000
FXUS63 KUNR 202314
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
514 PM MDT MON MAY 20 2013
.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 158 PM MDT MON MAY 20 2013
19Z SURFACE ANALYSIS HAD LOW OVER THE SD/NE/MN BORDER. TIGHT
PRESSURE GRADIENT ASSOCIATED WITH LOW BRINGING WINDY WEATHER TO
THE CWA THIS AFTERNOON. UPPER LOW STACKED ON TOP OF SURFACE
LOW...WHICH IS PINWHEELING SEVERAL EMBEDDED SHORTWAVES THROUGH THE
CWA UNDER STRONG CYCLONIC FLOW ALOFT. REGIONAL RADARS SHOW MANY
BATCHES OF SHRA TO MOVE THROUGH THE AREA TONIGHT...SO HIGH POPS
CONTINUE TO BE WARRANTED. FORECAST SOUNDINGS SUGGEST WIND WILL
TAPER SOME THIS EVENING...BUT LIKELY STAY IN THE MARGINAL WIND
ADVISORY AREA OVERNIGHT. WET BULB ZERO DROPS TO AROUND 7KFT MSL
LATER TONIGHT...SO WOULD NOT BE SURPRISED TO SEE SOME SNOW OVER
THE HIGHER ELEVATIONS OF THE BLACK HILLS WHERE UPSLOPE-ENHANCED
PRECIPITATION...FROUDE NUMBER ABOVE 1 WITH 0-2KM AGL
SATURATION...WILL FALL. TEMPERATURES NEAR GUIDANCE.
TUESDAY...STACKED UPPER LOW BEGINS TO MOVE EAST WITH PRECIPITATION
BECOMING LESS WIDESPREAD OVER THE CWA. HOWEVER...STEEP LOW LEVEL
LAPSE RATES...CYCLONIC FLOW ALOFT...AND IMPULSES ROTATING AROUND THE
LOW WILL RESULT IN NUMEROUS SHOWERS. A BIT OF SNOW POSSIBLE IN THE
MORNING OVER THE HIGHER ELEVATION OF THE BLACK HILLS. FROUDE NUMBER
DROPS BELOW 1 BY AFTERNOON...SO UPSLOPE ENHANCEMENT WILL SLACKEN.
LATEST GUIDANCE SHOWS TOP OF BOUNDARY LAYER WIND SPEEDS DROPPING TO
20-25KTS BY AFTERNOON AND THUS WE SHOULD SEE WIND SPEEDS SLOWLY
DECLINE. WILL END WIND ADVISORY AT 18Z. CONDITIONS WILL IMPROVE
MORESO TUESDAY NIGHT AS MOISTURE BEGINS TO DIMINISH AND FORCING
SHIFTS EAST. TEMPERATURES NEAR GUIDANCE.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 158 PM MDT MON MAY 20 2013
THE STORM SYSTEM WILL CONTINUE TO SLOWLY MOVE EAST OF THE REGION
ON WEDNESDAY...WITH ONLY ISOLATED TO SCATTERED SHOWERS
EXPECTED...MAINLY IN THE MORNING OVER NORTHERN AND EASTERN
PORTIONS OF THE CWA. WEAK RIDGING DEVELOPS BEHIND THE EXITING
SYSTEM ALLOWING TEMPERATURES TO RETURN TO NORMAL. MOST AREAS WILL
BE DRY ON WEDNESDAY NIGHT...BUT DID KEEP SLIGHT CHANCE OF POPS
OVER CAMPBELL COUNTY WY SINCE A SHOWER OR TWO COULD REACH THE AREA
AS IT COMES OFF THE BIGHORNS. WITH RETURN FLOW WEDNESDAY NIGHT AND
THURSDAY...EXPECT GUSTY SOUTHEASTERLY WINDS ACROSS THE CWA. THUS
INCREASED WIND SPEEDS FOR THIS PERIOD FROM THE PREVIOUS FORECAST.
THE RIDGE AXIS PUSHES EAST BY FRIDAY...RESULTING IN SOUTHWEST FLOW
ALOFT FOR THE REST OF THE EXTENDED AS AN UPPER LOW STALLS ACROSS THE
PACIFIC NORTHWEST. LOW LEVEL MOISTURE WILL INCREASE...ALLOWING FOR A
DAILY CHANCE FOR SHOWERS AND THUNDERSTORMS. THIS COULD BE AN ACTIVE
PERIOD FOR SEVERE WEATHER...ESPECIALLY FOR THE BLACK HILLS AND
EASTWARD ACROSS THE SD PLAINS...BUT WILL DEPEND ON THE TIMING OF THE
DISTURBANCES. MODELS ARE IN FAIRLY GOOD AGREEMENT KEEPING THIS
PATTERN IN PLACE FOR THE CWA THROUGH THE END OF THE MONTH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 512 PM MDT MON MAY 20 2013
SCATERED RAIN SHOWERS WILL CONTINUE TONIGHT AND TUESDAY...WITH MVFR/IFR
CONDITIONS PERSISTING ACROSS MOST OF THE AREA. A MORE STEADY RAIN
IS EXPECTED TO CONTINUE ACROSS THE FAVORED UPSLOPE AREAS OF THE
NORTHERN BLACK HILLS AND INTO PORTIONS OF WESTERN SOUTH DAKOTA.
GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH THE PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL NOON MDT TUESDAY FOR SDZ001-002-012-013-026-
030-031-072-073.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM...MLS
AVIATION...10
000
FXUS63 KUNR 201959
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
159 PM MDT MON MAY 20 2013
.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 158 PM MDT MON MAY 20 2013
19Z SURFACE ANALYSIS HAD LOW OVER THE SD/NE/MN BORDER. TIGHT
PRESSURE GRADIENT ASSOCIATED WITH LOW BRINGING WINDY WEATHER TO
THE CWA THIS AFTERNOON. UPPER LOW STACKED ON TOP OF SURFACE
LOW...WHICH IS PINWHEELING SEVERAL EMBEDDED SHORTWAVES THROUGH THE
CWA UNDER STRONG CYCLONIC FLOW ALOFT. REGIONAL RADARS SHOW MANY
BATCHES OF SHRA TO MOVE THROUGH THE AREA TONIGHT...SO HIGH POPS
CONTINUE TO BE WARRANTED. FORECAST SOUNDINGS SUGGEST WIND WILL
TAPER SOME THIS EVENING...BUT LIKELY STAY IN THE MARGINAL WIND
ADVISORY AREA OVERNIGHT. WET BULB ZERO DROPS TO AROUND 7KFT MSL
LATER TONIGHT...SO WOULD NOT BE SURPRISED TO SEE SOME SNOW OVER
THE HIGHER ELEVATIONS OF THE BLACK HILLS WHERE UPSLOPE-ENHANCED
PRECIPITATION...FROUDE NUMBER ABOVE 1 WITH 0-2KM AGL
SATURATION...WILL FALL. TEMPERATURES NEAR GUIDANCE.
TUESDAY...STACKED UPPER LOW BEGINS TO MOVE EAST WITH PRECIPITATION
BECOMING LESS WIDESPREAD OVER THE CWA. HOWEVER...STEEP LOW LEVEL
LAPSE RATES...CYCLONIC FLOW ALOFT...AND IMPULSES ROTATING AROUND THE
LOW WILL RESULT IN NUMEROUS SHOWERS. A BIT OF SNOW POSSIBLE IN THE
MORNING OVER THE HIGHER ELEVATION OF THE BLACK HILLS. FROUDE NUMBER
DROPS BELOW 1 BY AFTERNOON...SO UPSLOPE ENHANCEMENT WILL SLACKEN.
LATEST GUIDANCE SHOWS TOP OF BOUNDARY LAYER WIND SPEEDS DROPPING TO
20-25KTS BY AFTERNOON AND THUS WE SHOULD SEE WIND SPEEDS SLOWLY
DECLINE. WILL END WIND ADVISORY AT 18Z. CONDITIONS WILL IMPROVE
MORESO TUESDAY NIGHT AS MOISTURE BEGINS TO DIMINISH AND FORCING
SHIFTS EAST. TEMPERATURES NEAR GUIDANCE.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 158 PM MDT MON MAY 20 2013
THE STORM SYSTEM WILL CONTINUE TO SLOWLY MOVE EAST OF THE REGION
ON WEDNESDAY...WITH ONLY ISOLATED TO SCATTERED SHOWERS
EXPECTED...MAINLY IN THE MORNING OVER NORTHERN AND EASTERN
PORTIONS OF THE CWA. WEAK RIDGING DEVELOPS BEHIND THE EXITING
SYSTEM ALLOWING TEMPERATURES TO RETURN TO NORMAL. MOST AREAS WILL
BE DRY ON WEDNESDAY NIGHT...BUT DID KEEP SLIGHT CHANCE OF POPS
OVER CAMPBELL COUNTY WY SINCE A SHOWER OR TWO COULD REACH THE AREA
AS IT COMES OFF THE BIGHORNS. WITH RETURN FLOW WEDNESDAY NIGHT AND
THURSDAY...EXPECT GUSTY SOUTHEASTERLY WINDS ACROSS THE CWA. THUS
INCREASED WIND SPEEDS FOR THIS PERIOD FROM THE PREVIOUS FORECAST.
THE RIDGE AXIS PUSHES EAST BY FRIDAY...RESULTING IN SOUTHWEST FLOW
ALOFT FOR THE REST OF THE EXTENDED AS AN UPPER LOW STALLS ACROSS THE
PACIFIC NORTHWEST. LOW LEVEL MOISTURE WILL INCREASE...ALLOWING FOR A
DAILY CHANCE FOR SHOWERS AND THUNDERSTORMS. THIS COULD BE AN ACTIVE
PERIOD FOR SEVERE WEATHER...ESPECIALLY FOR THE BLACK HILLS AND
EASTWARD ACROSS THE SD PLAINS...BUT WILL DEPEND ON THE TIMING OF THE
DISTURBANCES. MODELS ARE IN FAIRLY GOOD AGREEMENT KEEPING THIS
PATTERN IN PLACE FOR THE CWA THROUGH THE END OF THE MONTH.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON
ISSUED AT 158 PM MDT MON MAY 20 2013
OCCASIONAL RAIN SHOWERS WILL CONTINUE TONIGHT AND TUESDAY...WITH
MVFR/IFR CONDITIONS GENERALLY PERSISTING ACROSS MOST OF THE AREA. A
MORE STEADY RAIN IS EXPECTED TO CONTINUE ACROSS THE FAVORED UPSLOPE
AREAS OF THE NORTHERN BLACK HILLS AND INTO PORTIONS OF WESTERN SOUTH
DAKOTA. GUSTY NORTHWESTERLY WINDS WILL CONTINUE THROUGH THE PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM MDT TUESDAY FOR SDZ001-002-012-013-026-
030-031-041-072-073.
WY...NONE.
&&
$$
SHORT TERM...HELGESON
LONG TERM...MLS
AVIATION...MLS
000
FXUS63 KUNR 201735
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1135 AM MDT MON MAY 20 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 235 AM MDT MON MAY 20 2013
A CLOSED LOW WITH TWO WEAK SURFACE CENTERS IS WOBBLING
AROUND OVER CENTRAL AND EASTERN SOUTH DAKOTA THIS MORNING...
APPARENTLY NOT IN A HURRY TO MAKE EASTWARD PROGRESS. LIGHT TO
LOCALLY MODERATE RAIN SHOWERS ARE WRAPPING AROUND THE CENTER IN A
LARGE ARC WHICH EXTENDS NORTHWEST INTO NORTH DAKOTA AND THEN CURVES
BACK TO THE SOUTH THROUGH WESTERN SOUTH DAKOTA AND A SLIVER OF
NORTHEAST WYOMING. A STRONG SURFACE PRESSURE GRADIENT HAS SET UP IN
THE CYCLONIC FLOW OVER WESTERN SOUTH DAKOTA PROMPTING A WIND
ADVISORY YESTERDAY EVENING.
TODAY AND TONIGHT...WITH LITTLE MOVEMENT IN THE LOW CENTER...WEATHER
EVENTS WILL BE DRIVEN BY FEATURES ROTATING AROUND THE CENTERS. A
LOW AMPLITUDE TROUGH EXTENDING NORTHWESTWARD FROM THE NORTHERN MOST
LOW CENTER IS CURRENTLY SWEEPING COUNTER CLOCKWISE TOWARD THE
SOUTHWEST AND WILL BE THE FOCUS FOR MORE RAIN TO MOVE THROUGH THE
BLKHLS AND OTHER PARTS OF WESTERN SOUTH DAKOTA TODAY. INSTABILITY
AND SHEAR WILL REMAIN MINIMAL...HOWEVER LONG PERIODS OF CONTINUOUS
RAIN AND SOME UPSLOPE ENHANCEMENT IS EXPECTED TO PRODUCE OVER 2
INCHES OF RAIN IN THE FAVORED AREAS OF THE NORTHERN BLKHLS. ANOTHER
ONE OF THESE RADIAL TROUGHS IS FORECAST TO DO PRETTY MUCH THE SAME
THING THIS EVENING BEFORE THE LOW CENTER SHIFTS EASTWARD EARLY
TUESDAY. AS WELL AS SUPPORTING THE PRECIPITATION WITH LARGE SCALE
ASCENT THESE TROUGHS SERVE TO TIGHTEN THE PRESSURE GRADIENT AND
ENHANCE THE SURFACE WIND SPEEDS.
TUESDAY...BY EARLY TUESDAY MORNING THE LOW CENTER IS FORECAST TO
MOVE OUT OF EASTERN SOUTH DAKOTA AND THE LARGE SPIRAL BAND OF
MOISTURE GOES WITH IT. A GRADUALLY DISSIPATION OF THE CLOUD COVER
AND PRECIPITATION WILL CHARACTERIZE THE DAY AS WELL AS DECREASING
WIND SPEEDS. THE ONLY THING THAT WON`T IMPROVE MUCH IS TEMPERATURES
SINCE LINGERING CLOUD COVER AND CONTINUED COLD ADVECTION IN THE
NORTHERLY FLOW WILL KEEP THE SPRING SUN FROM WARMING THE AIRMASS
MUCH.
&&
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 235 AM MDT MON MAY 20 2013
THE STORM SYSTEM WILL CONTINUE TO SLOWLY MOVE EAST OF THE REGION ON
WEDNESDAY...WITH ONLY ISOLATED TO WIDELY SCATTERED SHOWERS
EXPECTED...MAINLY IN THE MORNING OVER NORTHERN AND EASTERN PORTIONS
OF THE CWA. WEAK RIDGING BEHIND THE EXITING SYSTEM WILL BRING MOSTLY
DRY CONDITIONS LATE WEDNESDAY INTO THURSDAY. A SHOWER OR TWO COULD
MAKE IT INTO PORTIONS OF NORTHEASTERN WY FROM THE MTS WEDNESDAY
NIGHT.
A GRADUAL WARM UP IS EXPECTED LATE IN THE WEEK...WITH TEMPERATURES
BACK ABOVE AVERAGE LEVELS BY THE WEEKEND. SOUTHWEST FLOW ALOFT WILL
DEVELOP ACROSS THE REGION BY THE END OF THE WEEK AS AN UPPER LOW
STALLS ACROSS THE PACIFIC NW. SOUTHEASTERLY WINDS AT THE SURFACE
WILL BRING INCREASING LOW LEVEL MOISTURE INTO THE NORTHERN
PLAINS...ESPECIALLY EAST OF THE BLACK HILLS. THIS SETUP SHOULD BRING
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS TO A GOOD PORTION OF THE
AREA FROM FRIDAY THROUGH THE HOLIDAY WEEKEND. DEPENDING ON THE
TIMING AND STRENGTH OF THE DISTURBANCES PASSING THROUGH THE
AREA...THIS COULD BE AN ACTIVE PERIOD FOR SEVERE WX...ESPECIALLY FOR
THE BLACK HILLS AND EASTWARD ACROSS THE SD PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1132 AM MDT MON MAY 20 2013
OCCASIONAL RAIN SHOWERS WILL CONTINUE INTO TONIGHT...WITH
MVFR/IFR CONDITIONS GENERALLY PERSISTING ACROSS MOST OF THE AREA.
A MORE STEADY RAIN IS EXPECTED ACROSS THE NORTHERN BLACK HILLS
INTO PORTIONS OF NORTHEASTERN WYOMING AND FAR NORTHWESTERN SOUTH
DAKOTA FOR MUCH OF THE AFTERNOON. GUSTY NORTHWESTERLY WINDS WILL
CONTINUE THROUGH THE PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM MDT TUESDAY FOR SDZ001-002-012-013-026-
030-031-041-072-073.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...MLS
000
FXUS63 KUNR 201132
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
532 AM MDT MON MAY 20 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 235 AM MDT MON MAY 20 2013
A CLOSED LOW WITH TWO WEAK SURFACE CENTERS IS WOBBLING
AROUND OVER CENTRAL AND EASTERN SOUTH DAKOTA THIS MORNING...
APPARENTLY NOT IN A HURRY TO MAKE EASTWARD PROGRESS. LIGHT TO
LOCALLY MODERATE RAIN SHOWERS ARE WRAPPING AROUND THE CENTER IN A
LARGE ARC WHICH EXTENDS NORTHWEST INTO NORTH DAKOTA AND THEN CURVES
BACK TO THE SOUTH THROUGH WESTERN SOUTH DAKOTA AND A SLIVER OF
NORTHEAST WYOMING. A STRONG SURFACE PRESSURE GRADIENT HAS SET UP IN
THE CYCLONIC FLOW OVER WESTERN SOUTH DAKOTA PROMPTING A WIND
ADVISORY YESTERDAY EVENING.
TODAY AND TONIGHT...WITH LITTLE MOVEMENT IN THE LOW CENTER...WEATHER
EVENTS WILL BE DRIVEN BY FEATURES ROTATING AROUND THE CENTERS. A
LOW AMPLITUDE TROUGH EXTENDING NORTHWESTWARD FROM THE NORTHERN MOST
LOW CENTER IS CURRENTLY SWEEPING COUNTER CLOCKWISE TOWARD THE
SOUTHWEST AND WILL BE THE FOCUS FOR MORE RAIN TO MOVE THROUGH THE
BLKHLS AND OTHER PARTS OF WESTERN SOUTH DAKOTA TODAY. INSTABILITY
AND SHEAR WILL REMAIN MINIMAL...HOWEVER LONG PERIODS OF CONTINUOUS
RAIN AND SOME UPSLOPE ENHANCEMENT IS EXPECTED TO PRODUCE OVER 2
INCHES OF RAIN IN THE FAVORED AREAS OF THE NORTHERN BLKHLS. ANOTHER
ONE OF THESE RADIAL TROUGHS IS FORECAST TO DO PRETTY MUCH THE SAME
THING THIS EVENING BEFORE THE LOW CENTER SHIFTS EASTWARD EARLY
TUESDAY. AS WELL AS SUPPORTING THE PRECIPITATION WITH LARGE SCALE
ASCENT THESE TROUGHS SERVE TO TIGHTEN THE PRESSURE GRADIENT AND
ENHANCE THE SURFACE WIND SPEEDS.
TUESDAY...BY EARLY TUESDAY MORNING THE LOW CENTER IS FORECAST TO
MOVE OUT OF EASTERN SOUTH DAKOTA AND THE LARGE SPIRAL BAND OF
MOISTURE GOES WITH IT. A GRADUALLY DISSIPATION OF THE CLOUD COVER
AND PRECIPITATION WILL CHARACTERIZE THE DAY AS WELL AS DECREASING
WIND SPEEDS. THE ONLY THING THAT WON`T IMPROVE MUCH IS TEMPERATURES
SINCE LINGERING CLOUD COVER AND CONTINUED COLD ADVECTION IN THE
NORTHLY FLOW WILL KEEP THE SPRING SUN FROM WARMING THE AIRMASS
MUCH.
&&
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 235 AM MDT MON MAY 20 2013
THE STORM SYSTEM WILL CONTINUE TO SLOWLY MOVE EAST OF THE REGION ON
WEDNESDAY...WITH ONLY ISOLATED TO WIDELY SCATTERED SHOWERS
EXPECTED...MAINLY IN THE MORNING OVER NORTHERN AND EASTERN PORTIONS
OF THE CWA. WEAK RIDGING BEHIND THE EXITING SYSTEM WILL BRING MOSTLY
DRY CONDITIONS LATE WEDNESDAY INTO THURSDAY. A SHOWER OR TWO COULD
MAKE IT INTO PORTIONS OF NORTHEASTERN WY FROM THE MTS WEDNESDAY
NIGHT.
A GRADUAL WARMUP IS EXPECTED LATE IN THE WEEK...WITH TEMPERATURES
BACK ABOVE AVERAGE LEVELS BY THE WEEKEND. SOUTHWEST FLOW ALOFT WILL
DEVELOP ACROSS THE REGION BY THE END OF THE WEEK AS AN UPPER LOW
STALLS ACROSS THE PACIFIC NW. SOUTHEASTERLY WINDS AT THE SURFACE
WILL BRING INCREASING LOW LEVEL MOISTURE INTO THE NORTHERN
PLAINS...ESPECIALLY EAST OF THE BLACK HILLS. THIS SETUP SHOULD BRING
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS TO A GOOD PORTION OF THE
AREA FROM FRIDAY THROUGH THE HOLIDAY WEEKEND. DEPENDING ON THE
TIMING AND STRENGTH OF THE DISTURBANCES PASSING THROUGH THE
AREA...THIS COULD BE AN ACTIVE PERIOD FOR SEVERE WX...ESPECIALLY FOR
THE BLACK HILLS AND EASTWARD ACROSS THE SD PLAINS.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 532 AM MDT MON MAY 20 2013
OCCASIONAL RAIN SHOWERS WILL CONTINUE TODAY AND INTO TONIGHT...WITH
MVFR/IFR CONDITIONS GENERALLY PERSISTING ACROSS MOST OF THE AREA.
HOWEVER...VFR CONDITIONS COULD PERSIST AT KRAP THROUGH MUCH OF
TODAY. A MORE STEADY RAIN IS EXPECTED ACROSS THE NORTHERN BLACK
HILLS INTO PORTIONS OF NORTHEASTERN WYOMING AND FAR NORTHWESTERN
SOUTH DAKOTA TODAY. STRONG NORTHWESTERLY WINDS WILL CONTINUE ACROSS
MUCH OF THE PLAINS TODAY...ESPECIALLY THE FAR WESTERN SD PLAINS.
WINDS WILL DIMINISH SOME THIS EVENING...BUT REMAIN GUSTY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM MDT TUESDAY FOR SDZ001-002-012-013-026-
031-072-073.
WIND ADVISORY UNTIL 7 PM MDT TUESDAY FOR SDZ030-041.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...26
000
FXUS63 KUNR 200838
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
238 AM MDT MON MAY 20 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 235 AM MDT MON MAY 20 2013
A CLOSED LOW WITH TWO WEAK SURFACE CENTERS IS WOBBLING
AROUND OVER CENTRAL AND EASTERN SOUTH DAKOTA THIS MORNING...
APPARENTLY NOT IN A HURRY TO MAKE EASTWARD PROGRESS. LIGHT TO
LOCALLY MODERATE RAIN SHOWERS ARE WRAPPING AROUND THE CENTER IN A
LARGE ARC WHICH EXTENDS NORTHWEST INTO NORTH DAKOTA AND THEN CURVES
BACK TO THE SOUTH THROUGH WESTERN SOUTH DAKOTA AND A SLIVER OF
NORTHEAST WYOMING. A STRONG SURFACE PRESSURE GRADIENT HAS SET UP IN
THE CYCLONIC FLOW OVER WESTERN SOUTH DAKOTA PROMPTING A WIND
ADVISORY YESTERDAY EVENING.
TODAY AND TONIGHT...WITH LITTLE MOVEMENT IN THE LOW CENTER...WEATHER
EVENTS WILL BE DRIVEN BY FEATURES ROTATING AROUND THE CENTERS. A
LOW AMPLITUDE TROUGH EXTENDING NORTHWESTWARD FROM THE NORTHERN MOST
LOW CENTER IS CURRENTLY SWEEPING COUNTER CLOCKWISE TOWARD THE
SOUTHWEST AND WILL BE THE FOCUS FOR MORE RAIN TO MOVE THROUGH THE
BLKHLS AND OTHER PARTS OF WESTERN SOUTH DAKOTA TODAY. INSTABILITY
AND SHEAR WILL REMAIN MINIMAL...HOWEVER LONG PERIODS OF CONTINUOUS
RAIN AND SOME UPSLOPE ENHANCEMENT IS EXPECTED TO PRODUCE OVER 2
INCHES OF RAIN IN THE FAVORED AREAS OF THE NORTHERN BLKHLS. ANOTHER
ONE OF THESE RADIAL TROUGHS IS FORECAST TO DO PRETTY MUCH THE SAME
THING THIS EVENING BEFORE THE LOW CENTER SHIFTS EASTWARD EARLY
TUESDAY. AS WELL AS SUPPORTING THE PRECIPITATION WITH LARGE SCALE
ASCENT THESE TROUGHS SERVE TO TIGHTEN THE PRESSURE GRADIENT AND
ENHANCE THE SURFACE WIND SPEEDS.
TUESDAY...BY EARLY TUESDAY MORNING THE LOW CENTER IS FORECAST TO
MOVE OUT OF EASTERN SOUTH DAKOTA AND THE LARGE SPIRAL BAND OF
MOISTURE GOES WITH IT. A GRADUALLY DISSIPATION OF THE CLOUD COVER
AND PRECIPITATION WILL CHARACTERIZE THE DAY AS WELL AS DECREASING
WIND SPEEDS. THE ONLY THING THAT WON`T IMPROVE MUCH IS TEMPERATURES
SINCE LINGERING CLOUD COVER AND CONTINUED COLD ADVECTION IN THE
NORTHLY FLOW WILL KEEP THE SPRING SUN FROM WARMING THE AIRMASS
MUCH.
&&
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 235 AM MDT MON MAY 20 2013
THE STORM SYSTEM WILL CONTINUE TO SLOWLY MOVE EAST OF THE REGION ON
WEDNESDAY...WITH ONLY ISOLATED TO WIDELY SCATTERED SHOWERS
EXPECTED...MAINLY IN THE MORNING OVER NORTHERN AND EASTERN PORTIONS
OF THE CWA. WEAK RIDGING BEHIND THE EXITING SYSTEM WILL BRING MOSTLY
DRY CONDITIONS LATE WEDNESDAY INTO THURSDAY. A SHOWER OR TWO COULD
MAKE IT INTO PORTIONS OF NORTHEASTERN WY FROM THE MTS WEDNESDAY
NIGHT.
A GRADUAL WARMUP IS EXPECTED LATE IN THE WEEK...WITH TEMPERATURES
BACK ABOVE AVERAGE LEVELS BY THE WEEKEND. SOUTHWEST FLOW ALOFT WILL
DEVELOP ACROSS THE REGION BY THE END OF THE WEEK AS AN UPPER LOW
STALLS ACROSS THE PACIFIC NW. SOUTHEASTERLY WINDS AT THE SURFACE
WILL BRING INCREASING LOW LEVEL MOISTURE INTO THE NORTHERN
PLAINS...ESPECIALLY EAST OF THE BLACK HILLS. THIS SETUP SHOULD BRING
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS TO A GOOD PORTION OF THE
AREA FROM FRIDAY THROUGH THE HOLIDAY WEEKEND. DEPENDING ON THE
TIMING AND STRENGTH OF THE DISTURBANCES PASSING THROUGH THE
AREA...THIS COULD BE AN ACTIVE PERIOD FOR SEVERE WX...ESPECIALLY FOR
THE BLACK HILLS AND EASTWARD ACROSS THE SD PLAINS.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT
ISSUED AT 235 AM MDT MON MAY 20 2013
OCCASIONAL RAIN SHOWERS WILL CONTINUE THROUGH TODAY AND INTO TONIGHT
ACROSS THE AREA...WITH MVFR/IFR CONDITIONS GENERALLY PERSISTING
ACROSS MOST OF THE AREA. A MORE STEADY RAIN IS EXPECTED ACROSS THE
NORTHERN BLACK HILLS INTO PORTIONS OF NORTHEASTERN WYOMING AND FAR
NORTHWESTERN SOUTH DAKOTA TODAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM MDT TUESDAY FOR SDZ001-002-012-013-026-
031-072-073.
WIND ADVISORY FROM 6 AM THIS MORNING TO 7 PM MDT TUESDAY FOR
SDZ030-041.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...26
000
FXUS63 KUNR 200422
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1022 PM MDT SUN MAY 19 2013
.UPDATE...
ISSUED AT 1015 PM MDT SUN MAY 19 2013
LATEST SFC ANALYSIS SHOWS LOW PRESSURE CENTERED OVER NORTH
CENTRAL SD. A SFC TROUGH ROTATING AROUND THE WEST SIDE OF THE LOW
IS TIGHTENING THE SFC PRESSURE GRADIENT AND INCREASING THE WIND OVER
NORTHWESTERN SOUTH DAKOTA. THEREFORE WILL START THE WIND ADVISORY
OVER NORTHWESTERN SOUTH DAKOTA NOW INSTEAD OF AT MIDNIGHT AS
ORIGINALLY PLANNED.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 300 PM MDT SUN MAY 19 2013
LARGE UPPER LOW IS CURRENTLY OVER NORTH CENTRAL SD. RAIN SHOWERS ARE
WRAPPING AROUND IT OVER THE BLACK HILLS INTO SOUTHWESTERN SD WITH
ANOTHER BAND MOVING SOUTHWARD FROM WESTERN NORTH DAKOTA. SURFACE LOW
PRESSURE HAS BEEN STATIONARY JUST WEST OF ABR WITH STRONG PRESSURE
GRADIENT BEHIND IT.
UPPER LOW WILL REMAIN OVER THE DAKOTAS-WESTERN MINNESOTA THROUGH
TUESDAY MORNING...AND PRODUCE WIDESPREAD RAIN TO THE FORECAST AREA.
FORECAST MODELS SHOW FRONTOGENESIS OVER NORTHWESTERN SD TONIGHT...MOVING
INTO SOUTHWESTERN SD MONDAY MORNING. VIRTUALLY NO INSTABILITY
INDICATED... SO DID NOT INCLUDE MENTION OF THUNDER. STRONG THETA-E
ADVECTION WILL BE ACROSS NORTH DAKOTA...AND MODELS HAVE
DRASTICALLY CUT BACK QPF FROM LAST RUN...WITH MOST AREAS NOW
SHOWING POTENTIAL FOR 0.50 TO 1.00 INCHES OF RAIN. HEAVIEST RAIN
WILL FALL OVER THE NORTHERN BLACK HILLS AS STRONG NORTHWEST
UPSLOPE WINDS WILL PRODUCE HIGH FROUDE VALUES THROUGH MIDDAY
TUESDAY...WITH AS MUCH AS 2 TO 3 INCHES OF RAIN WILL FALL. 850MB
TEMPERATURES WILL COOL TO AROUND 4C...SO SOME SNOW IS POSSIBLE
OVER THE HIGHEST ELEVATIONS OF THE BLACK HILL...BUT LEAD WILL NOT
SET ANY SNOWFALL RECORDS. THE RAIN THAT HAS FALLEN ALREADY HAS
BEEN SOAKING INTO THE GROUND...SO ADDITIONAL RAIN WILL START
RUNNING INTO STREAMS...BUT DO NOT EXPECT FLOODING.
THE SURFACE LOW WILL WOBBLE AROUND THE EASTERN DAKOTAS-WESTERN
MINNESOTA...WITH A STRONG PRESSURE GRADIENT OVER WESTERN SD
PLAINS. MOMENTUM TRANSFER SHOWS WINDS OF 30-40 KT ON THE PLAINS
FROM BUFFALO TO EDGEMONT LATE TONIGHT THROUGH MONDAY...SO ISSUED A WIND
ADVISORY. COOLER AIR WILL MOVE OVER THE FORECAST AREA.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 300 PM MDT SUN MAY 19 2013
SHOWERS WILL REMAIN AROUND THE AREA ON TUESDAY AS UPPER LOW IS
PROGGED TO BE SOMEWHERE OVER EASTERN SD DURING THE DAY. THE HIGHEST
CHANCES FOR RAINFALL ON TUESDAY WILL LIKELY BE ACROSS THE NORTHERN
BLACK HILLS...WHERE MOIST UPSLOPE FLOW WILL CONTINUE...ESPECIALLY IN
THE MORNING. ELSEWHERE...SHOWERS SHOULD BEGIN TO TAPER OFF IN
INTENSITY...AND EVENTUALLY IN COVERAGE AS WELL...TUESDAY INTO
TUESDAY NIGHT. MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH LOW
FINALLY SHIFTING EASTWARD ACROSS THE UPPER MIDWEST TUESDAY NIGHT AND
WEDNESDAY...WITH SHOWERS GENERALLY DISSIPATING FROM WEST TO EAST
ACROSS THE CWA DURING THIS TIME.
WEAK RIDGING BEHIND EXITING SYSTEM WILL BRING MOSTLY DRY CONDITIONS
LATER WEDNESDAY INTO THURSDAY. A GRADUAL WARMUP IS EXPECTED LATE IN
THE WEEK...WITH TEMPERATURES BACK ABOVE AVERAGE LEVELS BY THE
WEEKEND. SOUTHWEST FLOW ALOFT WILL DEVELOP AGAIN BY THE END OF THE
WEEK...SO WILL SEE CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1015 PM MDT SUN MAY 19 2013
SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE TONIGHT AND
MONDAY...WITH WIDESPREAD MVFR/IFR CONDITIONS. MORE WIDESPREAD
STEADY RAIN CAN BE EXPECTED ACROSS THE NORTHERN BLACK HILLS INTO
PORTIONS OF NORTHEASTERN WYOMING AND NORTHWESTERN SOUTH DAKOTA.
WIDESPREAD IFR TO LOCAL LIFR CONDITIONS ARE EXPECTED OVERNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM MDT TUESDAY FOR SDZ001-002-012-013-026-
031-072-073.
WIND ADVISORY FROM 6 AM MONDAY TO 7 PM MDT TUESDAY FOR SDZ030-
041.
WY...NONE.
&&
$$
UPDATE...10
SHORT TERM...55
LONG TERM...15
AVIATION...10
000
FXUS63 KUNR 192310
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
510 PM MDT SUN MAY 19 2013
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 300 PM MDT SUN MAY 19 2013
LARGE UPPER LOW IS CURRENTLY OVER NORTH CENTRAL SD. RAIN SHOWERS ARE
WRAPPING AROUND IT OVER THE BLACK HILLS INTO SOUTHWESTERN SD WITH
ANOTHER BAND MOVING SOUTHWARD FROM WESTERN NORTH DAKOTA. SURFACE LOW
PRESSURE HAS BEEN STATIONARY JUST WEST OF ABR WITH STRONG PRESSURE
GRADIENT BEHIND IT.
UPPER LOW WILL REMAIN OVER THE DAKOTAS-WESTERN MINNESOTA THROUGH
TUESDAY MORNING...AND PRODUCE WIDESPREAD RAIN TO THE FORECAST AREA.
FORECAST MODELS SHOW FRONTOGENESIS OVER NORTHWESTERN SD TONIGHT...MOVING
INTO SOUTHWESTERN SD MONDAY MORNING. VIRTUALLY NO INSTABILITY
INDICATED... SO DID NOT INCLUDE MENTION OF THUNDER. STRONG THETA-E
ADVECTION WILL BE ACROSS NORTH DAKOTA...AND MODELS HAVE
DRASTICALLY CUT BACK QPF FROM LAST RUN...WITH MOST AREAS NOW
SHOWING POTENTIAL FOR 0.50 TO 1.00 INCHES OF RAIN. HEAVIEST RAIN
WILL FALL OVER THE NORTHERN BLACK HILLS AS STRONG NORTHWEST
UPSLOPE WINDS WILL PRODUCE HIGH FROUDE VALUES THROUGH MIDDAY
TUESDAY...WITH AS MUCH AS 2 TO 3 INCHES OF RAIN WILL FALL. 850MB
TEMPERATURES WILL COOL TO AROUND 4C...SO SOME SNOW IS POSSIBLE
OVER THE HIGHEST ELEVATIONS OF THE BLACK HILL...BUT LEAD WILL NOT
SET ANY SNOWFALL RECORDS. THE RAIN THAT HAS FALLEN ALREADY HAS
BEEN SOAKING INTO THE GROUND...SO ADDITIONAL RAIN WILL START
RUNNING INTO STREAMS...BUT DO NOT EXPECT FLOODING.
THE SURFACE LOW WILL WOBBLE AROUND THE EASTERN DAKOTAS-WESTERN
MINNESOTA...WITH A STRONG PRESSURE GRADIENT OVER WESTERN SD
PLAINS. MOMENTUM TRANSFER SHOWS WINDS OF 30-40 KT ON THE PLAINS
FROM BUFFALO TO EDGEMONT LATE TONIGHT THROUGH MONDAY...SO ISSUED A WIND
ADVISORY. COOLER AIR WILL MOVE OVER THE FORECAST AREA.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 300 PM MDT SUN MAY 19 2013
SHOWERS WILL REMAIN AROUND THE AREA ON TUESDAY AS UPPER LOW IS
PROGGED TO BE SOMEWHERE OVER EASTERN SD DURING THE DAY. THE HIGHEST
CHANCES FOR RAINFALL ON TUESDAY WILL LIKELY BE ACROSS THE NORTHERN
BLACK HILLS...WHERE MOIST UPSLOPE FLOW WILL CONTINUE...ESPECIALLY IN
THE MORNING. ELSEWHERE...SHOWERS SHOULD BEGIN TO TAPER OFF IN
INTENSITY...AND EVENTUALLY IN COVERAGE AS WELL...TUESDAY INTO
TUESDAY NIGHT. MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH LOW
FINALLY SHIFTING EASTWARD ACROSS THE UPPER MIDWEST TUESDAY NIGHT AND
WEDNESDAY...WITH SHOWERS GENERALLY DISSIPATING FROM WEST TO EAST
ACROSS THE CWA DURING THIS TIME.
WEAK RIDGING BEHIND EXITING SYSTEM WILL BRING MOSTLY DRY CONDITIONS
LATER WEDNESDAY INTO THURSDAY. A GRADUAL WARMUP IS EXPECTED LATE IN
THE WEEK...WITH TEMPERATURES BACK ABOVE AVERAGE LEVELS BY THE
WEEKEND. SOUTHWEST FLOW ALOFT WILL DEVELOP AGAIN BY THE END OF THE
WEEK...SO WILL SEE CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 508 PM MDT SUN MAY 19 2013
SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE INTO THIS EVENING
OVER MUCH OF WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING...WITH
WIDESPREAD MVFR/IFR CONDITIONS. A FEW EMBEDDED THUNDERSTORMS WILL
BE POSSIBLE ACROSS SOUTHERN AND SOUTH CENTRAL SOUTH DAKOTA THROUGH
EARLY EVENING. RAIN SHOWERS WILL CONTINUE OVERNIGHT ACROSS THE
AREA...WITH MORE WIDESPREAD STEADY RAIN ACROSS THE NORTHERN BLACK
HILLS INTO PORTIONS OF NORTHEASTERN WYOMING AND NORTHWESTERN SOUTH
DAKOTA. WIDESPREAD IFR TO LOCAL LIFR CONDITIONS ARE EXPECTED
OVERNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM MDT TUESDAY FOR
SDZ001-002-012-013-026-031-072-073.
WIND ADVISORY FROM 6 AM MONDAY TO 7 PM MDT TUESDAY FOR SDZ030-
041.
WY...NONE.
&&
$$
SHORT TERM...55
LONG TERM...15
AVIATION...10
000
FXUS63 KUNR 192101
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
301 PM MDT SUN MAY 19 2013
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 300 PM MDT SUN MAY 19 2013
LARGE UPPER LOW IS CURRENTLY OVER NORTH CENTRAL SD. RAIN SHOWERS ARE
WRAPPING AROUND IT OVER THE BLACK HILLS INTO SOUTHWESTERN SD WITH
ANOTHER BAND MOVING SOUTHWARD FROM WESTERN NORTH DAKOTA. SURFACE LOW
PRESSURE HAS BEEN STATIONARY JUST WEST OF ABR WITH STRONG PRESSURE
GRADIENT BEHIND IT.
UPPER LOW WILL REMAIN OVER THE DAKOTAS-WESTERN MINNESOTA THROUGH
TUESDAY MORNING...AND PRODUCE WIDESPREAD RAIN TO THE FORECAST AREA.
FORECAST MODELS SHOW FRONTOGENESIS OVER NORTHWESTERN SD TONIGHT...MOVING
INTO SOUTHWESTERN SD MONDAY MORNING. VIRTUALLY NO INSTABILITY
INDICATED... SO DID NOT INCLUDE MENTION OF THUNDER. STRONG THETA-E
ADVECTION WILL BE ACROSS NORTH DAKOTA...AND MODELS HAVE
DRASTICALLY CUT BACK QPF FROM LAST RUN...WITH MOST AREAS NOW
SHOWING POTENTIAL FOR 0.50 TO 1.00 INCHES OF RAIN. HEAVIEST RAIN
WILL FALL OVER THE NORTHERN BLACK HILLS AS STRONG NORTHWEST
UPSLOPE WINDS WILL PRODUCE HIGH FROUDE VALUES THROUGH MIDDAY
TUESDAY...WITH AS MUCH AS 2 TO 3 INCHES OF RAIN WILL FALL. 850MB
TEMPERATURES WILL COOL TO AROUND 4C...SO SOME SNOW IS POSSIBLE
OVER THE HIGHEST ELEVATIONS OF THE BLACK HILL...BUT LEAD WILL NOT
SET ANY SNOWFALL RECORDS. THE RAIN THAT HAS FALLEN ALREADY HAS
BEEN SOAKING INTO THE GROUND...SO ADDITIONAL RAIN WILL START
RUNNING INTO STREAMS...BUT DO NOT EXPECT FLOODING.
THE SURFACE LOW WILL WABBLE AROUND THE EASTERN DAKOTAS-WESTERN
MINNESOTA...WITH A STRONG PRESSURE GRADIENT OVER WESTERN SD
PLAINS. MOMENTUM TRANSFER SHOWS WINDS OF 30-40 KT ON THE PLAINS FROM
BUFFALO TO EDGEMONT MONDAY...SO ISSUED A WIND ADVISORY FOR THE
DAYTIME HOURS. COOLER AIR WILL MOVE OVER THE FORECAST
AREA.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 300 PM MDT SUN MAY 19 2013
SHOWERS WILL REMAIN AROUND THE AREA ON TUESDAY AS UPPER LOW IS
PROGGED TO BE SOMEWHERE OVER EASTERN SD DURING THE DAY. THE HIGHEST
CHANCES FOR RAINFALL ON TUESDAY WILL LIKELY BE ACROSS THE NORTHERN
BLACK HILLS...WHERE MOIST UPSLOPE FLOW WILL CONTINUE...ESPECIALLY IN
THE MORNING. ELSEWHERE...SHOWERS SHOULD BEGIN TO TAPER OFF IN
INTENSITY...AND EVENTUALLY IN COVERAGE AS WELL...TUESDAY INTO
TUESDAY NIGHT. MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH LOW
FINALLY SHIFTING EASTWARD ACROSS THE UPPER MIDWEST TUESDAY NIGHT AND
WEDNESDAY...WITH SHOWERS GENERALLY DISSIPATING FROM WEST TO EAST
ACROSS THE CWA DURING THIS TIME.
WEAK RIDGING BEHIND EXITING SYSTEM WILL BRING MOSTLY DRY CONDITIONS
LATER WEDNESDAY INTO THURSDAY. A GRADUAL WARMUP IS EXPECTED LATE IN
THE WEEK...WITH TEMPERATURES BACK ABOVE AVERAGE LEVELS BY THE
WEEKEND. SOUTHWEST FLOW ALOFT WILL DEVELOP AGAIN BY THE END OF THE
WEEK...SO WILL SEE CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE
THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON
ISSUED AT 300 PM MDT SUN MAY 19 2013
SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE INTO THIS EVENING
OVER MUCH OF WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING...WITH
AREAS OF MVFR/IFR CONDITIONS. A FEW EMBEDDED THUNDERSTORMS WILL BE
POSSIBLE ACROSS SOUTHERN AND SOUTH CENTRAL SOUTH DAKOTA THROUGH
EARLY EVENING. RAIN SHOWERS WILL CONTINUE OVERNIGHT ACROSS THE
AREA...WITH MORE WIDESPREAD STEADY RAIN ACROSS THE NORTHERN BLACK
HILLS INTO PORTIONS OF NORTHEASTERN WYOMING AND NORTHWESTERN SOUTH
DAKOTA. WIDESPREAD MVFR/IFR TO LOCAL LIFR CONDITIONS ARE EXPECTED
OVERNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 7 AM MONDAY TO 7 PM MDT TUESDAY FOR SDZ001-
002-012-013-026-030-031-041-072-073.
WY...NONE.
&&
$$
SHORT TERM...SS
LONG TERM...15
AVIATION...15
000
FXUS63 KUNR 191735
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1135 AM MDT SUN MAY 19 2013
.UPDATE...
ISSUED AT 1021 AM MDT SUN MAY 19 2013
UPPER LOW OVER CENTRAL DAKOTAS WITH LARGE BAND OF RAIN MOVING
AROUND THE LOW FROM ND INTO NWRN SD. RAIN OVER THE NORTHERN BLACK
HILLS IS UPSLOPE ENHANCED. SURFACE LOW NEAR ABR WITH STRONG
PRESSURE GRADIENT ACROSS WESTERN SD AND INCREASING NW WINDS.
TEMPERATURES WILL NOT WARM MUCH TODAY.
&&
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 242 AM MDT SUN MAY 19 2013
TODAY THROUGH MONDAY...STRONG THETA E ADVECTION IN THE CYCLONIC
FLOW INTO WESTERN SOUTH DAKOTA WILL CONTINUE FOR MOST OF THE NEXT
TWO DAYS. THIS FLOW COMBINED WITH AN ALREADY SATURATED AIRMASS AND
AN UPSLOPE GRADIENT WILL SUPPORT CONTINUOUS PRECIPITATION OVER
WESTERN SOUTH DAKOTA THROUGH MONDAY AND BEYOND. THE NORTHERN BLACK
HILLS IS THE AREA OF CONCERN THROUGH MONDAY BECAUSE THE UPSLOPE
ENHANCEMENT SHOULD BE GREATEST IN THIS AREA. WILL ISSUE A
HYDROLOGIC OUTLOOK FOR THIS SITUATION LATER THIS MORNING...AND
WOULD EXPECT SOME TYPE OF FLOOD WATCH FOR THAT AREA LATER TODAY.
OTHERWISE THE ADVANCING PACIFIC AIRMASS WILL RESULT IN MAXIMUM
TEMPERATURES ABOUT 10 DEGREES COOLER THAN YESTERDAY...AND THEN
DROPPING SEVERAL MORE DEGREES MONDAY AND TUESDAY. GUSTY NORTHERLY
WINDS ARE EXPECTED TO DEVELOP IN THE CYCLONIC FLOW AROUND THE
EASTERN SOUTH DAKOTA LOW CENTER LATE TODAY AND CONTINUE THROUGH
MONDAY. WIND SPEEDS ARE EXPECTED TO REMAIN BELOW ADVISORY
CRITERIA.
&&
.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 242 AM MDT SUN MAY 19 2013
SHOWERS WILL REMAIN AROUND THE AREA ON TUESDAY AS UPPER LOW IS
PROGGED TO BE SOMEWHERE OVER EASTERN SD DURING THE DAY. THE HEAVIEST
RAINFALL POTENTIAL ON TUESDAY WILL LIKELY BE ACROSS THE NORTHERN
BLACK HILLS...WHERE MOIST UPSLOPE FLOW WILL CONTINUE...ESPECIALLY IN
THE MORNING. ELSEWHERE...SHOWERS SHOULD BEGIN TO TAPER OFF IN
INTENSITY...AND EVENTUALLY IN COVERAGE AS WELL...TUESDAY INTO
TUESDAY NIGHT. MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH LOW
FINALLY SHIFTING EASTWARD ACROSS THE UPPER MIDWEST TUESDAY NIGHT AND
WEDNESDAY...WITH SHOWERS GENERALLY DISSIPATING FROM WEST TO EAST
ACROSS THE CWA DURING THIS TIME.
WEAK RIDGING BEHIND EXITING SYSTEM WILL BRING MOSTLY DRY CONDITIONS
LATER WEDNESDAY INTO THURSDAY. A GRADUAL WARMUP IS EXPECTED LATE IN
THE WEEK...WITH TEMPERATURES BACK TO NEAR TO ABOVE AVERAGE LEVELS BY
THE WEEKEND. SOUTHWEST FLOW ALOFT WILL DEVELOP AGAIN BY THE END OF
THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1128 AM MDT SUN MAY 19 2013
SCATTERED TO NUMEROUS RAIN SHOWERS WILL CONTINUE TODAY OVER MUCH
OF WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING...WITH AREAS OF
MVFR/IFR CONDITIONS. A FEW EMBEDDED THUNDERSTORMS WILL BE POSSIBLE
ACROSS SOUTHERN AND SOUTH CENTRAL SOUTH DAKOTA. RAIN SHOWERS WILL
CONTINUE TONIGHT ACROSS THE AREA...WITH MORE WIDESPREAD STEADY
RAIN ACROSS THE NORTHERN BLACK HILLS INTO PORTIONS OF NORTHEASTERN
WYOMING AND NORTHWESTERN SOUTH DAKOTA. WIDESPREAD MVFR/IFR TO
LOCAL LIFR CONDITIONS ARE EXPECTED OVERNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...WFO UNR
LONG TERM...26
AVIATION...15
000
FXUS63 KUNR 191623
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1023 AM MDT SUN MAY 19 2013
.UPDATE...
ISSUED AT 1021 AM MDT SUN MAY 19 2013
UPPER LOW OVER CENTRAL DAKOTAS WITH LARGE BAND OF RAIN MOVING
AROUND THE LOW FROM ND INTO NWRN SD. RAIN OVER THE NORTHERN BLACK
HILLS IS UPSLOPE ENHANCED. SURFACE LOW NEAR ABR WITH STRONG
PRESSURE GRADIENT ACROSS WESTERN SD AND INCREASING NW WINDS.
TEMPERATURES WILL NOT WARM MUCH TODAY.
&&
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 242 AM MDT SUN MAY 19 2013
TODAY THROUGH MONDAY...STRONG THETA E ADVECTION IN THE CYCLONIC
FLOW INTO WESTERN SOUTH DAKOTA WILL CONTINUE FOR MOST OF THE NEXT
TWO DAYS. THIS FLOW COMBINED WITH AN ALREADY SATURATED AIRMASS AND
AN UPSLOPE GRADIENT WILL SUPPORT CONTINUOUS PRECIPITATION OVER
WESTERN SOUTH DAKOTA THROUGH MONDAY AND BEYOND. THE NORTHERN BLACK
HILLS IS THE AREA OF CONCERN THROUGH MONDAY BECAUSE THE UPSLOPE
ENHANCEMENT SHOULD BE GREATEST IN THIS AREA. WILL ISSUE A
HYDROLOGIC OUTLOOK FOR THIS SITUATION LATER THIS MORNING...AND
WOULD EXPECT SOME TYPE OF FLOOD WATCH FOR THAT AREA LATER TODAY.
OTHERWISE THE ADVANCING PACIFIC AIRMASS WILL RESULT IN MAXIMUM
TEMPERATURES ABOUT 10 DEGREES COOLER THAN YESTERDAY...AND THEN
DROPPING SEVERAL MORE DEGREES MONDAY AND TUESDAY. GUSTY NORTHERLY
WINDS ARE EXPECTED TO DEVELOP IN THE CYCLONIC FLOW AROUND THE
EASTERN SOUTH DAKOTA LOW CENTER LATE TODAY AND CONTINUE THROUGH
MONDAY. WIND SPEEDS ARE EXPECTED TO REMAIN BELOW ADVISORY
CRITERIA.
&&
.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 242 AM MDT SUN MAY 19 2013
SHOWERS WILL REMAIN AROUND THE AREA ON TUESDAY AS UPPER LOW IS
PROGGED TO BE SOMEWHERE OVER EASTERN SD DURING THE DAY. THE HEAVIEST
RAINFALL POTENTIAL ON TUESDAY WILL LIKELY BE ACROSS THE NORTHERN
BLACK HILLS...WHERE MOIST UPSLOPE FLOW WILL CONTINUE...ESPECIALLY IN
THE MORNING. ELSEWHERE...SHOWERS SHOULD BEGIN TO TAPER OFF IN
INTENSITY...AND EVENTUALLY IN COVERAGE AS WELL...TUESDAY INTO
TUESDAY NIGHT. MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH LOW
FINALLY SHIFTING EASTWARD ACROSS THE UPPER MIDWEST TUESDAY NIGHT AND
WEDNESDAY...WITH SHOWERS GENERALLY DISSIPATING FROM WEST TO EAST
ACROSS THE CWA DURING THIS TIME.
WEAK RIDGING BEHIND EXITING SYSTEM WILL BRING MOSTLY DRY CONDITIONS
LATER WEDNESDAY INTO THURSDAY. A GRADUAL WARMUP IS EXPECTED LATE IN
THE WEEK...WITH TEMPERATURES BACK TO NEAR TO ABOVE AVERAGE LEVELS BY
THE WEEEKEND. SOUTHWEST FLOW ALOFT WILL DEVELOP AGAIN BY THE END OF
THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING
ISSUED AT 544 AM MDT SUN MAY 19 2013
SCATTERED TO NUMEROUS SHOWERS WILL CONTINUE THIS MORNING OVER MUCH
OF WESTERN SOUTH DAKOTA AND FAR NORTHEASTERN WYOMING...WITH AREAS OF
MVFR/IFR CONDITIONS. RAIN SHOWERS WILL BECOME MORE WIDESPREAD THIS
AFTERNOON WITH A FEW EMBEDDED THUNDERSTORMS POSSIBLE...ESPECIALLY
TOWARD SOUTH CENTRAL SD. MVFR/IFR CIGS WILL BECOME FAIRLY WIDESPREAD
ACROSS THE AREA BY THE EVENING. RAIN WILL CONTINUE TONIGHT...
ESPECIALLY ACROSS THE NORTHERN BLACK HILLS INTO PORTIONS OF
NORTHEASTERN WY AND NORTHWESTERN SD. WIDESPREAD MVFR/IFR CONDITIONS
ARE EXPECTED OVERNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...WFO UNR
LONG TERM...26
AVIATION...26
000
FXUS63 KUNR 191145
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
545 AM MDT SUN MAY 19 2013
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 242 AM MDT SUN MAY 19 2013
A CLOSED LOW HAS SET UP OVER EAST CENTRAL SOUTH DAKOTA
THIS MORNING. SATELLITE IMAGERY SHOWS THE DEVELOPMENT OF A LARGE
BAND OF CLOUDS WRAPPING AROUND THE LOW TO THE NORTH AND WEST INTO A
WELL DEVELOPED COMMA WHICH IS EXTENDING INTO NORTHWEST SOUTH DAKOTA
AND SURROUNDING AREAS. A PERSISTENT BAND OF LIGHT TO MODERATE
SHOWERS ARCING SOUTHWARD FROM NORTH DAKOTA HAS BEGUN TO SLOWLY
EXPAND IN AREA AND NOW COVERS MOST OF WESTERN SOUTH DAKOTA.
TODAY THROUGH MONDAY...STRONG THETA E ADVECTION IN THE CYCLONIC FLOW
INTO WESTERN SOUTH DAKOTA WILL CONTINUE FOR MOST OF THE NEXT TWO
DAYS. THIS FLOW COMBINED WITH AN ALREADY SATURATED AIRMASS AND AN
UPSLOPE GRADIENT WILL SUPPORT CONTINUOUS PRECIPITATION OVER WESTERN
SOUTH DAKOTA THROUGH MONDAY AND BEYOND. THE NORTHERN BLACK HILLS IS
THE AREA OF CONCERN THROUGH MONDAY BECAUSE THE UPSLOPE ENHANCEMENT
SHOULD BE GREATEST IN THIS AREA. WILL ISSUE A HYDROLOGIC OUTLOOK
FOR THIS SITUATION LATER THIS MORNING...AND WOULD EXPECT SOME TYPE
OF FLOOD WATCH FOR THAT AREA LATER TODAY. OTHERWISE THE ADVANCING
PACIFIC AIRMASS WILL RESULT IN MAXIMUM TEMPERATURES ABOUT 10 DEGREES
COOLER THAN YESTERDAY...AND THEN DROPPING SEVERAL MORE DEGREES
MONDAY AND TUESDAY. GUSTY NORTHERLY WINDS ARE EXPECTED TO DEVELOP
IN THE CYCLONIC FLOW AROUND THE EASTERN SOUTH DAKOTA LOW CENTER LATE
TODAY AND CONTINUE THROUGH MONDAY. WIND SPEEDS ARE EXPECTED TO
REMAIN BELOW ADVISORY CRITERIA.
&&
.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 242 AM MDT SUN MAY 19 2013
SHOWERS WILL REMAIN AROUND THE AREA ON TUESDAY AS UPPER LOW IS
PROGGED TO BE SOMEWHERE OVER EASTERN SD DURING THE DAY. THE HEAVIEST
RAINFALL POTENTIAL ON TUESDAY WILL LIKELY BE ACROSS THE NORTHERN
BLACK HILLS...WHERE MOIST UPSLOPE FLOW WILL CONTINUE...ESPECIALLY IN
THE MORNING. ELSEWHERE...SHOWERS SHOULD BEGIN TO TAPER OFF IN
INTENSITY...AND EVENTUALLY IN COVERAGE AS WELL...TUESDAY INTO
TUESDAY NIGHT. MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH LOW
FINALLY SHIFTING EASTWARD ACROSS THE UPPER MIDWEST TUESDAY NIGHT AND
WEDNESDAY...WITH SHOWERS GENERALLY DISSIPATING FROM WEST TO EAST
ACROSS THE CWA DURING THIS TIME.
WEAK RIDGING BEHIND EXITING SYSTEM WILL BRING MOSTLY DRY CONDITIONS
LATER WEDNESDAY INTO THURSDAY. A GRADUAL WARMUP IS EXPECTED LATE IN
THE WEEK...WITH TEMPERATURES BACK TO NEAR TO ABOVE AVERAGE LEVELS BY
THE WEEEKEND. SOUTHWEST FLOW ALOFT WILL DEVELOP AGAIN BY THE END OF
THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING
ISSUED AT 544 AM MDT SUN MAY 19 2013
SCATTERED TO NUMEROUS SHOWERS WILL CONTINUE THIS MORNING OVER MUCH
OF WESTERN SOUTH DAKOTA AND FAR NORTHEASTERN WYOMING...WITH AREAS OF
MVFR/IFR CONDITIONS. RAIN SHOWERS WILL BECOME MORE WIDESPREAD THIS
AFTERNOON WITH A FEW EMBEDDED THUNDERSTORMS POSSIBLE...ESPECIALLY
TOWARD SOUTH CENTRAL SD. MVFR/IFR CIGS WILL BECOME FAIRLY WIDESPREAD
ACROSS THE AREA BY THE EVENING. RAIN WILL CONTINUE TONIGHT...
ESPECIALLY ACROSS THE NORTHERN BLACK HILLS INTO PORTIONS OF
NORTHEASTERN WY AND NORTHWESTERN SD. WIDESPREAD MVFR/IFR CONDITIONS
ARE EXPECTED OVERNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...26
000
FXUS63 KUNR 190844
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
244 AM MDT SUN MAY 19 2013
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 242 AM MDT SUN MAY 19 2013
A CLOSED LOW HAS SET UP OVER EAST CENTRAL SOUTH DAKOTA
THIS MORNING. SATELLITE IMAGERY SHOWS THE DEVELOPMENT OF A LARGE
BAND OF CLOUDS WRAPPING AROUND THE LOW TO THE NORTH AND WEST INTO A
WELL DEVELOPED COMMA WHICH IS EXTENDING INTO NORTHWEST SOUTH DAKOTA
AND SURROUNDING AREAS. A PERSISTENT BAND OF LIGHT TO MODERATE
SHOWERS ARCING SOUTHWARD FROM NORTH DAKOTA HAS BEGUN TO SLOWLY
EXPAND IN AREA AND NOW COVERS MOST OF WESTERN SOUTH DAKOTA.
TODAY THROUGH MONDAY...STRONG THETA E ADVECTION IN THE CYCLONIC FLOW
INTO WESTERN SOUTH DAKOTA WILL CONTINUE FOR MOST OF THE NEXT TWO
DAYS. THIS FLOW COMBINED WITH AN ALREADY SATURATED AIRMASS AND AN
UPSLOPE GRADIENT WILL SUPPORT CONTINUOUS PRECIPITATION OVER WESTERN
SOUTH DAKOTA THROUGH MONDAY AND BEYOND. THE NORTHERN BLACK HILLS IS
THE AREA OF CONCERN THROUGH MONDAY BECAUSE THE UPSLOPE ENHANCEMENT
SHOULD BE GREATEST IN THIS AREA. WILL ISSUE A HYDROLOGIC OUTLOOK
FOR THIS SITUATION LATER THIS MORNING...AND WOULD EXPECT SOME TYPE
OF FLOOD WATCH FOR THAT AREA LATER TODAY. OTHERWISE THE ADVANCING
PACIFIC AIRMASS WILL RESULT IN MAXIMUM TEMPERATURES ABOUT 10 DEGREES
COOLER THAN YESTERDAY...AND THEN DROPPING SEVERAL MORE DEGREES
MONDAY AND TUESDAY. GUSTY NORTHERLY WINDS ARE EXPECTED TO DEVELOP
IN THE CYCLONIC FLOW AROUND THE EASTERN SOUTH DAKOTA LOW CENTER LATE
TODAY AND CONTINUE THROUGH MONDAY. WIND SPEEDS ARE EXPECTED TO
REMAIN BELOW ADVISORY CRITERIA.
&&
.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 242 AM MDT SUN MAY 19 2013
SHOWERS WILL REMAIN AROUND THE AREA ON TUESDAY AS UPPER LOW IS
PROGGED TO BE SOMEWHERE OVER EASTERN SD DURING THE DAY. THE HEAVIEST
RAINFALL POTENTIAL ON TUESDAY WILL LIKELY BE ACROSS THE NORTHERN
BLACK HILLS...WHERE MOIST UPSLOPE FLOW WILL CONTINUE...ESPECIALLY IN
THE MORNING. ELSEWHERE...SHOWERS SHOULD BEGIN TO TAPER OFF IN
INTENSITY...AND EVENTUALLY IN COVERAGE AS WELL...TUESDAY INTO
TUESDAY NIGHT. MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH LOW
FINALLY SHIFTING EASTWARD ACROSS THE UPPER MIDWEST TUESDAY NIGHT AND
WEDNESDAY...WITH SHOWERS GENERALLY DISSIPATING FROM WEST TO EAST
ACROSS THE CWA DURING THIS TIME.
WEAK RIDGING BEHIND EXITING SYSTEM WILL BRING MOSTLY DRY CONDITIONS
LATER WEDNESDAY INTO THURSDAY. A GRADUAL WARMUP IS EXPECTED LATE IN
THE WEEK...WITH TEMPERATURES BACK TO NEAR TO ABOVE AVERAGE LEVELS BY
THE WEEEKEND. SOUTHWEST FLOW ALOFT WILL DEVELOP AGAIN BY THE END OF
THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT
ISSUED AT 242 AM MDT SUN MAY 19 2013
SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS WILL
CONTINUE THROUGH THE EARLY MORNING HOURS OVER WESTERN AND SOUTH
CENTRAL SOUTH DAKOTA AND PARTS OF NORTHEASTERN WYOMING. RAIN SHOWERS
WILL BECOME MORE WIDESPREAD TODAY WITH A FEW EMBEDDED THUNDERSTORMS
POSSIBLE...ESPECIALLY TOWARD SOUTH CENTRAL SD. MVFR/IFR CIGS WILL
INCREASE IN COVERAGE ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST
THIS MORNING...WITH FAIRLY WIDESPREAD MVFR/IFR CONDITIONS BY THE
AFTERNOON. RAIN WILL CONTINUE TONIGHT...MODERATE TO LOCALLY HEAVY AT
TIMES. WIDESPREAD MVFR/IFR CONDITIONS CAN BE EXPECTED.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...26
000
FXUS63 KUNR 190104
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
704 PM MDT SAT MAY 18 2013
.UPDATE...
ISSUED AT 658 PM MDT SAT MAY 18 2013
SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS MUCH OF THE AREA
THIS EVENING. BEST CHANCES FOR SEVERE STORMS WILL BE ALONG A WEAK
SURFACE BOUNDARY FROM ZIEBACH COUNTY THROUGH JACKSON AND BENNETT
COUNTIES. SOME OF THESE STORMS ALONG THE BOUNDARY HAVE BEEN SLOW
MOVING AND PRODUCING HEAVY RAINFALL...SO LOCALIZED FLOODING WILL
BE AN ISSUE THROUGH THE EVENING. AS THE EVENING
PROGRESSES...STORMS WILL SLOWLY SHIFT EAST INTO SOUTH CENTRAL
SOUTH DAKOTA.
&&
.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 203 PM MDT SAT MAY 18 2013
CURRENT SURFACE MAP PLACES WEAK TROF/WARM FRONT ACROSS SOUTHWEST
INTO SOUTH CENTRAL SOUTH DAKOTA. LOW CLOUDS GRADUALLY DISSIPATING
ACROSS THE AREA. ISOLATED TSRA OVER THE BLACK HILLS AND SOUTHWEST
SOUTH DAKOTA. CONVECTION COVERAGE/INTENSITY WILL INCREASE RAPIDLY
THIS AFTERNOON WITH 1000-2000J/KB SBCAPE. SEVERE THUNDERSTORMS
POSSIBLE FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA THIS
AFTERNOON AND EVENING.
UPPER LOW CLOSES OFF OVER SOUTH DAKOTA ON SUNDAY...WITH SOME
DIFFERENCES AMONG MODELS. GFS/GEM MORE INTENSE AND A LITTLE FURTHER
WEST WITH 700MB LOW THAN NAM. WIDESPREAD SHOWERS EXPECTED ACROSS
NORTHEAST WYOMING/WESTERN SOUTH DAKOTA AS STRONG THETA-E ADVECTION
WRAPS AROUND THE NORTH-NORTHWEST SIDE OF UPPER LOW. INCREASING LOW
LEVEL FLOW OUT OF THE NORTH AND STEEP LOW/MID LEVEL LAPSE RATES WILL
RESULT IN UPSLOPE ENHANCED RAINFALL OVER THE NORTHERN BLACK HILLS
AND BEAR LODGE MOUNTAIN...ESPECIALLY SUNDAY NIGHT. WILL BECOME WINDY
ACROSS PLAINS OF WESTERN SOUTH DAKOTA.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 203 PM MDT SAT MAY 18 2013
MEDIUM RANGE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH
PROGRESSION AND TRACK OF UPPER LOW EARLY NEXT WEEK. WITH THE LOW
STILL PROJECTED TO STALL OUT ACROSS THE NORTHERN AND CENTRAL PLAINS
MONDAY INTO TUESDAY...PLENTY OF WRAP AROUND RAINFALL CAN BE EXPECTED
ACROSS MUCH OF THE FORECAST AREA. THERE IS STILL SOME UNCERTAINTY AT
THIS POINT...BUT 1 TO 2 INCHES OF RAIN SHOULD BE COMMON ACROSS THE
AREA FROM LATER SUNDAY INTO TUESDAY...WITH SOME HIGHER AMOUNTS
LIKELY ACROSS THE NORTHERN BLACK HILLS AREA...WHERE UPSLOPE ENHANCED
PRECIPITATION WILL OCCUR. COOL AND WINDY CONDITIONS CAN BE EXPECTED
MONDAY AND TUESDAY...WITH HIGHS IN THE UPPER 40S TO UPPER 50S.
SYSTEM WILL SLOWLY DRIFT EAST OUT OF THE REGION TUESDAY NIGHT OR
EARLY WEDNESDAY...WITH GRADUALLY IMPROVING CONDITIONS FROM WEST TO
EAST. BEYOND WEDNESDAY...THERE SHOULD BE A GRADUAL WARMUP THROUGH
THE LATTER PART OF THE WEEK...ESPECIALLY ACROSS WESTERN AREAS...AS A
WEAK RIDGE MOVES INTO THE PLAINS. WILL GO WITH A MAINLY DRY FORECAST
FOR LATE WEDNESDAY INTO THURSDAY. SOUTHWEST FLOW ALOFT WILL DEVELOP
AGAIN BY THE END OF THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 520 PM MDT SAT MAY 18 2013
AREAS OF MVFR CEILINGS AND VISIBILITIES WITH SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE INTO TONIGHT...WITH SEVERE THUNDERSTORMS
EXPECTED THROUGH THIS EVENING FROM THE BLACK HILLS EASTWARD. LOCAL
IFR/LIFR CONDITIONS EXPECTED NEAR STRONGER STORMS. WIDESPREAD IFR
CIGS AND SOME -SHRA WILL DEVELOP ACROSS THE AREA AFTER MIDNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...15
SHORT TERM...7
LONG TERM...15
AVIATION...10
000
FXUS63 KUNR 182332
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
532 PM MDT SAT MAY 18 2013
.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 203 PM MDT SAT MAY 18 2013
CURRENT SURFACE MAP PLACES WEAK TROF/WARM FRONT ACROSS SOUTHWEST
INTO SOUTH CENTRAL SOUTH DAKOTA. LOW CLOUDS GRADUALLY DISSIPATING
ACROSS THE AREA. ISOLATED TSRA OVER THE BLACK HILLS AND SOUTHWEST
SOUTH DAKOTA. CONVECTION COVERAGE/INTENSITY WILL INCREASE RAPIDLY
THIS AFTERNOON WITH 1000-2000J/KB SBCAPE. SEVERE THUNDERSTORMS
POSSIBLE FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA THIS
AFTERNOON AND EVENING.
UPPER LOW CLOSES OFF OVER SOUTH DAKOTA ON SUNDAY...WITH SOME
DIFFERENCES AMONG MODELS. GFS/GEM MORE INTENSE AND A LITTLE FURTHER
WEST WITH 700MB LOW THAN NAM. WIDESPREAD SHOWERS EXPECTED ACROSS
NORTHEAST WYOMING/WESTERN SOUTH DAKOTA AS STRONG THETA-E ADVECTION
WRAPS AROUND THE NORTH-NORTHWEST SIDE OF UPPER LOW. INCREASING LOW
LEVEL FLOW OUT OF THE NORTH AND STEEP LOW/MID LEVEL LAPSE RATES WILL
RESULT IN UPSLOPE ENHANCED RAINFALL OVER THE NORTHERN BLACK HILLS
AND BEAR LODGE MOUNTAIN...ESPECIALLY SUNDAY NIGHT. WILL BECOME WINDY
ACROSS PLAINS OF WESTERN SOUTH DAKOTA.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 203 PM MDT SAT MAY 18 2013
MEDIUM RANGE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH
PROGRESSION AND TRACK OF UPPER LOW EARLY NEXT WEEK. WITH THE LOW
STILL PROJECTED TO STALL OUT ACROSS THE NORTHERN AND CENTRAL PLAINS
MONDAY INTO TUESDAY...PLENTY OF WRAP AROUND RAINFALL CAN BE EXPECTED
ACROSS MUCH OF THE FORECAST AREA. THERE IS STILL SOME UNCERTAINTY AT
THIS POINT...BUT 1 TO 2 INCHES OF RAIN SHOULD BE COMMON ACROSS THE
AREA FROM LATER SUNDAY INTO TUESDAY...WITH SOME HIGHER AMOUNTS
LIKELY ACROSS THE NORTHERN BLACK HILLS AREA...WHERE UPSLOPE ENHANCED
PRECIPITATION WILL OCCUR. COOL AND WINDY CONDITIONS CAN BE EXPECTED
MONDAY AND TUESDAY...WITH HIGHS IN THE UPPER 40S TO UPPER 50S.
SYSTEM WILL SLOWLY DRIFT EAST OUT OF THE REGION TUESDAY NIGHT OR
EARLY WEDNESDAY...WITH GRADUALLY IMPROVING CONDITIONS FROM WEST TO
EAST. BEYOND WEDNESDAY...THERE SHOULD BE A GRADUAL WARMUP THROUGH
THE LATTER PART OF THE WEEK...ESPECIALLY ACROSS WESTERN AREAS...AS A
WEAK RIDGE MOVES INTO THE PLAINS. WILL GO WITH A MAINLY DRY FORECAST
FOR LATE WEDNESDAY INTO THURSDAY. SOUTHWEST FLOW ALOFT WILL DEVELOP
AGAIN BY THE END OF THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 520 PM MDT SAT MAY 18 2013
AREAS OF MVFR CEILINGS AND VISIBILITIES WITH SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE INTO TONIGHT...WITH SEVERE THUNDERSTORMS
EXPECTED THROUGH THIS EVENING FROM THE BLACK HILLS EASTWARD. LOCAL
IFR/LIFR CONDITIONS EXPECTED NEAR STRONGER STORMS. WIDESPREAD IFR
CIGS AND SOME -SHRA WILL DEVELOP ACROSS THE AREA AFTER MIDNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...7
LONG TERM...15
AVIATION...10
000
FXUS63 KUNR 182004
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
204 PM MDT SAT MAY 18 2013
.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 203 PM MDT SAT MAY 18 2013
CURRENT SURFACE MAP PLACES WEAK TROF/WARM FRONT ACROSS SOUTHWEST
INTO SOUTH CENTRAL SOUTH DAKOTA. LOW CLOUDS GRADUALLY DISSIPATING
ACROSS THE AREA. ISOLATED TSRA OVER THE BLACK HILLS AND SOUTHWEST
SOUTH DAKOTA. CONVECTION COVERAGE/INTENSITY WILL INCREASE RAPIDLY
THIS AFTERNOON WITH 1000-2000J/KB SBCAPE. SEVERE THUNDERSTORMS
POSSIBLE FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA THIS
AFTERNOON AND EVENING.
UPPER LOW CLOSES OFF OVER SOUTH DAKOTA ON SUNDAY...WITH SOME
DIFFERENCES AMONG MODELS. GFS/GEM MORE INTENSE AND A LITTLE FURTHER
WEST WITH 700MB LOW THAN NAM. WIDESPREAD SHOWERS EXPECTED ACROSS
NORTHEAST WYOMING/WESTERN SOUTH DAKOTA AS STRONG THETA-E ADVECTION
WRAPS AROUND THE NORTH-NORTHWEST SIDE OF UPPER LOW. INCREASING LOW
LEVEL FLOW OUT OF THE NORTH AND STEEP LOW/MID LEVEL LAPSE RATES WILL
RESULT IN UPSLOPE ENHANCED RAINFALL OVER THE NORTHERN BLACK HILLS
AND BEAR LODGE MOUNTAIN...ESPECIALLY SUNDAY NIGHT. WILL BECOME WINDY
ACROSS PLAINS OF WESTERN SOUTH DAKOTA.
.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 203 PM MDT SAT MAY 18 2013
MEDIUM RANGE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH
PROGRESSION AND TRACK OF UPPER LOW EARLY NEXT WEEK. WITH THE LOW
STILL PROJECTED TO STALL OUT ACROSS THE NORTHERN AND CENTRAL PLAINS
MONDAY INTO TUESDAY...PLENTY OF WRAP AROUND RAINFALL CAN BE EXPECTED
ACROSS MUCH OF THE FORECAST AREA. THERE IS STILL SOME UNCERTAINTY AT
THIS POINT...BUT 1 TO 2 INCHES OF RAIN SHOULD BE COMMON ACROSS THE
AREA FROM LATER SUNDAY INTO TUESDAY...WITH SOME HIGHER AMOUNTS
LIKELY ACROSS THE NORTHERN BLACK HILLS AREA...WHERE UPSLOPE ENHANCED
PRECIPITATION WILL OCCUR. COOL AND WINDY CONDITIONS CAN BE EXPECTED
MONDAY AND TUESDAY...WITH HIGHS IN THE UPPER 40S TO UPPER 50S.
SYSTEM WILL SLOWLY DRIFT EAST OUT OF THE REGION TUESDAY NIGHT OR
EARLY WEDNESDAY...WITH GRADUALLY IMPROVING CONDITIONS FROM WEST TO
EAST. BEYOND WEDNESDAY...THERE SHOULD BE A GRADUAL WARMUP THROUGH
THE LATTER PART OF THE WEEK...ESPECIALLY ACROSS WESTERN AREAS...AS A
WEAK RIDGE MOVES INTO THE PLAINS. WILL GO WITH A MAINLY DRY FORECAST
FOR LATE WEDNESDAY INTO THURSDAY. SOUTHWEST FLOW ALOFT WILL DEVELOP
AGAIN BY THE END OF THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON
ISSUED AT 203 PM MDT SAT MAY 18 2013
AREAS OF MVFR CEILINGS AND VISIBILITIES WITH SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE INTO TONIGHT...WITH SEVERE THUNDERSTORMS
EXPECTED THROUGH THIS EVENING FROM THE BLACK HILLS EASTWARD. LOCAL
IFR/LIFR CONDITIONS EXPECTED NEAR STRONGER STORMS. IFR AND LIFR
CEILINGS WITH RAIN WILL SET INTO NORTHEAST WYOMING AFTER MIDNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...7
LONG TERM...15
AVIATION...15
000
FXUS63 KUNR 181748
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1148 AM MDT SAT MAY 18 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 237 AM MDT SAT MAY 18 2013
08Z THE MOST INTENSE LINGERING CONVECTION IS MOSTLY
ALONG AND SOUTH OF THE WARM FRONT IN SOUTH CENTRAL SOUTH DAKOTA AND
NORTHWESTERN NEBRASKA. THE FRONT STRETCHES FROM SOUTHWEST SOUTH
DAKOTA NORTHEASTWARD INTO NORTH CENTRAL SOUTH DAKOTA. THUNDERSTORM
INTENSITIES HAVE DECREASED TO BELOW SEVERE CRITERIA...BUT BRIEF HEAVY
RAIN SMALL HAIL AND LIGHTNING ARE ALL THREATS FROM THESE
STORMS...ESPECIALLY THE CLUSTER MOVING THROUGH NORTHERN JACKSON
COUNTY...AND THE MEDIUM SIZE MCS MOVING NORTHEAST OUT OF CHERRY
COUNTY NEBRASKA. A SURFACE LOW HAS FORMED ON THE FRONT IN
SOUTHWESTERN SOUTH DAKOTA AS DEPICTED IN THE HPC PROGS. IN THE WAKE
OF THE LARGE CONVECTIVE COMPLEXES SKIES HAVE CLEARED SIGNIFICANTLY
OVER NORTHEASTERN WYOMING AND SOME OF WESTERN SOUTH DAKOTA. LOCALLY
DENSE FOG HAS FORMED OVER PARTS OF NORTHEAST WYOMING...AND MORE FOG
CAN BE EXPECTED TO DEVELOP IN WESTERN SOUTH DAKOTA AS SKIES CONTINUE
TO CLEAR TO THE EAST THROUGH THE MORNING HOURS.
TODAY AND TONIGHT...THE PREVIOUS LARGE SCALE SCENARIO DESCRIPTION
IS STILL ON TRACK WITH THE NORTHERN MOST OF THE TWO WEAK SURFACE
LOWS NOW IN SOUTHWESTERN SOUTH DAKOTA AND DRIFTING NORTHEASTWARD.
THIS IS LIKELY TO DEVELOP A SHARP KINK IN THE FRONT EARLY THIS
MORNING...SETTING UP A NORTH/SOUTH BOUNDARY IN THE EASTERN PART OF
THE UNR CWA BY MIDDAY. THIS BOUNDARY SHOULD SERVE AS THE FOCUS FOR
THE FIRST ROUND OF CONVECTION WHILE SKIES ARE STILL MOSTLY SUNNY
THROUGH EARLY AFTERNOON. BY LATER IN THE DAY THE UPPER LEVEL
DYNAMICS ASSOCIATED WITH THE MAIN BODY OF THE PACIFIC TROUGH WILL
DETERMINE WHERE THE LARGEST CLUSTERS OF THUNDERSTORMS DEVELOP FOR
THE REMAINDER OF THE EVENT. MODEL SOUNDINGS SHOW A VERY MOIST
AIRMASS WITH PLENTY OF INSTABILITY AND SHEAR FOR
SUPERCELLS...ESPECIALLY NEAR THE FRONT. MCS DEVELOPMENT IS LIKELY
AS THE MAIN VORTICITY CENTER MOVES ACROSS WESTERN SOUTH DAKOTA
SATURDAY EVENING. A FEW SPOTS RECEIVED SEVERAL INCHES OF RAIN
FRIDAY EVENING AND WILL NEED TO BE MONITORED FOR FLASH FLOOD
POTENTIAL THIS AFTERNOON.
SUNDAY...PRECIPITATION PRODUCTION WILL SWITCH OVER MOSTLY TO
ISENTROPIC PROCESSES AS THE SURFACE TROUGH MOVES INTO THE EASTERN
DAKOTAS DURING THE OVERNIGHT HOURS EARLY SUNDAY MORNING. SHEAR AND
INSTABILITY ARE EXPECTED TO DECREASE SIGNIFICANTLY IN THE SATURATED
AIRMASS AS THE WRAP AROUND CONVEYOR SETS UP FOR THE HIGH PLAINS.
THE POTENTIAL FOR A SLOW GENTLE RAIN EVENT FOR MOST AREAS ON SUNDAY
IS APPEALING AS DROUGHT CONDITIONS HAVE ONLY IMPROVED A LITTLE.
MAXIMUM TEMPERATURES WILL TOP OUT IN THE 60S IN THE COOL PACIFIC
AIRMASS ACCOMPANYING THE TROUGH.
&&
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 237 AM MDT SAT MAY 18 2013
MEDIUM RANGE MODELS REMAIN IN GENERAL AGREEMENT WITH PROGRESSION AND
TRACK OF UPPER LOW EARLY NEXT WEEK...BUT CONTINUE TO TREND THE
SYSTEM A BIT FURTHER SOUTH WITH EACH MODEL RUN. WITH THE LOW STILL
PROJECTED TO STALL OUT ACROSS THE SOUTHEASTERN SD AREA MONDAY INTO
TUESDAY...PLENTY OF WRAP AROUND RAINFALL CAN BE EXPECTED ACROSS MUCH
OF THE FORECAST AREA. THE LATEST CONSENSUS WOULD STILL BRING
SIGNIFICANT RAINFALL TO THE AREA...WITH SOUTHERN SD POTENTIALLY
RECEIVING THE HIGHEST AMOUNTS AND FAR NORTHERN PORTIONS OF NW SD
INTO NORTHEASTERN WY POSSIBLY SEEING A BIT LESS RAINFALL. THERE IS
STILL PLENTY OF UNCERTAINTY AT THIS POINT...BUT 1 TO 2 INCHES OF
RAIN SHOULD BE COMMON ACROSS THE AREA FROM LATER SUNDAY INTO
TUESDAY...WITH SOME HIGHER AMOUNTS LIKELY ACROSS SOUTHERN
SD...ESPECIALLY TOWARD SOUTH CENTRAL SD. WILL KEEP LIKELY TO
CATEGORICAL POPS ACROSS THE AREA MONDAY AND MONDAY NIGHT. THERE
STILL LOOKS TO BE SOME POTENTIAL FOR SNOW ACROSS THE HIGHEST
ELEVATIONS OF THE BLACK HILLS LATE MONDAY NIGHT/EARLY TUESDAY...BUT
WILL LEAVE OUT POSSIBILITY UNTIL THE FORECAST BECOMES MORE CLEAR.
COOL AND BREEZY/WINDY CONDITIONS CAN BE EXPECTED MONDAY AND
TUESDAY...WITH HIGHS IN THE 50S AND LOWER 60S.
AT THIS POINT...IT STILL LOOKS THE SYSTEM WILL EJECT EASTWARD OUT OF
THE REGION LATER TUESDAY AND TUESDAY NIGHT...WITH GRADUALLY
IMPROVING CONDITIONS FROM WEST TO EAST. BEYOND TUESDAY...THERE
SHOULD BE A GRADUAL WARMUP FOR THE MIDDLE INTO THE LATTER PART OF
THE WEEK...ESPECIALLY ACROSS WESTERN AREAS...AS A WEAK RIDGE PASSES
THROUGH THE PLAINS. WILL GO WITH A MAINLY DRY FORECAST FOR WEDNESDAY
INTO THURSDAY AS THE RIDGE PASSES. SOUTHWEST FLOW ALOFT WILL DEVELOP
AGAIN BY THE END OF THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1142 AM MDT SAT MAY 18 2013
LOW STRATUS WILL PERSIST ACROSS AREAS OF THE PLAINS THROUGH MID
AFTERNOON...ESPECIALLY NORTHEASTERN WYOMING AND SOUTHERN PORTIONS
OF SD...WITH MVFR AND LOCAL IFR CEILINGS. SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND CONTINUE INTO
TONIGHT...WITH SEVERE THUNDERSTORMS EXPECTED THROUGH THIS EVENING
FROM THE BLACK HILLS EASTWARD. IFR AND LIFR CEILINGS WITH RAIN
WILL SET INTO NORTHEAST WYOMING AFTER MIDNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...15
000
FXUS63 KUNR 181127
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
527 AM MDT SAT MAY 18 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 237 AM MDT SAT MAY 18 2013
08Z THE MOST INTENSE LINGERING CONVECTION IS MOSTLY
ALONG AND SOUTH OF THE WARM FRONT IN SOUTH CENTRAL SOUTH DAKOTA AND
NORTHWESTERN NEBRASKA. THE FRONT STRETCHES FROM SOUTHWEST SOUTH
DAKOTA NORTHEASTWARD INTO NORTH CENTRAL SOUTH DAKOTA. THUNDERSTORM
INTENSITIES HAVE DECREASED TO BELOW SEVERE CRIERIA...BUT BRIEF HEAVY
RAIN SMALL HAIL AND LIGHTNING ARE ALL THREATS FROM THESE
STORMS...ESPECIALLY THE CLUSTER MOVING THROUGH NORTHERN JACKSON
COUNTY...AND THE MEDIUM SIZE MCS MOVING NORTHEAST OUT OF CHERRY
COUNTY NEBRASKA. A SURFACE LOW HAS FORMED ON THE FRONT IN
SOUTHWESTERN SOUTH DAKOTA AS DEPICTED IN THE HPC PROGS. IN THE WAKE
OF THE LARGE CONVECTIVE COMPLEXES SKIES HAVE CLEARED SIGNIFICANTLY
OVER NORTHEASTERN WYOMING AND SOME OF WESTERN SOUTH DAKOTA. LOCALLY
DENSE FOG HAS FORMED OVER PARTS OF NORTHEAST WYOMING...AND MORE FOG
CAN BE EXPECTED TO DEVELOP IN WESTERN SOUTH DAKOTA AS SKIES CONTINUE
TO CLEAR TO THE EAST THROUGH THE MORNING HOURS.
TODAY AND TONIGHT...THE PREVIOUS LARGE SCALE SENARIO DESCRIPTION IS STILL
ON TRACK WITH THE NORTHERN MOST OF THE TWO WEAK SURFACE LOWS NOW IN
SOUTHWESTERN SOUTH DAKOTA AND DRIFTING NORTHEASTWARD. THIS IS LIKELY
TO DEVELOP A SHARP KINK IN THE FRONT EARLY THIS MORNING...SETTING UP
A NORTH/SOUTH BOUNDARY IN THE EASTERN PART OF THE UNR CWA BY MIDDAY.
THIS BOUNDAY SHOULD SERVE AS THE FOCUS FOR THE FIRST ROUND OF
CONVECTION WHILE SKIES ARE STILL MOSTLY SUNNY THROUGH EARLY
AFTERNOON. BY LATER IN THE DAY THE UPPER LEVEL DYNAMICS ASSOCIATED
WITH THE MAIN BODY OF THE PACIFIC TROUGH WILL DETERMINE WHERE THE
LARGEST CLUSTERS OF THUNDERSTORMS DEVELOP FOR THE REMAINDER OF THE
EVENT. MODEL SOUNDINGS SHOW A VERY MOIST AIRMASS WITH PLENTY OF
INSTABILITY AND SHEAR FOR SUPERCELLS...ESPECIALLY NEAR THE FRONT.
MCS DEVELOPMENT IS LIKELY AS THE MAIN VORTICITY CENTER MOVES ACROSS
WESTERN SOUTH DAKOTA SATURDAY EVENING. A FEW SPOTS RECIEVED SEVERAL
INCHES OF RAIN FRIDAY EVENING AND WILL NEED TO BE MONITORED FOR
FLASH FLOOD POTENTIAL THIS AFTERNOON.
SUNDAY...PRECIPITATION PRODUCTION WILL SWITCH OVER MOSTLY TO
ISENTROPIC PROCESSES AS THE SURFACE TROUGH MOVES INTO THE EASTERN
DAKOTAS DURING THE OVERNIGHT HOURS EARLY SUNDAY MORNING. SHEAR AND
INSTABILITY ARE EXPECTED TO DECREASE SIGNIFICANTLY IN THE SATURATED
AIRMASS AS THE WRAP AROUND CONVEYOR SETS UP FOR THE HIGH PLAINS.
THE POTENTIAL FOR A SLOW GENTLE RAIN EVENT FOR MOST AREAS ON SUNDAY
IS APPEALING AS DROUGHT CONDITIONS HAVE ONLY IMPROVED A LITTLE.
MAXIMUM TEMPERATURES WILL TOP OUT IN THE 60S IN THE COOL PACIFIC
AIRMASS ACCOMPANYING THE TROUGH.
&&
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 237 AM MDT SAT MAY 18 2013
MEDIUM RANGE MODELS REMAIN IN GENERAL AGREEMENT WITH PROGRESSION AND
TRACK OF UPPER LOW EARLY NEXT WEEK...BUT CONTINUE TO TREND THE
SYSTEM A BIT FURTHER SOUTH WITH EACH MODEL RUN. WITH THE LOW STILL
PROJECTED TO STALL OUT ACROSS THE SOUTHEASTERN SD AREA MONDAY INTO
TUESDAY...PLENTY OF WRAP AROUND RAINFALL CAN BE EXPECTED ACROSS MUCH
OF THE FORECAST AREA. THE LATEST CONSENSUS WOULD STILL BRING
SIGNIFICANT RAINFALL TO THE AREA...WITH SOUTHERN SD POTENTIALLY
RECEIVING THE HIGHEST AMOUNTS AND FAR NORTHERN PORTIONS OF NW SD
INTO NORTHEASTERN WY POSSIBLY SEEING A BIT LESS RAINFALL. THERE IS
STILL PLENTY OF UNCERTAINTY AT THIS POINT...BUT 1 TO 2 INCHES OF
RAIN SHOULD BE COMMON ACROSS THE AREA FROM LATER SUNDAY INTO
TUESDAY...WITH SOME HIGHER AMOUNTS LIKELY ACROSS SOUTHERN
SD...ESPECIALLY TOWARD SOUTH CENTRAL SD. WILL KEEP LIKELY TO
CATEGORICAL POPS ACROSS THE AREA MONDAY AND MONDAY NIGHT. THERE
STILL LOOKS TO BE SOME POTENTIAL FOR SNOW ACROSS THE HIGHEST
ELEVATIONS OF THE BLACK HILLS LATE MONDAY NIGHT/EARLY TUESDAY...BUT
WILL LEAVE OUT POSSIBILITY UNTIL THE FORECAST BECOMES MORE CLEAR.
COOL AND BREEZY/WINDY CONDITIONS CAN BE EXPECTED MONDAY AND
TUESDAY...WITH HIGHS IN THE 50S AND LOWER 60S.
AT THIS POINT...IT STILL LOOKS THE SYSTEM WILL EJECT EASTWARD OUT OF
THE REGION LATER TUESDAY AND TUESDAY NIGHT...WITH GRADUALLY
IMPROVING CONDITIONS FROM WEST TO EAST. BEYOND TUESDAY...THERE
SHOULD BE A GRADUAL WARMUP FOR THE MIDDLE INTO THE LATTER PART OF
THE WEEK...ESPECIALLY ACROSS WESTERN AREAS...AS A WEAK RIDGE PASSES
THROUGH THE PLAINS. WILL GO WITH A MAINLY DRY FORECAST FOR WEDNESDAY
INTO THURSDAY AS THE RIDGE PASSES. SOUTHWEST FLOW ALOFT WILL DEVELOP
AGAIN BY THE END OF THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING
ISSUED AT 525 AM MDT SAT MAY 18 2013
SHOWERS AND THUNDERSTORMS ACROSS FAR EASTERN PORTIONS OF THE CWA
WILL TRACK EAST OUT OF THE AREA OVER THE NEXT COUPLE OF HOURS. ONLY
ISOLATED SHOWER ACTIVITY IS THEN EXPECTED THROUGH THE REST OF THE
MORNING...MAINLY ACROSS NORTHEASTERN WY...THE BLACK HILLS...AND
NORTHWESTERN SD. LOW CLOUDS AND PATCHY FOG WILL PERSIST ACROSS
AREAS ON THE PLAINS FOR MUCH OF THIS MORNING...ESPECIALLY
NORTHEASTERN WY AND FAR WESTERN SD...WITH IFR AND LOCAL LIFR
CONDITIONS. MORE WIDESPREAD THUNDERSTORM ACTIVITY WILL DEVELOP
THIS AFTERNOON AND CONTINUE INTO TONIGHT...WITH SEVERE
THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING FROM THE BLACK
HILLS EASTWARD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...26
000
FXUS63 KUNR 180839
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
239 AM MDT SAT MAY 18 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 237 AM MDT SAT MAY 18 2013
08Z THE MOST INTENSE LINGERING CONVECTION IS MOSTLY
ALONG AND SOUTH OF THE WARM FRONT IN SOUTH CENTRAL SOUTH DAKOTA AND
NORTHWESTERN NEBRASKA. THE FRONT STRETCHES FROM SOUTHWEST SOUTH
DAKOTA NORTHEASTWARD INTO NORTH CENTRAL SOUTH DAKOTA. THUNDERSTORM
INTENSITIES HAVE DECREASED TO BELOW SEVERE CRIERIA...BUT BRIEF HEAVY
RAIN SMALL HAIL AND LIGHTNING ARE ALL THREATS FROM THESE
STORMS...ESPECIALLY THE CLUSTER MOVING THROUGH NORTHERN JACKSON
COUNTY...AND THE MEDIUM SIZE MCS MOVING NORTHEAST OUT OF CHERRY
COUNTY NEBRASKA. A SURFACE LOW HAS FORMED ON THE FRONT IN
SOUTHWESTERN SOUTH DAKOTA AS DEPICTED IN THE HPC PROGS. IN THE WAKE
OF THE LARGE CONVECTIVE COMPLEXES SKIES HAVE CLEARED SIGNIFICANTLY
OVER NORTHEASTERN WYOMING AND SOME OF WESTERN SOUTH DAKOTA. LOCALLY
DENSE FOG HAS FORMED OVER PARTS OF NORTHEAST WYOMING...AND MORE FOG
CAN BE EXPECTED TO DEVELOP IN WESTERN SOUTH DAKOTA AS SKIES CONTINUE
TO CLEAR TO THE EAST THROUGH THE MORNING HOURS.
TODAY AND TONIGHT...THE PREVIOUS LARGE SCALE SENARIO DESCRIPTION IS STILL
ON TRACK WITH THE NORTHERN MOST OF THE TWO WEAK SURFACE LOWS NOW IN
SOUTHWESTERN SOUTH DAKOTA AND DRIFTING NORTHEASTWARD. THIS IS LIKELY
TO DEVELOP A SHARP KINK IN THE FRONT EARLY THIS MORNING...SETTING UP
A NORTH/SOUTH BOUNDARY IN THE EASTERN PART OF THE UNR CWA BY MIDDAY.
THIS BOUNDAY SHOULD SERVE AS THE FOCUS FOR THE FIRST ROUND OF
CONVECTION WHILE SKIES ARE STILL MOSTLY SUNNY THROUGH EARLY
AFTERNOON. BY LATER IN THE DAY THE UPPER LEVEL DYNAMICS ASSOCIATED
WITH THE MAIN BODY OF THE PACIFIC TROUGH WILL DETERMINE WHERE THE
LARGEST CLUSTERS OF THUNDERSTORMS DEVELOP FOR THE REMAINDER OF THE
EVENT. MODEL SOUNDINGS SHOW A VERY MOIST AIRMASS WITH PLENTY OF
INSTABILITY AND SHEAR FOR SUPERCELLS...ESPECIALLY NEAR THE FRONT.
MCS DEVELOPMENT IS LIKELY AS THE MAIN VORTICITY CENTER MOVES ACROSS
WESTERN SOUTH DAKOTA SATURDAY EVENING. A FEW SPOTS RECIEVED SEVERAL
INCHES OF RAIN FRIDAY EVENING AND WILL NEED TO BE MONITORED FOR
FLASH FLOOD POTENTIAL THIS AFTERNOON.
SUNDAY...PRECIPITATION PRODUCTION WILL SWITCH OVER MOSTLY TO
ISENTROPIC PROCESSES AS THE SURFACE TROUGH MOVES INTO THE EASTERN
DAKOTAS DURING THE OVERNIGHT HOURS EARLY SUNDAY MORNING. SHEAR AND
INSTABILITY ARE EXPECTED TO DECREASE SIGNIFICANTLY IN THE SATURATED
AIRMASS AS THE WRAP AROUND CONVEYOR SETS UP FOR THE HIGH PLAINS.
THE POTENTIAL FOR A SLOW GENTLE RAIN EVENT FOR MOST AREAS ON SUNDAY
IS APPEALING AS DROUGHT CONDITIONS HAVE ONLY IMPROVED A LITTLE.
MAXIMUM TEMPERATURES WILL TOP OUT IN THE 60S IN THE COOL PACIFIC
AIRMASS ACCOMPANYING THE TROUGH.
&&
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 237 AM MDT SAT MAY 18 2013
MEDIUM RANGE MODELS REMAIN IN GENERAL AGREEMENT WITH PROGRESSION AND
TRACK OF UPPER LOW EARLY NEXT WEEK...BUT CONTINUE TO TREND THE
SYSTEM A BIT FURTHER SOUTH WITH EACH MODEL RUN. WITH THE LOW STILL
PROJECTED TO STALL OUT ACROSS THE SOUTHEASTERN SD AREA MONDAY INTO
TUESDAY...PLENTY OF WRAP AROUND RAINFALL CAN BE EXPECTED ACROSS MUCH
OF THE FORECAST AREA. THE LATEST CONSENSUS WOULD STILL BRING
SIGNIFICANT RAINFALL TO THE AREA...WITH SOUTHERN SD POTENTIALLY
RECEIVING THE HIGHEST AMOUNTS AND FAR NORTHERN PORTIONS OF NW SD
INTO NORTHEASTERN WY POSSIBLY SEEING A BIT LESS RAINFALL. THERE IS
STILL PLENTY OF UNCERTAINTY AT THIS POINT...BUT 1 TO 2 INCHES OF
RAIN SHOULD BE COMMON ACROSS THE AREA FROM LATER SUNDAY INTO
TUESDAY...WITH SOME HIGHER AMOUNTS LIKELY ACROSS SOUTHERN
SD...ESPECIALLY TOWARD SOUTH CENTRAL SD. WILL KEEP LIKELY TO
CATEGORICAL POPS ACROSS THE AREA MONDAY AND MONDAY NIGHT. THERE
STILL LOOKS TO BE SOME POTENTIAL FOR SNOW ACROSS THE HIGHEST
ELEVATIONS OF THE BLACK HILLS LATE MONDAY NIGHT/EARLY TUESDAY...BUT
WILL LEAVE OUT POSSIBILITY UNTIL THE FORECAST BECOMES MORE CLEAR.
COOL AND BREEZY/WINDY CONDITIONS CAN BE EXPECTED MONDAY AND
TUESDAY...WITH HIGHS IN THE 50S AND LOWER 60S.
AT THIS POINT...IT STILL LOOKS THE SYSTEM WILL EJECT EASTWARD OUT OF
THE REGION LATER TUESDAY AND TUESDAY NIGHT...WITH GRADUALLY
IMPROVING CONDITIONS FROM WEST TO EAST. BEYOND TUESDAY...THERE
SHOULD BE A GRADUAL WARMUP FOR THE MIDDLE INTO THE LATTER PART OF
THE WEEK...ESPECIALLY ACROSS WESTERN AREAS...AS A WEAK RIDGE PASSES
THROUGH THE PLAINS. WILL GO WITH A MAINLY DRY FORECAST FOR WEDNESDAY
INTO THURSDAY AS THE RIDGE PASSES. SOUTHWEST FLOW ALOFT WILL DEVELOP
AGAIN BY THE END OF THE WEEK...SO WILL SEE CHANCES FOR SHOWERS AND
THUNDERSTORMS INCREASE THURSDAY NIGHT INTO NEXT WEEKEND.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT
ISSUED AT 237 AM MDT SAT MAY 18 2013
SHOWERS AND THUNDERSTORMS ACROSS FAR EASTERN PORTIONS OF THE CWA
WILL TRACK OUT OF THE AREA EARLY THIS MORNING. ONLY ISOLATED SHOWER
ACTIVITY IS THEN EXPECTED THROUGH THE REST OF THE MORNING...MAINLY
ACROSS NORTHEASTERN WY...THE BLACK HILLS...AND NORTHWESTERN SD. LOW
CLOUDS AND PATCHY FOG HAVE DEVELOPED ACROSS AREAS ON THE PLAINS...
ESPECIALLY NORTHEASTERN WY AND FAR WESTERN SD...WITH IFR AND LOCAL
LIFR CONDITIONS. MORE WIDESPREAD THUNDERSTORM ACTIVITY WILL DEVELOP
THIS AFTERNOON AND CONTINUE INTO TONIGHT...WITH SEVERE THUNDERSTORMS
EXPECTED THIS AFTERNOON AND EVENING FROM THE BLACK HILLS EASTWARD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...26
AVIATION...26
000
FXUS63 KUNR 180404
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1004 PM MDT FRI MAY 17 2013
.UPDATE...
ISSUED AT 957 PM MDT FRI MAY 17 2013
EXTENDED WATCH TIL 06Z FOR PORTIONS OF WCNTRL SD TO ACCOUNT FOR
STRONG/SVR LINE CURRENTLY EXTENDING FROM NORTHWEST OF NEWELL TO
NEWCASTLE. DO EXPECT SLOW DECREASE IN ACTIVITY AS THE NIGHT
PROGRESSES.
UPDATE ISSUED AT 415 PM MDT FRI MAY 17 2013
HAVE ADDED TRIPP COUNTY TO WATCH GIVEN CONVECTION OVER ERN CHERRY
COUNTY. HAVE ALSO UPPED POPS SIGNIFICANTLY FOR SWRN SD GIVEN
COMPLEX MOVING NEWD THRU THE NEB PANHANDLE...AND ALSO UPPED POPS
FOR NERN WY GIVEN ACTIVITY ALONG/EAST OF THE BIGHORNS.
&&
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 147 PM MDT FRI MAY 17 2013
19Z SURFACE ANALYSIS HAD LOW PRESSURE OVER SOUTHEAST
WY WITH WARM FRONT NORTHEAST/EAST ACROSS FAR SOUTHERN SD. WATER
VAPOR SHOWED UPPER RIDGE BUILDING OVER THE DAKOTAS AND SHORTWAVE
OVER WESTERN WY. SHORTWAVE WILL TRAVEL NORTHEAST TONIGHT ON A 45KT
MID-LEVEL JET STREAK. SYNOPTIC FORCING WILL SLIGHTLY DEEPEN THE
SURFACE LOW AS IT INCHES NORTHEAST ALONG THE WARM FRONT INTO THE NE
PANHANDLE OVERNIGHT. TD/S IN THE MID/UPPER 50S HAVE POOLED/ADVECTED
WEST AHEAD OF THE WARM FRONT OVER THE SD PLAINS AND FAR NORTHEAST
WY. 1-1.5KJ/KG MLCAPE VALUES EXPECTED DURING PEAK HEATING LATE THIS
AFTERNOON/EARLY THIS EVENING ALONG WITH 0-6KM BULK SHEAR VALUES
RISING TO 20M/S. 0-1KM BULK SHEAR PEAKS NEAR 10M/S EARLY THIS
EVENING NORTHEAST OF SURFACE LOW OVER FAR NORTHEAST WY/BLACK
HILLS/FAR NORTHWEST SD. IF UPPER LEVEL RIDGE BUILDING OVER THE
DAKOTAS DOESN/T SUPPRESS CONVECTION...WOULD EXPECT CLUSTER OF TSRA
TO DEVELOP IN THE FAR NORTHWEST REACHES OF THE CWA LATER THIS
AFTERNOON...MOVING EAST/NORTHEAST OVERNIGHT. ADDITIONAL CLUSTER OF
STORMS MAY DEVELOP NEAR THE WARM FRONT AS 35KT LOW LEVEL JET
DEVELOPS THIS EVENING. CONVECTIVE-ALLOWING MODELS SUPPORT THIS
SCENARIO AS WELL AS A COUPLE OF SUPERCELLS BRINGING LARGE
HAIL/DAMAGING WINDS. ISOLATED TORNADO THREAT LATE THIS
AFTERNOON/EARLY THIS EVENING OVER FAR NORTHEAST WY/AREAS NORTH OF
THE BLACK HILLS. ACTIVITY WILL MERGE INTO A LARGER SCALE CONVECTIVE
SYSTEM AND MOVE EAST OF THE CWA OVERNIGHT. TEMPERATURES NEAR
GUIDANCE.
SATURDAY...SURFACE LOW OVER NE PANHANDLE SINKS INTO EASTERN CO AS
FLOW AHEAD OF IT PUSHES WARM FRONT NORTH INTO A NORTH/SOUTH ORIENTED
BOUNDARY FROM CENTRAL ND INTO NORTHEAST CO. STRONGER SHORTWAVE
ROUNDS UPPER TROUGH OVER THE ROCKIES AND BEGINS TO IMPINGE ON
FRONTAL BOUNDARY SATURDAY AFTERNOON. 2-3KJ/KG SBCAPE FORECAST ALONG
WITH PLENTY OF SHEAR FOR SUPERCELLS. ACTIVITY WILL MERGE INTO A
LARGE CONVECTIVE CLUSTER AHEAD OF SURFACE BOUNDARY SATURDAY EVENING.
ORGANIZED SEVERE THUNDERSTORMS LOOK LIKE A GOOD BET EAST OF THE
BLACK HILLS. AS MCS MOVES EAST OF THE AREA SATURDAY NIGHT...SYNOPTIC
SCALE FORCING AHEAD OF UPPER TROUGH WILL KEEP SHRA/ISOLATED TSRA
GOING OVERNIGHT OVER MUCH THE AREA. TEMPERATURES NEAR GUIDANCE.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 147 PM MDT FRI MAY 17 2013
MEDIUM RANGE MODELS REMAIN IN GENERAL AGREEMENT WITH PROGRESSION
AND TRACK OF UPPER TROF/LOW LATER THIS WEEKEND AND EARLY NEXT
WEEK...WITH MODELS CONTINUING TO TREND THE SYSTEM A BIT FURTHER
SOUTH ACROSS THE REGION. THE CONSENSUS OF THE MODELS AT 00Z WAS TO
MOVE THE TROF ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS SUNDAY INTO SUNDAY NIGHT. UPPER LOW IS THEN PROGGED TO
DEVELOP ACROSS SD SUNDAY NIGHT...WITH THE SYSTEM CUTTING OFF AND
STALLING SOMEWHERE ACROSS EASTERN SD MONDAY INTO TUESDAY. THE
LATEST CONSENSUS WOULD BRING A SIGNIFICANT AMOUNT OF RAINFALL TO
MUCH OF THE FORECAST AREA...ESPECIALLY FROM THE BLACK HILLS AREA
EASTWARD ACROSS MUCH OF SD. 1 TO 3 INCHES OF RAINFALL WOULD
GENERALLY BE EXPECTED ACROSS THESE AREAS FROM SUNDAY INTO
TUESDAY...ESPECIALLY IF THE SYSTEM STALLS OUT OVER EASTERN SD FOR
AS LONG AS IS PROJECTED. ANY DEVIATIONS TO THE TRACK AND SPEED
WOULD ALTER THIS POTENTIAL...BUT THIS IS LOOKING MORE AND MORE
LIKE A SIGNIFICANT RAINFALL EVENT FOR MUCH OF THE AREA.
HAVE RAISED POPS FOR MOST AREAS FROM SUNDAY TO TUESDAY...WITH LIKELY
POPS ACROSS MUCH OF THE AREA SUNDAY THROUGH MONDAY NIGHT. SOME
THUNDERSTORMS ARE EXPECTED ACROSS THE AREA ON SUNDAY...BUT THIS
SHOULD BECOME MORE OF A GENERAL RAIN/SHOWER EVENT SUNDAY NIGHT AND
EARLY NEXT WEEK AS LOW DEVELOPS EAST OF THE AREA AND INSTABILITY
DIMINISHES. TEMPS COULD BECOME COLD ENOUGH LATE SUNDAY NIGHT AND
MONDAY NIGHT FOR SOME SNOW ACROSS THE HIGHEST ELEVATIONS OF THE
BLACK HILLS...BUT WILL LEAVE OUT POSSIBILITY FOR NOW UNTIL THINGS
BECOME A BIT CLEARER WITH REGARD TO THE TRACK. HIGHS SUNDAY ARE
EXPECTED TO BE IN THE 60S TO MID 70S...WARMEST TOWARD SOUTH CENTRAL
SD. COOL AND BREEZY/WINDY CONDITIONS ARE THEN EXPECTED MONDAY AND
TUESDAY.
AT THIS POINT...IT LOOKS THE SYSTEM WILL EJECT SLOWLY EASTWARD OUT
OF THE REGION TUESDAY AND TUESDAY NIGHT...WITH GRADUALLY IMPROVING
CONDITIONS FROM WEST TO EAST. FORECAST UNCERTAINTY INCREASES FOR THE
REST OF THE FORECAST...AS IT WILL BE DETERMINED BY THE PROGRESSION
OF THIS SYSTEM. THERE SHOULD BE A GENERAL WARMING TREND FOR THE
MIDDLE AND LATTER PART OF THE WEEK...ESPECIALLY ACROSS WESTERN
AREAS...BUT POSSIBLY NOT AS SIGNIFICANT AS HAS BEEN EXPECTED. WILL GO
WITH A MAINLY DRY FORECAST FOR WEDNESDAY AND WEDNESDAY NIGHT AS WEAK
RIDGING IS PROGGED TO PASS THROUGH THE REGION BEHIND EXITING SYSTEM.
SOUTHWEST FLOW ALOFT COULD DEVELOP AGAIN BY THE END OF THE
WEEK...WHICH WOULD BRING BACK CHANCES FOR SHOWERS AND STORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 957 PM MDT FRI MAY 17 2013
WIDESPREAD SHOWER AND SEVERE THUNDERSTORM ACTIVITY WILL CONTINUE
SPREADING EWD LATE THIS EVE/EARLY SATURDAY MORNING ACROSS WRN SD...WITH
LOCAL IFR CONDITIONS EXPECTED NEAR HEAVIER STORMS. IFR/LIFR
STRATUS/FOG IS EXPECTED TO REDEVELOP ON THE SD PLAINS LATE TONIGHT
AND EARLY SATURDAY MORNING. ADDITIONAL WIDESPREAD SHOWER AND
SEVERE THUNDERSTORM ACTIVITY IS EXPECTED SATURDAY AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JOHNSON
SHORT TERM...HELGESON
LONG TERM...13
AVIATION...JOHNSON
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