CONSIDERABLY LESS. -MWS

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...

THE NORTHERN STREAM FRONT REFERENCED IN THE NEAR TERM DISCUSSION - A
FRONT LIKELY ENHANCED BY NE MARITIME FLOW FROM CHESAPEAKE BAY
REGION - WILL NOT DRIFT SOUTHWARD THROUGH CENTRAL NC UNTIL THE
AFTERNOON WEDNESDAY. HOWEVER...THE MAIN CONVERGENCE AXIS WITH THE
LEAD FRONT TRAILING THE SURFACE WAVE TRACKING FROM THE MID-SOUTH TO
NC COAST WILL HAVE DRIFTED INTO SOUTHERN OR SOUTHEASTERN NC BY WED
MORNING. AS SUCH...HAVE TRENDED POPS DOWNWARD INTO THE CHANCE
RANGE...RANGING FROM AROUND 30 PERCENT NW...TO 50 PERCENT IN CLOSEST
PROXIMITY TO THE LEAD FRONT/CONVERGENCE AXIS AND WHERE BOUNDARY
LAYER MOISTURE IN THE UPPER 60S IS LIKELY TO LINGER...OVER THE SE.
HIGHS...WITH A MIX OF SUN AND CLOUDS...AGAIN IN THE LOWER TO MIDDLE
80S. CLEARING AND COOLER WITH LOWS IN THE LOWER TO MIDDLE 60S
OVERNIGHT...THOUGH A FEW PATCHES OF STRATUS IN NE LOW LEVEL FLOW
WILL BE POSSIBLE LATE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...

THURSDAY THROUGH FRIDAY NIGHT...HIGH PRESSURE BUILDS ACROSS SOUTHERN
NEW ENGLAND SHORE...EXTENDING DOWN THE MID ATLANTIC COAST WITH DRY
NORTHEAST TO EAST FLOW. THE PLEASANT ENSUING COOL DAMMING SCENARIO
WILL LINGER INTO THE WEEKEND...WITH THICKNESSES INDICATIVE OF TEMPS
A GOOD CATEGORY BELOW NORMAL...LOW-MID 80S. WILL MAKE SOME GRID
ADJUSTMENTS ON THURSDAY AND FRIDAY TO FAVOR COOLER TEMPS IN THE
NORTHEAST WHERE MARITIME FLOW WILL BE STRONGEST/COOLEST. MINS WILL
BE GENERALLY LOW AND MID 60S.

SATURDAY THROUGH MONDAY...THE COOL SURFACE HIGH WILL WEAKEN AND
DRIFT EAST WITH A GRADUAL RETURN OF MORE SOUTHERLY FLOW BY LATE
WEEKEND. MEANWHILE...UPPER RIDGING WILL BUILD EAST OUT OF THE
MIDWEST INTO THE EASTERN CONUS SATURDAY THROUGH MONDAY. SOUTHERLY
FLOW WILL RESULT IN INCREASING HUMIDITY SUNDAY INTO MONDAY. WITH THE
CAPPING MID LEVEL RIDGE OVERHEAD...CONVECTION WILL BE ISOLATED
OUTSIDE OF PERHAPS SOME DIFFERENTIAL HEATING ON THE EASTERN SLOPES
AND POTENTIAL FOR SOME SEA BREEZE CONVECTION TO MIGRATE INLAND INTO
THE COASTAL PLAIN. AT THIS POINT...THE CHANCES ARE TOO SMALL TO
MENTION IN THE FORECAST. THE AIRMASS WILL GRADUALLY WARM UP WITH THE
SOUTHERLY FLOW AND PERSISTENCE OF THE UPPER RIDGE INTO MONDAY...
HIGHS WILL WARM FROM THE MID 80S SATURDAY TO THE UPPER 80S...PERHAPS
LOWER 90S ON MONDAY. MINS WILL BE IN THE 60S.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 645 AM TUESDAY...

CEILINGS WILL BE HIGHLY VARIABLE IN THE UNSETTLED AIRMASS OVER THE
AREA TODAY. PATCHY LINGERING IFR CEILINGS THIS MORNING WILL LIFT TO
MVFR BY MID MORNING AND SHOULD REMAIN MOSTLY VFR/MVFR OUTSIDE OF
PRECIPITATION.

A COLD FRONT STALLED NORTH OF THE AREA WILL BE MOVING SOUTHEAST AND
ACROSS THE AREA LATE TODAY. FORCING WILL BE RATHER WEAK AHEAD OF THE
FRONT...BUT THE AIRMASS OVER THE AREA IS MOIST AND WARM...THUS PRONE
FOR ALMOST RANDOM SCATTERED SHOWER AND ISOLATED THUNDER DEVELOPMENT
THIS MORNING. THE FRONT...ACCOMPANIED BY A MORE WIDESPREAD AREA OF
SHOWERS AND THUNDERSTORMS...WILL BE MOVING INTO THE NORTHWEST DURING
PRIME DIURNAL TIMING...AROUND 18Z...WITH ACTIVITY PROGRESSING
SOUTHEAST. STORMS WILL BE ACCOMPANIED BY WIND GUSTS TO 25 KNOTS.
CONFIDENCE IN THE SPEED OF FRONTAL PROGRESSION IS NOT HIGH...BUT
EXPECT ACTIVITY TO BE LARGELY OUT OF THE AREA BY 19/06Z. SOUTH TO
SOUTHWEST WINDS WILL BE DOMINANT TODAY...SWINGING MORE WESTERLY
AFTER THE FRONT MOVES THROUGH THIS EVENING...THEN NORTHERLY
BY THE END OF THE TAF PERIOD.

VFR CONDITIONS ARE GENERALLY EXPECTED FROM WEDNESDAY ONWARD...
OUTSIDE OF POSSIBLY SOME EARLY MORNING STRATUS AND OR FOG DURING THE
PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS/MWS
SHORT TERM...MWS
LONG TERM...MLM
AVIATION...MLM

000
FXUS62 KRAH 181043
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
645 AM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE TODAY...AND MOVE
SLOWLY SOUTHEAST ACROSS THE REGION TONIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM TUESDAY...

SURFACE ANALYSIS THIS MORNING REVEALED A LEESIDE TROUGH OVER THE NC
FOOTHILLS. IN ADDITION...A 1011 MB SURFACE WAVE WAS CENTERED OVER
THE MID SOUTH...ALONG A FRONTAL ZONE DRAPED FROM THE SOUTHERN PLAINS
NORTHEASTWARD THROUGH THE EASTERN TN VALLEY/CENTRAL APPALACHIANS TO
THE DELMARVA/NEW JERSEY COAST. A SEPARATE NORTHERN STREAM FRONT
ARCED FROM NEW ENGLAND SOUTHWESTWARD TO AN ELONGATED 1011 MB AREA OF
LOW PRESSURE FROM OH TO IL...THEN NORTHWESTWARD TO INTO THE UPPER
MIDWEST.

TODAY: WHILE A MOIST...WEAKLY INHIBITED...AND MARGINALLY UNSTABLE
AIRMASS OVER NC WILL NOT NEED MUCH IMPETUS TO FORCE CONVECTION...THE
COMBINATION OF SUBSIDENCE IN THE WAKE OF A LEAD MCV OVER
SOUTHEASTERN NC AT PRESENT...AND THE LOCATION OF THE SOUTHERNMOST
FRONTAL ZONE ACROSS THE TN VALLEY AND CENTRAL APPALACHIANS (IE. TO
OUR NW) SHOULD TEND TO LIMIT CONVECTIVE COVERAGE OVER CENTRAL NC
THROUGH EARLY TO MID AFTERNOON. HOWEVER...A SHORTWAVE TROUGH OVER
THE MO VALLEY THIS MORNING IS PROGGED TO LIFT ENE TO NE ALONG THE
SPINE OF THE APPALACHIAN CHAIN THIS AFTERNOON...AND THE ASSOCIATED
BRUNT OF THIS FORCING FROM THE NW NC PIEDMONT NORTHWARD THROUGH VA
SHOULD HELP FOCUS CONVECTIVE DEVELOPMENT ALONG A THE LEE TROUGH OVER
WESTERN NC/VA...WITH THIS ACTIVITY LIKELY TO SPREAD ENE ACROSS THE
WESTERN AND NORTHERN NC PIEDMONT AFTER 3 OR 4 PM. MEANWHILE...MORE
THAN A COUPLE OF THE HI-RES CAMS INDICATE AN AREA OF STORMS AND AN
ASSOCIATED MCV OVER MS/NORTHWESTERN AL THIS MORNING MAY PIVOT ENE
ACROSS THE SANDHILLS AND COASTAL PLAIN LATER THIS AFTERNOON AND
EVENING...POSSIBLY MERGING WITH THE ACTIVITY FROM THE PIEDMONT.

BOTH MARGINAL INSTABILITY OF 1000 J/KG OR LESS OWING TO WEAK LAPSE
RATES ALOFT...AS WELL AS MARGINAL EFFECTIVE BULK SHEAR IN THE 20-30
KT RANGE...STILL SUGGEST ANY SEVERE THREAT WILL BE LOW...WITH
PERHAPS A FEW STRONG PRECIPITATION-LOADED WIND GUSTS. A MORE LIKELY
SCENARIO REMAINS A THREAT OF DOWNPOURS AND LOCALIZED FLOODING...
THOUGH ANY SUCH FLOODING WILL NOT BE WIDESPREAD AND INSTEAD CONFINED
MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED SOIL HAS DRIED IN
THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH FLOOD GUIDANCE VALUES
HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE FOR ONE HOUR FOR
EXAMPLE. HIGH TEMPERATURES TODAY ARE LIKELY TO REACH THE LOWER TO
MIDDLE 80S...WITH A FEW UPPER 80S POSSIBLE TOWARD KFAY AND KGSB.

TONIGHT: WHILE THERE MAY BE A LULL THIS EVENING AFTER THE AFTERNOON
AND EARLY EVENING CONVECTION...THE LEAD SURFACE BOUNDARY IS FORECAST
TO SETTLE SOUTHEASTWARD INTO CENTRAL NC ABOUT THE TIME THE SURFACE
WAVE OVER THE MID SOUTH TRACKS TOWARD INTO OUR REGION. THE PASSAGE
OF THE SURFACE WAVE - ONE SUPPORTED FROM ALOFT BY THE APPROACH OF A
NORTHERN STREAM SHORTWAVE TROUGH FROM THE UPPER MIDWEST THIS
MORNING - WILL ENCOURAGE RENEWED DEVELOPMENT OF AN AREA OF SHOWERS
AND ISOLATED STORMS OVER CENTRAL NC OVERNIGHT. LOWS...WITH MOSTLY
CLOUDY SKIES...IN THE MIDDLE 60S TO AROUND 70 DEGREES. TOTAL
RAINFALL AMOUNTS IN THE ONE TO TWO INCH RANGE WILL BE COMMON...
HIGHEST NORTH AND NORTHWEST...THOUGH AS WITH ANY CONVECTIVE
PRECIPITATION THERE WILL BE SOME AREAS THAT LIKELY RECEIVE
CONSIDERABLY LESS.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...

THE NORTHERN STREAM FRONT REFERENCED IN THE NEAR TERM DISCUSSION - A
FRONT LIKELY ENHANCED BY NE MARITIME FLOW FROM CHESAPEAKE BAY
REGION - WILL NOT DRIFT SOUTHWARD THROUGH CENTRAL NC UNTIL THE
AFTERNOON WEDNESDAY. HOWEVER...THE MAIN CONVERGENCE AXIS WITH THE
LEAD FRONT TRAILING THE SURFACE WAVE TRACKING FROM THE MID-SOUTH TO
NC COAST WILL HAVE DRIFTED INTO SOUTHERN OR SOUTHEASTERN NC BY WED
MORNING. AS SUCH...HAVE TRENDED POPS DOWNWARD INTO THE CHANCE
RANGE...RANGING FROM AROUND 30 PERCENT NW...TO 50 PERCENT IN CLOSEST
PROXIMITY TO THE LEAD FRONT/CONVERGENCE AXIS AND WHERE BOUNDARY
LAYER MOISTURE IN THE UPPER 60S IS LIKELY TO LINGER...OVER THE SE.
HIGHS...WITH A MIX OF SUN AND CLOUDS...AGAIN IN THE LOWER TO MIDDLE
80S. CLEARING AND COOLER WITH LOWS IN THE LOWER TO MIDDLE 60S
OVERNIGHT...THOUGH A FEW PATCHES OF STRATUS IN NE LOW LEVEL FLOW
WILL BE POSSIBLE LATE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...

THURSDAY THROUGH FRIDAY NIGHT...HIGH PRESSURE BUILDS ACROSS SOUTHERN
NEW ENGLAND SHORE...EXTENDING DOWN THE MID ATLANTIC COAST WITH DRY
NORTHEAST TO EAST FLOW. THE PLEASANT ENSUING COOL DAMMING SCENARIO
WILL LINGER INTO THE WEEKEND...WITH THICKNESSES INDICATIVE OF TEMPS
A GOOD CATEGORY BELOW NORMAL...LOW-MID 80S. WILL MAKE SOME GRID
ADJUSTMENTS ON THURSDAY AND FRIDAY TO FAVOR COOLER TEMPS IN THE
NORTHEAST WHERE MARITIME FLOW WILL BE STRONGEST/COOLEST. MINS WILL
BE GENERALLY LOW AND MID 60S.

SATURDAY THROUGH MONDAY...THE COOL SURFACE HIGH WILL WEAKEN AND
DRIFT EAST WITH A GRADUAL RETURN OF MORE SOUTHERLY FLOW BY LATE
WEEKEND. MEANWHILE...UPPER RIDGING WILL BUILD EAST OUT OF THE
MIDWEST INTO THE EASTERN CONUS SATURDAY THROUGH MONDAY. SOUTHERLY
FLOW WILL RESULT IN INCREASING HUMIDITY SUNDAY INTO MONDAY. WITH THE
CAPPING MID LEVEL RIDGE OVERHEAD...CONVECTION WILL BE ISOLATED
OUTSIDE OF PERHAPS SOME DIFFERENTIAL HEATING ON THE EASTERN SLOPES
AND POTENTIAL FOR SOME SEA BREEZE CONVECTION TO MIGRATE INLAND INTO
THE COASTAL PLAIN. AT THIS POINT...THE CHANCES ARE TOO SMALL TO
MENTION IN THE FORECAST. THE AIRMASS WILL GRADUALLY WARM UP WITH THE
SOUTHERLY FLOW AND PERSISTENCE OF THE UPPER RIDGE INTO MONDAY...
HIGHS WILL WARM FROM THE MID 80S SATURDAY TO THE UPPER 80S...PERHAPS
LOWER 90S ON MONDAY. MINS WILL BE IN THE 60S.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 645 AM TUESDAY...

CEILINGS WILL BE HIGHLY VARIABLE IN THE UNSETTLED AIRMASS OVER THE
AREA TODAY. PATCHY LINGERING IFR CEILINGS THIS MORNING WILL LIFT TO
MVFR BY MID MORNING AND SHOULD REMAIN MOSTLY VFR/MVFR OUTSIDE OF
PRECIPITATION.

A COLD FRONT STALLED NORTH OF THE AREA WILL BE MOVING SOUTHEAST AND
ACROSS THE AREA LATE TODAY. FORCING WILL BE RATHER WEAK AHEAD OF THE
FRONT...BUT THE AIRMASS OVER THE AREA IS MOIST AND WARM...THUS PRONE
FOR ALMOST RANDOM SCATTERED SHOWER AND ISOLATED THUNDER DEVELOPMENT
THIS MORNING. THE FRONT...ACCOMPANIED BY A MORE WIDESPREAD AREA OF
SHOWERS AND THUNDERSTORMS...WILL BE MOVING INTO THE NORTHWEST DURING
PRIME DIURNAL TIMING...AROUND 18Z...WITH ACTIVITY PROGRESSING
SOUTHEAST. STORMS WILL BE ACCOMPANIED BY WIND GUSTS TO 25 KNOTS.
CONFIDENCE IN THE SPEED OF FRONTAL PROGRESSION IS NOT HIGH...BUT
EXPECT ACTIVITY TO BE LARGELY OUT OF THE AREA BY 19/06Z. SOUTH TO
SOUTHWEST WINDS WILL BE DOMINANT TODAY...SWINGING MORE WESTERLY
AFTER THE FRONT MOVES THROUGH THIS EVENING...THEN NORTHERLY
BY THE END OF THE TAF PERIOD.

VFR CONDITIONS ARE GENERALLY EXPECTED FROM WEDNESDAY ONWARD...
OUTSIDE OF POSSIBLY SOME EARLY MORNING STRATUS AND OR FOG DURING THE
PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...MLM
AVIATION...MLM

000
FXUS62 KRAH 180729
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
329 AM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE TODAY...AND MOVE
SLOWLY SOUTHEAST ACROSS THE REGION TONIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM TUESDAY...

SURFACE ANALYSIS THIS MORNING REVEALED A LEESIDE TROUGH OVER THE NC
FOOTHILLS. IN ADDITION...A 1011 MB SURFACE WAVE WAS CENTERED OVER
THE MID SOUTH...ALONG A FRONTAL ZONE DRAPED FROM THE SOUTHERN PLAINS
NORTHEASTWARD THROUGH THE EASTERN TN VALLEY/CENTRAL APPALACHIANS TO
THE DELMARVA/NEW JERSEY COAST. A SEPARATE NORTHERN STREAM FRONT
ARCED FROM NEW ENGLAND SOUTHWESTWARD TO AN ELONGATED 1011 MB AREA OF
LOW PRESSURE FROM OH TO IL...THEN NORTHWESTWARD TO INTO THE UPPER
MIDWEST.

TODAY: WHILE A MOIST...WEAKLY INHIBITED...AND MARGINALLY UNSTABLE
AIRMASS OVER NC WILL NOT NEED MUCH IMPETUS TO FORCE CONVECTION...THE
COMBINATION OF SUBSIDENCE IN THE WAKE OF A LEAD MCV OVER
SOUTHEASTERN NC AT PRESENT...AND THE LOCATION OF THE SOUTHERNMOST
FRONTAL ZONE ACROSS THE TN VALLEY AND CENTRAL APPALACHIANS (IE. TO
OUR NW) SHOULD TEND TO LIMIT CONVECTIVE COVERAGE OVER CENTRAL NC
THROUGH EARLY TO MID AFTERNOON. HOWEVER...A SHORTWAVE TROUGH OVER
THE MO VALLEY THIS MORNING IS PROGGED TO LIFT ENE TO NE ALONG THE
SPINE OF THE APPALACHIAN CHAIN THIS AFTERNOON...AND THE ASSOCIATED
BRUNT OF THIS FORCING FROM THE NW NC PIEDMONT NORTHWARD THROUGH VA
SHOULD HELP FOCUS CONVECTIVE DEVELOPMENT ALONG A THE LEE TROUGH OVER
WESTERN NC/VA...WITH THIS ACTIVITY LIKELY TO SPREAD ENE ACROSS THE
WESTERN AND NORTHERN NC PIEDMONT AFTER 3 OR 4 PM. MEANWHILE...MORE
THAN A COUPLE OF THE HI-RES CAMS INDICATE AN AREA OF STORMS AND AN
ASSOCIATED MCV OVER MS/NORTHWESTERN AL THIS MORNING MAY PIVOT ENE
ACROSS THE SANDHILLS AND COASTAL PLAIN LATER THIS AFTERNOON AND
EVENING...POSSIBLY MERGING WITH THE ACTIVITY FROM THE PIEDMONT.

BOTH MARGINAL INSTABILITY OF 1000 J/KG OR LESS OWING TO WEAK LAPSE
RATES ALOFT...AS WELL AS MARGINAL EFFECTIVE BULK SHEAR IN THE 20-30
KT RANGE...STILL SUGGEST ANY SEVERE THREAT WILL BE LOW...WITH
PERHAPS A FEW STRONG PRECIPITATION-LOADED WIND GUSTS. A MORE LIKELY
SCENARIO REMAINS A THREAT OF DOWNPOURS AND LOCALIZED FLOODING...
THOUGH ANY SUCH FLOODING WILL NOT BE WIDESPREAD AND INSTEAD CONFINED
MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED SOIL HAS DRIED IN
THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH FLOOD GUIDANCE VALUES
HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE FOR ONE HOUR FOR
EXAMPLE. HIGH TEMPERATURES TODAY ARE LIKELY TO REACH THE LOWER TO
MIDDLE 80S...WITH A FEW UPPER 80S POSSIBLE TOWARD KFAY AND KGSB.

TONIGHT: WHILE THERE MAY BE A LULL THIS EVENING AFTER THE AFTERNOON
AND EARLY EVENING CONVECTION...THE LEAD SURFACE BOUNDARY IS FORECAST
TO SETTLE SOUTHEASTWARD INTO CENTRAL NC ABOUT THE TIME THE SURFACE
WAVE OVER THE MID SOUTH TRACKS TOWARD INTO OUR REGION. THE PASSAGE
OF THE SURFACE WAVE - ONE SUPPORTED FROM ALOFT BY THE APPROACH OF A
NORTHERN STREAM SHORTWAVE TROUGH FROM THE UPPER MIDWEST THIS
MORNING - WILL ENCOURAGE RENEWED DEVELOPMENT OF AN AREA OF SHOWERS
AND ISOLATED STORMS OVER CENTRAL NC OVERNIGHT. LOWS...WITH MOSTLY
CLOUDY SKIES...IN THE MIDDLE 60S TO AROUND 70 DEGREES. TOTAL
RAINFALL AMOUNTS IN THE ONE TO TWO INCH RANGE WILL BE COMMON...
HIGHEST NORTH AND NORTHWEST...THOUGH AS WITH ANY CONVECTIVE
PRECIPITATION THERE WILL BE SOME AREAS THAT LIKELY RECEIVE
CONSIDERABLY LESS.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...

THE NORTHERN STREAM FRONT REFERENCED IN THE NEAR TERM DISCUSSION - A
FRONT LIKELY ENHANCED BY NE MARITIME FLOW FROM CHESAPEAKE BAY
REGION - WILL NOT DRIFT SOUTHWARD THROUGH CENTRAL NC UNTIL THE
AFTERNOON WEDNESDAY. HOWEVER...THE MAIN CONVERGENCE AXIS WITH THE
LEAD FRONT TRAILING THE SURFACE WAVE TRACKING FROM THE MID-SOUTH TO
NC COAST WILL HAVE DRIFTED INTO SOUTHERN OR SOUTHEASTERN NC BY WED
MORNING. AS SUCH...HAVE TRENDED POPS DOWNWARD INTO THE CHANCE
RANGE...RANGING FROM AROUND 30 PERCENT NW...TO 50 PERCENT IN CLOSEST
PROXIMITY TO THE LEAD FRONT/CONVERGENCE AXIS AND WHERE BOUNDARY
LAYER MOISTURE IN THE UPPER 60S IS LIKELY TO LINGER...OVER THE SE.
HIGHS...WITH A MIX OF SUN AND CLOUDS...AGAIN IN THE LOWER TO MIDDLE
80S. CLEARING AND COOLER WITH LOWS IN THE LOWER TO MIDDLE 60S
OVERNIGHT...THOUGH A FEW PATCHES OF STRATUS IN NE LOW LEVEL FLOW
WILL BE POSSIBLE LATE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...

THURSDAY THROUGH FRIDAY NIGHT...HIGH PRESSURE BUILDS ACROSS SOUTHERN
NEW ENGLAND SHORE...EXTENDING DOWN THE MID ATLANTIC COAST WITH DRY
NORTHEAST TO EAST FLOW. THE PLEASANT ENSUING COOL DAMMING SCENARIO
WILL LINGER INTO THE WEEKEND...WITH THICKNESSES INDICATIVE OF TEMPS
A GOOD CATEGORY BELOW NORMAL...LOW-MID 80S. WILL MAKE SOME GRID
ADJUSTMENTS ON THURSDAY AND FRIDAY TO FAVOR COOLER TEMPS IN THE
NORTHEAST WHERE MARITIME FLOW WILL BE STRONGEST/COOLEST. MINS WILL
BE GENERALLY LOW AND MID 60S.

SATURDAY THROUGH MONDAY...THE COOL SURFACE HIGH WILL WEAKEN AND
DRIFT EAST WITH A GRADUAL RETURN OF MORE SOUTHERLY FLOW BY LATE
WEEKEND. MEANWHILE...UPPER RIDGING WILL BUILD EAST OUT OF THE
MIDWEST INTO THE EASTERN CONUS SATURDAY THROUGH MONDAY. SOUTHERLY
FLOW WILL RESULT IN INCREASING HUMIDITY SUNDAY INTO MONDAY. WITH THE
CAPPING MID LEVEL RIDGE OVERHEAD...CONVECTION WILL BE ISOLATED
OUTSIDE OF PERHAPS SOME DIFFERENTIAL HEATING ON THE EASTERN SLOPES
AND POTENTIAL FOR SOME SEA BREEZE CONVECTION TO MIGRATE INLAND INTO
THE COASTAL PLAIN. AT THIS POINT...THE CHANCES ARE TOO SMALL TO
MENTION IN THE FORECAST. THE AIRMASS WILL GRADUALLY WARM UP WITH THE
SOUTHERLY FLOW AND PERSISTENCE OF THE UPPER RIDGE INTO MONDAY...
HIGHS WILL WARM FROM THE MID 80S SATURDAY TO THE UPPER 80S...PERHAPS
LOWER 90S ON MONDAY. MINS WILL BE IN THE 60S.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...

CONVECTION HAS WEAKENED WITH THE LOSS OF HEATING AND PATCHY LIGHT
RAIN LINGERS EARLY THIS MORNING. MVFR/IFR CEILINGS ARE LIKELY TO
COME AND GO JUST ABOUT ANYWHERE IN THE AREA FOR THE REMAINDER OF THE
NIGHT...WITH LIFR CEILINGS AND MVFR FOG POSSIBLE TOWARDS 12Z.

TODAY...MVFR CIGS AND VSBYS CAN BE EXPECTED IN SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS...WITH ACTIVITY PEAKING IN THE AFTERNOON
AND EVENING HOURS. ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA
ACCOMPANYING THE WEAK COLD FRONT TONIGHT...AGAIN WITH PERIODS OF
SHOWERS AND STORMS PRODUCING SUB-VFR CONDITIONS.

VFR CONDITIONS ARE GENERALLY EXPECTED FROM THURSDAY ONWARD...
OUTSIDE OF POSSIBLY SOME EARLY MORNING STRATUS AND OR FOG DURING THE
PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...MLM
AVIATION...MLM

000
FXUS62 KRAH 180717
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
317 AM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE TODAY...AND MOVE
SLOWLY SOUTHEAST ACROSS THE REGION TONIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM TUESDAY...

SURFACE ANALYSIS THIS MORNING REVEALED A LEESIDE TROUGH OVER THE NC
FOOTHILLS. IN ADDITION...A 1011 MB SURFACE WAVE WAS CENTERED OVER
THE MID SOUTH...ALONG A FRONTAL ZONE DRAPED FROM THE SOUTHERN PLAINS
NORTHEASTWARD THROUGH THE EASTERN TN VALLEY/CENTRAL APPALACHIANS TO
THE DELMARVA/NEW JERSEY COAST. A SEPARATE NORTHERN STREAM FRONT
ARCED FROM NEW ENGLAND SOUTHWESTWARD TO AN ELONGATED 1011 MB AREA OF
LOW PRESSURE FROM OH TO IL...THEN NORTHWESTWARD TO INTO THE UPPER
MIDWEST.

TODAY: WHILE A MOIST...WEAKLY INHIBITED...AND MARGINALLY UNSTABLE
AIRMASS OVER NC WILL NOT NEED MUCH IMPETUS TO FORCE CONVECTION...THE
COMBINATION OF SUBSIDENCE IN THE WAKE OF A LEAD MCV OVER
SOUTHEASTERN NC AT PRESENT...AND THE LOCATION OF THE SOUTHERNMOST
FRONTAL ZONE ACROSS THE TN VALLEY AND CENTRAL APPALACHIANS (IE. TO
OUR NW) SHOULD TEND TO LIMIT CONVECTIVE COVERAGE OVER CENTRAL NC
THROUGH EARLY TO MID AFTERNOON. HOWEVER...A SHORTWAVE TROUGH OVER
THE MO VALLEY THIS MORNING IS PROGGED TO LIFT ENE TO NE ALONG THE
SPINE OF THE APPALACHIAN CHAIN THIS AFTERNOON...AND THE ASSOCIATED
BRUNT OF THIS FORCING FROM THE NW NC PIEDMONT NORTHWARD THROUGH VA
SHOULD HELP FOCUS CONVECTIVE DEVELOPMENT ALONG A THE LEE TROUGH OVER
WESTERN NC/VA...WITH THIS ACTIVITY LIKELY TO SPREAD ENE ACROSS THE
WESTERN AND NORTHERN NC PIEDMONT AFTER 3 OR 4 PM. MEANWHILE...MORE
THAN A COUPLE OF THE HI-RES CAMS INDICATE AN AREA OF STORMS AND AN
ASSOCIATED MCV OVER MS/NORTHWESTERN AL THIS MORNING MAY PIVOT ENE
ACROSS THE SANDHILLS AND COASTAL PLAIN LATER THIS AFTERNOON AND
EVENING...POSSIBLY MERGING WITH THE ACTIVITY FROM THE PIEDMONT.

BOTH MARGINAL INSTABILITY OF 1000 J/KG OR LESS OWING TO WEAK LAPSE
RATES ALOFT...AS WELL AS MARGINAL EFFECTIVE BULK SHEAR IN THE 20-30
KT RANGE...STILL SUGGEST ANY SEVERE THREAT WILL BE LOW...WITH
PERHAPS A FEW STRONG PRECIPITATION-LOADED WIND GUSTS. A MORE LIKELY
SCENARIO REMAINS A THREAT OF DOWNPOURS AND LOCALIZED FLOODING...
THOUGH ANY SUCH FLOODING WILL NOT BE WIDESPREAD AND INSTEAD CONFINED
MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED SOIL HAS DRIED IN
THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH FLOOD GUIDANCE VALUES
HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE FOR ONE HOUR FOR
EXAMPLE. HIGH TEMPERATURES TODAY ARE LIKELY TO REACH THE LOWER TO
MIDDLE 80S...WITH A FEW UPPER 80S POSSIBLE TOWARD KFAY AND KGSB.

TONIGHT: WHILE THERE MAY BE A LULL THIS EVENING AFTER THE AFTERNOON
AND EARLY EVENING CONVECTION...THE LEAD SURFACE BOUNDARY IS FORECAST
TO SETTLE SOUTHEASTWARD INTO CENTRAL NC ABOUT THE TIME THE SURFACE
WAVE OVER THE MID SOUTH TRACKS TOWARD INTO OUR REGION. THE PASSAGE
OF THE SURFACE WAVE - ONE SUPPORTED FROM ALOFT BY THE APPROACH OF A
NORTHERN STREAM SHORTWAVE TROUGH FROM THE UPPER MIDWEST THIS
MORNING - WILL ENCOURAGE RENEWED DEVELOPMENT OF AN AREA OF SHOWERS
AND ISOLATED STORMS OVER CENTRAL NC OVERNIGHT. LOWS...WITH MOSTLY
CLOUDY SKIES...IN THE MIDDLE 60S TO AROUND 70 DEGREES. TOTAL
RAINFALL AMOUNTS IN THE ONE TO TWO INCH RANGE WILL BE COMMON...
HIGHEST NORTH AND NORTHWEST...THOUGH AS WITH ANY CONVECTIVE
PRECIPITATION THERE WILL BE SOME AREAS THAT LIKELY RECEIVE
CONSIDERABLY LESS.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 240 PM MONDAY...

TUESDAY:
MAIN S/W TROUGH AND ASSOCIATED WEAK COLD FRONT ARE EXPECTED TO
APPROACH THE REGION ON TUESDAY... WITH MOST MODELS NOW SHOWING THE
FEATURES CROSSING THE REGION BEYOND THE NEAR TERM FORECAST TIME
FRAME. HAVE TRENDED THE FORECAST TOWARDS A BLEND OF THE 12Z/17TH
NAM AND 00Z/17TH ECMWF FOR TIMING AND STRENGTH OF THE NEXT SYSTEM
(WHICH HOLDS THE SYSTEM TO THE WEST OF THE AREA THROUGH 00Z/19TH)...
WHICH IS IN LINE WITH THE ABOVE THINKING. THUS... HAVE LOWERED POPS
A BIT FOR TUESDAY. HOWEVER... STILL HAVE LIKELY POPS... AND EXPECT
AT LEAST SCATTERED SHOWERS AND STORMS ASSOCIATED WITH CONTINUED WEAK
DISTURBANCES CROSSING THE AREA IN THE INCREASINGLY CYCLONIC FLOW
ALOFT (WEST-SOUTHWESTERLY MID LEVEL FLOW) AND MOIST ATMO. THIS WILL
HELP TO SHARPEN UP A PRE-FRONTAL TROUGH TUESDAY AFTERNOON. EXPECT WE
WILL AGAIN HAVE A MARGINAL SVR THREAT... WITH STRONG TO DAMAGING
WINDS THE MAIN THREAT. DEEP LAYER SHEAR IS EXPECTED TO BE IN THE 20
TO 30 KT RANGE... WITH MLCAPE VALUES AGAIN AROUND 1000 J/KG. WITH
THE EXPECTED INCREASE IN CONVECTIVE COVERAGE... WE WILL NEED TO KEEP
AN EYE ON URBAN AREAS THAT RECEIVE ANY HEAVY RAIN FROM THE SHOWERS
AND STORMS (FLASH FLOODING THREAT). EXPECT HIGH TEMPS WILL AGAIN BE
HAMPERED BY CLOUD COVER. THUS... WILL GO WITH HIGHS RANGING FROM THE
LOWER TO MID 80S... WITH PERHAPS SOME UPPER 80S ACROSS OUR FAR EAST
AND SOUTH.

THE 12Z CANADIAN/12Z NAM AND 00Z ECMWF FAVOR A SLOWER (6-12 HOURS
SLOWER) SOLUTION. FAVORING MODEL CONSENSUS WOULD SUGGEST PAINTING
THE HIGHEST POPS OVERNIGHT TUESDAY NIGHT THROUGH WEDNESDAY MORNING
WITH RAIN CHANCES DECREASING FROM THE WEST-NW WEDNESDAY AFTERNOON.
THE SHORT TERM MODEL GUIDANCE DEPICT A SFC WAVE CROSSING CENTRAL NC
LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS FEATURE SHOULD
ENHANCE LOW LEVEL HELICITY WHICH IS DEPICTED NICELY (BUT ONLY FOR AN
HOUR OR TWO) BY BUFKIT HODOGRAPHS DISPLAY WITH AN ARCHING HODOGRAPH
IN THE SFC-3KM RANGE. WOULD PREFER A SLIGHTLY STRONGER WIND PROFILE
PLUS AIR MASS MORE THAN MARGINALLY UNSTABLE BEFORE HIGHLIGHTING
SEVERE STORM THREAT IN THE HWO.

FOR NOW WILL INTRODUCE A TREND OF INCREASING POPS LATE TUESDAY NIGHT
THROUGH EARLY AFTERNOON WEDNESDAY THEN DECREASING POPS MID AFTERNOON
WEDNESDAY THROUGH EARLY WEDNESDAY EVENING.

HIGH TEMPS WEDNESDAY WILL BE HELD BACK BY EXTENSIVE CLOUDINESS AND
SCATTERED-NUMEROUS SHOWERS AND THUNDERSTORMS. PLAN TO MAINTAIN MAX
TEMPS NEAR 80-LOWER 80S. MIN TEMPS TUESDAY NIGHT WILL BE WARM IN THE
HUMID AIR MASS (UPPER 60S TO LOWER 70S) WHILE TEMPS OVERNIGHT
WEDNESDAY NIGHT SHOULD BE 3-5 DEGREES COOLER (LOW-MID 60S) BEHIND
THE SFC FRONT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...

THURSDAY THROUGH FRIDAY NIGHT...HIGH PRESSURE BUILDS ACROSS SOUTHERN
NEW ENGLAND SHORE...EXTENDING DOWN THE MID ATLANTIC COAST WITH DRY
NORTHEAST TO EAST FLOW. THE PLEASANT ENSUING COOL DAMMING SCENARIO
WILL LINGER INTO THE WEEKEND...WITH THICKNESSES INDICATIVE OF TEMPS
A GOOD CATEGORY BELOW NORMAL...LOW-MID 80S. WILL MAKE SOME GRID
ADJUSTMENTS ON THURSDAY AND FRIDAY TO FAVOR COOLER TEMPS IN THE
NORTHEAST WHERE MARITIME FLOW WILL BE STRONGEST/COOLEST. MINS WILL
BE GENERALLY LOW AND MID 60S.

SATURDAY THROUGH MONDAY...THE COOL SURFACE HIGH WILL WEAKEN AND
DRIFT EAST WITH A GRADUAL RETURN OF MORE SOUTHERLY FLOW BY LATE
WEEKEND. MEANWHILE...UPPER RIDGING WILL BUILD EAST OUT OF THE
MIDWEST INTO THE EASTERN CONUS SATURDAY THROUGH MONDAY. SOUTHERLY
FLOW WILL RESULT IN INCREASING HUMIDITY SUNDAY INTO MONDAY. WITH THE
CAPPING MID LEVEL RIDGE OVERHEAD...CONVECTION WILL BE ISOLATED
OUTSIDE OF PERHAPS SOME DIFFERENTIAL HEATING ON THE EASTERN SLOPES
AND POTENTIAL FOR SOME SEA BREEZE CONVECTION TO MIGRATE INLAND INTO
THE COASTAL PLAIN. AT THIS POINT...THE CHANCES ARE TOO SMALL TO
MENTION IN THE FORECAST. THE AIRMASS WILL GRADUALLY WARM UP WITH THE
SOUTHERLY FLOW AND PERSISTENCE OF THE UPPER RIDGE INTO MONDAY...
HIGHS WILL WARM FROM THE MID 80S SATURDAY TO THE UPPER 80S...PERHAPS
LOWER 90S ON MONDAY. MINS WILL BE IN THE 60S.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...

CONVECTION HAS WEAKENED WITH THE LOSS OF HEATING AND PATCHY LIGHT
RAIN LINGERS EARLY THIS MORNING. MVFR/IFR CEILINGS ARE LIKELY TO
COME AND GO JUST ABOUT ANYWHERE IN THE AREA FOR THE REMAINDER OF THE
NIGHT...WITH LIFR CEILINGS AND MVFR FOG POSSIBLE TOWARDS 12Z.

TODAY...MVFR CIGS AND VSBYS CAN BE EXPECTED IN SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS...WITH ACTIVITY PEAKING IN THE AFTERNOON
AND EVENING HOURS. ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA
ACCOMPANYING THE WEAK COLD FRONT TONIGHT...AGAIN WITH PERIODS OF
SHOWERS AND STORMS PRODUCING SUB-VFR CONDITIONS.

VFR CONDITIONS ARE GENERALLY EXPECTED FROM THURSDAY ONWARD...
OUTSIDE OF POSSIBLY SOME EARLY MORNING STRATUS AND OR FOG DURING THE
PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...MWS
SHORT TERM...WSS
LONG TERM...MLM
AVIATION...MLM

000
FXUS62 KRAH 180526
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
130 AM EDT TUE JUN 18 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE TODAY...AND MOVE
SLOWLY SOUTHEAST ACROSS THE REGION TONIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 PM MONDAY...

AN MCV CONTINUES TO MOVE EASTWARD ACROSS THE SOUTHERN TIER OF OUR
COUNTIES. MUCH OF THE LEAD STRONGER CONVECTION HAS WEAKENED LEAVING
A CLUSTER OF LOCALLY HEAVY SHOWERS AND ISOLATED THUNDERSTORMS
SPREADING OUT INTO A LARGE STRATIFORM RAIN AREA. LIGHT TO MODERATE
RAIN WILL CONTINUE ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES
THROUGH 100 TO 200 AM... BEFORE THE MCV MOVES OFFSHORE. POPS WILL
SHOW THIS TREND WITH POP DROPPING BACK TO 20 PERCENT ACROSS THESE
REGIONS AFTER 200 AM. ELSEWHERE... GIVEN THE CURRENT SET UP... WITH
VERY MOIST AND CONDITIONALLY UNSTABLE CONDITIONS... AN ISOLATED
STORM MAY DEVELOP JUST ABOUT ANYWHERE OVERNIGHT. HOWEVER...
ORGANIZED CONVECTION SHOULD HOLD OFF UNTIL THE APPROACH OF THE
STRONG UPPER LEVEL SYSTEM FROM THE WEST ON TUESDAY.

PATCHY STRATUS AND FOG ARE LIKELY LATER TONIGHT. SEE THE AVIATION
DISCUSSION BELOW. OTHERWISE... PARTLY TO MOSTLY CLOUDY... WARM AND
HUMID. LOWS 68-73.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 PM MONDAY...

TUESDAY:
MAIN S/W TROUGH AND ASSOCIATED WEAK COLD FRONT ARE EXPECTED TO
APPROACH THE REGION ON TUESDAY... WITH MOST MODELS NOW SHOWING THE
FEATURES CROSSING THE REGION BEYOND THE NEAR TERM FORECAST TIME
FRAME. HAVE TRENDED THE FORECAST TOWARDS A BLEND OF THE 12Z/17TH
NAM AND 00Z/17TH ECMWF FOR TIMING AND STRENGTH OF THE NEXT SYSTEM
(WHICH HOLDS THE SYSTEM TO THE WEST OF THE AREA THROUGH 00Z/19TH)...
WHICH IS IN LINE WITH THE ABOVE THINKING. THUS... HAVE LOWERED POPS
A BIT FOR TUESDAY. HOWEVER... STILL HAVE LIKELY POPS... AND EXPECT
AT LEAST SCATTERED SHOWERS AND STORMS ASSOCIATED WITH CONTINUED WEAK
DISTURBANCES CROSSING THE AREA IN THE INCREASINGLY CYCLONIC FLOW
ALOFT (WEST-SOUTHWESTERLY MID LEVEL FLOW) AND MOIST ATMO. THIS WILL
HELP TO SHARPEN UP A PRE-FRONTAL TROUGH TUESDAY AFTERNOON. EXPECT WE
WILL AGAIN HAVE A MARGINAL SVR THREAT... WITH STRONG TO DAMAGING
WINDS THE MAIN THREAT. DEEP LAYER SHEAR IS EXPECTED TO BE IN THE 20
TO 30 KT RANGE... WITH MLCAPE VALUES AGAIN AROUND 1000 J/KG. WITH
THE EXPECTED INCREASE IN CONVECTIVE COVERAGE... WE WILL NEED TO KEEP
AN EYE ON URBAN AREAS THAT RECEIVE ANY HEAVY RAIN FROM THE SHOWERS
AND STORMS (FLASH FLOODING THREAT). EXPECT HIGH TEMPS WILL AGAIN BE
HAMPERED BY CLOUD COVER. THUS... WILL GO WITH HIGHS RANGING FROM THE
LOWER TO MID 80S... WITH PERHAPS SOME UPPER 80S ACROSS OUR FAR EAST
AND SOUTH.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODEL GUIDANCE CONTINUES TO OFFER VARYING TIMING SCENARIOS
CONCERNING THE MID LEVEL S/W AND ATTENDANT SFC FRONT WHICH IS
EXPECTED TO EFFECT OUR REGION TUESDAY NIGHT INTO WEDNESDAY. THE
12Z/17TH GFS HAS TRENDED SLIGHTLY SHARPER AND FASTER WITH THE
TROUGH. THE 12Z CANADIAN/12Z NAM AND 00Z ECMWF FAVOR A SLOWER (6-12
HOURS SLOWER) SOLUTION. FAVORING MODEL CONSENSUS WOULD SUGGEST
PAINTING THE HIGHEST POPS OVERNIGHT TUESDAY NIGHT THROUGH WEDNESDAY
MORNING WITH RAIN CHANCES DECREASING FROM THE WEST-NW WEDNESDAY
AFTERNOON. THE SHORT TERM MODEL GUIDANCE DEPICT A SFC WAVE CROSSING
CENTRAL NC LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS FEATURE
SHOULD ENHANCE LOW LEVEL HELICITY WHICH IS DEPICTED NICELY (BUT ONLY
FOR AN HOUR OR TWO) BY BUFKIT HODOGRAPHS DISPLAY WITH AN ARCHING
HODOGRAPH IN THE SFC-3KM RANGE. WOULD PREFER A SLIGHTLY STRONGER
WIND PROFILE PLUS AIR MASS MORE THAN MARGINALLY UNSTABLE BEFORE
HIGHLIGHTING SEVERE STORM THREAT IN THE HWO.

FOR NOW WILL INTRODUCE A TREND OF INCREASING POPS LATE TUESDAY NIGHT
THROUGH EARLY AFTERNOON WEDNESDAY THEN DECREASING POPS MID AFTERNOON
WEDNESDAY THROUGH EARLY WEDNESDAY EVENING.

HIGH TEMPS WEDNESDAY WILL BE HELD BACK BY EXTENSIVE CLOUDINESS AND
SCATTERED-NUMEROUS SHOWERS AND THUNDERSTORMS. PLAN TO MAINTAIN MAX
TEMPS NEAR 80-LOWER 80S. MIN TEMPS TUESDAY NIGHT WILL BE WARM IN THE
HUMID AIR MASS (UPPER 60S TO LOWER 70S) WHILE TEMPS OVERNIGHT
WEDNESDAY NIGHT SHOULD BE 3-5 DEGREES COOLER (LOW-MID 60S) BEHIND
THE SFC FRONT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...

THURSDAY THROUGH FRIDAY NIGHT...SFC HIGH PRESSURE WILL EXTEND ACROSS
CENTRAL NC THU-FRI BEHIND THE EXITING MID LEVEL S/W. LOW LEVEL NE
FLOW WILL SPREAD AND MAINTAIN A DRY STABLE AIR MASS OVER CENTRAL NC.
THIS WILL LIMIT/INHIBIT CONVECTIVE DEVELOPMENT. LOW LEVEL
THICKNESSES AVERAGE 10M BELOW NORMAL. THIS TRANSLATES TO HIGH TEMPS
IN THE LOW-MID 80S. OVERNIGHT TEMPS GENERALLY IN THE LOW-MID 60S.

SATURDAY THROUGH MONDAY...A NARROW UPPER RIDGE WILL STRETCH FROM THE
SOUTHERN PLAINS INTO THE CENTRAL APPALACHIANS AND MID ATLANTIC
SATURDAY THROUGH MONDAY. ATTENDANT SFC RIDGE WILL GRADUALLY WEAKEN
THROUGH THE WEEKEND. THIS WILL CAUSE THE LOW LEVEL FLOW TO GRADUALLY
VEER FROM E-NE ON SATURDAY TO A S-SE FLOW LATE SUNDAY INTO MONDAY.
THIS SLY FLOW REGIME WILL RESULT IN AN UPTICK IN HUMIDITY LEVELS
SUNDAY INTO MONDAY. AT THIS TIME...CHANCES FOR AFTERNOON-EVENING
CONVECTION APPEAR TOO SMALL TO MENTION IN FORECAST.

PRESENCE OF UPPER LEVEL RIDGE WILL CAUSE AIR MASS TO MODIFY AS
WELL...YIELDING LOW LEVEL THICKNESSES ABOUT 10M ABOVE NORMAL BY
EARLY NEXT WEEK. THUS EXPECT HIGH TEMPS IN THE MID-UPPER 80S
SATURDAY...WARMING INTO THE UPPER 80S TO LOWER 90S ON MONDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...

CONVECTION HAS WEAKENED WITH THE LOSS OF HEATING AND PATCHY LIGHT
RAIN LINGERS EARLY THIS MORNING. MVFR/IFR CEILINGS ARE LIKELY TO
COME AND GO JUST ABOUT ANYWHERE IN THE AREA FOR THE REMAINDER OF THE
NIGHT...WITH LIFR CEILINGS AND MVFR FOG POSSIBLE TOWARDS 12Z.

TODAY...MVFR CIGS AND VSBYS CAN BE EXPECTED IN SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS...WITH ACTIVITY PEAKING IN THE AFTERNOON
AND EVENING HOURS. ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA
ACCOMPANYING THE WEAK COLD FRONT TONIGHT...AGAIN WITH PERIODS OF
SHOWERS AND STORMS PRODUCING SUB-VFR CONDITIONS.

VFR CONDITIONS ARE GENERALLY EXPECTED FROM THURSDAY ONWARD...
OUTSIDE OF POSSIBLY SOME EARLY MORNING STRATUS AND OR FOG DURING THE
PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...BADGETT/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...MLM

000
FXUS62 KRAH 180219
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1015 PM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY MOVE ACROSS
OUR REGION TUESDAY NIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 PM MONDAY...

AN MCV CONTINUES TO MOVE EASTWARD ACROSS THE SOUTHERN TIER OF OUR
COUNTIES. MUCH OF THE LEAD STRONGER CONVECTION HAS WEAKENED LEAVING
A CLUSTER OF LOCALLY HEAVY SHOWERS AND ISOLATED THUNDERSTORMS
SPREADING OUT INTO A LARGE STRATIFORM RAIN AREA. LIGHT TO MODERATE
RAIN WILL CONTINUE ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES
THROUGH 100 TO 200 AM... BEFORE THE MCV MOVES OFFSHORE. POPS WILL
SHOW THIS TREND WITH POP DROPPING BACK TO 20 PERCENT ACROSS THESE
REGIONS AFTER 200 AM. ELSEWHERE... GIVEN THE CURRENT SET UP... WITH
VERY MOIST AND CONDITIONALLY UNSTABLE CONDITIONS... AN ISOLATED
STORM MAY DEVELOP JUST ABOUT ANYWHERE OVERNIGHT. HOWEVER...
ORGANIZED CONVECTION SHOULD HOLD OFF UNTIL THE APPROACH OF THE
STRONG UPPER LEVEL SYSTEM FROM THE WEST ON TUESDAY.

PATCHY STRATUS AND FOG ARE LIKELY LATER TONIGHT. SEE THE AVIATION
DISCUSSION BELOW. OTHERWISE... PARTLY TO MOSTLY CLOUDY... WARM AND
HUMID. LOWS 68-73.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 PM MONDAY...

TUESDAY:
MAIN S/W TROUGH AND ASSOCIATED WEAK COLD FRONT ARE EXPECTED TO
APPROACH THE REGION ON TUESDAY... WITH MOST MODELS NOW SHOWING THE
FEATURES CROSSING THE REGION BEYOND THE NEAR TERM FORECAST TIME
FRAME. HAVE TRENDED THE FORECAST TOWARDS A BLEND OF THE 12Z/17TH
NAM AND 00Z/17TH ECMWF FOR TIMING AND STRENGTH OF THE NEXT SYSTEM
(WHICH HOLDS THE SYSTEM TO THE WEST OF THE AREA THROUGH 00Z/19TH)...
WHICH IS IN LINE WITH THE ABOVE THINKING. THUS... HAVE LOWERED POPS
A BIT FOR TUESDAY. HOWEVER... STILL HAVE LIKELY POPS... AND EXPECT
AT LEAST SCATTERED SHOWERS AND STORMS ASSOCIATED WITH CONTINUED WEAK
DISTURBANCES CROSSING THE AREA IN THE INCREASINGLY CYCLONIC FLOW
ALOFT (WEST-SOUTHWESTERLY MID LEVEL FLOW) AND MOIST ATMO. THIS WILL
HELP TO SHARPEN UP A PRE-FRONTAL TROUGH TUESDAY AFTERNOON. EXPECT WE
WILL AGAIN HAVE A MARGINAL SVR THREAT... WITH STRONG TO DAMAGING
WINDS THE MAIN THREAT. DEEP LAYER SHEAR IS EXPECTED TO BE IN THE 20
TO 30 KT RANGE... WITH MLCAPE VALUES AGAIN AROUND 1000 J/KG. WITH
THE EXPECTED INCREASE IN CONVECTIVE COVERAGE... WE WILL NEED TO KEEP
AN EYE ON URBAN AREAS THAT RECEIVE ANY HEAVY RAIN FROM THE SHOWERS
AND STORMS (FLASH FLOODING THREAT). EXPECT HIGH TEMPS WILL AGAIN BE
HAMPERED BY CLOUD COVER. THUS... WILL GO WITH HIGHS RANGING FROM THE
LOWER TO MID 80S... WITH PERHAPS SOME UPPER 80S ACROSS OUR FAR EAST
AND SOUTH.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODEL GUIDANCE CONTINUES TO OFFER VARYING TIMING SCENARIOS
CONCERNING THE MID LEVEL S/W AND ATTENDANT SFC FRONT WHICH IS
EXPECTED TO EFFECT OUR REGION TUESDAY NIGHT INTO WEDNESDAY. THE
12Z/17TH GFS HAS TRENDED SLIGHTLY SHARPER AND FASTER WITH THE
TROUGH. THE 12Z CANADIAN/12Z NAM AND 00Z ECMWF FAVOR A SLOWER (6-12
HOURS SLOWER) SOLUTION. FAVORING MODEL CONSENSUS WOULD SUGGEST
PAINTING THE HIGHEST POPS OVERNIGHT TUESDAY NIGHT THROUGH WEDNESDAY
MORNING WITH RAIN CHANCES DECREASING FROM THE WEST-NW WEDNESDAY
AFTERNOON. THE SHORT TERM MODEL GUIDANCE DEPICT A SFC WAVE CROSSING
CENTRAL NC LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS FEATURE
SHOULD ENHANCE LOW LEVEL HELICITY WHICH IS DEPICTED NICELY (BUT ONLY
FOR AN HOUR OR TWO) BY BUFKIT HODOGRAPHS DISPLAY WITH AN ARCHING
HODOGRAPH IN THE SFC-3KM RANGE. WOULD PREFER A SLIGHTLY STRONGER
WIND PROFILE PLUS AIR MASS MORE THAN MARGINALLY UNSTABLE BEFORE
HIGHLIGHTING SEVERE STORM THREAT IN THE HWO.

FOR NOW WILL INTRODUCE A TREND OF INCREASING POPS LATE TUESDAY NIGHT
THROUGH EARLY AFTERNOON WEDNESDAY THEN DECREASING POPS MID AFTERNOON
WEDNESDAY THROUGH EARLY WEDNESDAY EVENING.

HIGH TEMPS WEDNESDAY WILL BE HELD BACK BY EXTENSIVE CLOUDINESS AND
SCATTERED-NUMEROUS SHOWERS AND THUNDERSTORMS. PLAN TO MAINTAIN MAX
TEMPS NEAR 80-LOWER 80S. MIN TEMPS TUESDAY NIGHT WILL BE WARM IN THE
HUMID AIR MASS (UPPER 60S TO LOWER 70S) WHILE TEMPS OVERNIGHT
WEDNESDAY NIGHT SHOULD BE 3-5 DEGREES COOLER (LOW-MID 60S) BEHIND
THE SFC FRONT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...

THURSDAY THROUGH FRIDAY NIGHT...SFC HIGH PRESSURE WILL EXTEND ACROSS
CENTRAL NC THU-FRI BEHIND THE EXITING MID LEVEL S/W. LOW LEVEL NE
FLOW WILL SPREAD AND MAINTAIN A DRY STABLE AIR MASS OVER CENTRAL NC.
THIS WILL LIMIT/INHIBIT CONVECTIVE DEVELOPMENT. LOW LEVEL
THICKNESSES AVERAGE 10M BELOW NORMAL. THIS TRANSLATES TO HIGH TEMPS
IN THE LOW-MID 80S. OVERNIGHT TEMPS GENERALLY IN THE LOW-MID 60S.

SATURDAY THROUGH MONDAY...A NARROW UPPER RIDGE WILL STRETCH FROM THE
SOUTHERN PLAINS INTO THE CENTRAL APPALACHIANS AND MID ATLANTIC
SATURDAY THROUGH MONDAY. ATTENDANT SFC RIDGE WILL GRADUALLY WEAKEN
THROUGH THE WEEKEND. THIS WILL CAUSE THE LOW LEVEL FLOW TO GRADUALLY
VEER FROM E-NE ON SATURDAY TO A S-SE FLOW LATE SUNDAY INTO MONDAY.
THIS SLY FLOW REGIME WILL RESULT IN AN UPTICK IN HUMIDITY LEVELS
SUNDAY INTO MONDAY. AT THIS TIME...CHANCES FOR AFTERNOON-EVENING
CONVECTION APPEAR TOO SMALL TO MENTION IN FORECAST.

PRESENCE OF UPPER LEVEL RIDGE WILL CAUSE AIR MASS TO MODIFY AS
WELL...YIELDING LOW LEVEL THICKNESSES ABOUT 10M ABOVE NORMAL BY
EARLY NEXT WEEK. THUS EXPECT HIGH TEMPS IN THE MID-UPPER 80S
SATURDAY...WARMING INTO THE UPPER 80S TO LOWER 90S ON MONDAY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 740 PM MONDAY...

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS SOUTHERN NC
THIS EVENING. MVFR/IFR CIGS/VSBYS CONDITIONS POSSIBLE ALONG WITH
GUSTY WINDS TO 35-40 MPH WITH THE STRONGEST STORMS MAINLY SOUTH OF
KFAY.

A VERY MOIST AIR MASS WILL BE FAVORABLE FOR PATCHY FOG AND IFR/LIFR
CEILINGS OVERNIGHT... AND ADDITIONAL SCATTERED SHOWERS ARE POSSIBLE.

TUESDAY... MVFR TO IFR CIGS AND VSBYS CAN BE EXPECTED WITH SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS... MAINLY IN THE AFTERNOON AND
EVENING HOURS.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY NIGHT INTO WEDNESDAY...WITH PERIODS OF SHOWERS
AND STORMS PRODUCING SUB-VFR CONDITIONS.

VFR CONDITIONS ARE GENERALLY EXPECTED FROM THURSDAY ONWARD...
OUTSIDE OF POSSIBLY SOME EARLY MORNING STRATUS AND OR FOG DURING THE
PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BSD
NEAR TERM...BADGETT/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BADGETT/BSD

000
FXUS62 KRAH 172341
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
740 PM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY MOVE ACROSS
OUR REGION TUESDAY NIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 740 PM MONDAY...

CONVECTIVE TRENDS OF THE PAST 3-4 HOURS CONTINUE TO POINT TO THE
SOUTHERN HALF OF CENTRAL NC AS THE PRIMARY FOCUS FOR SCATTERED
CONVECTION THIS EVENING. WE WILL CARRY THE HIGHEST POP ACROSS AREAS
FROM WADESBORO AND ROCKINGHAM EAST TO FAYETTEVILLE AND CLINTON. TO
THE NORTH... CONDITIONS WERE NOT QUITE AS FAVORABLE FOR STRONG
CONVECTION DUE TO LOWER INSTABILITY... EXCEPT NEAR THE NC/VA BORDER
WHERE THERE THERE IS A LOW CHANCE OF THUNDERSTORMS IN THE NEXT FEW
HOURS.

THE MAIN HAZARD WITH THE STORMS DOWN SOUTH BESIDES THE TYPICAL
LIGHTNING HAZARD WITH SUMMER STORMS... CONTINUES TO BE HEAVY
RAINFALL. AN URBAN AND SMALL STREAM FLOOD ADVISORY WAS ISSUED FOR
ANSON COUNTY EARLIER DUE TO RAINFALL RATES OF 1.5 TO 2 INCHES PER
HOUR. THESE RATES WERE JUST BELOW THE FLASH FLOOD GUIDANCE FOR THE
COUNTY. IT APPEARS THE THREAT OF THE HEAVIEST RAIN MAY SHIFT MORE
TOWARD THE NC/SC BORDER... OR POSSIBLY INTO SC OVER THE NEXT FEW
HOURS. GRIDS ADJUSTED ACCORDINGLY.

OTHERWISE... PARTLY TO MOSTLY CLOUDY... WARM AND HUMID. LOWS 68-73.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 PM MONDAY...

TUESDAY:
MAIN S/W TROUGH AND ASSOCIATED WEAK COLD FRONT ARE EXPECTED TO
APPROACH THE REGION ON TUESDAY... WITH MOST MODELS NOW SHOWING THE
FEATURES CROSSING THE REGION BEYOND THE NEAR TERM FORECAST TIME
FRAME. HAVE TRENDED THE FORECAST TOWARDS A BLEND OF THE 12Z/17TH
NAM AND 00Z/17TH ECMWF FOR TIMING AND STRENGTH OF THE NEXT SYSTEM
(WHICH HOLDS THE SYSTEM TO THE WEST OF THE AREA THROUGH 00Z/19TH)...
WHICH IS IN LINE WITH THE ABOVE THINKING. THUS... HAVE LOWERED POPS
A BIT FOR TUESDAY. HOWEVER... STILL HAVE LIKELY POPS... AND EXPECT
AT LEAST SCATTERED SHOWERS AND STORMS ASSOCIATED WITH CONTINUED WEAK
DISTURBANCES CROSSING THE AREA IN THE INCREASINGLY CYCLONIC FLOW
ALOFT (WEST-SOUTHWESTERLY MID LEVEL FLOW) AND MOIST ATMO. THIS WILL
HELP TO SHARPEN UP A PRE-FRONTAL TROUGH TUESDAY AFTERNOON. EXPECT WE
WILL AGAIN HAVE A MARGINAL SVR THREAT... WITH STRONG TO DAMAGING
WINDS THE MAIN THREAT. DEEP LAYER SHEAR IS EXPECTED TO BE IN THE 20
TO 30 KT RANGE... WITH MLCAPE VALUES AGAIN AROUND 1000 J/KG. WITH
THE EXPECTED INCREASE IN CONVECTIVE COVERAGE... WE WILL NEED TO KEEP
AN EYE ON URBAN AREAS THAT RECEIVE ANY HEAVY RAIN FROM THE SHOWERS
AND STORMS (FLASH FLOODING THREAT). EXPECT HIGH TEMPS WILL AGAIN BE
HAMPERED BY CLOUD COVER. THUS... WILL GO WITH HIGHS RANGING FROM THE
LOWER TO MID 80S... WITH PERHAPS SOME UPPER 80S ACROSS OUR FAR EAST
AND SOUTH.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODEL GUIDANCE CONTINUES TO OFFER VARYING TIMING SCENARIOS
CONCERNING THE MID LEVEL S/W AND ATTENDANT SFC FRONT WHICH IS
EXPECTED TO EFFECT OUR REGION TUESDAY NIGHT INTO WEDNESDAY. THE
12Z/17TH GFS HAS TRENDED SLIGHTLY SHARPER AND FASTER WITH THE
TROUGH. THE 12Z CANADIAN/12Z NAM AND 00Z ECMWF FAVOR A SLOWER (6-12
HOURS SLOWER) SOLUTION. FAVORING MODEL CONSENSUS WOULD SUGGEST
PAINTING THE HIGHEST POPS OVERNIGHT TUESDAY NIGHT THROUGH WEDNESDAY
MORNING WITH RAIN CHANCES DECREASING FROM THE WEST-NW WEDNESDAY
AFTERNOON. THE SHORT TERM MODEL GUIDANCE DEPICT A SFC WAVE CROSSING
CENTRAL NC LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS FEATURE
SHOULD ENHANCE LOW LEVEL HELICITY WHICH IS DEPICTED NICELY (BUT ONLY
FOR AN HOUR OR TWO) BY BUFKIT HODOGRAPHS DISPLAY WITH AN ARCHING
HODOGRAPH IN THE SFC-3KM RANGE. WOULD PREFER A SLIGHTLY STRONGER
WIND PROFILE PLUS AIR MASS MORE THAN MARGINALLY UNSTABLE BEFORE
HIGHLIGHTING SEVERE STORM THREAT IN THE HWO.

FOR NOW WILL INTRODUCE A TREND OF INCREASING POPS LATE TUESDAY NIGHT
THROUGH EARLY AFTERNOON WEDNESDAY THEN DECREASING POPS MID AFTERNOON
WEDNESDAY THROUGH EARLY WEDNESDAY EVENING.

HIGH TEMPS WEDNESDAY WILL BE HELD BACK BY EXTENSIVE CLOUDINESS AND
SCATTERED-NUMEROUS SHOWERS AND THUNDERSTORMS. PLAN TO MAINTAIN MAX
TEMPS NEAR 80-LOWER 80S. MIN TEMPS TUESDAY NIGHT WILL BE WARM IN THE
HUMID AIR MASS (UPPER 60S TO LOWER 70S) WHILE TEMPS OVERNIGHT
WEDNESDAY NIGHT SHOULD BE 3-5 DEGREES COOLER (LOW-MID 60S) BEHIND
THE SFC FRONT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...

THURSDAY THROUGH FRIDAY NIGHT...SFC HIGH PRESSURE WILL EXTEND ACROSS
CENTRAL NC THU-FRI BEHIND THE EXITING MID LEVEL S/W. LOW LEVEL NE
FLOW WILL SPREAD AND MAINTAIN A DRY STABLE AIR MASS OVER CENTRAL NC.
THIS WILL LIMIT/INHIBIT CONVECTIVE DEVELOPMENT. LOW LEVEL
THICKNESSES AVERAGE 10M BELOW NORMAL. THIS TRANSLATES TO HIGH TEMPS
IN THE LOW-MID 80S. OVERNIGHT TEMPS GENERALLY IN THE LOW-MID 60S.

SATURDAY THROUGH MONDAY...A NARROW UPPER RIDGE WILL STRETCH FROM THE
SOUTHERN PLAINS INTO THE CENTRAL APPALACHIANS AND MID ATLANTIC
SATURDAY THROUGH MONDAY. ATTENDANT SFC RIDGE WILL GRADUALLY WEAKEN
THROUGH THE WEEKEND. THIS WILL CAUSE THE LOW LEVEL FLOW TO GRADUALLY
VEER FROM E-NE ON SATURDAY TO A S-SE FLOW LATE SUNDAY INTO MONDAY.
THIS SLY FLOW REGIME WILL RESULT IN AN UPTICK IN HUMIDITY LEVELS
SUNDAY INTO MONDAY. AT THIS TIME...CHANCES FOR AFTERNOON-EVENING
CONVECTION APPEAR TOO SMALL TO MENTION IN FORECAST.

PRESENCE OF UPPER LEVEL RIDGE WILL CAUSE AIR MASS TO MODIFY AS
WELL...YIELDING LOW LEVEL THICKNESSES ABOUT 10M ABOVE NORMAL BY
EARLY NEXT WEEK. THUS EXPECT HIGH TEMPS IN THE MID-UPPER 80S
SATURDAY...WARMING INTO THE UPPER 80S TO LOWER 90S ON MONDAY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 740 PM MONDAY...

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS SOUTHERN NC
THIS EVENING. MVFR/IFR CIGS/VSBYS CONDITIONS POSSIBLE ALONG WITH
GUSTY WINDS TO 35-40 MPH WITH THE STRONGEST STORMS MAINLY SOUTH OF
KFAY.

A VERY MOIST AIR MASS WILL BE FAVORABLE FOR PATCHY FOG AND IFR/LIFR
CEILINGS OVERNIGHT... AND ADDITIONAL SCATTERED SHOWERS ARE POSSIBLE.

TUESDAY... MVFR TO IFR CIGS AND VSBYS CAN BE EXPECTED WITH SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS... MAINLY IN THE AFTERNOON AND
EVENING HOURS.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY NIGHT INTO WEDNESDAY...WITH PERIODS OF SHOWERS
AND STORMS PRODUCING SUB-VFR CONDITIONS.

VFR CONDITIONS ARE GENERALLY EXPECTED FROM THURSDAY ONWARD...
OUTSIDE OF POSSIBLY SOME EARLY MORNING STRATUS AND OR FOG DURING THE
PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BSD
NEAR TERM...BADGETT/BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BADGETT/BSD

000
FXUS62 KRAH 171920
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
320 PM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY MOVE ACROSS
OUR REGION TUESDAY NIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 3 PM MONDAY...

REST OF TODAY AND TONIGHT:
A SERIES OF MID LEVEL DISTURBANCE ARE EXPECTED TO MOVE ACROSS
CENTRAL NC THIS AFTERNOON INTO THE EVENING. THE LEAD DISTURBANCE IS
CURRENTLY HELPING TO FUEL SHOWER AND THUNDERSTORM ACTIVITY ACROSS
THE COASTAL PLAIN AND EASTERN SANDHILLS.... WITH THE SECOND AND
LIKELY MORE PROBLEMATIC DISTURBANCE MOVING EASTWARD OUT OF THE
HIGHER TERRAIN NOW AND HELPING TO DEVELOP SHOWERS AND STORMS ACROSS
THE HIGHER TERRAIN (ALONG WITH DIFFERENTIAL HEATING) AND WESTERN
PIEDMONT. EXPECT THIS ACTIVITY SHOULD MOVE EASTWARD ACROSS THE
AREA... AS THE MEAN 850-300MB FLOW IS WESTERLY AT AROUND 20 KTS. WRT
A SEVERE THREAT... THE SPC MESOPAGE IS SHOWING MLCAPES ARE GENERALLY
AROUND 500 TO 1000 J/KG... WITH NOW UPWARDS OF 25 TO 30 KTS OF
EFFECTIVE DEEP LAYER SHEAR. EXPECT MLCAPE VALUES WILL TOP OUT IN THE
1000-1200 J/KG RANGE THIS AFTERNOON. THUS... WITH A LITTLE BETTER
INSTABILITY AND SHEAR THAN FIRST THOUGH... THINK WE MIGHT SEE A
LITTLE ORGANIZATION ASSOCIATED WITH THE CONVECTION AS THE SECOND
DISTURBANCE CROSS THE AREA THIS AFTERNOON INTO THE EVENING. GIVEN
MID LEVEL LAPSE RATES REMAIN POOR WITH PW`S IN THE 1.7 TO 2.0 INCH
RANGE... THINK THE SEVERE THREAT WILL STILL REMAIN LOW... WITH THE
DAMAGING WINDS THE MAIN THREAT AND LOCALIZED FLOODING IN URBAN AREAS.

EXPECT ANY SHOWER AND THUNDERSTORM ACTIVITY SHOULD END/DECREASE IN
COVERAGE FROM A WEST TO EAST FASHION THIS EVENING AS THE WEAK MID
LEVEL DISTURBANCE PUSHES EASTWARD AND EVENTUALLY THROUGH OUR
AREA/COUPLED WITH NOCTURNAL COOLING. HOWEVER... WILL MAINTAIN AT
LEAST A SLIGHT CHANCE POP THROUGHOUT THE NIGHT AS WE WILL CONTINUE
TO BE WARM AND MOIST (PW`S 1.75 TO 2.0) WITH POSSIBLE WEAK/SUBTLE
PERTURBATIONS ALOFT APT TO CROSS THE AREA IN THE WESTERLY FLOW
OVERNIGHT... GIVEN AT LEAST ISOLATED TO SCATTERED CONVECTION EXTENDS
WESTWARD SOUTHEASTERN KS AND SOUTHERN MO. EXPECT LOW TEMPS TONIGHT
WILL BE AROUND 70/LOWER 70S.

TUESDAY:
MAIN S/W TROUGH AND ASSOCIATED WEAK COLD FRONT ARE EXPECTED TO
APPROACH THE REGION ON TUESDAY... WITH MOST MODELS NOW SHOWING THE
FEATURES CROSSING THE REGION BEYOND THE NEAR TERM FORECAST TIME
FRAME. HAVE TRENDED THE FORECAST TOWARDS A BLEND OF THE 12Z/17TH
NAM AND 00Z/17TH ECMWF FOR TIMING AND STRENGTH OF THE NEXT SYSTEM
(WHICH HOLDS THE SYSTEM TO THE WEST OF THE AREA THROUGH 00Z/19TH)...
WHICH IS IN LINE WITH THE ABOVE THINKING. THUS... HAVE LOWERED POPS
A BIT FOR TUESDAY. HOWEVER... STILL HAVE LIKELY POPS... AND EXPECT
AT LEAST SCATTERED SHOWERS AND STORMS ASSOCIATED WITH CONTINUED WEAK
DISTURBANCES CROSSING THE AREA IN THE INCREASINGLY CYCLONIC FLOW
ALOFT (WEST-SOUTHWESTERLY MID LEVEL FLOW) AND MOIST ATMO. THIS WILL
HELP TO SHARPEN UP A PRE-FRONTAL TROUGH TUESDAY AFTERNOON. EXPECT WE
WILL AGAIN HAVE A MARGINAL SVR THREAT... WITH STRONG TO DAMAGING
WINDS THE MAIN THREAT. DEEP LAYER SHEAR IS EXPECTED TO BE IN THE 20
TO 30 KT RANGE... WITH MLCAPE VALUES AGAIN AROUND 1000 J/KG. WITH
THE EXPECTED INCREASE IN CONVECTIVE COVERAGE... WE WILL NEED TO KEEP
AN EYE ON URBAN AREAS THAT RECEIVE ANY HEAVY RAIN FROM THE SHOWERS
AND STORMS (FLASH FLOODING THREAT). EXPECT HIGH TEMPS WILL AGAIN BE
HAMPERED BY CLOUD COVER. THUS... WILL GO WITH HIGHS RANGING FROM THE
LOWER TO MID 80S... WITH PERHAPS SOME UPPER 80S ACROSS OUR FAR EAST
AND SOUTH.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 240 PM MONDAY...

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODEL GUIDANCE CONTINUES TO OFFER VARYING TIMING SCENARIOS
CONCERNING THE MID LEVEL S/W AND ATTENDANT SFC FRONT WHICH IS
EXPECTED TO EFFECT OUR REGION TUESDAY NIGHT INTO WEDNESDAY. THE
12Z/17TH GFS HAS TRENDED SLIGHTLY SHARPER AND FASTER WITH THE
TROUGH. THE 12Z CANADIAN/12Z NAM AND 00Z ECMWF FAVOR A SLOWER (6-12
HOURS SLOWER) SOLUTION. FAVORING MODEL CONSENSUS WOULD SUGGEST
PAINTING THE HIGHEST POPS OVERNIGHT TUESDAY NIGHT THROUGH WEDNESDAY
MORNING WITH RAIN CHANCES DECREASING FROM THE WEST-NW WEDNESDAY
AFTERNOON. THE SHORT TERM MODEL GUIDANCE DEPICT A SFC WAVE CROSSING
CENTRAL NC LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS FEATURE
SHOULD ENHANCE LOW LEVEL HELICITY WHICH IS DEPICTED NICELY (BUT ONLY
FOR AN HOUR OR TWO) BY BUFKIT HODOGRAPHS DISPLAY WITH AN ARCHING
HODOGRAPH IN THE SFC-3KM RANGE. WOULD PREFER A SLIGHTLY STRONGER
WIND PROFILE PLUS AIR MASS MORE THAN MARGINALLY UNSTABLE BEFORE
HIGHLIGHTING SEVERE STORM THREAT IN THE HWO.

FOR NOW WILL INTRODUCE A TREND OF INCREASING POPS LATE TUESDAY NIGHT
THROUGH EARLY AFTERNOON WEDNESDAY THEN DECREASING POPS MID AFTERNOON
WEDNESDAY THROUGH EARLY WEDNESDAY EVENING.

HIGH TEMPS WEDNESDAY WILL BE HELD BACK BY EXTENSIVE CLOUDINESS AND
SCATTERED-NUMEROUS SHOWERS AND THUNDERSTORMS. PLAN TO MAINTAIN MAX
TEMPS NEAR 80-LOWER 80S. MIN TEMPS TUESDAY NIGHT WILL BE WARM IN THE
HUMID AIR MASS (UPPER 60S TO LOWER 70S) WHILE TEMPS OVERNIGHT
WEDNESDAY NIGHT SHOULD BE 3-5 DEGREES COOLER (LOW-MID 60S) BEHIND
THE SFC FRONT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...

THURSDAY THROUGH FRIDAY NIGHT...SFC HIGH PRESSURE WILL EXTEND ACROSS
CENTRAL NC THU-FRI BEHIND THE EXITING MID LEVEL S/W. LOW LEVEL NE
FLOW WILL SPREAD AND MAINTAIN A DRY STABLE AIR MASS OVER CENTRAL NC.
THIS WILL LIMIT/INHIBIT CONVECTIVE DEVELOPMENT. LOW LEVEL
THICKNESSES AVERAGE 10M BELOW NORMAL. THIS TRANSLATES TO HIGH TEMPS
IN THE LOW-MID 80S. OVERNIGHT TEMPS GENERALLY IN THE LOW-MID 60S.

SATURDAY THROUGH MONDAY...A NARROW UPPER RIDGE WILL STRETCH FROM THE
SOUTHERN PLAINS INTO THE CENTRAL APPALACHIANS AND MID ATLANTIC
SATURDAY THROUGH MONDAY. ATTENDANT SFC RIDGE WILL GRADUALLY WEAKEN
THROUGH THE WEEKEND. THIS WILL CAUSE THE LOW LEVEL FLOW TO GRADUALLY
VEER FROM E-NE ON SATURDAY TO A S-SE FLOW LATE SUNDAY INTO MONDAY.
THIS SLY FLOW REGIME WILL RESULT IN AN UPTICK IN HUMIDITY LEVELS
SUNDAY INTO MONDAY. AT THIS TIME...CHANCES FOR AFTERNOON-EVENING
CONVECTION APPEAR TOO SMALL TO MENTION IN FORECAST.

PRESENCE OF UPPER LEVEL RIDGE WILL CAUSE AIR MASS TO MODIFY AS
WELL...YIELDING LOW LEVEL THICKNESSES ABOUT 10M ABOVE NORMAL BY
EARLY NEXT WEEK. THUS EXPECT HIGH TEMPS IN THE MID-UPPER 80S
SATURDAY...WARMING INTO THE UPPER 80S TO LOWER 90S ON MONDAY.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 310 PM MONDAY...

ISOLATED TO SCATTERED SHOWERS AND STORMS ARE EXPECTED ACROSS
CENTRAL NC THIS AFTERNOON AND THIS EVENING.... WITH MVFR/IFR
CONDITIONS POSSIBLE ALONG WITH GUSTY WINDS WITH THE STRONGEST
SHOWERS AND STORMS. EXPECT A LULL OVERNIGHT ACROSS AT LEAST THE
NORTHERN TIER IN SUBSIDENCE BEHIND A WEAK UPPER SHORTWAVE. VERY
MOIST AIRMASS WILL BE FAVORABLE FOR FOG AND PERHAPS SOME IFR/LIFR
CEILINGS IF WE GET SOME BREAKS TO ALLOW RADIATIONAL COOLING AND
WINDS CALM IN THE PREDAWN. ANY SUB VFR CONDITIONS ARE EXPECTED TO
LIFT AFTER DAYBREAK TOMORROW... ALTHOUGH WE MAY SEE CIGS SLOWLY
RISE. AT THIS TIME WILL SHOW SUB VFR CIGS SCATTERING OUT BY 12Z...
ALTHOUGH CONFIDENCE REMAINS LOW... AND WE MAY SEE A BRIEF PERIOD OF
MVFR CIGS AS DIURNAL MIXING DEEPENS THROUGH THE MORNING.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY NIGHT INTO WEDNESDAY...WITH PERIODS OF SHOWERS
AND STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BSD
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/MLM

000
FXUS62 KRAH 171909
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
308 PM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY MOVE ACROSS
OUR REGION TUESDAY NIGHT INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 3 PM MONDAY...

REST OF TODAY AND TONIGHT:
A SERIES OF MID LEVEL DISTURBANCE ARE EXPECTED TO MOVE ACROSS
CENTRAL NC THIS AFTERNOON INTO THE EVENING. THE LEAD DISTURBANCE IS
CURRENTLY HELPING TO FUEL SHOWER AND THUNDERSTORM ACTIVITY ACROSS
THE COASTAL PLAIN AND EASTERN SANDHILLS.... WITH THE SECOND AND
LIKELY MORE PROBLEMATIC DISTURBANCE MOVING EASTWARD OUT OF THE
HIGHER TERRAIN NOW AND HELPING TO DEVELOP SHOWERS AND STORMS ACROSS
THE HIGHER TERRAIN (ALONG WITH DIFFERENTIAL HEATING) AND WESTERN
PIEDMONT. EXPECT THIS ACTIVITY SHOULD MOVE EASTWARD ACROSS THE
AREA... AS THE MEAN 850-300MB FLOW IS WESTERLY AT AROUND 20 KTS. WRT
A SEVERE THREAT... THE SPC MESOPAGE IS SHOWING MLCAPES ARE GENERALLY
AROUND 500 TO 1000 J/KG... WITH NOW UPWARDS OF 25 TO 30 KTS OF
EFFECTIVE DEEP LAYER SHEAR. EXPECT MLCAPE VALUES WILL TOP OUT IN THE
1000-1200 J/KG RANGE THIS AFTERNOON. THUS... WITH A LITTLE BETTER
INSTABILITY AND SHEAR THAN FIRST THOUGH... THINK WE MIGHT SEE A
LITTLE ORGANIZATION ASSOCIATED WITH THE CONVECTION AS THE SECOND
DISTURBANCE CROSS THE AREA THIS AFTERNOON INTO THE EVENING. GIVEN
MID LEVEL LAPSE RATES REMAIN POOR WITH PW`S IN THE 1.7 TO 2.0 INCH
RANGE... THINK THE SEVERE THREAT WILL STILL REMAIN LOW... WITH THE
DAMAGING WINDS THE MAIN THREAT AND LOCALIZED FLOODING IN URBAN AREAS.

EXPECT ANY SHOWER AND THUNDERSTORM ACTIVITY SHOULD END/DECREASE IN
COVERAGE FROM A WEST TO EAST FASHION THIS EVENING AS THE WEAK MID
LEVEL DISTURBANCE PUSHES EASTWARD AND EVENTUALLY THROUGH OUR
AREA/COUPLED WITH NOCTURNAL COOLING. HOWEVER... WILL MAINTAIN AT
LEAST A SLIGHT CHANCE POP THROUGHOUT THE NIGHT AS WE WILL CONTINUE
TO BE WARM AND MOIST (PW`S 1.75 TO 2.0) WITH POSSIBLE WEAK/SUBTLE
PERTURBATIONS ALOFT APT TO CROSS THE AREA IN THE WESTERLY FLOW
OVERNIGHT... GIVEN AT LEAST ISOLATED TO SCATTERED CONVECTION EXTENDS
WESTWARD SOUTHEASTERN KS AND SOUTHERN MO. EXPECT LOW TEMPS TONIGHT
WILL BE AROUND 70/LOWER 70S.

TUESDAY:
MAIN S/W TROUGH AND ASSOCIATED WEAK COLD FRONT ARE EXPECTED TO
APPROACH THE REGION ON TUESDAY... WITH MOST MODELS NOW SHOWING THE
FEATURES CROSSING THE REGION BEYOND THE NEAR TERM FORECAST TIME
FRAME. HAVE TRENDED THE FORECAST TOWARDS A BLEND OF THE 12Z/17TH
NAM AND 00Z/17TH ECMWF FOR TIMING AND STRENGTH OF THE NEXT SYSTEM
(WHICH HOLDS THE SYSTEM TO THE WEST OF THE AREA THROUGH 00Z/19TH)...
WHICH IS IN LINE WITH THE ABOVE THINKING. THUS... HAVE LOWERED POPS
A BIT FOR TUESDAY. HOWEVER... STILL HAVE LIKELY POPS... AND EXPECT
AT LEAST SCATTERED SHOWERS AND STORMS ASSOCIATED WITH CONTINUED WEAK
DISTURBANCES CROSSING THE AREA IN THE INCREASINGLY CYCLONIC FLOW
ALOFT (WEST-SOUTHWESTERLY MID LEVEL FLOW) AND MOIST ATMO. THIS WILL
HELP TO SHARPEN UP A PRE-FRONTAL TROUGH TUESDAY AFTERNOON. EXPECT WE
WILL AGAIN HAVE A MARGINAL SVR THREAT... WITH STRONG TO DAMAGING
WINDS THE MAIN THREAT. DEEP LAYER SHEAR IS EXPECTED TO BE IN THE 20
TO 30 KT RANGE... WITH MLCAPE VALUES AGAIN AROUND 1000 J/KG. WITH
THE EXPECTED INCREASE IN CONVECTIVE COVERAGE... WE WILL NEED TO KEEP
AN EYE ON URBAN AREAS THAT RECEIVE ANY HEAVY RAIN FROM THE SHOWERS
AND STORMS (FLASH FLOODING THREAT). EXPECT HIGH TEMPS WILL AGAIN BE
HAMPERED BY CLOUD COVER. THUS... WILL GO WITH HIGHS RANGING FROM THE
LOWER TO MID 80S... WITH PERHAPS SOME UPPER 80S ACROSS OUR FAR EAST
AND SOUTH.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 240 PM MONDAY...

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODEL GUIDANCE CONTINUES TO OFFER VARYING TIMING SCENARIOS
CONCERNING THE MID LEVEL S/W AND ATTENDANT SFC FRONT WHICH IS
EXPECTED TO EFFECT OUR REGION TUESDAY NIGHT INTO WEDNESDAY. THE
12Z/17TH GFS HAS TRENDED SLIGHTLY SHARPER AND FASTER WITH THE
TROUGH. THE 12Z CANADIAN/12Z NAM AND 00Z ECMWF FAVOR A SLOWER (6-12
HOURS SLOWER) SOLUTION. FAVORING MODEL CONSENSUS WOULD SUGGEST
PAINTING THE HIGHEST POPS OVERNIGHT TUESDAY NIGHT THROUGH WEDNESDAY
MORNING WITH RAIN CHANCES DECREASING FROM THE WEST-NW WEDNESDAY
AFTERNOON. THE SHORT TERM MODEL GUIDANCE DEPICT A SFC WAVE CROSSING
CENTRAL NC LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS FEATURE
SHOULD ENHANCE LOW LEVEL HELICITY WHICH IS DEPICTED NICELY (BUT ONLY
FOR AN HOUR OR TWO) BY BUFKIT HODOGRAPHS DISPLAY WITH AN ARCHING
HODOGRAPH IN THE SFC-3KM RANGE. WOULD PREFER A SLIGHTLY STRONGER
WIND PROFILE PLUS AIR MASS MORE THAN MARGINALLY UNSTABLE BEFORE
HIGHLIGHTING SEVERE STORM THREAT IN THE HWO.

FOR NOW WILL INTRODUCE A TREND OF INCREASING POPS LATE TUESDAY NIGHT
THROUGH EARLY AFTERNOON WEDNESDAY THEN DECREASING POPS MID AFTERNOON
WEDNESDAY THROUGH EARLY WEDNESDAY EVENING.

HIGH TEMPS WEDNESDAY WILL BE HELD BACK BY EXTENSIVE CLOUDINESS AND
SCATTERED-NUMEROUS SHOWERS AND THUNDERSTORMS. PLAN TO MAINTAIN MAX
TEMPS NEAR 80-LOWER 80S. MIN TEMPS TUESDAY NIGHT WILL BE WARM IN THE
HUMID AIR MASS (UPPER 60S TO LOWER 70S) WHILE TEMPS OVERNIGHT
WEDNESDAY NIGHT SHOULD BE 3-5 DEGREES COOLER (LOW-MID 60S) BEHIND
THE SFC FRONT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...

THURSDAY THROUGH FRIDAY NIGHT...SFC HIGH PRESSURE WILL EXTEND ACROSS
CENTRAL NC THU-FRI BEHIND THE EXITING MID LEVEL S/W. LOW LEVEL NE
FLOW WILL SPREAD AND MAINTAIN A DRY STABLE AIR MASS OVER CENTRAL NC.
THIS WILL LIMIT/INHIBIT CONVECTIVE DEVELOPMENT. LOW LEVEL
THICKNESSES AVERAGE 10M BELOW NORMAL. THIS TRANSLATES TO HIGH TEMPS
IN THE LOW-MID 80S. OVERNIGHT TEMPS GENERALLY IN THE LOW-MID 60S.

SATURDAY THROUGH MONDAY...A NARROW UPPER RIDGE WILL STRETCH FROM THE
SOUTHERN PLAINS INTO THE CENTRAL APPALACHIANS AND MID ATLANTIC
SATURDAY THROUGH MONDAY. ATTENDANT SFC RIDGE WILL GRADUALLY WEAKEN
THROUGH THE WEEKEND. THIS WILL CAUSE THE LOW LEVEL FLOW TO GRADUALLY
VEER FROM E-NE ON SATURDAY TO A S-SE FLOW LATE SUNDAY INTO MONDAY.
THIS SLY FLOW REGIME WILL RESULT IN AN UPTICK IN HUMIDITY LEVELS
SUNDAY INTO MONDAY. AT THIS TIME...CHANCES FOR AFTERNOON-EVENING
CONVECTION APPEAR TOO SMALL TO MENTION IN FORECAST.

PRESENCE OF UPPER LEVEL RIDGE WILL CAUSE AIR MASS TO MODIFY AS
WELL...YIELDING LOW LEVEL THICKNESSES ABOUT 10M ABOVE NORMAL BY
EARLY NEXT WEEK. THUS EXPECT HIGH TEMPS IN THE MID-UPPER 80S
SATURDAY...WARMING INTO THE UPPER 80S TO LOWER 90S ON MONDAY.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 630 AM MONDAY...

CONDITIONS WILL BE VFR OUTSIDE OF CONVECTION THROUGH LATE TONIGHT.
CONVECTION MOVING EAST OFF THE MOUNTAINS INTO THE NORTHERN PIEDMONT
THIS MORNING WILL WEAKEN AS IT MOVES TOWARDS THE TRIANGLE AND INTO
MORE STABLE AIR. HEATING WILL NOT BE STRONG DUE TO MID LEVEL
CEILINGS...BUT WEAKLY FORCED FLOW WILL PRODUCE SCATTERED SHOWERS AND
WIDELY SCATTERED THUNDER THIS AFTERNOON....CONFIDENCE IN THE TIMING
IS LOW AND THE COVERAGE NOT EXPECTED TO BE SUBSTANTIAL ENOUGH TO
WARRANT INCLUSION IN THE TAFS. EXPECT A LULL OVERNIGHT ACROSS THE
NORTHERN TIER IN SUBSIDENCE BEHIND A WEAK UPPER SHORTWAVE. VERY
MOIST AIRMASS WILL BE FAVORABLE FOR FOG AND PERHAPS SOME IFR/LIFR
CEILINGS IF WE GET SOME BREAKS TO ALLOW RADIATIONAL COOLING AND
WINDS CALM IN THE PREDAWN.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BSD
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/MLM

000
FXUS62 KRAH 171508
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1107 AM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ACROSS OUR
REGION LATE TUESDAY.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 11 AM MONDAY...

TODAY:
A WEAK SHEAR AXIS IS CURRENTLY MOVING ACROSS THE AREA THIS MORNING
IN THE WESTERLY MID LEVEL FLOW... HELPING TO SPREAD MOSTLY CLOUDY TO
OVERCAST SKIES ACROSS MOST OF THE AREA... WITH EVEN A FEW SHOWERS
AND STORMS ACROSS THE PIEDMONT. THIS SHEAR AXIS IS EXPECTED TO
SLOWLY SHIFT EASTWARD THIS MORNING AND EARLY AFTERNOON... WITH
PERHAPS SOME SHOWERS AND STORMS DEVELOPING ALONG AND TO THE EAST OF
THE FEATURE. IN FACT... SOME GUIDANCE SUGGEST THAT WE COULD SEE SOME
UPWARD TREND IN INTENSITY... WITH THE SHOWERS AND STORMS ASSOCIATED
WITH THIS DISTURBANCE... BRIEFLY ACROSS OUR FAR EAST/SOUTHEAST...
BEFORE THE WAVE PUSHES TO THE EAST OF OUR AREA. HOWEVER... THE MAIN
FOCUS FOR SHOWERS AND STORMS TODAY IS EXPECTED TO BE ASSOCIATED WITH
ANOTHER WEAK MID LEVEL DISTURBANCE EXPECTED TO MOVE ACROSS THE AREA
THIS AFTERNOON INTO THE EVENING... CURRENTLY SUPPORTING SHOWERS AND
STORMS ACROSS THE EASTERN TN... NORTHERN GA AND FAR WESTERN NC.
HI-RES MODELS SHOW THIS ACTIVITY MOVING INTO THE WESTERN PORTION OF
THE AREA SOMETIME IN THE 18-21Z TIME FRAME... THEN SPREADING
EASTWARD THROUGH THE REST OF THE AFTERNOON AND EVENING... WITH ANY
REMAINING ACTIVITY LATE THIS EVENING DWINDLING IN COVERAGE AND
INTENSITY WITH NOCTURNAL COOLING. WRT A SEVERE THREAT... WITH SKIES
MOSTLY CLOUDY AND PW`S IN THE 1.7 TO 2.0 INCH RANGE TODAY... THINK
WE WILL ONLY SEE MODEST MLCAPE VALUES AT BEST... GENERALLY AROUND
1000 J/KG DURING PEAK HEATING. DEEP LAYER SHEAR IS EXPECTED TO
REMAIN WEAK... IN A GENERALLY WEAK WESTERLY MID LEVEL FLOW. THUS...
EXPECT THE SEVERE POTENTIAL TO BE LOW... WITH THE HIGHEST THREAT OF
ANY HAZARDOUS WEATHER FROM POSSIBLE HEAVY SHOWERS AND STORMS MOVING
OVER AN URBAN AREA (FLASH FLOODING). HOWEVER... THINK COVERAGE WILL
REMAIN MORE SCATTERED TODAY AND GIVEN THE MEAN FLOW OF 10 TO 20
KTS... THINK THE FLASH FLOODING THREAT WILL BE LOW TOO. ALSO... IT
IS WORTH NOTING THAT SOME OF THE HI-RES MODELS DO APPEAR TO SHOW
SOME TYPE OF ORGANIZATION LATE IN THE DAY WITH THE SHOWERS AND
STORMS (THINK THIS IS A BIT OVERDONE THOUGH). TEMPS TODAY WILL BE
HAMPERED BY THE EXTENSIVE CLOUD COVER. THUS... THINK PREVIOUS
FORECAST HIGHS OF 83 TO 87 STILL LOOK GOOD.

TONIGHT:
BOTH THE GFS AND ECM SHOW A LULL ACROSS THE NORTHERN TIER TONIGHT
ACROSS THE NORTHERN TIER IN SUBSIDENCE BEHIND THE INITIAL UPPER
SHORT WAVE. THUNDER WILL BE TOUGH TO PRODUCE GIVEN SUBSIDENCE AND
UNFAVORABLE NOCTURNAL TREND. WILL TREND POPS FOR SHOWERS TOWARDS
THE SOUTHEAST. MINS WILL BE PERSISTENCE AND ON THE MILD SIDE...UPPER
60S.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...

A SERIES OF DISTURBANCES ALOFT...WHICH HAVE TRENDED WEAKER IN NWP
GUIDANCE DURING THE PAST FEW DAYS AND WHOSE TIMING IS UNCERTAIN
GIVEN THE PROBABILITY OF BEING MODULATED BY UPSTREAM
CONVECTION...WILL MIGRATE THROUGH THE BASE OF A BROAD TROUGH ALOFT
EAST OF THE ROCKIES...AND ACROSS THE CENTRAL APPALACHIANS/NC THROUGH
WED. MEANWHILE AT THE SURFACE...A PRE-FRONTAL TROUGH OVER THE MIDDLE
ATLANTIC REGION THIS MORNING WILL STRENGTHEN THROUGH TUE...THEN BE
OVERTAKEN BY A COLD FRONT THAT WILL SETTLE SLOWLY SOUTHWARD FROM THE
MASON DIXON LINE TUE EVENING TO THE NC/SC LINE BY WED EVENING.

PRECIPITABLE WATER VALUES WILL CONSEQUENTLY REMAIN ABOVE
AVERAGE...BETWEEN 1.5 AND 1.8 INCHES... UNTIL FRONTAL PASSAGE. THE
DEEP MOISTURE AND ASSOCIATED UNINHIBITED CONDITIONAL INSTABILITY...
WHICH IS FORECAST TO MAXIMIZE IN THE 1000-1500 J/KG EACH
AFTERNOON...WILL SUPPORT NUMEROUS TO WIDESPREAD THUNDERSTORMS...WITH
COVERAGE DIMINISHING WITH NOCTURNAL COOLING TUE NIGHT...AND THEN
FROM NORTH TO SOUTH WITH THE FRONTAL PASSAGE ON WED. GIVEN THE
EXPECTATION OF WEAKER DISTURBANCES THAN PREVIOUSLY INDICATED...NOTED
ABOVE...MID LEVEL FLOW AND ASSOCIATED BULK SHEAR VALUES ARE NOW
FORECAST TO PEAK ONLY IN THE 20-25 KT RANGE...HIGHEST WED. AS
SUCH...ALREADY MINIMAL SEVERE POTENTIAL WILL BE FURTHER MUTED UNLESS
POCKETS OF STRONGER INSOLATION AND MODERATE INSTABILITY ARE
REALIZED...IN WHICH CASE A FEW STRONG-MARGINALLY SEVERE WET
MICROBURSTS WOULD BE PROBABLE. A MORE LIKELY SCENARIO REMAINS A
THREAT OF DOWNPOURS AND LOCALIZED FLOODING IN TRAINING
CONVECTION...OWING TO WSW MEAN FLOW ALIGNED PARALLEL TO THE MYRIAD
OF UNDERLYING SURFACE BOUNDARIES (TROUGH/EFFECTIVE FRONT-OUTFLOW
/ACTUAL FRONT...AND TO BACKBUILDING INDICATED BY SMALL FORECAST
CORFIDI VECTORS. ANY SUCH FLOODING WILL NOT BE WIDESPREAD...AND
INSTEAD CONFINED MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED
SOIL HAS DRIED IN THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH
FLOOD GUIDANCE VALUES HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE
FOR ONE HOUR FOR EXAMPLE.

PROVIDED THERE ARE AT LEAST A FEW BREAKS IN OTHERWISE MOSTLY CLOUDY
SKIES AND CONVECTION...TEMPERATURES SHOULD CLIMB INTO THE LOWER TO
MIDDLE 80S...WARMEST SANDHILLS TUE. OTHERWISE...UPPER 70S WOULD BE
PROBABLE (IE. IN AREAS THAT EXPERIENCE MORE FREQUENT SHOWERS AND
STORMS). LOWS TUE NIGHT MOSTLY IN THE UPPER 60S...TO AROUND 70
DEGREES SOUTH...COOLING A CATEGORY TO TWO IN COOLER POST-FRONTAL NE
FLOW WED NIGHT.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM SUNDAY...

THU THROUGH FRI: BELOW AVERAGE TEMPERATURES - GENERALLY IN THE LOWER
TO MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE AND ASSOCIATED NE
TO EAST LOW LEVEL FLOW AND STABILITY...WILL THEN PREVAIL THROUGH THE
END OF THE WEEK. WILL ACCORDINGLY MAINTAIN THE FLAVOR OF PREVIOUS
GENERALLY DRY FORECASTS FOR THU-FRI...EXCEPT FOR THE SLIGHTEST OF
CHANCES ALONG THE FAR SOUTHERN AND WESTERN TIER...WHERE BOUNDARY
LAYER MOISTURE WOULD SUPPORT A LATE DAY SHOWER OR STORM. EVEN THAT
SLIGHT CHANCE MAY BE OVERDONE GIVEN AN APPARENT LACK OF TRIGGER
AMIDST DIVERGENT ANTICYCLONIC FLOW WITHIN THE AFOREMENTIONED SURFACE
RIDGE AXIS.

THIS WEEKEND: A SHALLOW UPPER LOW WILL HAVE DRIFTED INTO THE
SOUTHEAST STATES BY THE START OF THE WEEKEND...BUT INSTEAD OF
LIFTING TOWARD THE EAST COAST...GUIDANCE SUGGESTS THIS FEATURE WILL
MOVE WESTWARD AROUND THE SOUTHERN PERIPHERY OF A DEVELOPING
MID-UPPER RIDGE FROM THE SOUTHERN PLAINS TO THE MIDDLE ATLANTIC
REGION. AS SUCH...TEMPERATURES...AND HUMIDITY LEVELS WILL GRADUALLY
INCREASE IN INCREASINGLY SE TO SOUTHERLY RETURN FLOW. THE INCREASING
WARMTH AND HUMIDITY WILL ALSO SUPPORT A SLIGHT UPTICK IN PROBABILITY
OF PRECIPITATION...THOUGH STILL BELOW CLIMATOLOGICAL VALUES IN THE
20TH PERCENTILE GIVEN THE AFOREMENTIONED EXPANSION OF RIDGING
ALOFT...AND LACK OF LOW LEVEL FOCI OTHER THAN PERHAPS THE SEA
BREEZE.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 630 AM MONDAY...

CONDITIONS WILL BE VFR OUTSIDE OF CONVECTION THROUGH LATE TONIGHT.
CONVECTION MOVING EAST OFF THE MOUNTAINS INTO THE NORTHERN PIEDMONT
THIS MORNING WILL WEAKEN AS IT MOVES TOWARDS THE TRIANGLE AND INTO
MORE STABLE AIR. HEATING WILL NOT BE STRONG DUE TO MID LEVEL
CEILINGS...BUT WEAKLY FORCED FLOW WILL PRODUCE SCATTERED SHOWERS AND
WIDELY SCATTERED THUNDER THIS AFTERNOON....CONFIDENCE IN THE TIMING
IS LOW AND THE COVERAGE NOT EXPECTED TO BE SUBSTANTIAL ENOUGH TO
WARRANT INCLUSION IN THE TAFS. EXPECT A LULL OVERNIGHT ACROSS THE
NORTHERN TIER IN SUBSIDENCE BEHIND A WEAK UPPER SHORTWAVE. VERY
MOIST AIRMASS WILL BE FAVORABLE FOR FOG AND PERHAPS SOME IFR/LIFR
CEILINGS IF WE GET SOME BREAKS TO ALLOW RADIATIONAL COOLING AND
WINDS CALM IN THE PREDAWN.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...BSD/MLM
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...MLM

000
FXUS62 KRAH 171037
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
630 AM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ACROSS OUR
REGION LATE TUESDAY.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 315 AM MONDAY...

HIGH CLOUDINESS HAS BEEN INCREASING AND PATCHY LIGHT RAIN HAS BEEN
THREATENING TO ENCIRCLE THE RAH CWFA OVERNIGHT. EXPECT TO SEE
SCATTERED SHOWERS AND A FEW STORMS SPREAD IN FROM THE WEST AS
WEAK FORCING FROM OVERNIGHT CONVECTION ADVECTS INTO THE AREA IN
CONCERT WITH A MINOR SHORT WAVE PRESSING IN FROM THE NORTHWEST. THIS
WILL FINALLY GIVE OUR WARM AND INCREASINGLY MOIST AIRMASS A REASON
TO PRECIPITATE. WILL TREND INCREASING POPS...ALTHOUGH STILL KEEPING
THEM IN THE CHANCE CATEGORY...THROUGH THE MORNING FROM THE WEST.
WILL NOT MAKE A LOT OF DISTINCTION ACROSS THE AREA AS IT IS
DIFFICULT TO PINPOINT AN AREA THAT MIGHT BE PARTICULARLY PRONE TO
INCREASED COVERAGE GIVEN THE RELATIVE UNIFORMITY OF THE AIRMASS AND
WEAKNESS OF THE FORCING. GUIDANCE HIGH TEMPS SEEM RATHER HIGH GIVEN
THE CLOUD TRENDS...THINK THAT AT LEAST THE NORTHWEST PIEDMONT
SHOULDN`T MAKE THE UPPER 80S AND WILL GO GENERALLY MID 80S ACROSS
THE BOARD.

BOTH THE GFS AND ECM SHOW A LULL ACROSS THE NORTHERN TIER TONIGHT
ACROSS THE NORTHERN TIER IN SUBSIDENCE BEHIND THE INITIAL UPPER
SHORT WAVE. THUNDER WILL BE TOUGH TO PRODUCE GIVEN SUBSIDENCE AND
UNFAVORABLE NOCTURNAL TREND. WILL TREND POPS FOR SHOWERS TOWARDS
THE SOUTHEAST. MINS WILL BE PERSISTENCE AND ON THE MILD SIDE...UPPER
60S.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...

A SERIES OF DISTURBANCES ALOFT...WHICH HAVE TRENDED WEAKER IN NWP
GUIDANCE DURING THE PAST FEW DAYS AND WHOSE TIMING IS UNCERTAIN
GIVEN THE PROBABILITY OF BEING MODULATED BY UPSTREAM
CONVECTION...WILL MIGRATE THROUGH THE BASE OF A BROAD TROUGH ALOFT
EAST OF THE ROCKIES...AND ACROSS THE CENTRAL APPALACHIANS/NC THROUGH
WED. MEANWHILE AT THE SURFACE...A PRE-FRONTAL TROUGH OVER THE MIDDLE
ATLANTIC REGION THIS MORNING WILL STRENGTHEN THROUGH TUE...THEN BE
OVERTAKEN BY A COLD FRONT THAT WILL SETTLE SLOWLY SOUTHWARD FROM THE
MASON DIXON LINE TUE EVENING TO THE NC/SC LINE BY WED EVENING.

PRECIPITABLE WATER VALUES WILL CONSEQUENTLY REMAIN ABOVE
AVERAGE...BETWEEN 1.5 AND 1.8 INCHES... UNTIL FRONTAL PASSAGE. THE
DEEP MOISTURE AND ASSOCIATED UNINHIBITED CONDITIONAL INSTABILITY...
WHICH IS FORECAST TO MAXIMIZE IN THE 1000-1500 J/KG EACH
AFTERNOON...WILL SUPPORT NUMEROUS TO WIDESPREAD THUNDERSTORMS...WITH
COVERAGE DIMINISHING WITH NOCTURNAL COOLING TUE NIGHT...AND THEN
FROM NORTH TO SOUTH WITH THE FRONTAL PASSAGE ON WED. GIVEN THE
EXPECTATION OF WEAKER DISTURBANCES THAN PREVIOUSLY INDICATED...NOTED
ABOVE...MID LEVEL FLOW AND ASSOCIATED BULK SHEAR VALUES ARE NOW
FORECAST TO PEAK ONLY IN THE 20-25 KT RANGE...HIGHEST WED. AS
SUCH...ALREADY MINIMAL SEVERE POTENTIAL WILL BE FURTHER MUTED UNLESS
POCKETS OF STRONGER INSOLATION AND MODERATE INSTABILITY ARE
REALIZED...IN WHICH CASE A FEW STRONG-MARGINALLY SEVERE WET
MICROBURSTS WOULD BE PROBABLE. A MORE LIKELY SCENARIO REMAINS A
THREAT OF DOWNPOURS AND LOCALIZED FLOODING IN TRAINING
CONVECTION...OWING TO WSW MEAN FLOW ALIGNED PARALLEL TO THE MYRIAD
OF UNDERLYING SURFACE BOUNDARIES (TROUGH/EFFECTIVE FRONT-OUTFLOW
/ACTUAL FRONT...AND TO BACKBUILDING INDICATED BY SMALL FORECAST
CORFIDI VECTORS. ANY SUCH FLOODING WILL NOT BE WIDESPREAD...AND
INSTEAD CONFINED MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED
SOIL HAS DRIED IN THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH
FLOOD GUIDANCE VALUES HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE
FOR ONE HOUR FOR EXAMPLE.

PROVIDED THERE ARE AT LEAST A FEW BREAKS IN OTHERWISE MOSTLY CLOUDY
SKIES AND CONVECTION...TEMPERATURES SHOULD CLIMB INTO THE LOWER TO
MIDDLE 80S...WARMEST SANDHILLS TUE. OTHERWISE...UPPER 70S WOULD BE
PROBABLE (IE. IN AREAS THAT EXPERIENCE MORE FREQUENT SHOWERS AND
STORMS). LOWS TUE NIGHT MOSTLY IN THE UPPER 60S...TO AROUND 70
DEGREES SOUTH...COOLING A CATEGORY TO TWO IN COOLER POST-FRONTAL NE
FLOW WED NIGHT.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM SUNDAY...

THU THROUGH FRI: BELOW AVERAGE TEMPERATURES - GENERALLY IN THE LOWER
TO MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE AND ASSOCIATED NE
TO EAST LOW LEVEL FLOW AND STABILITY...WILL THEN PREVAIL THROUGH THE
END OF THE WEEK. WILL ACCORDINGLY MAINTAIN THE FLAVOR OF PREVIOUS
GENERALLY DRY FORECASTS FOR THU-FRI...EXCEPT FOR THE SLIGHTEST OF
CHANCES ALONG THE FAR SOUTHERN AND WESTERN TIER...WHERE BOUNDARY
LAYER MOISTURE WOULD SUPPORT A LATE DAY SHOWER OR STORM. EVEN THAT
SLIGHT CHANCE MAY BE OVERDONE GIVEN AN APPARENT LACK OF TRIGGER
AMIDST DIVERGENT ANTICYCLONIC FLOW WITHIN THE AFOREMENTIONED SURFACE
RIDGE AXIS.

THIS WEEKEND: A SHALLOW UPPER LOW WILL HAVE DRIFTED INTO THE
SOUTHEAST STATES BY THE START OF THE WEEKEND...BUT INSTEAD OF
LIFTING TOWARD THE EAST COAST...GUIDANCE SUGGESTS THIS FEATURE WILL
MOVE WESTWARD AROUND THE SOUTHERN PERIPHERY OF A DEVELOPING
MID-UPPER RIDGE FROM THE SOUTHERN PLAINS TO THE MIDDLE ATLANTIC
REGION. AS SUCH...TEMPERATURES...AND HUMIDITY LEVELS WILL GRADUALLY
INCREASE IN INCREASINGLY SE TO SOUTHERLY RETURN FLOW. THE INCREASING
WARMTH AND HUMIDITY WILL ALSO SUPPORT A SLIGHT UPTICK IN PROBABILITY
OF PRECIPITATION...THOUGH STILL BELOW CLIMATOLOGICAL VALUES IN THE
20TH PERCENTILE GIVEN THE AFOREMENTIONED EXPANSION OF RIDGING
ALOFT...AND LACK OF LOW LEVEL FOCI OTHER THAN PERHAPS THE SEA
BREEZE.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 630 AM MONDAY...

CONDITIONS WILL BE VFR OUTSIDE OF CONVECTION THROUGH LATE TONIGHT.
CONVECTION MOVING EAST OFF THE MOUNTAINS INTO THE NORTHERN PIEDMONT
THIS MORNING WILL WEAKEN AS IT MOVES TOWARDS THE TRIANGLE AND INTO
MORE STABLE AIR. HEATING WILL NOT BE STRONG DUE TO MID LEVEL
CEILINGS...BUT WEAKLY FORCED FLOW WILL PRODUCE SCATTERED SHOWERS AND
WIDELY SCATTERED THUNDER THIS AFTERNOON....CONFIDENCE IN THE TIMING
IS LOW AND THE COVERAGE NOT EXPECTED TO BE SUBSTANTIAL ENOUGH TO
WARRANT INCLUSION IN THE TAFS. EXPECT A LULL OVERNIGHT ACROSS THE
NORTHERN TIER IN SUBSIDENCE BEHIND A WEAK UPPER SHORTWAVE. VERY
MOIST AIRMASS WILL BE FAVORABLE FOR FOG AND PERHAPS SOME IFR/LIFR
CEILINGS IF WE GET SOME BREAKS TO ALLOW RADIATIONAL COOLING AND
WINDS CALM IN THE PREDAWN.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...MLM
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...MLM

000
FXUS62 KRAH 170725
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ACROSS OUR
REGION LATE TUESDAY.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 315 AM MONDAY...

HIGH CLOUDINESS HAS BEEN INCREASING AND PATCHY LIGHT RAIN HAS BEEN
THREATENING TO ENCIRCLE THE RAH CWFA OVERNIGHT. EXPECT TO SEE
SCATTERED SHOWERS AND A FEW STORMS SPREAD IN FROM THE WEST AS
WEAK FORCING FROM OVERNIGHT CONVECTION ADVECTS INTO THE AREA IN
CONCERT WITH A MINOR SHORT WAVE PRESSING IN FROM THE NORTHWEST. THIS
WILL FINALLY GIVE OUR WARM AND INCREASINGLY MOIST AIRMASS A REASON
TO PRECIPITATE. WILL TREND INCREASING POPS...ALTHOUGH STILL KEEPING
THEM IN THE CHANCE CATEGORY...THROUGH THE MORNING FROM THE WEST.
WILL NOT MAKE A LOT OF DISTINCTION ACROSS THE AREA AS IT IS
DIFFICULT TO PINPOINT AN AREA THAT MIGHT BE PARTICULARLY PRONE TO
INCREASED COVERAGE GIVEN THE RELATIVE UNIFORMITY OF THE AIRMASS AND
WEAKNESS OF THE FORCING. GUIDANCE HIGH TEMPS SEEM RATHER HIGH GIVEN
THE CLOUD TRENDS...THINK THAT AT LEAST THE NORTHWEST PIEDMONT
SHOULDN`T MAKE THE UPPER 80S AND WILL GO GENERALLY MID 80S ACROSS
THE BOARD.

BOTH THE GFS AND ECM SHOW A LULL ACROSS THE NORTHERN TIER TONIGHT
ACROSS THE NORTHERN TIER IN SUBSIDENCE BEHIND THE INITIAL UPPER
SHORT WAVE. THUNDER WILL BE TOUGH TO PRODUCE GIVEN SUBSIDENCE AND
UNFAVORABLE NOCTURNAL TREND. WILL TREND POPS FOR SHOWERS TOWARDS
THE SOUTHEAST. MINS WILL BE PERSISTENCE AND ON THE MILD SIDE...UPPER
60S.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...

A SERIES OF DISTURBANCES ALOFT...WHICH HAVE TRENDED WEAKER IN NWP
GUIDANCE DURING THE PAST FEW DAYS AND WHOSE TIMING IS UNCERTAIN
GIVEN THE PROBABILITY OF BEING MODULATED BY UPSTREAM
CONVECTION...WILL MIGRATE THROUGH THE BASE OF A BROAD TROUGH ALOFT
EAST OF THE ROCKIES...AND ACROSS THE CENTRAL APPALACHIANS/NC THROUGH
WED. MEANWHILE AT THE SURFACE...A PRE-FRONTAL TROUGH OVER THE MIDDLE
ATLANTIC REGION THIS MORNING WILL STRENGTHEN THROUGH TUE...THEN BE
OVERTAKEN BY A COLD FRONT THAT WILL SETTLE SLOWLY SOUTHWARD FROM THE
MASON DIXON LINE TUE EVENING TO THE NC/SC LINE BY WED EVENING.

PRECIPITABLE WATER VALUES WILL CONSEQUENTLY REMAIN ABOVE
AVERAGE...BETWEEN 1.5 AND 1.8 INCHES... UNTIL FRONTAL PASSAGE. THE
DEEP MOISTURE AND ASSOCIATED UNINHIBITED CONDITIONAL INSTABILITY...
WHICH IS FORECAST TO MAXIMIZE IN THE 1000-1500 J/KG EACH
AFTERNOON...WILL SUPPORT NUMEROUS TO WIDESPREAD THUNDERSTORMS...WITH
COVERAGE DIMINISHING WITH NOCTURNAL COOLING TUE NIGHT...AND THEN
FROM NORTH TO SOUTH WITH THE FRONTAL PASSAGE ON WED. GIVEN THE
EXPECTATION OF WEAKER DISTURBANCES THAN PREVIOUSLY INDICATED...NOTED
ABOVE...MID LEVEL FLOW AND ASSOCIATED BULK SHEAR VALUES ARE NOW
FORECAST TO PEAK ONLY IN THE 20-25 KT RANGE...HIGHEST WED. AS
SUCH...ALREADY MINIMAL SEVERE POTENTIAL WILL BE FURTHER MUTED UNLESS
POCKETS OF STRONGER INSOLATION AND MODERATE INSTABILITY ARE
REALIZED...IN WHICH CASE A FEW STRONG-MARGINALLY SEVERE WET
MICROBURSTS WOULD BE PROBABLE. A MORE LIKELY SCENARIO REMAINS A
THREAT OF DOWNPOURS AND LOCALIZED FLOODING IN TRAINING
CONVECTION...OWING TO WSW MEAN FLOW ALIGNED PARALLEL TO THE MYRIAD
OF UNDERLYING SURFACE BOUNDARIES (TROUGH/EFFECTIVE FRONT-OUTFLOW
/ACTUAL FRONT...AND TO BACKBUILDING INDICATED BY SMALL FORECAST
CORFIDI VECTORS. ANY SUCH FLOODING WILL NOT BE WIDESPREAD...AND
INSTEAD CONFINED MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED
SOIL HAS DRIED IN THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH
FLOOD GUIDANCE VALUES HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE
FOR ONE HOUR FOR EXAMPLE.

PROVIDED THERE ARE AT LEAST A FEW BREAKS IN OTHERWISE MOSTLY CLOUDY
SKIES AND CONVECTION...TEMPERATURES SHOULD CLIMB INTO THE LOWER TO
MIDDLE 80S...WARMEST SANDHILLS TUE. OTHERWISE...UPPER 70S WOULD BE
PROBABLE (IE. IN AREAS THAT EXPERIENCE MORE FREQUENT SHOWERS AND
STORMS). LOWS TUE NIGHT MOSTLY IN THE UPPER 60S...TO AROUND 70
DEGREES SOUTH...COOLING A CATEGORY TO TWO IN COOLER POST-FRONTAL NE
FLOW WED NIGHT.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM SUNDAY...

THU THROUGH FRI: BELOW AVERAGE TEMPERATURES - GENERALLY IN THE LOWER
TO MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE AND ASSOCIATED NE
TO EAST LOW LEVEL FLOW AND STABILITY...WILL THEN PREVAIL THROUGH THE
END OF THE WEEK. WILL ACCORDINGLY MAINTAIN THE FLAVOR OF PREVIOUS
GENERALLY DRY FORECASTS FOR THU-FRI...EXCEPT FOR THE SLIGHTEST OF
CHANCES ALONG THE FAR SOUTHERN AND WESTERN TIER...WHERE BOUNDARY
LAYER MOISTURE WOULD SUPPORT A LATE DAY SHOWER OR STORM. EVEN THAT
SLIGHT CHANCE MAY BE OVERDONE GIVEN AN APPARENT LACK OF TRIGGER
AMIDST DIVERGENT ANTICYCLONIC FLOW WITHIN THE AFOREMENTIONED SURFACE
RIDGE AXIS.

THIS WEEKEND: A SHALLOW UPPER LOW WILL HAVE DRIFTED INTO THE
SOUTHEAST STATES BY THE START OF THE WEEKEND...BUT INSTEAD OF
LIFTING TOWARD THE EAST COAST...GUIDANCE SUGGESTS THIS FEATURE WILL
MOVE WESTWARD AROUND THE SOUTHERN PERIPHERY OF A DEVELOPING
MID-UPPER RIDGE FROM THE SOUTHERN PLAINS TO THE MIDDLE ATLANTIC
REGION. AS SUCH...TEMPERATURES...AND HUMIDITY LEVELS WILL GRADUALLY
INCREASE IN INCREASINGLY SE TO SOUTHERLY RETURN FLOW. THE INCREASING
WARMTH AND HUMIDITY WILL ALSO SUPPORT A SLIGHT UPTICK IN PROBABILITY
OF PRECIPITATION...THOUGH STILL BELOW CLIMATOLOGICAL VALUES IN THE
20TH PERCENTILE GIVEN THE AFOREMENTIONED EXPANSION OF RIDGING
ALOFT...AND LACK OF LOW LEVEL FOCI OTHER THAN PERHAPS THE SEA
BREEZE.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...

WARM...MOIST...BUT WEAKLY FORCED ENVIRONMENT WILL REMAIN OVER
CENTRAL NC THIS TAF PERIOD. CONDITIONS WILL REMAIN VFR THROUGH THE
PERIOD OUTSIDE OF CONVECTION.

EXPECT A GRADUAL INCREASE THIS MORNING IN MID LEVEL CLOUDINESS
ACROSS THE NORTHERN TIER OF THE AREA. WEAK FORCING FROM OVERNIGHT
CONVECTION IN WESTERN TN AND NORTHERN GA WILL BE MIGRATING INTO THE
WESTERN PIEDMONT THIS MORNING...WITH SCATTERED SHOWERS AT INT/GSO
AFTER SUNRISE...PERHAPS MID MORNING FURTHER EAST...RDU AND RWI.
DECENT INSTABILITY WILL SUPPORT MORE WIDESPREAD SHOWERS AND WIDELY
SCATTERED THUNDER THIS AFTERNOON...TSRA COVERAGE AND CONFIDENCE IN
TIMING/PLACEMENT PRECLUDE TAF INCLUSION AT THIS TIME. EXPECT A LULL
OVERNIGHT ALTHOUGH SCATTERED SHOWERS ARE EXPECTED. WINDS WILL BE
SOUTH TO SOUTHWEST AT LESS THAN 10KT.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...MLM
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...MLM

000
FXUS62 KRAH 170708
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
308 AM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ACROSS OUR
REGION LATE TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM SUNDAY...

RELATIVELY BENIGN CONVECTION HAS BEEN MOVING WEST TO EAST ACROSS
KY/WV/VA THIS EVENING...WITHIN A ZONE OF PREFRONTAL CONVERGENCE AND
DEEP MOISTURE.  FURTHER SOUTH OVER THE LOWER TENNESSEE
VALLEY...WHERE DAYTIME INSTABILITY STILL LINGERS...A MORE WELL
DEFINED CLUSTER OF STORMS IS CURRENTLY MOVING ACROSS NORTHERN GA AND
AND INTO FAR WESTERN NC. THESE TWO AREAS WILL GRADUALLY POSE A
THREAT TO THE NORTHERN AND WESTERN PORTIONS OF CENTRAL NC THROUGH
MONDAY.  TONIGHT...FORCING WILL BE WEAK AS THE MOIST/CONVERGENCE
AXIS..WHERE PW VALUES AT 1.5-2"...SLOWLY SHIFTS SOUTHEASTWARD TOWARD
THE AREA.  THE AFOREMENTIONED CLUSTER OF STORMS APPROACHING WESTERN
NC SHOULD WEAKEN AS IT ENCOUNTERS MORE HOSTILE AIR EAST OF THE
MOUNTAINS...BUT THE LINGERING OUTFLOW COULD ALSO SERVE AS A CATALYST
FOR SHOWERS IF IT DRIFTS ALL THE WAY INTO THE SOUTHERN/WESTERN
PIEDMONT.  BASED ON CURRENT RADAR TRENDS AND LATEST HRRR DATA...HAVE
PUSHED CHANCE POPS BACK UNTIL AFTER 08Z.   OTHERWISE...TEMPS WILL
REMAIN RATHER MILD..FALLING INTO THE UPPER 60S AS CLOUDS STEADILY
INCREASE. -BLS

MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.

MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER
SOUTH...HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH
ANOTHER MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...

A SERIES OF DISTURBANCES ALOFT...WHICH HAVE TRENDED WEAKER IN NWP
GUIDANCE DURING THE PAST FEW DAYS AND WHOSE TIMING IS UNCERTAIN
GIVEN THE PROBABILITY OF BEING MODULATED BY UPSTREAM
CONVECTION...WILL MIGRATE THROUGH THE BASE OF A BROAD TROUGH ALOFT
EAST OF THE ROCKIES...AND ACROSS THE CENTRAL APPALACHIANS/NC THROUGH
WED. MEANWHILE AT THE SURFACE...A PRE-FRONTAL TROUGH OVER THE MIDDLE
ATLANTIC REGION THIS MORNING WILL STRENGTHEN THROUGH TUE...THEN BE
OVERTAKEN BY A COLD FRONT THAT WILL SETTLE SLOWLY SOUTHWARD FROM THE
MASON DIXON LINE TUE EVENING TO THE NC/SC LINE BY WED EVENING.

PRECIPITABLE WATER VALUES WILL CONSEQUENTLY REMAIN ABOVE
AVERAGE...BETWEEN 1.5 AND 1.8 INCHES... UNTIL FRONTAL PASSAGE. THE
DEEP MOISTURE AND ASSOCIATED UNINHIBITED CONDITIONAL INSTABILITY...
WHICH IS FORECAST TO MAXIMIZE IN THE 1000-1500 J/KG EACH
AFTERNOON...WILL SUPPORT NUMEROUS TO WIDESPREAD THUNDERSTORMS...WITH
COVERAGE DIMINISHING WITH NOCTURNAL COOLING TUE NIGHT...AND THEN
FROM NORTH TO SOUTH WITH THE FRONTAL PASSAGE ON WED. GIVEN THE
EXPECTATION OF WEAKER DISTURBANCES THAN PREVIOUSLY INDICATED...NOTED
ABOVE...MID LEVEL FLOW AND ASSOCIATED BULK SHEAR VALUES ARE NOW
FORECAST TO PEAK ONLY IN THE 20-25 KT RANGE...HIGHEST WED. AS
SUCH...ALREADY MINIMAL SEVERE POTENTIAL WILL BE FURTHER MUTED UNLESS
POCKETS OF STRONGER INSOLATION AND MODERATE INSTABILITY ARE
REALIZED...IN WHICH CASE A FEW STRONG-MARGINALLY SEVERE WET
MICROBURSTS WOULD BE PROBABLE. A MORE LIKELY SCENARIO REMAINS A
THREAT OF DOWNPOURS AND LOCALIZED FLOODING IN TRAINING
CONVECTION...OWING TO WSW MEAN FLOW ALIGNED PARALLEL TO THE MYRIAD
OF UNDERLYING SURFACE BOUNDARIES (TROUGH/EFFECTIVE FRONT-OUTFLOW
/ACTUAL FRONT...AND TO BACKBUILDING INDICATED BY SMALL FORECAST
CORFIDI VECTORS. ANY SUCH FLOODING WILL NOT BE WIDESPREAD...AND
INSTEAD CONFINED MOST LIKELY TO URBAN AREAS SINCE THE ANDREA-SOAKED
SOIL HAS DRIED IN THE PAST WEEK TO 10 DAYS...AND RESULTANT FLASH
FLOOD GUIDANCE VALUES HAVE INCREASED...INTO THE 2.5 TO 3 INCH RANGE
FOR ONE HOUR FOR EXAMPLE.

PROVIDED THERE ARE AT LEAST A FEW BREAKS IN OTHERWISE MOSTLY CLOUDY
SKIES AND CONVECTION...TEMPERATURES SHOULD CLIMB INTO THE LOWER TO
MIDDLE 80S...WARMEST SANDHILLS TUE. OTHERWISE...UPPER 70S WOULD BE
PROBABLE (IE. IN AREAS THAT EXPERIENCE MORE FREQUENT SHOWERS AND
STORMS). LOWS TUE NIGHT MOSTLY IN THE UPPER 60S...TO AROUND 70
DEGREES SOUTH...COOLING A CATEGORY TO TWO IN COOLER POST-FRONTAL NE
FLOW WED NIGHT.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM SUNDAY...

THU THROUGH FRI: BELOW AVERAGE TEMPERATURES - GENERALLY IN THE LOWER
TO MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE AND ASSOCIATED NE
TO EAST LOW LEVEL FLOW AND STABILITY...WILL THEN PREVAIL THROUGH THE
END OF THE WEEK. WILL ACCORDINGLY MAINTAIN THE FLAVOR OF PREVIOUS
GENERALLY DRY FORECASTS FOR THU-FRI...EXCEPT FOR THE SLIGHTEST OF
CHANCES ALONG THE FAR SOUTHERN AND WESTERN TIER...WHERE BOUNDARY
LAYER MOISTURE WOULD SUPPORT A LATE DAY SHOWER OR STORM. EVEN THAT
SLIGHT CHANCE MAY BE OVERDONE GIVEN AN APPARENT LACK OF TRIGGER
AMIDST DIVERGENT ANTICYCLONIC FLOW WITHIN THE AFOREMENTIONED SURFACE
RIDGE AXIS.

THIS WEEKEND: A SHALLOW UPPER LOW WILL HAVE DRIFTED INTO THE
SOUTHEAST STATES BY THE START OF THE WEEKEND...BUT INSTEAD OF
LIFTING TOWARD THE EAST COAST...GUIDANCE SUGGESTS THIS FEATURE WILL
MOVE WESTWARD AROUND THE SOUTHERN PERIPHERY OF A DEVELOPING
MID-UPPER RIDGE FROM THE SOUTHERN PLAINS TO THE MIDDLE ATLANTIC
REGION. AS SUCH...TEMPERATURES...AND HUMIDITY LEVELS WILL GRADUALLY
INCREASE IN INCREASINGLY SE TO SOUTHERLY RETURN FLOW. THE INCREASING
WARMTH AND HUMIDITY WILL ALSO SUPPORT A SLIGHT UPTICK IN PROBABILITY
OF PRECIPITATION...THOUGH STILL BELOW CLIMATOLOGICAL VALUES IN THE
20TH PERCENTILE GIVEN THE AFOREMENTIONED EXPANSION OF RIDGING
ALOFT...AND LACK OF LOW LEVEL FOCI OTHER THAN PERHAPS THE SEA
BREEZE.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...

WARM...MOIST...BUT WEAKLY FORCED ENVIRONMENT WILL REMAIN OVER
CENTRAL NC THIS TAF PERIOD. CONDITIONS WILL REMAIN VFR THROUGH THE
PERIOD OUTSIDE OF CONVECTION.

EXPECT A GRADUAL INCREASE THIS MORNING IN MID LEVEL CLOUDINESS
ACROSS THE NORTHERN TIER OF THE AREA. WEAK FORCING FROM OVERNIGHT
CONVECTION IN WESTERN TN AND NORTHERN GA WILL BE MIGRATING INTO THE
WESTERN PIEDMONT THIS MORNING...WITH SCATTERED SHOWERS AT INT/GSO
AFTER SUNRISE...PERHAPS MID MORNING FURTHER EAST...RDU AND RWI.
DECENT INSTABILITY WILL SUPPORT MORE WIDESPREAD SHOWERS AND WIDELY
SCATTERED THUNDER THIS AFTERNOON...TSRA COVERAGE AND CONFIDENCE IN
TIMING/PLACEMENT PRECLUDE TAF INCLUSION AT THIS TIME. EXPECT A LULL
OVERNIGHT ALTHOUGH SCATTERED SHOWERS ARE EXPECTED. WINDS WILL BE
SOUTH TO SOUTHWEST AT LESS THAN 10KT.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...DJF/BLS
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...MLM

000
FXUS62 KRAH 170559
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
140 AM EDT MON JUN 17 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND ACROSS OUR
REGION LATE TUESDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 940 PM SUNDAY...

RELATIVELY BENIGN CONVECTION HAS BEEN MOVING WEST TO EAST ACROSS
KY/WV/VA THIS EVENING...WITHIN A ZONE OF PREFRONTAL CONVERGENCE AND
DEEP MOISTURE.  FURTHER SOUTH OVER THE LOWER TENNESSEE
VALLEY...WHERE DAYTIME INSTABILITY STILL LINGERS...A MORE WELL
DEFINED CLUSTER OF STORMS IS CURRENTLY MOVING ACROSS NORTHERN GA AND
AND INTO FAR WESTERN NC. THESE TWO AREAS WILL GRADUALLY POSE A
THREAT TO THE NORTHERN AND WESTERN PORTIONS OF CENTRAL NC THROUGH
MONDAY.  TONIGHT...FORCING WILL BE WEAK AS THE MOIST/CONVERGENCE
AXIS..WHERE PW VALUES AT 1.5-2"...SLOWLY SHIFTS SOUTHEASTWARD TOWARD
THE AREA.  THE AFOREMENTIONED CLUSTER OF STORMS APPROACHING WESTERN
NC SHOULD WEAKEN AS IT ENCOUNTERS MORE HOSTILE AIR EAST OF THE
MOUNTAINS...BUT THE LINGERING OUTFLOW COULD ALSO SERVE AS A CATALYST
FOR SHOWERS IF IT DRIFTS ALL THE WAY INTO THE SOUTHERN/WESTERN
PIEDMONT.  BASED ON CURRENT RADAR TRENDS AND LATEST HRRR DATA...HAVE
PUSHED CHANCE POPS BACK UNTIL AFTER 08Z.   OTHERWISE...TEMPS WILL
REMAIN RATHER MILD..FALLING INTO THE UPPER 60S AS CLOUDS STEADILY
INCREASE. -BLS

MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM SUNDAY...

MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER SOUTH...
HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH ANOTHER
MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70. -DJF

TUESDAY...A DAMPENING MID LEVEL S/W CROSSING CENTRAL NC DURING PRIME
HEATING SHOULD INTERACT WITH THE MOIST AND SLIGHTLY UNSTABLE AIR
MASS IN PLACE TO TRIGGER NUMEROUS-WIDESPREAD SHOWERS AND A FEW
T-STORMS...MAINLY TUESDAY AFTERNOON. LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED ALONG A SWD DRIFTING SFC BOUNDARY WILL LIFT ALOFT A RESULT
OF THE WEAKENING S/W AND 300MB JET CROSSING SOUTHERN NEW ENGLAND
PLACING CENTRAL NC IN THE FAVORABLE RIGHT ENTRANCE REGION. DYNAMICS
NOT OVERLY IMPRESSIVE THOUGH 30KTS OF BULK SHEAR OCCUR IN THE
AFTERNOON ACROSS THE NORTH AND MLCAPE (GFS) REACHES 1000-1400 J/KG
IN THE AFTERNOON. AS ELUDED TO IN PREVIOUS FORECAST...POTENTIAL FOR
SHOWERS/STORMS TO PASS REPEATEDLY OVER THE SAME LOCATION AS MEAN
FLOW PARALLEL TO THE SWD DRIFTING SFC BOUNDARY. THIS MAY LEAD TO
LOCALIZED FLOODING ISSUES...MAINLY IN URBAN AREAS. ANY UPDRAFTS ABLE
TO SUSTAIN MORE THAN 20 MINUTES MAY PRODUCE A WET MICROBURST BUT A
MARGINAL WIND PROFILE AND DEEP MOISTURE (LACK OF DRY AIR
ENTRAINMENT) SUGGEST ANY DAMAGING WINDS WILL BE QUITE ISOLATED.

TUESDAY NIGHT INTO WEDNESDAY...MID LEVEL TROUGH AND ASSOCIATED SFC
BOUNDARY DRIFT SE AND EXIT THE REGION TUESDAY EVENING. THIS SUGGEST
A GRADUAL DIMINISHING IN CONVECTIVE COVERAGE FROM THE NORTH TUESDAY.
ON WEDNESDAY...S/W IN THE ACTIVE NORTHERN STREAM WILL CROSS THE MID
ATLANTIC WEDNESDAY. THIS FEATURE WILL SEND ANOTHER SFC FRONT SWD
ACROSS CENTRAL NC ON WEDNESDAY. WEAK CONVERGENCE ALONG THIS BOUNDARY
COUPLED WITH MODEST UPPER AIR SUPPORT MAY TRIGGER/SUSTAIN
ISOLATED-SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY. COVERAGE
APPEARS TO BE BETTER SOUTH VERSUS NORTH AS AIR MASS ACROSS THE NORTH
WILL BE DRIER AND MORE STABLE.

HIGH TEMPERATURES TUESDAY DEPENDENT ON CONVECTIVE COVERAGE. IF
WIDESPREAD CONVECTION OCCURS SOONER THAN ANTICIPATED...MAX TEMPS MAY
BE 3-4 DEGREES TOO WARM. A SFC N-NE FLOW WILL SLOWLY ADVECT COOLER
AIR INTO CENTRAL NC WEDNESDAY. LOW LEVEL THICKNESSES SUPPORT MAX
TEMPS NEAR 80-LOWER 80S. -WSS

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SURFACE RIDGE WILL
STRENGTHEN OVER CENTRAL NC. RESULTANT LOW LEVEL NE FLOW WILL
MAINTAIN A RELATIVELY COOL AND STABLE AIR MASS OVER THE BULK OF
CENTRAL NC. THE EXCEPTION WILL BE THE FAR SOUTH AND WEST AS ENOUGH
LIFT/MOISTURE MAY EXIST AROUND THE PERIPHERY OF THE RIDGE TO PERMIT
ISOLATED CONVECTION TO OCCUR. AFTERNOON TEMPS THURSDAY WILL AGAIN
AVERAGE A FEW DEGREES BELOW NORMAL WITH MOST SPOTS IN THE LOWER 80S.
MIN TEMPS BOTH NIGHTS IN THE LOW-MID 60S.

FRI-SUN:  MEDIUM RANGE GUIDANCE DIFFER IN THE UPPER AIR PATTERN OVER
THE CAROLINAS AT THE END OF THE WEEK. GFS DEPICTION OF A SERIES OF
S/W CROSSING THE OH VALLEY INTO THE NORTHERN MID ATLANTIC EXTENDING
SWD INTO CENTRAL NC  FRI-SAT WOULD SUGGEST A THREAT OF SCATTERED
CONVECTION OVER OUR REGION. MEANWHILE...ECMWF DEPICTS AN ELONGATED
UPPER LEVEL LOW/SHEAR AXIS OFF THE SE U.S. COAST THAT MOVES LITTLE
FRI-SAT. THIS FEATURE ALONG WITH THE MAIN STORM TRACK ACROSS THE
LOWER GREAT LAKES INTO THE NORTHERN MID ATLANTIC PERMITS A NARROW
RIDGE OF HIGH PRESSURE TO EXTEND ACROSS THE CAROLINAS FROM AN
ANTI-CYCLONE POSITIONED OVER THE SOUTHERN PLAINS/LOWER MS VALLEY.
THIS SCENARIO WOULD KEEP CENTRAL NC DRY FRI AND SAT. DIFFICULT TO
SAY AT THIS TIME WHICH SCENARIO MOST LIKELY TO VERIFY AS EACH
SCENARIO HAS AN EQUAL CHANCE TO VERIFY. BY SUNDAY....MODEL CONSENSUS
KEYS ON UPPER RIDGE EXPANDING EWD INTO THE CAROLINAS FROM THE
TN-LOWER OH VALLEY. ANY SHEAR AXES ASSOCIATED WITH CONVECTION
OCCURRING ALONG THE STORM TRACK FROM THE GREAT LAKES INTO THE
NORTHERN MID ATLANTIC WOULD BRUSH OUR FAR NE COUNTIES.

AIR MASS WILL GRADUALLY MODIFY THIS PERIOD WITH AFTERNOON TEMPS
RETURNING TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS BY SUNDAY.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...

WARM...MOIST...BUT WEAKLY FORCED ENVIRONMENT WILL REMAIN OVER
CENTRAL NC THIS TAF PERIOD. CONDITIONS WILL REMAIN VFR THROUGH THE
PERIOD OUTSIDE OF CONVECTION.

EXPECT A GRADUAL INCREASE THIS MORNING IN MID LEVEL CLOUDINESS
ACROSS THE NORTHERN TIER OF THE AREA. WEAK FORCING FROM OVERNIGHT
CONVECTION IN WESTERN TN AND NORTHERN GA WILL BE MIGRATING INTO THE
WESTERN PIEDMONT THIS MORNING...WITH SCATTERED SHOWERS AT INT/GSO
AFTER SUNRISE...PERHAPS MID MORNING FURTHER EAST...RDU AND RWI.
DECENT INSTABILITY WILL SUPPORT MORE WIDESPREAD SHOWERS AND WIDELY
SCATTERED THUNDER THIS AFTERNOON...TSRA COVERAGE AND CONFIDENCE IN
TIMING/PLACEMENT PRECLUDE TAF INCLUSION AT THIS TIME. EXPECT A LULL
OVERNIGHT ALTHOUGH SCATTERED SHOWERS ARE EXPECTED. WINDS WILL BE
SOUTH TO SOUTHWEST AT LESS THAN 10KT.

ADDITIONAL DISTURBANCES WILL BE CROSSING THE AREA ALONG WITH A WEAK
COLD FRONT TUESDAY INTO WEDNESDAY...WITH PERIODS OF SHOWERS AND
STORMS PRODUCING SUB-VFR CONDITIONS. VFR CONDITIONS ARE
GENERALLY EXPECTED FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME
EARLY MORNING STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH
MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MLM
NEAR TERM...DJF/BLS
SHORT TERM...DJF/WSS
LONG TERM...WSS
AVIATION...MLM

000
FXUS62 KRAH 170147
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
940 PM EDT SUN JUN 16 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND MOVE ACROSS
OUR REGION LATE TUESDAY INTO EARLY WEDNESDAY MORNING.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 940 PM SUNDAY...

RELATIVELY BENIGN CONVECTION HAS BEEN MOVING WEST TO EAST ACROSS
KY/WV/VA THIS EVENING...WITHIN A ZONE OF PREFRONTAL CONVERGENCE AND
DEEP MOISTURE.  FURTHER SOUTH OVER THE LOWER TENNESSEE
VALLEY...WHERE DAYTIME INSTABILITY STILL LINGERS...A MORE WELL
DEFINED CLUSTER OF STORMS IS CURRENTLY MOVING ACROSS NORTHERN GA AND
AND INTO FAR WESTERN NC. THESE TWO AREAS WILL GRADUALLY POSE A
THREAT TO THE NORTHERN AND WESTERN PORTIONS OF CENTRAL NC THROUGH
MONDAY.  TONIGHT...FORCING WILL BE WEAK AS THE MOIST/CONVERGENCE
AXIS..WHERE PW VALUES AT 1.5-2"...SLOWLY SHIFTS SOUTHEASTWARD TOWARD
THE AREA.  THE AFOREMENTIONED CLUSTER OF STORMS APPROACHING WESTERN
NC SHOULD WEAKEN AS IT ENCOUNTERS MORE HOSTILE AIR EAST OF THE
MOUNTAINS...BUT THE LINGERING OUTFLOW COULD ALSO SERVE AS A CATALYST
FOR SHOWERS IF IT DRIFTS ALL THE WAY INTO THE SOUTHERN/WESTERN
PIEDMONT.  BASED ON CURRENT RADAR TRENDS AND LATEST HRRR DATA...HAVE
PUSHED CHANCE POPS BACK UNTIL AFTER 08Z.   OTHERWISE...TEMPS WILL
REMAIN RATHER MILD..FALLING INTO THE UPPER 60S AS CLOUDS STEADILY
INCREASE. -BLS

MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM SUNDAY...

MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER SOUTH...
HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH ANOTHER
MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70. -DJF

TUESDAY...A DAMPENING MID LEVEL S/W CROSSING CENTRAL NC DURING PRIME
HEATING SHOULD INTERACT WITH THE MOIST AND SLIGHTLY UNSTABLE AIR
MASS IN PLACE TO TRIGGER NUMEROUS-WIDESPREAD SHOWERS AND A FEW
T-STORMS...MAINLY TUESDAY AFTERNOON. LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED ALONG A SWD DRIFTING SFC BOUNDARY WILL LIFT ALOFT A RESULT
OF THE WEAKENING S/W AND 300MB JET CROSSING SOUTHERN NEW ENGLAND
PLACING CENTRAL NC IN THE FAVORABLE RIGHT ENTRANCE REGION. DYNAMICS
NOT OVERLY IMPRESSIVE THOUGH 30KTS OF BULK SHEAR OCCUR IN THE
AFTERNOON ACROSS THE NORTH AND MLCAPE (GFS) REACHES 1000-1400 J/KG
IN THE AFTERNOON. AS ELUDED TO IN PREVIOUS FORECAST...POTENTIAL FOR
SHOWERS/STORMS TO PASS REPEATEDLY OVER THE SAME LOCATION AS MEAN
FLOW PARALLEL TO THE SWD DRIFTING SFC BOUNDARY. THIS MAY LEAD TO
LOCALIZED FLOODING ISSUES...MAINLY IN URBAN AREAS. ANY UPDRAFTS ABLE
TO SUSTAIN MORE THAN 20 MINUTES MAY PRODUCE A WET MICROBURST BUT A
MARGINAL WIND PROFILE AND DEEP MOISTURE (LACK OF DRY AIR
ENTRAINMENT) SUGGEST ANY DAMAGING WINDS WILL BE QUITE ISOLATED.

TUESDAY NIGHT INTO WEDNESDAY...MID LEVEL TROUGH AND ASSOCIATED SFC
BOUNDARY DRIFT SE AND EXIT THE REGION TUESDAY EVENING. THIS SUGGEST
A GRADUAL DIMINISHING IN CONVECTIVE COVERAGE FROM THE NORTH TUESDAY.
ON WEDNESDAY...S/W IN THE ACTIVE NORTHERN STREAM WILL CROSS THE MID
ATLANTIC WEDNESDAY. THIS FEATURE WILL SEND ANOTHER SFC FRONT SWD
ACROSS CENTRAL NC ON WEDNESDAY. WEAK CONVERGENCE ALONG THIS BOUNDARY
COUPLED WITH MODEST UPPER AIR SUPPORT MAY TRIGGER/SUSTAIN
ISOLATED-SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY. COVERAGE
APPEARS TO BE BETTER SOUTH VERSUS NORTH AS AIR MASS ACROSS THE NORTH
WILL BE DRIER AND MORE STABLE.

HIGH TEMPERATURES TUESDAY DEPENDENT ON CONVECTIVE COVERAGE. IF
WIDESPREAD CONVECTION OCCURS SOONER THAN ANTICIPATED...MAX TEMPS MAY
BE 3-4 DEGREES TOO WARM. A SFC N-NE FLOW WILL SLOWLY ADVECT COOLER
AIR INTO CENTRAL NC WEDNESDAY. LOW LEVEL THICKNESSES SUPPORT MAX
TEMPS NEAR 80-LOWER 80S. -WSS

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SURFACE RIDGE WILL
STRENGTHEN OVER CENTRAL NC. RESULTANT LOW LEVEL NE FLOW WILL
MAINTAIN A RELATIVELY COOL AND STABLE AIR MASS OVER THE BULK OF
CENTRAL NC. THE EXCEPTION WILL BE THE FAR SOUTH AND WEST AS ENOUGH
LIFT/MOISTURE MAY EXIST AROUND THE PERIPHERY OF THE RIDGE TO PERMIT
ISOLATED CONVECTION TO OCCUR. AFTERNOON TEMPS THURSDAY WILL AGAIN
AVERAGE A FEW DEGREES BELOW NORMAL WITH MOST SPOTS IN THE LOWER 80S.
MIN TEMPS BOTH NIGHTS IN THE LOW-MID 60S.

FRI-SUN:  MEDIUM RANGE GUIDANCE DIFFER IN THE UPPER AIR PATTERN OVER
THE CAROLINAS AT THE END OF THE WEEK. GFS DEPICTION OF A SERIES OF
S/W CROSSING THE OH VALLEY INTO THE NORTHERN MID ATLANTIC EXTENDING
SWD INTO CENTRAL NC  FRI-SAT WOULD SUGGEST A THREAT OF SCATTERED
CONVECTION OVER OUR REGION. MEANWHILE...ECMWF DEPICTS AN ELONGATED
UPPER LEVEL LOW/SHEAR AXIS OFF THE SE U.S. COAST THAT MOVES LITTLE
FRI-SAT. THIS FEATURE ALONG WITH THE MAIN STORM TRACK ACROSS THE
LOWER GREAT LAKES INTO THE NORTHERN MID ATLANTIC PERMITS A NARROW
RIDGE OF HIGH PRESSURE TO EXTEND ACROSS THE CAROLINAS FROM AN
ANTI-CYCLONE POSITIONED OVER THE SOUTHERN PLAINS/LOWER MS VALLEY.
THIS SCENARIO WOULD KEEP CENTRAL NC DRY FRI AND SAT. DIFFICULT TO
SAY AT THIS TIME WHICH SCENARIO MOST LIKELY TO VERIFY AS EACH
SCENARIO HAS AN EQUAL CHANCE TO VERIFY. BY SUNDAY....MODEL CONSENSUS
KEYS ON UPPER RIDGE EXPANDING EWD INTO THE CAROLINAS FROM THE
TN-LOWER OH VALLEY. ANY SHEAR AXES ASSOCIATED WITH CONVECTION
OCCURRING ALONG THE STORM TRACK FROM THE GREAT LAKES INTO THE
NORTHERN MID ATLANTIC WOULD BRUSH OUR FAR NE COUNTIES.

AIR MASS WILL GRADUALLY MODIFY THIS PERIOD WITH AFTERNOON TEMPS
RETURNING TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS BY SUNDAY.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 825 PM SUNDAY...

MID LEVEL RIDGE AXIS (OF HIGH PRESSURE) IS CURRENTLY PUSHING TO THE
EAST OF THE AREA THIS EVENING. MEANWHILE... A WEAK DISTURBANCE IS
EXPECTED TO PUSH INTO THE AREA OVERNIGHT. THIS MAY ALLOW FOR SOME
SHOWERS TO MOVE INTO NORTHWESTERN PORTIONS OF CENTRAL NC VERY LATE
THIS EVENING/EARLY MONDAY MORNING. THUS... HAVE INCLUDED A TEMPO
GROUP FOR SHOWERS AND POSSIBLY MVFR CIGS AND VISBYS IN THE 06-09Z
TIME FRAME AT KGSO AND KINT. ELSEWHERE.... EXPECT VFR CONDITIONS
WILL CONTINUE THROUGH AT LEAST 12Z MONDAY. UNSETTLED WEATHER IS
EXPECTED ON MONDAY. FOR NOW WILL SHOW VFR CONDITIONS AT ALL TAF
SITES OUTSIDE OF THE NORTHWEST (KGSO/KINT)... AS CONFIDENCE IS NOT
HIGH ENOUGH OF SUB-VFR CONDITIONS OUTSIDE OF ANY SCATTERED SHOWERS
AND STORMS. HOWEVER... EXPECT WE MAY HAVE PERIODS OF SHOWERS AND
STORMS MID MORNING THROUGH THE LATE AFTERNOON (WEST)/REST OF THE 00Z
TAF PERIOD (EAST)... AND POSSIBLE MVFR/IFR CONDITIONS ASSOCIATED
WITH THE MOIST CONDITIONS AND WITH SHOWERS AND STORMS.

WE MAY BRIEFLY SEE A PERIOD OF DRY CONDITIONS MONDAY EVENING INTO
EARLY TUESDAY MORNING... BEFORE ADDITIONAL DISTURBANCES MOVE ACROSS
THE AREA ALONG WITH A WEAK COLD FRONT LATE TUESDAY THROUGH
WEDNESDAY. UNTIL THEN EXPECT PERIOD OF SHOWERS AND STORMS... WITH
POSSIBLE SUB-VFR CONDITIONS. VFR CONDITIONS ARE GENERALLY EXPECTED
FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME EARLY MORNING
STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...KMC/DJF
NEAR TERM...DJF/BLS
SHORT TERM...DJF/WSS
LONG TERM...WSS
AVIATION...BSD

000
FXUS62 KRAH 170045
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
841 PM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS EVENING...AHEAD OF AN UPPER
LEVEL DISTURBANCE THAT MOVES THROUGH THE REGION OVERNIGHT AND
MONDAY. A COLD FRONT SLOWLY APPROACHES FROM THE NORTHWEST LATE
MONDAY AND MOVES ACROSS THE REGION LATE TUESDAY INTO WEDNESDAY
MORNING.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 250 PM SUNDAY...

THE NAM AND THE GFS ARE FAIRLY SIMILAR ON THE FORECAST DETAILS
DURING THE NEAR-TERM PERIOD...WITH THE AIR MASS GRADUALLY MOISTENING
AHEAD OF A MODEST MID-LEVEL SHORTWAVE THAT BOTH MODELS MOVE THROUGH
CENTRAL NORTH CAROLINA OVERNIGHT AND MONDAY. THE 12Z RAOB ANALYSIS
SHOWED AMPLE 850MB MOISTURE TO OUR SOUTHWEST WITH WIDESPREAD DEW
POINT IN THE TEENS CELSIUS...AND OVERNIGHT THROUGH MONDAY BOTH THE
NAM AND THE GFS FORECAST PRECIPITABLE WATER VALUES INCREASING TO
AROUND TWO INCHES. THE GFS IS ACTUALLY AS HIGH AS 2.25 INCHES...BUT
THAT MAY END UP BEING OVERDONE. REGARDLESS...WITH A MOISTENING AIR
MASS AND CONTINUED COOLING ALOFT AS HAS BEEN A CONSISTENT FORECAST
PARAMETER OVER THE LAST SEVERAL MODEL RUNS...CHANCES FOR
PRECIPITATION SHOULD INCREASE. THE GUIDANCE HAS ACTUALLY BECOME
NOTICEABLY MORE BULLISH WITH PRECIPITATION CHANCES FROM LATE THIS
EVENING THROUGH MONDAY...WITH THE NAM MOS INTRODUCING CATEGORICAL
POPS INTO THE TRIAD TONIGHT AND GENERALLY LOW LIKELY POPS THROUGHOUT
CENTRAL NORTH CAROLINA FOR MONDAY. AT LEAST OVERNIGHT...OF CONCERN
IS THE CAP STILL IN PLACE OVER A GOOD PART OF CENTRAL NORTH CAROLINA
AT THE MOMENT...AND THE PRECIPITATION FROM THE NORTHWEST TRYING TO
PUSH SOUTHEAST TOWARD A LINGERING 850MB RIDGE. MUCH OF THE AVAILABLE
WRF GUIDANCE...MOSTLY FROM NCEP...SUGGESTS THAT UPSTREAM
PRECIPITATION MAY ACTUALLY WANE AS IT TRIES TO PUSH SOUTHEAST
OVERNIGHT. WHAT MAY INDEED END UP HAPPENING IS THAT THE HIGH POPS OF
THE NAM ARE CORRECT IN THE TRIAD FOR LOW-QPF PRECIPITATION...WITH
WHATEVER PRECIPITATION REMAINS MAKING DIFFICULT HEADWAY SOUTHEAST.
THE MID-LEVEL DISTURBANCE...AS FORECAST...APPEARS STRONG ENOUGH WITH
MID-LEVEL COOLING AND INCREASING MOISTURE TO WARRANT CHANCE POPS
OVER AREAS MAINLY NORTH OF A LINE FROM ABOUT KVUJ TO KETC TONIGHT...
SLIGHT CHANCES FOR MOST AREAS TO THE SOUTH...KEEPING AREAS DRY ALONG
AND SOUTH OF A LINE FROM KMEB TO KGSB. OVERNIGHT LOWS CONTINUE TO
WARM IN INCREASING MOISTURE AND CLOUDS...MID TO UPPER 60S.

MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM SUNDAY...

MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER SOUTH...
HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH ANOTHER
MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70. -DJF

TUESDAY...A DAMPENING MID LEVEL S/W CROSSING CENTRAL NC DURING PRIME
HEATING SHOULD INTERACT WITH THE MOIST AND SLIGHTLY UNSTABLE AIR
MASS IN PLACE TO TRIGGER NUMEROUS-WIDESPREAD SHOWERS AND A FEW
T-STORMS...MAINLY TUESDAY AFTERNOON. LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED ALONG A SWD DRIFTING SFC BOUNDARY WILL LIFT ALOFT A RESULT
OF THE WEAKENING S/W AND 300MB JET CROSSING SOUTHERN NEW ENGLAND
PLACING CENTRAL NC IN THE FAVORABLE RIGHT ENTRANCE REGION. DYNAMICS
NOT OVERLY IMPRESSIVE THOUGH 30KTS OF BULK SHEAR OCCUR IN THE
AFTERNOON ACROSS THE NORTH AND MLCAPE (GFS) REACHES 1000-1400 J/KG
IN THE AFTERNOON. AS ELUDED TO IN PREVIOUS FORECAST...POTENTIAL FOR
SHOWERS/STORMS TO PASS REPEATEDLY OVER THE SAME LOCATION AS MEAN
FLOW PARALLEL TO THE SWD DRIFTING SFC BOUNDARY. THIS MAY LEAD TO
LOCALIZED FLOODING ISSUES...MAINLY IN URBAN AREAS. ANY UPDRAFTS ABLE
TO SUSTAIN MORE THAN 20 MINUTES MAY PRODUCE A WET MICROBURST BUT A
MARGINAL WIND PROFILE AND DEEP MOISTURE (LACK OF DRY AIR
ENTRAINMENT) SUGGEST ANY DAMAGING WINDS WILL BE QUITE ISOLATED.

TUESDAY NIGHT INTO WEDNESDAY...MID LEVEL TROUGH AND ASSOCIATED SFC
BOUNDARY DRIFT SE AND EXIT THE REGION TUESDAY EVENING. THIS SUGGEST
A GRADUAL DIMINISHING IN CONVECTIVE COVERAGE FROM THE NORTH TUESDAY.
ON WEDNESDAY...S/W IN THE ACTIVE NORTHERN STREAM WILL CROSS THE MID
ATLANTIC WEDNESDAY. THIS FEATURE WILL SEND ANOTHER SFC FRONT SWD
ACROSS CENTRAL NC ON WEDNESDAY. WEAK CONVERGENCE ALONG THIS BOUNDARY
COUPLED WITH MODEST UPPER AIR SUPPORT MAY TRIGGER/SUSTAIN
ISOLATED-SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY. COVERAGE
APPEARS TO BE BETTER SOUTH VERSUS NORTH AS AIR MASS ACROSS THE NORTH
WILL BE DRIER AND MORE STABLE.

HIGH TEMPERATURES TUESDAY DEPENDENT ON CONVECTIVE COVERAGE. IF
WIDESPREAD CONVECTION OCCURS SOONER THAN ANTICIPATED...MAX TEMPS MAY
BE 3-4 DEGREES TOO WARM. A SFC N-NE FLOW WILL SLOWLY ADVECT COOLER
AIR INTO CENTRAL NC WEDNESDAY. LOW LEVEL THICKNESSES SUPPORT MAX
TEMPS NEAR 80-LOWER 80S. -WSS

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SURFACE RIDGE WILL
STRENGTHEN OVER CENTRAL NC. RESULTANT LOW LEVEL NE FLOW WILL
MAINTAIN A RELATIVELY COOL AND STABLE AIR MASS OVER THE BULK OF
CENTRAL NC. THE EXCEPTION WILL BE THE FAR SOUTH AND WEST AS ENOUGH
LIFT/MOISTURE MAY EXIST AROUND THE PERIPHERY OF THE RIDGE TO PERMIT
ISOLATED CONVECTION TO OCCUR. AFTERNOON TEMPS THURSDAY WILL AGAIN
AVERAGE A FEW DEGREES BELOW NORMAL WITH MOST SPOTS IN THE LOWER 80S.
MIN TEMPS BOTH NIGHTS IN THE LOW-MID 60S.

FRI-SUN:  MEDIUM RANGE GUIDANCE DIFFER IN THE UPPER AIR PATTERN OVER
THE CAROLINAS AT THE END OF THE WEEK. GFS DEPICTION OF A SERIES OF
S/W CROSSING THE OH VALLEY INTO THE NORTHERN MID ATLANTIC EXTENDING
SWD INTO CENTRAL NC  FRI-SAT WOULD SUGGEST A THREAT OF SCATTERED
CONVECTION OVER OUR REGION. MEANWHILE...ECMWF DEPICTS AN ELONGATED
UPPER LEVEL LOW/SHEAR AXIS OFF THE SE U.S. COAST THAT MOVES LITTLE
FRI-SAT. THIS FEATURE ALONG WITH THE MAIN STORM TRACK ACROSS THE
LOWER GREAT LAKES INTO THE NORTHERN MID ATLANTIC PERMITS A NARROW
RIDGE OF HIGH PRESSURE TO EXTEND ACROSS THE CAROLINAS FROM AN
ANTI-CYCLONE POSITIONED OVER THE SOUTHERN PLAINS/LOWER MS VALLEY.
THIS SCENARIO WOULD KEEP CENTRAL NC DRY FRI AND SAT. DIFFICULT TO
SAY AT THIS TIME WHICH SCENARIO MOST LIKELY TO VERIFY AS EACH
SCENARIO HAS AN EQUAL CHANCE TO VERIFY. BY SUNDAY....MODEL CONSENSUS
KEYS ON UPPER RIDGE EXPANDING EWD INTO THE CAROLINAS FROM THE
TN-LOWER OH VALLEY. ANY SHEAR AXES ASSOCIATED WITH CONVECTION
OCCURRING ALONG THE STORM TRACK FROM THE GREAT LAKES INTO THE
NORTHERN MID ATLANTIC WOULD BRUSH OUR FAR NE COUNTIES.

AIR MASS WILL GRADUALLY MODIFY THIS PERIOD WITH AFTERNOON TEMPS
RETURNING TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS BY SUNDAY.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 825 PM SUNDAY...

MID LEVEL RIDGE AXIS (OF HIGH PRESSURE) IS CURRENTLY PUSHING TO THE
EAST OF THE AREA THIS EVENING. MEANWHILE... A WEAK DISTURBANCE IS
EXPECTED TO PUSH INTO THE AREA OVERNIGHT. THIS MAY ALLOW FOR SOME
SHOWERS TO MOVE INTO NORTHWESTERN PORTIONS OF CENTRAL NC VERY LATE
THIS EVENING/EARLY MONDAY MORNING. THUS... HAVE INCLUDED A TEMPO
GROUP FOR SHOWERS AND POSSIBLY MVFR CIGS AND VISBYS IN THE 06-09Z
TIME FRAME AT KGSO AND KINT. ELSEWHERE.... EXPECT VFR CONDITIONS
WILL CONTINUE THROUGH AT LEAST 12Z MONDAY. UNSETTLED WEATHER IS
EXPECTED ON MONDAY. FOR NOW WILL SHOW VFR CONDITIONS AT ALL TAF
SITES OUTSIDE OF THE NORTHWEST (KGSO/KINT)... AS CONFIDENCE IS NOT
HIGH ENOUGH OF SUB-VFR CONDITIONS OUTSIDE OF ANY SCATTERED SHOWERS
AND STORMS. HOWEVER... EXPECT WE MAY HAVE PERIODS OF SHOWERS AND
STORMS MID MORNING THROUGH THE LATE AFTERNOON (WEST)/REST OF THE 00Z
TAF PERIOD (EAST)... AND POSSIBLE MVFR/IFR CONDITIONS ASSOCIATED
WITH THE MOIST CONDITIONS AND WITH SHOWERS AND STORMS.

WE MAY BRIEFLY SEE A PERIOD OF DRY CONDITIONS MONDAY EVENING INTO
EARLY TUESDAY MORNING... BEFORE ADDITIONAL DISTURBANCES MOVE ACROSS
THE AREA ALONG WITH A WEAK COLD FRONT LATE TUESDAY THROUGH
WEDNESDAY. UNTIL THEN EXPECT PERIOD OF SHOWERS AND STORMS... WITH
POSSIBLE SUB-VFR CONDITIONS. VFR CONDITIONS ARE GENERALLY EXPECTED
FROM THURSDAY ONWARD... OUTSIDE OF POSSIBLY SOME EARLY MORNING
STRATUS AND OR FOG DURING THE PRE-DAWN HOURS OF EACH MORNING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...KMC/DJF
NEAR TERM...DJF
SHORT TERM...DJF/WSS
LONG TERM...WSS
AVIATION...BSD

000
FXUS62 KRAH 161850
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
250 PM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS EVENING...AHEAD OF AN UPPER
LEVEL DISTURBANCE THAT MOVES THROUGH THE REGION OVERNIGHT AND
MONDAY. A COLD FRONT SLOWLY APPROACHES FROM THE NORTHWEST LATE
MONDAY AND MOVES ACROSS THE REGION LATE TUESDAY INTO WEDNESDAY
MORNING.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 250 PM SUNDAY...

THE NAM AND THE GFS ARE FAIRLY SIMILAR ON THE FORECAST DETAILS
DURING THE NEAR-TERM PERIOD...WITH THE AIR MASS GRADUALLY MOISTENING
AHEAD OF A MODEST MID-LEVEL SHORTWAVE THAT BOTH MODELS MOVE THROUGH
CENTRAL NORTH CAROLINA OVERNIGHT AND MONDAY. THE 12Z RAOB ANALYSIS
SHOWED AMPLE 850MB MOISTURE TO OUR SOUTHWEST WITH WIDESPREAD DEW
POINT IN THE TEENS CELSIUS...AND OVERNIGHT THROUGH MONDAY BOTH THE
NAM AND THE GFS FORECAST PRECIPITABLE WATER VALUES INCREASING TO
AROUND TWO INCHES. THE GFS IS ACTUALLY AS HIGH AS 2.25 INCHES...BUT
THAT MAY END UP BEING OVERDONE. REGARDLESS...WITH A MOISTENING AIR
MASS AND CONTINUED COOLING ALOFT AS HAS BEEN A CONSISTENT FORECAST
PARAMETER OVER THE LAST SEVERAL MODEL RUNS...CHANCES FOR
PRECIPITATION SHOULD INCREASE. THE GUIDANCE HAS ACTUALLY BECOME
NOTICEABLY MORE BULLISH WITH PRECIPITATION CHANCES FROM LATE THIS
EVENING THROUGH MONDAY...WITH THE NAM MOS INTRODUCING CATEGORICAL
POPS INTO THE TRIAD TONIGHT AND GENERALLY LOW LIKELY POPS THROUGHOUT
CENTRAL NORTH CAROLINA FOR MONDAY. AT LEAST OVERNIGHT...OF CONCERN
IS THE CAP STILL IN PLACE OVER A GOOD PART OF CENTRAL NORTH CAROLINA
AT THE MOMENT...AND THE PRECIPITATION FROM THE NORTHWEST TRYING TO
PUSH SOUTHEAST TOWARD A LINGERING 850MB RIDGE. MUCH OF THE AVAILABLE
WRF GUIDANCE...MOSTLY FROM NCEP...SUGGESTS THAT UPSTREAM
PRECIPITATION MAY ACTUALLY WANE AS IT TRIES TO PUSH SOUTHEAST
OVERNIGHT. WHAT MAY INDEED END UP HAPPENING IS THAT THE HIGH POPS OF
THE NAM ARE CORRECT IN THE TRIAD FOR LOW-QPF PRECIPITATION...WITH
WHATEVER PRECIPITATION REMAINS MAKING DIFFICULT HEADWAY SOUTHEAST.
THE MID-LEVEL DISTURBANCE...AS FORECAST...APPEARS STRONG ENOUGH WITH
MID-LEVEL COOLING AND INCREASING MOISTURE TO WARRANT CHANCE POPS
OVER AREAS MAINLY NORTH OF A LINE FROM ABOUT KVUJ TO KETC TONIGHT...
SLIGHT CHANCES FOR MOST AREAS TO THE SOUTH...KEEPING AREAS DRY ALONG
AND SOUTH OF A LINE FROM KMEB TO KGSB. OVERNIGHT LOWS CONTINUE TO
WARM IN INCREASING MOISTURE AND CLOUDS...MID TO UPPER 60S.

MONDAY...THE MID-LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH CENTRAL
NORTH CAROLINA...LEAVING SOME SUBSIDENCE IN ITS WAKE LATE IN THE
DAY...MAINLY TOWARD THE TRIAD. THE NAM IS WEAKER WITH ITS
MIXED-LAYER CAPE...500-1000J/KG COMPARED TO THE 1000-1500J/KG OF THE
GFS. BOTH MODELS SHOW ONLY LIMITED DOWNDRAFT CAPE...MAINLY 200J/KG
OR LESS...UNDER WEAK 0-3KM SHEAR IN THE RANGE OF 15KT. 1000-500MB
LAPSE RATES ARE WEAK AS WELL...TO ABOUT 6C/KM BASED ON THE HIGHER
GFS. AS THE DISTURBANCE PASSES THROUGH WITH A WEAK SURFACE TROUGH IN
PLACE...WILL ESSENTIALLY CARRY HIGH CHANCE POPS FOR THE DAY...
CONFINING THOSE POPS MAINLY TO THE AFTERNOON IN THE FAR SOUTHEAST.
ANTICIPATING MORE CLOUDS...HAVE LOWERED MAXES FOR MONDAY TO THE
LOWER TO MID 80S.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM SUNDAY...

MONDAY NIGHT...BOTH THE NAM AND THE GFS FORECAST SOME SUBSIDENCE
BEHIND THE MID-LEVEL SHORTWAVE...PARTICULARLY FROM THE TRIANGLE
NORTHWEST AND NORTH OVERNIGHT. THIS MAY RESULT IN CHANCES FOR
PRECIPITATION BECOMING LIMITED IN THOSE AREAS. FARTHER SOUTH...
HIGHER MOISTURE AND INSTABILITY PERSISTS OVERNIGHT...WITH ANOTHER
MID-LEVEL SHORTWAVE SKIRTING THE AREA TO THE SOUTH. IF THIS
VERIFIES...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS COULD
LINGER INTO THE OVERNIGHT HOURS...ESPECIALLY ACROSS THE SANDHILLS
AND SOUTHERN COASTAL PLAIN. FOR THIS FORECAST...WILL SHOW A
DIMINISHING TREND TO PRECIPITATION CHANCES...ONLY SLIGHT CHANCE IN
THE TRIAD OVERNIGHT WITH CHANCES MAINLY ALONG AND SOUTH OF U.S. 64.
ONCE AGAIN...OVERNIGHT LOWS SHOULD BE WARM...WITHIN A DEGREE OR
THREE OF 70. -DJF

TUESDAY...A DAMPENING MID LEVEL S/W CROSSING CENTRAL NC DURING PRIME
HEATING SHOULD INTERACT WITH THE MOIST AND SLIGHTLY UNSTABLE AIR
MASS IN PLACE TO TRIGGER NUMEROUS-WIDESPREAD SHOWERS AND A FEW
T-STORMS...MAINLY TUESDAY AFTERNOON. LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED ALONG A SWD DRIFTING SFC BOUNDARY WILL LIFT ALOFT A RESULT
OF THE WEAKENING S/W AND 300MB JET CROSSING SOUTHERN NEW ENGLAND
PLACING CENTRAL NC IN THE FAVORABLE RIGHT ENTRANCE REGION. DYNAMICS
NOT OVERLY IMPRESSIVE THOUGH 30KTS OF BULK SHEAR OCCUR IN THE
AFTERNOON ACROSS THE NORTH AND MLCAPE (GFS) REACHES 1000-1400 J/KG
IN THE AFTERNOON. AS ELUDED TO IN PREVIOUS FORECAST...POTENTIAL FOR
SHOWERS/STORMS TO PASS REPEATEDLY OVER THE SAME LOCATION AS MEAN
FLOW PARALLEL TO THE SWD DRIFTING SFC BOUNDARY. THIS MAY LEAD TO
LOCALIZED FLOODING ISSUES...MAINLY IN URBAN AREAS. ANY UPDRAFTS ABLE
TO SUSTAIN MORE THAN 20 MINUTES MAY PRODUCE A WET MICROBURST BUT A
MARGINAL WIND PROFILE AND DEEP MOISTURE (LACK OF DRY AIR
ENTRAINMENT) SUGGEST ANY DAMAGING WINDS WILL BE QUITE ISOLATED.

TUESDAY NIGHT INTO WEDNESDAY...MID LEVEL TROUGH AND ASSOCIATED SFC
BOUNDARY DRIFT SE AND EXIT THE REGION TUESDAY EVENING. THIS SUGGEST
A GRADUAL DIMINISHING IN CONVECTIVE COVERAGE FROM THE NORTH TUESDAY.
ON WEDNESDAY...S/W IN THE ACTIVE NORTHERN STREAM WILL CROSS THE MID
ATLANTIC WEDNESDAY. THIS FEATURE WILL SEND ANOTHER SFC FRONT SWD
ACROSS CENTRAL NC ON WEDNESDAY. WEAK CONVERGENCE ALONG THIS BOUNDARY
COUPLED WITH MODEST UPPER AIR SUPPORT MAY TRIGGER/SUSTAIN
ISOLATED-SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY. COVERAGE
APPEARS TO BE BETTER SOUTH VERSUS NORTH AS AIR MASS ACROSS THE NORTH
WILL BE DRIER AND MORE STABLE.

HIGH TEMPERATURES TUESDAY DEPENDENT ON CONVECTIVE COVERAGE. IF
WIDESPREAD CONVECTION OCCURS SOONER THAN ANTICIPATED...MAX TEMPS MAY
BE 3-4 DEGREES TOO WARM. A SFC N-NE FLOW WILL SLOWLY ADVECT COOLER
AIR INTO CENTRAL NC WEDNESDAY. LOW LEVEL THICKNESSES SUPPORT MAX
TEMPS NEAR 80-LOWER 80S. -WSS

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SURFACE RIDGE WILL
STRENGTHEN OVER CENTRAL NC. RESULTANT LOW LEVEL NE FLOW WILL
MAINTAIN A RELATIVELY COOL AND STABLE AIR MASS OVER THE BULK OF
CENTRAL NC. THE EXCEPTION WILL BE THE FAR SOUTH AND WEST AS ENOUGH
LIFT/MOISTURE MAY EXIST AROUND THE PERIPHERY OF THE RIDGE TO PERMIT
ISOLATED CONVECTION TO OCCUR. AFTERNOON TEMPS THURSDAY WILL AGAIN
AVERAGE A FEW DEGREES BELOW NORMAL WITH MOST SPOTS IN THE LOWER 80S.
MIN TEMPS BOTH NIGHTS IN THE LOW-MID 60S.

FRI-SUN:  MEDIUM RANGE GUIDANCE DIFFER IN THE UPPER AIR PATTERN OVER
THE CAROLINAS AT THE END OF THE WEEK. GFS DEPICTION OF A SERIES OF
S/W CROSSING THE OH VALLEY INTO THE NORTHERN MID ATLANTIC EXTENDING
SWD INTO CENTRAL NC  FRI-SAT WOULD SUGGEST A THREAT OF SCATTERED
CONVECTION OVER OUR REGION. MEANWHILE...ECMWF DEPICTS AN ELONGATED
UPPER LEVEL LOW/SHEAR AXIS OFF THE SE U.S. COAST THAT MOVES LITTLE
FRI-SAT. THIS FEATURE ALONG WITH THE MAIN STORM TRACK ACROSS THE
LOWER GREAT LAKES INTO THE NORTHERN MID ATLANTIC PERMITS A NARROW
RIDGE OF HIGH PRESSURE TO EXTEND ACROSS THE CAROLINAS FROM AN
ANTI-CYCLONE POSITIONED OVER THE SOUTHERN PLAINS/LOWER MS VALLEY.
THIS SCENARIO WOULD KEEP CENTRAL NC DRY FRI AND SAT. DIFFICULT TO
SAY AT THIS TIME WHICH SCENARIO MOST LIKELY TO VERIFY AS EACH
SCENARIO HAS AN EQUAL CHANCE TO VERIFY. BY SUNDAY....MODEL CONSENSUS
KEYS ON UPPER RIDGE EXPANDING EWD INTO THE CAROLINAS FROM THE
TN-LOWER OH VALLEY. ANY SHEAR AXES ASSOCIATED WITH CONVECTION
OCCURRING ALONG THE STORM TRACK FROM THE GREAT LAKES INTO THE
NORTHERN MID ATLANTIC WOULD BRUSH OUR FAR NE COUNTIES.

AIR MASS WILL GRADUALLY MODIFY THIS PERIOD WITH AFTERNOON TEMPS
RETURNING TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS BY SUNDAY.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 210 PM SUNDAY...

SOMEWHAT CHALLENGING TAF FORECAST...DEPENDENT ON HOW MUCH
PRECIPITATION IS ABLE TO MAKE IT SOUTHEAST INTO THE SLIGHTLY MORE
CAPPED AIR MASS. OVERNIGHT...EXPECT A HIGH PROBABILITY OF VFR
CONDITIONS...WITH A CHANCE OF A PERIOD OF MVFR CONDITIONS IN
SCATTERED SHOWERS. THE CHANCES FOR AREAS OF MVFR CONDITIONS IMPROVE
LATE TONIGHT AND MONDAY...IN AT LEAST SCATTERED AREAS OF SHOWERS AND
WIDELY SCATTERED THUNDERSTORMS. SREF PROBABILITIES OF IFR CONDITIONS
ARE CURRENTLY LOW AND WILL SHOW CENTRAL NORTH CAROLINA TAF SITES
ONLY GETTING AS LOW AS MVFR DURING THE 18Z VALID TAF PERIOD.
MODESTLY GUSTY SOUTHWEST SURFACE WINDS THIS AFTERNOON WILL DIMINISH
TO MAINLY 5 TO 10KT OVERNIGHT...HOWEVER...DURING THE OVERNIGHT
PERIOD WINDS WITHIN 3K FEET OF THE SURFACE SHOULD INCREASE TO 25 TO
30KT...WITH WINDS AT THAT LEVEL DIMINISHING TOWARD 12Z MONDAY.
BEYOND THE 18Z VALID TAF PERIOD...GOOD PROBABILITY OF PERIODS OF
SUB-VFR CONDITIONS MONDAY AFTERNOON THROUGH TUESDAY IN LOW CLOUDS
AND SCATTERED-TO-NUMEROUS SHOWERS AND THUNDERSTORMS. CONDITIONS
BECOME PRIMARILY VFR WEDNESDAY THROUGH FRIDAY...OUTSIDE OF ANY
REMAINING ISOLATED SHOWERS AND THUNDERSTORMS.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...KMC/DJF
NEAR TERM...DJF
SHORT TERM...DJF/WSS
LONG TERM...WSS
AVIATION...DJF

000
FXUS62 KRAH 161809
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
210 PM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS EVENING...AHEAD OF AN UPPER
LEVEL DISTURBANCE THAT MOVES THROUGH THE REGION OVERNIGHT AND
MONDAY. A COLD FRONT SLOWLY APPROACHES FROM THE NORTHWEST LATE
MONDAY AND MOVES ACROSS THE REGION LATE TUESDAY INTO WEDNESDAY
MORNING.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1150 AM SUNDAY...

THE UPPER RIDGE WILL CONTINUE TO FLATTEN TODAY AS SURFACE HIGH
PRESSURE CONTINUES TO MOVE OFF TO THE SOUTHEAST...AND THE GRADIENT
TIGHTENS BETWEEN THE RETREATING HIGH AND SURFACE TROUGHINESS
SHARPENING OVER THE WESTERN PART OF THE STATE. THE 12Z KGSO
SOUNDING...AS WELL AS THE SOUNDING FROM KMHX...SHOWED A DECENT CAP
REMAINING AROUND 700MB...WHILE THE KRNK SOUNDING INDICATED JUST
SLIGHTLY COOLER TEMPERATURES JUST ABOVE 700MB ALBEIT WITH A WEAK CAP
IN PLACE. THE RAP SOUNDINGS FORECAST THIS CAP ESSENTIALLY REMAINING
FOR THE REST OF THE DAY...VERY GRADUALLY DIMINISHING ESPECIALLY
TOWARD THE NORTHWEST PIEDMONT AS THE RIDGE FLATTENS...UPPER LEVELS
COOL...AND THE OVERALL MOISTURE OF THE AIR MASS INCREASES. THE RAP
FORECASTS 850MB SUBSIDENCE THROUGHOUT THE DAY...WITH ANY MODEST UVV
WITH APPROACHING MID-LEVEL SHORTWAVES HOLDING OFF UNTIL 00Z AND
AFTER. THE LATEST HRRR WRF IS DRY AS WELL...ALONG WITH QPF FROM THE
RAP. WILL CONTINUE WITH A DRY FORECAST TODAY...AND EXPECT PERIODS OF
MOSTLY MID- AND SOME HIGH-LEVEL CLOUDS TO RESULT IN A
PARTLY-TO-MOSTLY SUNNY LATE MORNING AND AFTERNOON. ALREADY THERE
HAVE BEEN A FEW WIND GUSTS IN THE TEENS KNOTS AND...BASED ON THE
LATEST RAP SOUNDINGS AND THE WINDS ALOFT ON THE KRAX 88D VAD WIND
PROFILE...INCREASED THE GUSTS A TRIFLE ESPECIALLY OUTSIDE OF
SOUTHEAST AREAS TO MORE AROUND 20KT. WHILE THE MAV MOS HAS SIMPLY
BEEN TOO WARM OF LATE...THE MET MOS IS CLOSER TODAY TO THE MAV AND
TO THE ONGOING FORECAST. LOWERED A DEGREE TOWARD KRWI BASED ON THE
LATEST TRENDS AND MOS...AND AS A RESULT OF SLIGHTLY COOLER
1000-850MB THICKNESSES COMPARED TO THE REST OF CENTRAL NORTH
CAROLINA. STILL...HIGHS 85 TO 90.

THE VERY LATEST GUIDANCE HAS BEEN A LITTLE MORE AGGRESSIVE WITH THE
POTENTIAL FOR AT LEAST LIGHT QPF MOVING IN A LITTLE MORE IN EARNEST
INTO NORTHERN AREAS OVERNIGHT...MAINLY AFTER 02Z OR SO. MID-LEVEL
COOLING AND OVERALL MOISTENING ON THE NAM IS EFFICIENT OVERNIGHT...
AND THE LATEST HRRR WRF SUGGESTS UPSTREAM PRECIPITATION CURRENTLY
OVER SOUTHERN ILLINOIS INTO KENTUCKY ABLE TO MAKE STEADY PROGRESS
EAST-SOUTHEAST INTO AT LEAST THE TRIAD AND TOWARD KTDF AS
MOISTENING...AND COOLING ALOFT...OCCUR. FOR THE LATE MORNING
UPDATE...RAISED POPS INTO CHANCE FOR THAT AREA. WILL NOTE THE LATEST
NAM MOS GUIDANCE IS INTO CATEGORICAL IN THE TRIAD FOR THE OVERNIGHT
HOURS...DIMINISHING BUT STILL HIGHER ELSEWHERE. AFTER A REVIEW OF
THE GFS...MAY NEED TO SHOW SOME FURTHER INCREASE FOR MANY PARTS OF
CENTRAL NORTH CAROLINA OVERNIGHT. OTHERWISE...CLOUDINESS...AGAIN
MAINLY MID AND UPPER...WILL BECOME PREVALENT TONIGHT AS THE
APPROACHING FRONT TRANSLATES INTO THE LEE TROUGH. MINS WILL BE MILD
AND SEASONABLE...UPPER 60S.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM SUNDAY...

MONDAY AND MONDAY NIGHT...TRANSITION TO A BROAD LONGWAVE TROF WILL
BE UNDERWAY AND THE LINGERING LOW LEVEL TROFFING ALONG THE ATLANTIC
SEABOARD WILL PROMOTE AN INCREASINGLY MOIST AIRMASS. THICKNESSES ARE
RELATIVELY HIGH AND SIMILAR TO SUNDAY...WITH THE POTENTIAL FOR UPPER
80S. MOSTLY CLOUDY SKIES WILL HAMPER INSOLATION A BIT...MOSTLY MID
80S WEST TO UPPER 80S EAST. CHANCES OF SHOWERS WILL INCREASE MONDAY
AFTERNOON INTO MONDAY NIGHT IN INCREASINGLY DISTURBED FLOW...BUT ITS
DIFFICULT TO PICK OUT A PARTICULAR FEATURE DURING THIS TIME FRAME TO
FOCUS ACTIVITY...WILL CONTINUE CHANCE CATEGORY POPS FAVORING THE
WEST AND NORTH.

TUESDAY AND TUESDAY NIGHT: WITHIN A BROAD TROUGH ALOFT EAST OF THE
ROCKIES...A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE TROUGH...AND
PERHAPS A PRECEDING MCV FROM CONVECTION INITIATED AHEAD OF THIS WAVE
OVER THE CENTRAL PLAINS LATER TODAY AND TONIGHT...WILL MIGRATE
THROUGH THE BASE OF THE TROUGH/ACROSS THE CENTRAL APPALACHIANS AND
MIDDLE ATLANTIC REGION TUE. THESE FEATURES WILL BE FOLLOWED QUICKLY
BY AN ELONGATED BUT STRONGER NORTHERN STREAM WAVE IN NW FLOW FROM
THE UPPER MIDWEST TO THE CENTRAL APPALACHIANS TUE NIGHT.

IN THE LOW LEVELS...A PRE-FRONTAL TROUGH OVER VA/NC TUE WILL BE
OVERTAKEN BY A COLD FRONT ATTENDING THE AFOREMENTIONED NORTHERN
STREAM S/W TROUGH...AND THIS MERGED BOUNDARY WILL SETTLE SOUTHWARD
ACROSS CENTRAL NC TUE NIGHT. WITH A CONDITIONALLY UNSTABLE AND
UNCAPPED ENVIRONMENT PER BUFR SOUNDINGS...AND WITH FORECAST
PRECIPITABLE WATER VALUES APPROACHING TWO INCHES...THE WEAK (~20
METER/12 HR) HEIGHT FALLS ASSOCIATED WITH THE SERIES OF DISTURBANCES
ALOFT AND LOW LEVEL CONVERGENCE ALONG THE PRE-FRONTAL TROUGH/FRONT
WILL SUPPORT THE DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND
STORMS TUE. THE SLOW SOUTHWARD PASSAGE OF THE SURFACE FRONT WILL END
THE THREAT OF CONVECTION FROM NORTH TO SOUTH TUE EVENING AND
OVERNIGHT...WITH JUST A LINGERING CHANCE OF A FEW SHOWERS ALONG THE
FAR SOUTHERN TIER BY WED MORNING.

WHILE WSW MEAN FLOW ALIGNED PARALLEL TO THE UNDERLYING SURFACE FRONT
SUGGESTS DOWNPOURS/ LOCALIZED FLOODING IN TRAINING STORMS ALONG THE
BOUNDARY MAY PROVIDE THE GREATEST IMPACT...INCREASING MID LEVEL
FLOW/BULK SHEAR TO AROUND 30 KTS MAY ALSO SUPPORT MULTI-CELL STORM
ORGANIZATION WITH PRECIPITATION-LOADED STRONG WET MICROBURST WIND
GUSTS. IN ADDITION...FORECAST MAXIMUM SRH AROUND 100 M2/S2 COULD BE
NEARLY DOUBLED LOCALLY INVOF OUTFLOW/BACKED SURFACE FLOW...WHICH
COULD SUPPORT BRIEF SUPERCELLULAR STRUCTURES...THOUGH SUCH A
SCENARIO WILL BE DEPENDENT ON MESO AND STORM SCALE INFLUENCES WITH
LIMITED PREDICTABILITY BEYOND A FEW HOURS. AS SUCH...WILL INCLUDE
ONLY A GENERIC ONE SENTENCE MENTION OF A STRONG TO SEVERE STORM IN
THE HWO FOR NOW FOR TUE. MOSTLY CLOUDY AND STORMY CONDITIONS WILL
SUPPORT HIGHS FROM THE UPPER 70S NW...TO LOWER TO MIDDLE 80S OVER
THE SOUTH...WITH LOWS MOSTLY IN THE UPPER 60S...TO AROUND 70 DEGREES
SOUTH.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 255 AM SUNDAY...

WEDNESDAY THROUGH SATURDAY: BELOW AVERAGE TEMPERATURES - IN THE
UPPER 70S TO LOWER-MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE
AND ASSOCIATED GENERALLY EAST TO ENE LOW LEVEL FLOW...WILL THEN
PREVAIL THROUGH THE END OF THE WEEK. HOWEVER...THE SURFACE FRONT
WILL LIKELY LINGER OVER SC THROUGH THU GIVEN CONTINUED FRONT-
PARALLEL FLOW ALOFT IN THE BASE OF BROAD EASTERN CONUS TROUGH. WILL
ACCORDINGLY MAINTAIN A SLIGHT CHANCE OF A SHOWER OR STORM OVER THE
FAR SOUTHERN SANDHILLS AND COASTAL PLAIN...IN CLOSEST PROXIMITY TO
THIS FRONT AND HIGHER BL MOISTURE...AND ALSO TOWARD THE YADKIN RIVER
WHERE A FEW WEAKENING SHOWERS/STORMS MAY DRIFT AFTER INITIATION AND
PROPAGATION FROM THE EASTERN SLOPES. A WARMER SOUTHEASTERLY...TO
SOUTHERLY RETURN FLOW BY SATURDAY...WILL RESULT IN RISING
TEMPERATURES TO AROUND THE 30-YEAR AVERAGE...AND HUMIDITY
LEVELS...BY THE WEEKEND. A RISK OF A FEW LATE AFTERNOON PULSE
SHOWERS OR STORMS WILL CONSEQUENTLY INCREASE TO NEAR CLIMATOLOGICAL
PROBABILITIES...AROUND 20 PERCENT OR SO...BY SAT.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 210 PM SUNDAY...

SOMEWHAT CHALLENGING TAF FORECAST...DEPENDENT ON HOW MUCH
PRECIPITATION IS ABLE TO MAKE IT SOUTHEAST INTO THE SLIGHTLY MORE
CAPPED AIR MASS. OVERNIGHT...EXPECT A HIGH PROBABILITY OF VFR
CONDITIONS...WITH A CHANCE OF A PERIOD OF MVFR CONDITIONS IN
SCATTERED SHOWERS. THE CHANCES FOR AREAS OF MVFR CONDITIONS IMPROVE
LATE TONIGHT AND MONDAY...IN AT LEAST SCATTERED AREAS OF SHOWERS AND
WIDELY SCATTERED THUNDERSTORMS. SREF PROBABILITIES OF IFR CONDITIONS
ARE CURRENTLY LOW AND WILL SHOW CENTRAL NORTH CAROLINA TAF SITES
ONLY GETTING AS LOW AS MVFR DURING THE 18Z VALID TAF PERIOD.
MODESTLY GUSTY SOUTHWEST SURFACE WINDS THIS AFTERNOON WILL DIMINISH
TO MAINLY 5 TO 10KT OVERNIGHT...HOWEVER...DURING THE OVERNIGHT
PERIOD WINDS WITHIN 3K FEET OF THE SURFACE SHOULD INCREASE TO 25 TO
30KT...WITH WINDS AT THAT LEVEL DIMINISHING TOWARD 12Z MONDAY.
BEYOND THE 18Z VALID TAF PERIOD...GOOD PROBABILITY OF PERIODS OF
SUB-VFR CONDITIONS MONDAY AFTERNOON THROUGH TUESDAY IN LOW CLOUDS
AND SCATTERED-TO-NUMEROUS SHOWERS AND THUNDERSTORMS. CONDITIONS
BECOME PRIMARILY VFR WEDNESDAY THROUGH FRIDAY...OUTSIDE OF ANY
REMAINING ISOLATED SHOWERS AND THUNDERSTORMS.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...KMC/DJF
NEAR TERM...DJF/MLM
SHORT TERM...MLM/MWS
LONG TERM...MWS
AVIATION...DJF

000
FXUS62 KRAH 161551
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1151 AM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER OUR REGION TODAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST MONDAY AND MOVE ACROSS OUR REGION LATE
TUESDAY INTO EARLY WEDNESDAY MORNING.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1150 AM SUNDAY...

THE UPPER RIDGE WILL CONTINUE TO FLATTEN TODAY AS SURFACE HIGH
PRESSURE CONTINUES TO MOVE OFF TO THE SOUTHEAST...AND THE GRADIENT
TIGHTENS BETWEEN THE RETREATING HIGH AND SURFACE TROUGHINESS
SHARPENING OVER THE WESTERN PART OF THE STATE. THE 12Z KGSO
SOUNDING...AS WELL AS THE SOUNDING FROM KMHX...SHOWED A DECENT CAP
REMAINING AROUND 700MB...WHILE THE KRNK SOUNDING INDICATED JUST
SLIGHTLY COOLER TEMPERATURES JUST ABOVE 700MB ALBEIT WITH A WEAK CAP
IN PLACE. THE RAP SOUNDINGS FORECAST THIS CAP ESSENTIALLY REMAINING
FOR THE REST OF THE DAY...VERY GRADUALLY DIMINISHING ESPECIALLY
TOWARD THE NORTHWEST PIEDMONT AS THE RIDGE FLATTENS...UPPER LEVELS
COOL...AND THE OVERALL MOISTURE OF THE AIR MASS INCREASES. THE RAP
FORECASTS 850MB SUBSIDENCE THROUGHOUT THE DAY...WITH ANY MODEST UVV
WITH APPROACHING MID-LEVEL SHORTWAVES HOLDING OFF UNTIL 00Z AND
AFTER. THE LATEST HRRR WRF IS DRY AS WELL...ALONG WITH QPF FROM THE
RAP. WILL CONTINUE WITH A DRY FORECAST TODAY...AND EXPECT PERIODS OF
MOSTLY MID- AND SOME HIGH-LEVEL CLOUDS TO RESULT IN A
PARTLY-TO-MOSTLY SUNNY LATE MORNING AND AFTERNOON. ALREADY THERE
HAVE BEEN A FEW WIND GUSTS IN THE TEENS KNOTS AND...BASED ON THE
LATEST RAP SOUNDINGS AND THE WINDS ALOFT ON THE KRAX 88D VAD WIND
PROFILE...INCREASED THE GUSTS A TRIFLE ESPECIALLY OUTSIDE OF
SOUTHEAST AREAS TO MORE AROUND 20KT. WHILE THE MAV MOS HAS SIMPLY
BEEN TOO WARM OF LATE...THE MET MOS IS CLOSER TODAY TO THE MAV AND
TO THE ONGOING FORECAST. LOWERED A DEGREE TOWARD KRWI BASED ON THE
LATEST TRENDS AND MOS...AND AS A RESULT OF SLIGHTLY COOLER
1000-850MB THICKNESSES COMPARED TO THE REST OF CENTRAL NORTH
CAROLINA. STILL...HIGHS 85 TO 90.

THE VERY LATEST GUIDANCE HAS BEEN A LITTLE MORE AGGRESSIVE WITH THE
POTENTIAL FOR AT LEAST LIGHT QPF MOVING IN A LITTLE MORE IN EARNEST
INTO NORTHERN AREAS OVERNIGHT...MAINLY AFTER 02Z OR SO. MID-LEVEL
COOLING AND OVERALL MOISTENING ON THE NAM IS EFFICIENT OVERNIGHT...
AND THE LATEST HRRR WRF SUGGESTS UPSTREAM PRECIPITATION CURRENTLY
OVER SOUTHERN ILLINOIS INTO KENTUCKY ABLE TO MAKE STEADY PROGRESS
EAST-SOUTHEAST INTO AT LEAST THE TRIAD AND TOWARD KTDF AS
MOISTENING...AND COOLING ALOFT...OCCUR. FOR THE LATE MORNING
UPDATE...RAISED POPS INTO CHANCE FOR THAT AREA. WILL NOTE THE LATEST
NAM MOS GUIDANCE IS INTO CATEGORICAL IN THE TRIAD FOR THE OVERNIGHT
HOURS...DIMINISHING BUT STILL HIGHER ELSEWHERE. AFTER A REVIEW OF
THE GFS...MAY NEED TO SHOW SOME FURTHER INCREASE FOR MANY PARTS OF
CENTRAL NORTH CAROLINA OVERNIGHT. OTHERWISE...CLOUDINESS...AGAIN
MAINLY MID AND UPPER...WILL BECOME PREVALENT TONIGHT AS THE
APPROACHING FRONT TRANSLATES INTO THE LEE TROUGH. MINS WILL BE MILD
AND SEASONABLE...UPPER 60S.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM SUNDAY...

MONDAY AND MONDAY NIGHT...TRANSITION TO A BROAD LONGWAVE TROF WILL
BE UNDERWAY AND THE LINGERING LOW LEVEL TROFFING ALONG THE ATLANTIC
SEABOARD WILL PROMOTE AN INCREASINGLY MOIST AIRMASS. THICKNESSES ARE
RELATIVELY HIGH AND SIMILAR TO SUNDAY...WITH THE POTENTIAL FOR UPPER
80S. MOSTLY CLOUDY SKIES WILL HAMPER INSOLATION A BIT...MOSTLY MID
80S WEST TO UPPER 80S EAST. CHANCES OF SHOWERS WILL INCREASE MONDAY
AFTERNOON INTO MONDAY NIGHT IN INCREASINGLY DISTURBED FLOW...BUT ITS
DIFFICULT TO PICK OUT A PARTICULAR FEATURE DURING THIS TIME FRAME TO
FOCUS ACTIVITY...WILL CONTINUE CHANCE CATEGORY POPS FAVORING THE
WEST AND NORTH.

TUESDAY AND TUESDAY NIGHT: WITHIN A BROAD TROUGH ALOFT EAST OF THE
ROCKIES...A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE TROUGH...AND
PERHAPS A PRECEDING MCV FROM CONVECTION INITIATED AHEAD OF THIS WAVE
OVER THE CENTRAL PLAINS LATER TODAY AND TONIGHT...WILL MIGRATE
THROUGH THE BASE OF THE TROUGH/ACROSS THE CENTRAL APPALACHIANS AND
MIDDLE ATLANTIC REGION TUE. THESE FEATURES WILL BE FOLLOWED QUICKLY
BY AN ELONGATED BUT STRONGER NORTHERN STREAM WAVE IN NW FLOW FROM
THE UPPER MIDWEST TO THE CENTRAL APPALACHIANS TUE NIGHT.

IN THE LOW LEVELS...A PRE-FRONTAL TROUGH OVER VA/NC TUE WILL BE
OVERTAKEN BY A COLD FRONT ATTENDING THE AFOREMENTIONED NORTHERN
STREAM S/W TROUGH...AND THIS MERGED BOUNDARY WILL SETTLE SOUTHWARD
ACROSS CENTRAL NC TUE NIGHT. WITH A CONDITIONALLY UNSTABLE AND
UNCAPPED ENVIRONMENT PER BUFR SOUNDINGS...AND WITH FORECAST
PRECIPITABLE WATER VALUES APPROACHING TWO INCHES...THE WEAK (~20
METER/12 HR) HEIGHT FALLS ASSOCIATED WITH THE SERIES OF DISTURBANCES
ALOFT AND LOW LEVEL CONVERGENCE ALONG THE PRE-FRONTAL TROUGH/FRONT
WILL SUPPORT THE DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND
STORMS TUE. THE SLOW SOUTHWARD PASSAGE OF THE SURFACE FRONT WILL END
THE THREAT OF CONVECTION FROM NORTH TO SOUTH TUE EVENING AND
OVERNIGHT...WITH JUST A LINGERING CHANCE OF A FEW SHOWERS ALONG THE
FAR SOUTHERN TIER BY WED MORNING.

WHILE WSW MEAN FLOW ALIGNED PARALLEL TO THE UNDERLYING SURFACE FRONT
SUGGESTS DOWNPOURS/ LOCALIZED FLOODING IN TRAINING STORMS ALONG THE
BOUNDARY MAY PROVIDE THE GREATEST IMPACT...INCREASING MID LEVEL
FLOW/BULK SHEAR TO AROUND 30 KTS MAY ALSO SUPPORT MULTI-CELL STORM
ORGANIZATION WITH PRECIPITATION-LOADED STRONG WET MICROBURST WIND
GUSTS. IN ADDITION...FORECAST MAXIMUM SRH AROUND 100 M2/S2 COULD BE
NEARLY DOUBLED LOCALLY INVOF OUTFLOW/BACKED SURFACE FLOW...WHICH
COULD SUPPORT BRIEF SUPERCELLULAR STRUCTURES...THOUGH SUCH A
SCENARIO WILL BE DEPENDENT ON MESO AND STORM SCALE INFLUENCES WITH
LIMITED PREDICTABILITY BEYOND A FEW HOURS. AS SUCH...WILL INCLUDE
ONLY A GENERIC ONE SENTENCE MENTION OF A STRONG TO SEVERE STORM IN
THE HWO FOR NOW FOR TUE. MOSTLY CLOUDY AND STORMY CONDITIONS WILL
SUPPORT HIGHS FROM THE UPPER 70S NW...TO LOWER TO MIDDLE 80S OVER
THE SOUTH...WITH LOWS MOSTLY IN THE UPPER 60S...TO AROUND 70 DEGREES
SOUTH.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 255 AM SUNDAY...

WEDNESDAY THROUGH SATURDAY: BELOW AVERAGE TEMPERATURES - IN THE
UPPER 70S TO LOWER-MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE
AND ASSOCIATED GENERALLY EAST TO ENE LOW LEVEL FLOW...WILL THEN
PREVAIL THROUGH THE END OF THE WEEK. HOWEVER...THE SURFACE FRONT
WILL LIKELY LINGER OVER SC THROUGH THU GIVEN CONTINUED FRONT-
PARALLEL FLOW ALOFT IN THE BASE OF BROAD EASTERN CONUS TROUGH. WILL
ACCORDINGLY MAINTAIN A SLIGHT CHANCE OF A SHOWER OR STORM OVER THE
FAR SOUTHERN SANDHILLS AND COASTAL PLAIN...IN CLOSEST PROXIMITY TO
THIS FRONT AND HIGHER BL MOISTURE...AND ALSO TOWARD THE YADKIN RIVER
WHERE A FEW WEAKENING SHOWERS/STORMS MAY DRIFT AFTER INITIATION AND
PROPAGATION FROM THE EASTERN SLOPES. A WARMER SOUTHEASTERLY...TO
SOUTHERLY RETURN FLOW BY SATURDAY...WILL RESULT IN RISING
TEMPERATURES TO AROUND THE 30-YEAR AVERAGE...AND HUMIDITY
LEVELS...BY THE WEEKEND. A RISK OF A FEW LATE AFTERNOON PULSE
SHOWERS OR STORMS WILL CONSEQUENTLY INCREASE TO NEAR CLIMATOLOGICAL
PROBABILITIES...AROUND 20 PERCENT OR SO...BY SAT.

&&

.AVIATION /14Z SUNDAY THROUGH FRIDAY/...
AS OF 930 AM SUNDAY...

VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. SOUTHWEST WINDS
WILL BE INCREASING AHEAD OF AN APPROACHING FRONT...WITH 10-12KTS
SUSTAINED TODAY WITH GUSTS TO 20-22KTS FROM LATE MORNING THROUGH THE
AFTERNOON. MID LEVEL FLOW WILL BECOME MORE WESTERLY AND ALTOCUMULUS
WILL CONTINUE TO BE ON THE INCREASE TONIGHT. A DISTURBANCE MOVING
INTO THE NORTHWEST WILL GRAZE ACROSS THE NORTHERN TIER OF THE
AREA...PRODUCING A CHANCE OF SHOWERS MAINLY IN THE GSO/INT VICINITY
AFTER 06Z.

IN THE LONGER RANGE...THE APPROACHING FRONT WILL STALL ACROSS THE
AREA LATER MONDAY THROUGH TUESDAY...WITH MVFR/IFR CONDITIONS AND
INCREASING COVERAGE OF SHOWERS/STORMS. VFR CONDITIONS WILL RETURN
BEHIND THE FRONT LATE TUESDAY NIGHT AND DOMINATE THROUGH FRIDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...KMC
NEAR TERM...DJF/MLM
SHORT TERM...MLM/MWS
LONG TERM...MWS
AVIATION...DJF/MLM

000
FXUS62 KRAH 161331
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
931 AM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER OUR REGION TODAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST MONDAY AND MOVE ACROSS OUR REGION LATE
TUESDAY INTO EARLY WEDNESDAY MORNING.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...

THE UPPER RIDGE WILL CONTINUE TO FLATTEN TODAY AS SURFACE HIGH
PRESSURE CONTINUES TO MOVE OFF TO THE SOUTHEAST...AND THE GRADIENT
TIGHTENS BETWEEN THE RETREATING HIGH AND SURFACE TROUGHINESS
SHARPENING OVER THE WESTERN PART OF THE STATE. THE 12Z KGSO
SOUNDING...AS WELL AS THE SOUNDING FROM KMHX...SHOWED A DECENT CAP
REMAINING AROUND 700MB...WHILE THE KRNK SOUNDING INDICATED JUST
SLIGHTLY COOLER TEMPERATURES JUST ABOVE 700MB ALBEIT WITH A WEAK CAP
IN PLACE. THE RAP SOUNDINGS FORECAST THIS CAP ESSENTIALLY REMAINING
FOR THE REST OF THE DAY...VERY GRADUALLY DIMINISHING ESPECIALLY
TOWARD THE NORTHWEST PIEDMONT AS THE RIDGE FLATTENS...UPPER LEVELS
COOL...AND THE OVERALL MOISTURE OF THE AIR MASS INCREASES. THE RAP
FORECASTS 850MB SUBSIDENCE THROUGHOUT THE DAY...WITH ANY MODEST UVV
WITH APPROACHING MID-LEVEL SHORTWAVES HOLDING OFF UNTIL 00Z AND
AFTER. THE LATEST HRRR WRF IS DRY AS WELL...ALONG WITH QPF FROM THE
RAP. WILL CONTINUE WITH A DRY FORECAST TODAY...AND EXPECT PERIODS OF
MOSTLY MID- AND SOME HIGH-LEVEL CLOUDS TO RESULT IN A
PARTLY-TO-MOSTLY SUNNY LATE MORNING AND AFTERNOON. ALREADY THERE
HAVE BEEN A FEW WIND GUSTS IN THE TEENS KNOTS AND...BASED ON THE
LATEST RAP SOUNDINGS AND THE WINDS ALOFT ON THE KRAX 88D VAD WIND
PROFILE...INCREASED THE GUSTS A TRIFLE ESPECIALLY OUTSIDE OF
SOUTHEAST AREAS TO MORE AROUND 20KT. WHILE THE MAV MOS HAS SIMPLY
BEEN TOO WARM OF LATE...THE MET MOS IS CLOSER TODAY TO THE MAV AND
TO THE ONGOING FORECAST. LOWERED A DEGREE TOWARD KRWI BASED ON THE
LATEST TRENDS AND MOS...AND AS A RESULT OF SLIGHTLY COOLER
1000-850MB THICKNESSES COMPARED TO THE REST OF CENTRAL NORTH
CAROLINA. STILL...HIGHS 85 TO 90.

CLOUDINESS...AGAIN MAINLY MID AND UPPER...WILL BECOME PREVALENT
TONIGHT AS THE APPROACHING FRONT TRANSLATES INTO THE LEE TROUGH.
RAIN CHANCES ARE SMALL AND WILL BE MAINLY ACROSS THE NORTHERN TIER
WHICH WILL BE SKIRTED BY THE REMNANT OF A WEAKENING VORT MAX INDUCED
BY DEEP CONVECTION OVER THE OHIO VALLEY EARLY THIS MORNING. MINS
WILL BE MILD AND SEASONABLE...UPPER 60S.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM SUNDAY...

MONDAY AND MONDAY NIGHT...TRANSITION TO A BROAD LONGWAVE TROF WILL
BE UNDERWAY AND THE LINGERING LOW LEVEL TROFFING ALONG THE ATLANTIC
SEABOARD WILL PROMOTE AN INCREASINGLY MOIST AIRMASS. THICKNESSES ARE
RELATIVELY HIGH AND SIMILAR TO SUNDAY...WITH THE POTENTIAL FOR UPPER
80S. MOSTLY CLOUDY SKIES WILL HAMPER INSOLATION A BIT...MOSTLY MID
80S WEST TO UPPER 80S EAST. CHANCES OF SHOWERS WILL INCREASE MONDAY
AFTERNOON INTO MONDAY NIGHT IN INCREASINGLY DISTURBED FLOW...BUT ITS
DIFFICULT TO PICK OUT A PARTICULAR FEATURE DURING THIS TIME FRAME TO
FOCUS ACTIVITY...WILL CONTINUE CHANCE CATEGORY POPS FAVORING THE
WEST AND NORTH.

TUESDAY AND TUESDAY NIGHT: WITHIN A BROAD TROUGH ALOFT EAST OF THE
ROCKIES...A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE TROUGH...AND
PERHAPS A PRECEDING MCV FROM CONVECTION INITIATED AHEAD OF THIS WAVE
OVER THE CENTRAL PLAINS LATER TODAY AND TONIGHT...WILL MIGRATE
THROUGH THE BASE OF THE TROUGH/ACROSS THE CENTRAL APPALACHIANS AND
MIDDLE ATLANTIC REGION TUE. THESE FEATURES WILL BE FOLLOWED QUICKLY
BY AN ELONGATED BUT STRONGER NORTHERN STREAM WAVE IN NW FLOW FROM
THE UPPER MIDWEST TO THE CENTRAL APPALACHIANS TUE NIGHT.

IN THE LOW LEVELS...A PRE-FRONTAL TROUGH OVER VA/NC TUE WILL BE
OVERTAKEN BY A COLD FRONT ATTENDING THE AFOREMENTIONED NORTHERN
STREAM S/W TROUGH...AND THIS MERGED BOUNDARY WILL SETTLE SOUTHWARD
ACROSS CENTRAL NC TUE NIGHT. WITH A CONDITIONALLY UNSTABLE AND
UNCAPPED ENVIRONMENT PER BUFR SOUNDINGS...AND WITH FORECAST
PRECIPITABLE WATER VALUES APPROACHING TWO INCHES...THE WEAK (~20
METER/12 HR) HEIGHT FALLS ASSOCIATED WITH THE SERIES OF DISTURBANCES
ALOFT AND LOW LEVEL CONVERGENCE ALONG THE PRE-FRONTAL TROUGH/FRONT
WILL SUPPORT THE DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND
STORMS TUE. THE SLOW SOUTHWARD PASSAGE OF THE SURFACE FRONT WILL END
THE THREAT OF CONVECTION FROM NORTH TO SOUTH TUE EVENING AND
OVERNIGHT...WITH JUST A LINGERING CHANCE OF A FEW SHOWERS ALONG THE
FAR SOUTHERN TIER BY WED MORNING.

WHILE WSW MEAN FLOW ALIGNED PARALLEL TO THE UNDERLYING SURFACE FRONT
SUGGESTS DOWNPOURS/ LOCALIZED FLOODING IN TRAINING STORMS ALONG THE
BOUNDARY MAY PROVIDE THE GREATEST IMPACT...INCREASING MID LEVEL
FLOW/BULK SHEAR TO AROUND 30 KTS MAY ALSO SUPPORT MULTI-CELL STORM
ORGANIZATION WITH PRECIPITATION-LOADED STRONG WET MICROBURST WIND
GUSTS. IN ADDITION...FORECAST MAXIMUM SRH AROUND 100 M2/S2 COULD BE
NEARLY DOUBLED LOCALLY INVOF OUTFLOW/BACKED SURFACE FLOW...WHICH
COULD SUPPORT BRIEF SUPERCELLULAR STRUCTURES...THOUGH SUCH A
SCENARIO WILL BE DEPENDENT ON MESO AND STORM SCALE INFLUENCES WITH
LIMITED PREDICTABILITY BEYOND A FEW HOURS. AS SUCH...WILL INCLUDE
ONLY A GENERIC ONE SENTENCE MENTION OF A STRONG TO SEVERE STORM IN
THE HWO FOR NOW FOR TUE. MOSTLY CLOUDY AND STORMY CONDITIONS WILL
SUPPORT HIGHS FROM THE UPPER 70S NW...TO LOWER TO MIDDLE 80S OVER
THE SOUTH...WITH LOWS MOSTLY IN THE UPPER 60S...TO AROUND 70 DEGREES
SOUTH.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 255 AM SUNDAY...

WEDNESDAY THROUGH SATURDAY: BELOW AVERAGE TEMPERATURES - IN THE
UPPER 70S TO LOWER-MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE
AND ASSOCIATED GENERALLY EAST TO ENE LOW LEVEL FLOW...WILL THEN
PREVAIL THROUGH THE END OF THE WEEK. HOWEVER...THE SURFACE FRONT
WILL LIKELY LINGER OVER SC THROUGH THU GIVEN CONTINUED FRONT-
PARALLEL FLOW ALOFT IN THE BASE OF BROAD EASTERN CONUS TROUGH. WILL
ACCORDINGLY MAINTAIN A SLIGHT CHANCE OF A SHOWER OR STORM OVER THE
FAR SOUTHERN SANDHILLS AND COASTAL PLAIN...IN CLOSEST PROXIMITY TO
THIS FRONT AND HIGHER BL MOISTURE...AND ALSO TOWARD THE YADKIN RIVER
WHERE A FEW WEAKENING SHOWERS/STORMS MAY DRIFT AFTER INITIATION AND
PROPAGATION FROM THE EASTERN SLOPES. A WARMER SOUTHEASTERLY...TO
SOUTHERLY RETURN FLOW BY SATURDAY...WILL RESULT IN RISING
TEMPERATURES TO AROUND THE 30-YEAR AVERAGE...AND HUMIDITY
LEVELS...BY THE WEEKEND. A RISK OF A FEW LATE AFTERNOON PULSE
SHOWERS OR STORMS WILL CONSEQUENTLY INCREASE TO NEAR CLIMATOLOGICAL
PROBABILITIES...AROUND 20 PERCENT OR SO...BY SAT.

&&

.AVIATION /14Z SUNDAY THROUGH FRIDAY/...
AS OF 930 AM SUNDAY...

VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. SOUTHWEST WINDS
WILL BE INCREASING AHEAD OF AN APPROACHING FRONT...WITH 10-12KTS
SUSTAINED TODAY WITH GUSTS TO 20-22KTS FROM LATE MORNING THROUGH THE
AFTERNOON. MID LEVEL FLOW WILL BECOME MORE WESTERLY AND ALTOCUMULUS
WILL CONTINUE TO BE ON THE INCREASE TONIGHT. A DISTURBANCE MOVING
INTO THE NORTHWEST WILL GRAZE ACROSS THE NORTHERN TIER OF THE
AREA...PRODUCING A CHANCE OF SHOWERS MAINLY IN THE GSO/INT VICINITY
AFTER 06Z.

IN THE LONGER RANGE...THE APPROACHING FRONT WILL STALL ACROSS THE
AREA LATER MONDAY THROUGH TUESDAY...WITH MVFR/IFR CONDITIONS AND
INCREASING COVERAGE OF SHOWERS/STORMS. VFR CONDITIONS WILL RETURN
BEHIND THE FRONT LATE TUESDAY NIGHT AND DOMINATE THROUGH FRIDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...KMC
NEAR TERM...DJF/MLM
SHORT TERM...MLM/MWS
LONG TERM...MWS
AVIATION...DJF/MLM

000
FXUS62 KRAH 161013
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
615 AM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER OUR REGION TODAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST MONDAY AND MOVE ACROSS THE REGION
TUESDAY AND TUESDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SUNDAY...

FLATTENING OF THE UPPER RIDGE OVER THE MID ATLANTIC WILL RESULT IN
INCREASING WESTERLY FLOW ALOFT WITH MID AND HIGH CLOUDS SPREADING
ACROSS THE AREA TODAY. WESTERLY FLOW ALOFT AND APPROACHING FRONT
WILL TIGHTEN UP THE LEE TROF AND SOUTHWEST FLOW WILL STRENGTHEN TO
10-15 MPH WITH GUSTS TO PERHAPS 22 MPH THIS AFTERNOON. TEMPS WILL
BENEFIT FROM A MILDER START THIS MORNING AND ONGOING MID-UPPER 80S
FORECAST LOOKS GOOD.

CLOUDINESS...MAINLY MID AND UPPER...WILL BECOME PREVALENT TONIGHT AS
THE APPROACHING FRONT TRANSLATES INTO THE LEE TROF. RAIN CHANCES ARE
SMALL AND WILL BE MAINLY ACROSS THE NORTHERN TIER WHICH WILL BE
SKIRTED BY THE REMNANT OF A WEAKENING VORT MAX INDUCED BY CONVECTION
OVER THE OHIO VALLEY EARLY THIS MORNING. MINS WILL BE MILD AND
SEASONABLE...UPPER 60S.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM SUNDAY...

MONDAY AND MONDAY NIGHT...TRANSITION TO A BROAD LONGWAVE TROF WILL
BE UNDERWAY AND THE LINGERING LOW LEVEL TROFFING ALONG THE ATLANTIC
SEABOARD WILL PROMOTE AN INCREASINGLY MOIST AIRMASS. THICKNESSES ARE
RELATIVELY HIGH AND SIMILAR TO SUNDAY...WITH THE POTENTIAL FOR UPPER
80S. MOSTLY CLOUDY SKIES WILL HAMPER INSOLATION A BIT...MOSTLY MID
80S WEST TO UPPER 80S EAST. CHANCES OF SHOWERS WILL INCREASE MONDAY
AFTERNOON INTO MONDAY NIGHT IN INCREASINGLY DISTURBED FLOW...BUT ITS
DIFFICULT TO PICK OUT A PARTICULAR FEATURE DURING THIS TIME FRAME TO
FOCUS ACTIVITY...WILL CONTINUE CHANCE CATEGORY POPS FAVORING THE
WEST AND NORTH.

TUESDAY AND TUESDAY NIGHT: WITHIN A BROAD TROUGH ALOFT EAST OF THE
ROCKIES...A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE TROUGH...AND
PERHAPS A PRECEDING MCV FROM CONVECTION INITIATED AHEAD OF THIS WAVE
OVER THE CENTRAL PLAINS LATER TODAY AND TONIGHT...WILL MIGRATE
THROUGH THE BASE OF THE TROUGH/ACROSS THE CENTRAL APPALACHIANS AND
MIDDLE ATLANTIC REGION TUE. THESE FEATURES WILL BE FOLLOWED QUICKLY
BY AN ELONGATED BUT STRONGER NORTHERN STREAM WAVE IN NW FLOW FROM
THE UPPER MIDWEST TO THE CENTRAL APPALACHIANS TUE NIGHT.

IN THE LOW LEVELS...A PRE-FRONTAL TROUGH OVER VA/NC TUE WILL BE
OVERTAKEN BY A COLD FRONT ATTENDING THE AFOREMENTIONED NORTHERN
STREAM S/W TROUGH...AND THIS MERGED BOUNDARY WILL SETTLE SOUTHWARD
ACROSS CENTRAL NC TUE NIGHT. WITH A CONDITIONALLY UNSTABLE AND
UNCAPPED ENVIRONMENT PER BUFR SOUNDINGS...AND WITH FORECAST
PRECIPITABLE WATER VALUES APPROACHING TWO INCHES...THE WEAK (~20
METER/12 HR) HEIGHT FALLS ASSOCIATED WITH THE SERIES OF DISTURBANCES
ALOFT AND LOW LEVEL CONVERGENCE ALONG THE PRE-FRONTAL TROUGH/FRONT
WILL SUPPORT THE DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND
STORMS TUE. THE SLOW SOUTHWARD PASSAGE OF THE SURFACE FRONT WILL END
THE THREAT OF CONVECTION FROM NORTH TO SOUTH TUE EVENING AND
OVERNIGHT...WITH JUST A LINGERING CHANCE OF A FEW SHOWERS ALONG THE
FAR SOUTHERN TIER BY WED MORNING.

WHILE WSW MEAN FLOW ALIGNED PARALLEL TO THE UNDERLYING SURFACE FRONT
SUGGESTS DOWNPOURS/ LOCALIZED FLOODING IN TRAINING STORMS ALONG THE
BOUNDARY MAY PROVIDE THE GREATEST IMPACT...INCREASING MID LEVEL
FLOW/BULK SHEAR TO AROUND 30 KTS MAY ALSO SUPPORT MULTI-CELL STORM
ORGANIZATION WITH PRECIPITATION-LOADED STRONG WET MICROBURST WIND
GUSTS. IN ADDITION...FORECAST MAXIMUM SRH AROUND 100 M2/S2 COULD BE
NEARLY DOUBLED LOCALLY INVOF OUTFLOW/BACKED SURFACE FLOW...WHICH
COULD SUPPORT BRIEF SUPERCELLULAR STRUCTURES...THOUGH SUCH A
SCENARIO WILL BE DEPENDENT ON MESO AND STORM SCALE INFLUENCES WITH
LIMITED PREDICTABILITY BEYOND A FEW HOURS. AS SUCH...WILL INCLUDE
ONLY A GENERIC ONE SENTENCE MENTION OF A STRONG TO SEVERE STORM IN
THE HWO FOR NOW FOR TUE. MOSTLY CLOUDY AND STORMY CONDITIONS WILL
SUPPORT HIGHS FROM THE UPPER 70S NW...TO LOWER TO MIDDLE 80S OVER
THE SOUTH...WITH LOWS MOSTLY IN THE UPPER 60S...TO AROUND 70 DEGREES
SOUTH.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 255 AM SUNDAY...

WEDNESDAY THROUGH SATURDAY: BELOW AVERAGE TEMPERATURES - IN THE
UPPER 70S TO LOWER-MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE
AND ASSOCIATED GENERALLY EAST TO ENE LOW LEVEL FLOW...WILL THEN
PREVAIL THROUGH THE END OF THE WEEK. HOWEVER...THE SURFACE FRONT
WILL LIKELY LINGER OVER SC THROUGH THU GIVEN CONTINUED FRONT-
PARALLEL FLOW ALOFT IN THE BASE OF BROAD EASTERN CONUS TROUGH. WILL
ACCORDINGLY MAINTAIN A SLIGHT CHANCE OF A SHOWER OR STORM OVER THE
FAR SOUTHERN SANDHILLS AND COASTAL PLAIN...IN CLOSEST PROXIMITY TO
THIS FRONT AND HIGHER BL MOISTURE...AND ALSO TOWARD THE YADKIN RIVER
WHERE A FEW WEAKENING SHOWERS/STORMS MAY DRIFT AFTER INITIATION AND
PROPAGATION FROM THE EASTERN SLOPES. A WARMER SOUTHEASTERLY...TO
SOUTHERLY RETURN FLOW BY SATURDAY...WILL RESULT IN RISING
TEMPERATURES TO AROUND THE 30-YEAR AVERAGE...AND HUMIDITY
LEVELS...BY THE WEEKEND. A RISK OF A FEW LATE AFTERNOON PULSE
SHOWERS OR STORMS WILL CONSEQUENTLY INCREASE TO NEAR CLIMATOLOGICAL
PROBABILITIES...AROUND 20 PERCENT OR SO...BY SAT.

&&

.AVIATION /12Z SUNDAY THROUGH FRIDAY/...
AS OF 615 AM SUNDAY...

VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. GRADUALLY
INCREASING MOISTURE AND A WEAKENING CAP ALOFT WILL ALLOW A LITTLE
BETTER COVERAGE OF CUMULUS TODAY...POTENTIALLY BROKEN AT TIMES THIS
AFTERNOON WITH BASES AROUND 5KFT. SOUTHWEST WINDS WILL BE INCREASING
AHEAD OF AN APPROACHING FRONT...WITH 10-12KTS SUSTAINED TODAY WITH
GUSTS TO 20-22KTS FROM LATE MORNING THROUGH THE AFTERNOON. MID LEVEL
FLOW WILL BECOME MORE WESTERLY AND ALTOCUMULUS WILL BE ON THE
INCREASE TONIGHT. A DISTURBANCE MOVING INTO THE NORTHWEST WILL GRAZE
ACROSS THE NORTHERN TIER OF THE ARE...PRODUCING A CHANCE OF SHOWERS
IN THE GSO/INT VICINITY AFTER 06Z.

IN THE LONGER RANGE...THE APPROACHING FRONT WILL STALL ACROSS THE
AREA LATER MONDAY THROUGH TUESDAY...WITH MVFR/IFR CONDITIONS AND
INCREASING COVERAGE OF SHOWERS/STORMS. VFR CONDITIONS WILL RETURN
BEHIND THE FRONT LATE TUESDAY NIGHT AND DOMINATE THROUGH FRIDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...RAH
NEAR TERM...MLM
SHORT TERM...MLM/MWS
LONG TERM...MWS
AVIATION...MLM

000
FXUS62 KRAH 160728
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
320 AM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER OUR REGION TODAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST MONDAY AND MOVE ACROSS OUR REGION LATE
TUESDAY INTO EARLY WEDNESDAY MORNING.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SUNDAY...

FLATTENING OF THE UPPER RIDGE OVER THE MID ATLANTIC WILL RESULT IN
INCREASING WESTERLY FLOW ALOFT WITH MID AND HIGH CLOUDS SPREADING
ACROSS THE AREA TODAY. WESTERLY FLOW ALOFT AND APPROACHING FRONT
WILL TIGHTEN UP THE LEE TROF AND SOUTHWEST FLOW WILL STRENGTHEN TO
10-15 MPH WITH GUSTS TO PERHAPS 22 MPH THIS AFTERNOON. TEMPS WILL
BENEFIT FROM A MILDER START THIS MORNING AND ONGOING MID-UPPER 80S
FORECAST LOOKS GOOD.

CLOUDINESS...MAINLY MID AND UPPER...WILL BECOME PREVALENT TONIGHT AS
THE APPROACHING FRONT TRANSLATES INTO THE LEE TROF. RAIN CHANCES ARE
SMALL AND WILL BE MAINLY ACROSS THE NORTHERN TIER WHICH WILL BE
SKIRTED BY THE REMNANT OF A WEAKENING VORT MAX INDUCED BY CONVECTION
OVER THE OHIO VALLEY EARLY THIS MORNING. MINS WILL BE MILD AND
SEASONABLE...UPPER 60S.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM SUNDAY...

MONDAY AND MONDAY NIGHT...TRANSITION TO A BROAD LONGWAVE TROF WILL
BE UNDERWAY AND THE LINGERING LOW LEVEL TROFFING ALONG THE ATLANTIC
SEABOARD WILL PROMOTE AN INCREASINGLY MOIST AIRMASS. THICKNESSES ARE
RELATIVELY HIGH AND SIMILAR TO SUNDAY...WITH THE POTENTIAL FOR UPPER
80S. MOSTLY CLOUDY SKIES WILL HAMPER INSOLATION A BIT...MOSTLY MID
80S WEST TO UPPER 80S EAST. CHANCES OF SHOWERS WILL INCREASE MONDAY
AFTERNOON INTO MONDAY NIGHT IN INCREASINGLY DISTURBED FLOW...BUT ITS
DIFFICULT TO PICK OUT A PARTICULAR FEATURE DURING THIS TIME FRAME TO
FOCUS ACTIVITY...WILL CONTINUE CHANCE CATEGORY POPS FAVORING THE
WEST AND NORTH.

TUESDAY AND TUESDAY NIGHT: WITHIN A BROAD TROUGH ALOFT EAST OF THE
ROCKIES...A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE TROUGH...AND
PERHAPS A PRECEDING MCV FROM CONVECTION INITIATED AHEAD OF THIS WAVE
OVER THE CENTRAL PLAINS LATER TODAY AND TONIGHT...WILL MIGRATE
THROUGH THE BASE OF THE TROUGH/ACROSS THE CENTRAL APPALACHIANS AND
MIDDLE ATLANTIC REGION TUE. THESE FEATURES WILL BE FOLLOWED QUICKLY
BY AN ELONGATED BUT STRONGER NORTHERN STREAM WAVE IN NW FLOW FROM
THE UPPER MIDWEST TO THE CENTRAL APPALACHIANS TUE NIGHT.

IN THE LOW LEVELS...A PRE-FRONTAL TROUGH OVER VA/NC TUE WILL BE
OVERTAKEN BY A COLD FRONT ATTENDING THE AFOREMENTIONED NORTHERN
STREAM S/W TROUGH...AND THIS MERGED BOUNDARY WILL SETTLE SOUTHWARD
ACROSS CENTRAL NC TUE NIGHT. WITH A CONDITIONALLY UNSTABLE AND
UNCAPPED ENVIRONMENT PER BUFR SOUNDINGS...AND WITH FORECAST
PRECIPITABLE WATER VALUES APPROACHING TWO INCHES...THE WEAK (~20
METER/12 HR) HEIGHT FALLS ASSOCIATED WITH THE SERIES OF DISTURBANCES
ALOFT AND LOW LEVEL CONVERGENCE ALONG THE PRE-FRONTAL TROUGH/FRONT
WILL SUPPORT THE DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND
STORMS TUE. THE SLOW SOUTHWARD PASSAGE OF THE SURFACE FRONT WILL END
THE THREAT OF CONVECTION FROM NORTH TO SOUTH TUE EVENING AND
OVERNIGHT...WITH JUST A LINGERING CHANCE OF A FEW SHOWERS ALONG THE
FAR SOUTHERN TIER BY WED MORNING.

WHILE WSW MEAN FLOW ALIGNED PARALLEL TO THE UNDERLYING SURFACE FRONT
SUGGESTS DOWNPOURS/ LOCALIZED FLOODING IN TRAINING STORMS ALONG THE
BOUNDARY MAY PROVIDE THE GREATEST IMPACT...INCREASING MID LEVEL
FLOW/BULK SHEAR TO AROUND 30 KTS MAY ALSO SUPPORT MULTI-CELL STORM
ORGANIZATION WITH PRECIPITATION-LOADED STRONG WET MICROBURST WIND
GUSTS. IN ADDITION...FORECAST MAXIMUM SRH AROUND 100 M2/S2 COULD BE
NEARLY DOUBLED LOCALLY INVOF OUTFLOW/BACKED SURFACE FLOW...WHICH
COULD SUPPORT BRIEF SUPERCELLULAR STRUCTURES...THOUGH SUCH A
SCENARIO WILL BE DEPENDENT ON MESO AND STORM SCALE INFLUENCES WITH
LIMITED PREDICTABILITY BEYOND A FEW HOURS. AS SUCH...WILL INCLUDE
ONLY A GENERIC ONE SENTENCE MENTION OF A STRONG TO SEVERE STORM IN
THE HWO FOR NOW FOR TUE. MOSTLY CLOUDY AND STORMY CONDITIONS WILL
SUPPORT HIGHS FROM THE UPPER 70S NW...TO LOWER TO MIDDLE 80S OVER
THE SOUTH...WITH LOWS MOSTLY IN THE UPPER 60S...TO AROUND 70 DEGREES
SOUTH.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 255 AM SUNDAY...

WEDNESDAY THROUGH SATURDAY: BELOW AVERAGE TEMPERATURES - IN THE
UPPER 70S TO LOWER-MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE
AND ASSOCIATED GENERALLY EAST TO ENE LOW LEVEL FLOW...WILL THEN
PREVAIL THROUGH THE END OF THE WEEK. HOWEVER...THE SURFACE FRONT
WILL LIKELY LINGER OVER SC THROUGH THU GIVEN CONTINUED FRONT-
PARALLEL FLOW ALOFT IN THE BASE OF BROAD EASTERN CONUS TROUGH. WILL
ACCORDINGLY MAINTAIN A SLIGHT CHANCE OF A SHOWER OR STORM OVER THE
FAR SOUTHERN SANDHILLS AND COASTAL PLAIN...IN CLOSEST PROXIMITY TO
THIS FRONT AND HIGHER BL MOISTURE...AND ALSO TOWARD THE YADKIN RIVER
WHERE A FEW WEAKENING SHOWERS/STORMS MAY DRIFT AFTER INITIATION AND
PROPAGATION FROM THE EASTERN SLOPES. A WARMER SOUTHEASTERLY...TO
SOUTHERLY RETURN FLOW BY SATURDAY...WILL RESULT IN RISING
TEMPERATURES TO AROUND THE 30-YEAR AVERAGE...AND HUMIDITY
LEVELS...BY THE WEEKEND. A RISK OF A FEW LATE AFTERNOON PULSE
SHOWERS OR STORMS WILL CONSEQUENTLY INCREASE TO NEAR CLIMATOLOGICAL
PROBABILITIES...AROUND 20 PERCENT OR SO...BY SAT.

&&

.AVIATION /06Z SUNDAY THROUGH FRIDAY/...
AS OF 130 AM SUNDAY...

VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. GRADUALLY
INCREASING MOISTURE AND WARMER TEMPS WILL ALLOW BETTER COVERAGE OF
DIURNAL CLOUDS TODAY...POTENTIALLY BROKEN THIS AFTERNOON AROUND
5KFT. SOUTHWEST WINDS WILL BE INCREASING AHEAD OF AN APPROACHING
FRONT...WITH 10-12KTS SUSTAINED TODAY WITH GUSTS TO 20-22KTS THIS
AFTERNOON.  FRONT SAGGING SOUTH AND THE MID AND UPPER FLOW BECOMES
MORE WESTERLY SUNDAY NIGHT...WILL SEE MID LEVEL CLOUDS ON THE
INCREASE...WITH A SMALL CHANCE OF SHOWERS IN THE GSO/INT VICINITY
AFTER 00Z.

IN THE LONGER RANGE...THE APPROACHING FRONT WILL STALL ACROSS THE
AREA MONDAY NIGHT THROUGH TUESDAY...WITH MVFR/IFR CONDITIONS AND
INCREASING COVERAGE OF SHOWERS/STORMS. VFR CONDITIONS WILL RETURN
BEHIND THE FRONT LATE TUESDAY NIGHT AND DOMINATE THROUGH FRIDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...RAH
NEAR TERM...MLM
SHORT TERM...MLM/MWS
LONG TERM...MWS
AVIATION...MLM

000
FXUS62 KRAH 160700
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
258 AM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER OUR REGION TODAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST MONDAY AND MOVE ACROSS OUR REGION LATE
TUESDAY INTO EARLY WEDNESDAY MORNING.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 PM SATURDAY...

SUNDAY:
FALLING HEIGHTS OVER ONTARIO AND A WEAKENING OF THE MID
LEVEL RIDGE OVER THE GULF WILL LEAD TO FLATTENING MID LEVEL FLOW
FROM THE MIDWEST/PLAINS EASTWARD THROUGH THE OHIO VALLEY/MIDATLANTIC
AND NORTHEAST. THE SHORTWAVE TROUGH EXTENDING THROUGH ERN KS AND ERN
OK INTO TX TODAY WILL TRACK EASTWARD THROUGH THE MISS VALLEY AND
GREAT LAKES TONIGHT... AND WHILE THIS FEATURE ALSO DAMPENS... THE
INCREASING WESTERLY FLOW ALOFT WILL RESULT IN A CONTINUED INCREASE
IN MID AND HIGH CLOUDS AS THIS DISTURBANCE APPROACHES THE
APPALACHIANS IN THE AFTERNOON. THE 925 MB MOISTURE TRANSPORT WILL
ALSO BE ON THE INCREASE LATE TONIGHT THROUGH SUNDAY... WITH A FAIRLY
BRISK SW FLOW THROUGH THE BOUNDARY LAYER AND DEVELOPMENT OF A LEE
SURFACE TROUGH. SKIES SHOULD TREND TOWARD PARTLY CLOUDY ESPECIALLY
IN THE NORTH... THEN MOSTLY CLOUDY BY SUNDOWN... AGAIN WITH THE MOST
CLOUDINESS IN THE NORTH. THICKNESSES START CLOSE TO NORMAL AND RISE
STEADILY THROUGH THE DAY... THUS TEMPS SHOULD BE NEAR TO A BIT ABOVE
NORMAL FACTORING IN THE LATE DAY CLOUDS... WITH HIGHS 86-90. -GIH

A BROAD UPPER TROUGH OVER THE EASTERN TWO-THIRDS OF THE NATION WILL
GRADUALLY AMPLIFY THIS PERIOD AS AN UPPER RIDGE BUILDS OVER THE
SOUTHERN PLAINS INTO THE ROCKIES. A SERIES OF S/WS IN THE DEVELOPING
W-NW FLOW ALOFT WILL BRING A THREAT FOR SHOWERS AND T-STORMS TO THE
REGION MON INTO TUESDAY...AND POSSIBLY BY THE TAIL END OF THE WORK
WEEK. THE MAIN WEATHER HEADLINE FOR NEXT WEEK STILL LOOKS TO BE THE
GOOD PROBABILITY OF MAX TEMPS 4-7 DEGREES BELOW NORMAL FOR THE THIRD
WEEK IN JUNE. THE UPPER LEVEL JET FORECAST TO BE FARTHER SOUTH THAN
NORMAL FOR THIS TIME OF YEAR. THIS SWD POSITION WILL ALLOW COOLER
CANADIAN AIR TO SPILL INTO THE NORTHERN THIRD OF THE U.S. WITH SOME
RESIDUAL AFFECTS BEING FELT IN THE CAROLINAS.

SUNDAY NIGHT INTO EARLY MONDAY...THE AIR MASS OVER CENTRAL NC WILL
BECOME RATHER MOIST AS SW FLOW THROUGH THE LOWEST 10K FT ADVECT
MOISTURE CURRENTLY RESIDING OVER THE NORTHWEST GULF. MEANWHILE A
LINE OF CONVECTION ASSOCIATED WITH A SWD DRIFTING SURFACE BOUNDARY
WILL LIKELY CROSS NORTHERN VA LATE SUN. THIS LINE OF CONVECTION MAY
SEND AN OUTFLOW INTO NORTHERN NC SUNDAY SUNDAY EVENING. IF THIS
OCCURS...AVAILABLE MOISTURE AND LOW LEVEL INSTABILITY WOULD SUSTAIN
ISOLATED TO SCATTERED CONVECTION ACROSS OUR FAR NORTHERN COUNTIES
INTO THE NIGHT. PLAN TO MAINTAIN SLIGHT CHANCE POP FOR NOW. EXPECT
WARMER MIN TEMPS DUE TO MORE CLOUDS AND A LIGHT SLY WIND. MIN TEMPS
IN THE UPPER 60S TO NEAR 70. -WSS

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 305 PM SATURDAY...

MONDAY AND MONDAY NIGHT: RESIDUAL OUTFLOW BOUNDARIES AND THE
APPROACH OF A MID LEVEL TROUGH INTERACTING WITH A MOISTURE-LADEN AIR
MASS WILL TRIGGER SCATTERED CONVECTION...ESPECIALLY IN THE AFTERNOON
AND EVENING HOURS. WHILE INSTABILITY PARAMETERS SUPPORTIVE OF A FEW
STRONG STORMS...BULK SHEAR VALUES OF 20KTS OR LESS FAVOR
MULTI-CELLULAR/PULSE TYPE CONVECTION.PRESENCE OF A MID LEVEL TROUGH
TRUDGING SLOWLY EAST ACROSS THE REGION COUPLED WITH THE MOIST AIR
MASS AND ADEQUATE INSTABILITY WILL SUPPORT THE CONTINUED DEVELOPMENT
OF SCATTERED TO NUMEROUS SHOWERS AND T-STORMS MONDAY NIGHT.

AS OF 300 AM SUNDAY...

TUESDAY AND TUESDAY NIGHT: WITHIN A BROAD TROUGH ALOFT EAST OF THE
ROCKIES...A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE TROUGH...AND
PERHAPS A PRECEDING MCV FROM CONVECTION INITIATED AHEAD OF THIS WAVE
OVER THE CENTRAL PLAINS LATER TODAY AND TONIGHT...WILL MIGRATE
THROUGH THE BASE OF THE TROUGH/ACROSS THE CENTRAL APPALACHIANS AND
MIDDLE ATLANTIC REGION TUE. THESE FEATURES WILL BE FOLLOWED QUICKLY
BY AN ELONGATED BUT STRONGER NORTHERN STREAM WAVE IN NW FLOW FROM
THE UPPER MIDWEST TO THE CENTRAL APPALACHIANS TUE NIGHT.

IN THE LOW LEVELS...A PRE-FRONTAL TROUGH OVER VA/NC TUE WILL BE
OVERTAKEN BY A COLD FRONT ATTENDING THE AFOREMENTIONED NORTHERN
STREAM S/W TROUGH...AND THIS MERGED BOUNDARY WILL SETTLE SOUTHWARD
ACROSS CENTRAL NC TUE NIGHT. WITH A CONDITIONALLY UNSTABLE AND
UNCAPPED ENVIRONMENT PER BUFR SOUNDINGS...AND WITH FORECAST
PRECIPITABLE WATER VALUES APPROACHING TWO INCHES...THE WEAK (~20
METER/12 HR) HEIGHT FALLS ASSOCIATED WITH THE SERIES OF DISTURBANCES
ALOFT AND LOW LEVEL CONVERGENCE ALONG THE PRE-FRONTAL TROUGH/FRONT
WILL SUPPORT THE DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND
STORMS TUE. THE SLOW SOUTHWARD PASSAGE OF THE SURFACE FRONT WILL END
THE THREAT OF CONVECTION FROM NORTH TO SOUTH TUE EVENING AND
OVERNIGHT...WITH JUST A LINGERING CHANCE OF A FEW SHOWERS ALONG THE
FAR SOUTHERN TIER BY WED MORNING.

WHILE WSW MEAN FLOW ALIGNED PARALLEL TO THE UNDERLYING SURFACE FRONT
SUGGESTS DOWNPOURS/ LOCALIZED FLOODING IN TRAINING STORMS ALONG THE
BOUNDARY MAY PROVIDE THE GREATEST IMPACT...INCREASING MID LEVEL
FLOW/BULK SHEAR TO AROUND 30 KTS MAY ALSO SUPPORT MULTI-CELL STORM
ORGANIZATION WITH PRECIPITATION-LOADED STRONG WET MICROBURST WIND
GUSTS. IN ADDITION...FORECAST MAXIMUM SRH AROUND 100 M2/S2 COULD BE
NEARLY DOUBLED LOCALLY INVOF OUTFLOW/BACKED SURFACE FLOW...WHICH
COULD SUPPORT BRIEF SUPERCELLULAR STRUCTURES...THOUGH SUCH A
SCENARIO WILL BE DEPENDENT ON MESO AND STORM SCALE INFLUENCES WITH
LIMITED PREDICTABILITY BEYOND A FEW HOURS. AS SUCH...WILL INCLUDE
ONLY A GENERIC ONE SENTENCE MENTION OF A STRONG TO SEVERE STORM IN
THE HWO FOR NOW FOR TUE. MOSTLY CLOUDY AND STORMY CONDITIONS WILL
SUPPORT HIGHS FROM THE UPPER 70S NW...TO LOWER TO MIDDLE 80S OVER
THE SOUTH...WITH LOWS MOSTLY IN THE UPPER 60S...TO AROUND 70 DEGREES
SOUTH.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 255 AM SUNDAY...

WEDNESDAY THROUGH SATURDAY: BELOW AVERAGE TEMPERATURES - IN THE
UPPER 70S TO LOWER-MIDDLE 80S - IN WEAK POST-FRONTAL HIGH PRESSURE
AND ASSOCIATED GENERALLY EAST TO ENE LOW LEVEL FLOW...WILL THEN
PREVAIL THROUGH THE END OF THE WEEK. HOWEVER...THE SURFACE FRONT
WILL LIKELY LINGER OVER SC THROUGH THU GIVEN CONTINUED FRONT-
PARALLEL FLOW ALOFT IN THE BASE OF BROAD EASTERN CONUS TROUGH. WILL
ACCORDINGLY MAINTAIN A SLIGHT CHANCE OF A SHOWER OR STORM OVER THE
FAR SOUTHERN SANDHILLS AND COASTAL PLAIN...IN CLOSEST PROXIMITY TO
THIS FRONT AND HIGHER BL MOISTURE...AND ALSO TOWARD THE YADKIN RIVER
WHERE A FEW WEAKENING SHOWERS/STORMS MAY DRIFT AFTER INITIATION AND
PROPAGATION FROM THE EASTERN SLOPES. A WARMER SOUTHEASTERLY...TO
SOUTHERLY RETURN FLOW BY SATURDAY...WILL RESULT IN RISING
TEMPERATURES TO AROUND THE 30-YEAR AVERAGE...AND HUMIDITY
LEVELS...BY THE WEEKEND. A RISK OF A FEW LATE AFTERNOON PULSE
SHOWERS OR STORMS WILL CONSEQUENTLY INCREASE TO NEAR CLIMATOLOGICAL
PROBABILITIES...AROUND 20 PERCENT OR SO...BY SAT.

&&

.AVIATION /06Z SUNDAY THROUGH FRIDAY/...
AS OF 130 AM SUNDAY...

VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. GRADUALLY
INCREASING MOISTURE AND WARMER TEMPS WILL ALLOW BETTER COVERAGE OF
DIURNAL CLOUDS TODAY...POTENTIALLY BROKEN THIS AFTERNOON AROUND
5KFT. SOUTHWEST WINDS WILL BE INCREASING AHEAD OF AN APPROACHING
FRONT...WITH 10-12KTS SUSTAINED TODAY WITH GUSTS TO 20-22KTS THIS
AFTERNOON.  FRONT SAGGING SOUTH AND THE MID AND UPPER FLOW BECOMES
MORE WESTERLY SUNDAY NIGHT...WILL SEE MID LEVEL CLOUDS ON THE
INCREASE...WITH A SMALL CHANCE OF SHOWERS IN THE GSO/INT VICINITY
AFTER 00Z.

IN THE LONGER RANGE...THE APPROACHING FRONT WILL STALL ACROSS THE
AREA MONDAY NIGHT THROUGH TUESDAY...WITH MVFR/IFR CONDITIONS AND
INCREASING COVERAGE OF SHOWERS/STORMS. VFR CONDITIONS WILL RETURN
BEHIND THE FRONT LATE TUESDAY NIGHT AND DOMINATE THROUGH FRIDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...RAH
NEAR TERM...GIH/WSS
SHORT TERM...WSS/MWS
LONG TERM...MWS
AVIATION...MLM

000
FXUS62 KRAH 160540
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
140 AM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SUNDAY. A COLD
FRONT WILL APPROACH THE AREA FROM THE WEST MONDAY AND MOVE ACROSS
THE REGION LATE TUESDAY INTO EARLY WEDNESDAY MORNING.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 955 PM SATURDAY...

TONIGHT:
SURFACE HIGH PRESSURE LOCATED OFFSHORE COUPLED WITH WEAK SHORTWAVE
RIDGING LOFT EXPECTED TO BUILD ACROSS THE AREA TONIGHT WILL CONTINUE
TO PROVIDE QUITE WEATHER ACROSS CENTRAL NC FOR THE OVERNIGHT PERIOD.
HOWEVER... WITH MAY SEE A FEW MID AND HIGH LEVEL CLOUDS STREAM INTO
THE AREA AFTER MIDNIGHT TONIGHT FROM CONVECTION THAT DEVELOPED
ACROSS THE PLAINS AND MIDWEST TODAY. WITH THIS ADDED CLOUD COVER...
ALONG WITH A BIT TIGHTER MSLP GRADIENT AND WINDS OUT OF THE S/SW...
THINK WE SHOULD SEE OVERNIGHT LOWS A CATEGORY OR TWO WARMER THAN
THIS PAST MORNING. THIS YIELDS LOWS GENERALLY IN THE 60 TO 65 DEGREE
RANGE. -BSD

SUNDAY:
FALLING HEIGHTS OVER ONTARIO AND A WEAKENING OF THE MID
LEVEL RIDGE OVER THE GULF WILL LEAD TO FLATTENING MID LEVEL FLOW
FROM THE MIDWEST/PLAINS EASTWARD THROUGH THE OHIO VALLEY/MIDATLANTIC
AND NORTHEAST. THE SHORTWAVE TROUGH EXTENDING THROUGH ERN KS AND ERN
OK INTO TX TODAY WILL TRACK EASTWARD THROUGH THE MISS VALLEY AND
GREAT LAKES TONIGHT... AND WHILE THIS FEATURE ALSO DAMPENS... THE
INCREASING WESTERLY FLOW ALOFT WILL RESULT IN A CONTINUED INCREASE
IN MID AND HIGH CLOUDS AS THIS DISTURBANCE APPROACHES THE
APPALACHIANS IN THE AFTERNOON. THE 925 MB MOISTURE TRANSPORT WILL
ALSO BE ON THE INCREASE LATE TONIGHT THROUGH SUNDAY... WITH A FAIRLY
BRISK SW FLOW THROUGH THE BOUNDARY LAYER AND DEVELOPMENT OF A LEE
SURFACE TROUGH. SKIES SHOULD TREND TOWARD PARTLY CLOUDY ESPECIALLY
IN THE NORTH... THEN MOSTLY CLOUDY BY SUNDOWN... AGAIN WITH THE MOST
CLOUDINESS IN THE NORTH. THICKNESSES START CLOSE TO NORMAL AND RISE
STEADILY THROUGH THE DAY... THUS TEMPS SHOULD BE NEAR TO A BIT ABOVE
NORMAL FACTORING IN THE LATE DAY CLOUDS... WITH HIGHS 86-90. -GIH

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 305 PM SATURDAY...

A BROAD UPPER TROUGH OVER THE EASTERN TWO-THIRDS OF THE NATION WILL
GRADUALLY AMPLIFY THIS PERIOD AS AN UPPER RIDGE BUILDS OVER THE
SOUTHERN PLAINS INTO THE ROCKIES. A SERIES OF S/WS IN THE DEVELOPING
W-NW FLOW ALOFT WILL BRING A THREAT FOR SHOWERS AND T-STORMS TO THE
REGION MON INTO TUESDAY...AND POSSIBLY BY THE TAIL END OF THE WORK
WEEK. THE MAIN WEATHER HEADLINE FOR NEXT WEEK STILL LOOKS TO BE THE
GOOD PROBABILITY OF MAX TEMPS 4-7 DEGREES BELOW NORMAL FOR THE THIRD
WEEK IN JUNE. THE UPPER LEVEL JET FORECAST TO BE FARTHER SOUTH THAN
NORMAL FOR THIS TIME OF YEAR. THIS SWD POSITION WILL ALLOW COOLER
CANADIAN AIR TO SPILL INTO THE NORTHERN THIRD OF THE U.S. WITH SOME
RESIDUAL AFFECTS BEING FELT IN THE CAROLINAS.

SUNDAY NIGHT INTO EARLY MONDAY...THE AIR MASS OVER CENTRAL NC WILL
BECOME RATHER MOIST AS SW FLOW THROUGH THE LOWEST 10K FT ADVECT
MOISTURE CURRENTLY RESIDING OVER THE NORTHWEST GULF. MEANWHILE A
LINE OF CONVECTION ASSOCIATED WITH A SWD DRIFTING SURFACE BOUNDARY
WILL LIKELY CROSS NORTHERN VA LATE SUN. THIS LINE OF CONVECTION MAY
SEND AN OUTFLOW INTO NORTHERN NC SUNDAY SUNDAY EVENING. IF THIS
OCCURS...AVAILABLE MOISTURE AND LOW LEVEL INSTABILITY WOULD SUSTAIN
ISOLATED TO SCATTERED CONVECTION ACROSS OUR FAR NORTHERN COUNTIES
INTO THE NIGHT. PLAN TO MAINTAIN SLIGHT CHANCE POP FOR NOW. EXPECT
WARMER MIN TEMPS DUE TO MORE CLOUDS AND A LIGHT SLY WIND. MIN TEMPS
IN THE UPPER 60S TO NEAR 70.

RESIDUAL OUTFLOW BOUNDARIES AND THE APPROACH OF A MID LEVEL TROUGH
INTERACTING WITH A MOISTURE-LADEN AIR MASS WILL TRIGGER SCATTERED
CONVECTION...ESPECIALLY IN THE AFTERNOON AND EVENING HOURS. WHILE
INSTABILITY PARAMETERS SUPPORTIVE OF A FEW STRONG STORMS...BULK
SHEAR VALUES OF 20KTS OR LESS FAVOR MULTI-CELLULAR/PULSE TYPE
CONVECTION.

MONDAY NIGHT THROUGH TUESDAY NIGHT...PRESENCE OF A MID LEVEL TROUGH
TRUDGING SLOWLY EAST ACROSS THE REGION COUPLED WITH THE MOIST AIR
MASS AND ADEQUATE INSTABILITY WILL SUPPORT THE CONTINUED DEVELOPMENT
OF SCATTERED TO NUMEROUS SHOWERS AND T-STORMS MONDAY NIGHT AND MORE
SO TUESDAY. AN INCREASING MID LEVEL WIND FIELD WILL INCREASE THE
BULK SHEAR TO 30-35KTS ACROSS THE NORTHERN COUNTIES TUESDAY
AFTERNOON. THIS ADDED ENERGY MAY CAUSE CONVECTION TO FORM INTO
BROKEN LINE SEGMENTS LATE IN THE DAY. SINCE AIR MASS WILL BE VERY
MOIST (LITTLE OPPORTUNITY FOR DRY AIR ENTRAINMENT)...SEVERE
POTENTIAL LOOKS LIMITED THOUGH WILL NEED TO MONITOR ELEVATED CORES
FOR WET MICROBURST POTENTIAL.  AS MID LEVEL TROUGH AND ASSOCIATED
SURFACE BOUNDARY DRIFT SWD TUESDAY NIGHT...EXPECT CONVECTION TO
DIMINISH FROM THE NORTH.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 305 PM SATURDAY...

WEDNESDAY THROUGH THURSDAY SHOULD SEE A RELATIVELY TRANQUIL WEATHER
PATTERN AS HIGH PRESSURE OVER THE LOWER GREAT LAKES NOSES SEWD INTO
OUR REGION. DEVELOPING ELY FLOW BY THURSDAY MAY ADVECT ATLANTIC
MOISTURE INTO CENTRAL NC RESULTING IN PERIODS OF CLOUDINESS. ANY
CONVECTION THAT OCCURS SHOULD BE LIMITED TO THE FAR SOUTHERN AND
WESTERN SECTIONS OF TH FORECAST AREA WHERE BETTER MOISTURE WILL
RESIDE. CONSIDERABLE CLOUDINESS.

MODEST MID-UPPER LEVEL RIDGING MAY OCCUR ACROSS THE SE U.S. FRI INTO
SATURDAY AHEAD OF THE NEXT S/W. THIS PATTERN WILL SUPPORT MORE OF A
SUMMERLIKE PATTERN WITH WARM AND SLIGHTLY HUMID CONDITIONS BY THE
END OF THE WEEK.

TEMPERATURE WISE....TEMPS MONDAY SHOULD BE FAIRLY CLOSE TO NORMAL
WITH MAX TEMPS IN THE MID-UPPER 80S. MAX TEMPS TUESDAY-THURSDAY WILL
LIKELY AVERAGE 4-5 DEGREES BELOW NORMAL...MAINLY DUE TO WIDESPREAD
SHOWERS TUESDAY AND LOW LEVEL N-NE FLOW ADVECTING COOLER AIR INTO
THE REGION WED-THU. MODIFYING AIR MASS WILL SEND TEMPS TO NEAR
NORMAL LEVELS BY SATURDAY.

&&

.AVIATION /06Z SUNDAY THROUGH FRIDAY/...
AS OF 130 AM SUNDAY...

VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. GRADUALLY
INCREASING MOISTURE AND WARMER TEMPS WILL ALLOW BETTER COVERAGE OF
DIURNAL CLOUDS TODAY...POTENTIALLY BROKEN THIS AFTERNOON AROUND
5KFT. SOUTHWEST WINDS WILL BE INCREASING AHEAD OF AN APPROACHING
FRONT...WITH 10-12KTS SUSTAINED TODAY WITH GUSTS TO 20-22KTS THIS
AFTERNOON.  FRONT SAGGING SOUTH AND THE MID AND UPPER FLOW BECOMES
MORE WESTERLY SUNDAY NIGHT...WILL SEE MID LEVEL CLOUDS ON THE
INCREASE...WITH A SMALL CHANCE OF SHOWERS IN THE GSO/INT VICINITY
AFTER 00Z.

IN THE LONGER RANGE...THE APPROACHING FRONT WILL STALL ACROSS THE
AREA MONDAY NIGHT THROUGH TUESDAY...WITH MVFR/IFR CONDITIONS AND
INCREASING COVERAGE OF SHOWERS/STORMS. VFR CONDITIONS WILL RETURN
BEHIND THE FRONT LATE TUESDAY NIGHT AND DOMINATE THROUGH FRIDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BSD
NEAR TERM...BSD/HARTFIELD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...MLM