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000
FXUS63 KFGF 171452
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
952 AM CDT FRI MAY 17 2013

.UPDATE...
ISSUED AT 952 AM CDT FRI MAY 17 2013

CONTINUED THE TREND OF LOWERING SHOWER CHANCES FOR TODAY. THERE IS
AN UPPER WAVE THAT WILL CLIP THE NW FA WITH SCATTERED SHOWERS INTO
THE EARLY AFTERNOON. OTHERWISE...THERE IS LITTLE SUPPORT FOR
PRECIP UNTIL LATER THIS EVENING WHEN STRONGER LOW LEVEL FLOW WILL
INCREASE MOISTURE AND CONVERGENCE. ALSO UPDATED THE SKY TO
INDICATE A PERIOD OF CLEARING ACROSS THE SOUTHERN FA. LOW LEVEL
FLOW WILL INCREASE FROM THE SOUTH TODAY...AND THERE IS A SHARP
GRADIENT FROM 30F DEWPOINTS TO 50F DEWPOINTS JUST SOUTH OF THE FA.
THIS HIGHER MOISTURE SHOULD BE ADVECTED INTO THE FA THROUGH THE
DAY AND INCREASE LOW CLOUDS FROM THE SOUTH. NO BIG CHANGES TO MAX
TEMPS...BUT WE MAY BE TOO LOW FOR SOME AREAS THAT SEE A LONGER
PERIOD OF SOLAR.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 325 AM CDT FRI MAY 17 2013

FORECAST CHALLENGE CONCERNS PCPN CHANCES/AMOUNTS AND TEMPERATURES.
MODELS IN GENERAL AGREEMENT WITH MAIN FEATURES HOWEVER ALL DIFFER
ON QPF SCENARIOS THROUGH THE SHORT TERM. AT THIS POINT WILL USE A
GENERAL BLEND.

PERSISTENT BAND OF -SHRA ASSOCIATED WITH ELEVATED ZONE OF
ENHANCED WARM ADVECTION AND H7 CONVERGENCE SHOULD GRADUALLY WEAKEN
THROUGH THE MORNING AS ABOVE FEATURES WEAKEN AND SHIFT NE. WILL GO
WITH HIGH POP/LOW QPF INTO MID MORNING THEN TRIM BACK ON POPS.
ELSEWHERE CONFIDENCE LOW ON ANY PCPN POTENTIAL THROUGH THE BULK OF
THE DAY. SURFACE LOW AND E-W ORIENTED WARM FRONTAL BOUNDARY ALONG
SD/NE BORDER INTO IA LIFTS SLOWLY THROUGH SD DURING THE DAY.
EXPECT MOST PCPN WILL BE ORIENTED CLOSER TO LOW LEVEL BOUNDARY TO
OUR SOUTH. WILL INCREASE POPS SOMEWHAT LATER IN THE AFTERNOON AS
BOUNDARY APPROACHES. TEMPERATURES WILL BE HIGHLY INFLUENCED BY
CLOUDS. RAISED TEMPERATURES SLIGHTLY ACROSS THE SOUTH WHERE SOME
THINNER CLOUD COVER EXISTS OTHERWISE WILL STICK WITH PERSISTENCE.

AS WARM FRONT LIFTS NORTH TONIGHT EXPECT RAIN CHANCES TO INCREASE
AND BY MID EVENING SOUTHERN AND WESTERN FORECAST AREAS LOOK TO BE
FAVORED AREAS FOR SHRA/TSRA. BEST THUNDER POTENTIAL WILL BE ACROSS
THE SOUTH AS NORTHERN AREAS STILL PRETTY STABLE. BAND OF PCPN
SHOULD LIFT NORTHWARD OVERNIGHT NIGHT AND ADJUSTED POPS
ACCORDINGLY.

FRONTAL BOUNDARY WILL BE ORIENTED ACROSS FA SATURDAY SO INCREASED
POPS. SEVERE POTENTIAL LOOKS BEST LATE IN THE AFTERNOON ACROSS THE
SOUTH HALF OF THE FA WITH FAVORABLE CONVECTIVE PARAMETERS.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 AM CDT FRI MAY 17 2013

SEVERE CONVECTIVE THREAT WILL CONTINUE INTO THE EVENING. WITH
PRECIPITABLE H2O VALUES AROUND 1.5 INCHES HEAVY RAIN WILL BE A
POSSIBILITY. INITIALLY FAVORED AREA FOR HEAVY RAIN LOOKS TO BE
ACROSS S HALF OF FA LIFTING NORTHWARD DURING THE OVERNIGHT.

WITH CUT OFF LOW DEVELOPING VCNTY OF FA POTENTIAL FOR SIGNIFICANT
RAIN WILL CONTINUE THROUGH THE WEEKEND AND WILL NEED TO MONITOR
RAIN AMOUNTS CLOSELY. AT THIS POINT LONG DURATION RAIN EVENT FOR
SURE BUT NOT ENOUGH CONFIDENCE ON ANY PARTICULAR LOCATION FOR
FLOOD/FLASH FLOOD WATCH.

0 UTC GFS/ECMWF/GEM IN GOOD OVERALL AGREEMENT NEXT WEEK...SHOWING A
CLOSED 500 HPA LOW ACROSS SOUTHEAST SD MONDAY MORNING CRAWLING
PAINFULLY SLOW TO THE EAST THROUGH WEDNESDAY. THIS FIRMLY ENTRENCHES
THE FORECAST AREA IN WRAP-AROUND RAIN SHOWERS THROUGH TUESDAY...
SLOWLY DRYING OUT WEDNESDAY AND A RETURN TO DRY CONDITIONS ON THURSDAY.
WILL KEEP THUNDER MENTION THROUGH MONDAY...BUT MOST INSTABILITY
SHOULD MOVE TO THE SOUTH BY TUESDAY. WITH CLOUD COVER AND RAIN...
TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW MID-MAY NORMALS WITH
HIGHS IN THE UPPER 50S AND 60S AND LOWS IN THE 40S/LOWER 50S. WITH
GREATER SUNSHINE AND DRY CONDITIONS...SHOULD SEE SOME AREAS REACHING
70 DEGREES BY THURSDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 640 AM CDT FRI MAY 17 2013

PRIMARILY LOOKING AT VFR CONDITIONS THROUGH THE DAY. A FEW SHOWERS
MAY CLIP THE DVL AREA THIS MORNING. OTHERWISE FEEL ANY SHRA/STORM
DEVELOPMENT WILL HOLD OFF TIL THIS EVENING. SOME MVFR/IFR CIGS
ACROSS WESTERN DAKOTAS BUT NOT ENOUGH CONFIDENCE AS TO HOW FAR
EAST LOWER CIGS WILL GET. THIS WILL NEED TO BE MONITORED.


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

UPDATE...TG
SHORT TERM...VOELKER
LONG TERM...VOELKER/ROGERS
AVIATION...VOELKER