000
FXUS63 KFGF 150018 CCA
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
718 PM CDT FRI JUN 14 2013

CORRECTED FOR DIRECTIONAL ERROR IN THE UPDATE SECTION

.UPDATE...
ISSUED AT 718 PM CDT FRI JUN 14 2013

STILL WAITING TO SEE IF ANY STRONG THUNDERSTORMS CAN DEVELOP. THE
SURFACE BOUNDARY IS LOCATED JUST WEST OF THE FA...WITH MLCAPE
AROUND 1000 J/KG ALONG MUCH OF THIS FEATURE...AND NEAR 2000 J/KG
CLOSER TO THE SOUTH DAKOTA BORDER. INITIATION AND COVERAGE OF
STORMS THIS EVENING IS UNCERTAIN. ALTHOUGH SPC MESO-ANALYSIS
INDICATES THAT THE CAP HAD ERODED A FEW HOURS AGO...LAP ANALYSIS
INDICATES THAT THE MLCIN AT 22Z WAS AROUND 100 J/KG...AND HAS
LOWERED TO AROUND 10 J/KG AT 23Z. EXPECT INITIATION WITHIN THE
NEXT 1-2 HOURS IF THERE WILL BE ANYTHING. THE HRRR DOES SHOW THE
POTENTIAL FOR A STRONG STORM OR TWO ACROSS THE SOUTHWEST
FA...WHERE INSTABILITY IS STRONGER...AND SKY IS CLEAR JUST TO THE
WEST. OTHERWISE...MODELS INDICATE 850MB WARM AIR ADVECTION WILL
INCREASE ALONG AND EAST OF THE VALLEY THIS EVENING...WITH SHOWERS
AND THUNDERSTORMS INCREASING IN COVERAGE...ESPECIALLY ACROSS THE
NE FA. THESE STORMS WOULD LIKELY BE AHEAD OF THE STRONGER
INSTABILITY...WHICH WOULD LIMIT SEVERE POTENTIAL. MODIFIED THE POP
AND WX GRID TO ACCOUNT FOR CURRENT ACTIVITY AND THE 20Z HRRR.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM CDT FRI JUN 14 2013

FORECAST CHALLENGE CONCERNS MAINLY NEAR TERM THUNDERSTORM COVERAGE
AND SEVERE POTENTIAL. MODELS OK WITH MAIN FEATURES BUT DIFFER ON
CONVECTIVE QPF AND WILL USE BLEND.

SURFACE BOUNDARY PUSHING INTO CENTRAL DAKOTAS WITH WATER VAPOR
IMAGERY INDICATING SECONDARY WAVE INTO WESTERN DAKOTAS. SOME
MODEST CAPE/INSTABILITY...SHEAR AND 850MB MOISTURE TRANSPORT ALONG AND
AHEAD OF FRONT. THINNING CLOUDS HAVE ALLOWED FOR MORE SOLAR
HOWEVER TEMPERATURES LIKELY TO HOLD SHORT OF CONVECTIVE THRESHOLDS.
CONS FOR DEEP SEVERE POTENTIAL IS STILL QUITE A BIT OF CONVECTIVE
INHIBITION WITH WARM MID LEVEL TEMPERATURES. MODELS HAVE BEEN OVER
FORECASTING DEW POINT TEMPERATURES BY 5 TO 10 DEGREES. THIS
POSSIBLY A RESULT FROM OUR DELAY IN EVAPOTRANSPIRATION WITH SLOW
EMERGENCE OF CROPS. LASTLY LEAD WAVE LIFTING THROUGH NORTHERN FA
AND SUBSIDENCE IN ITS WAKE MAY LIMIT CONVECTIVE INITIATION
POTENTIAL. WITH UNCERTAINTIES REMAINING DID BACK OFF ON LIKELY
POPS FOR A GOOD SHARE OF THE EVENING. BOUNDARY TO PROPAGATE EAST
OVERNIGHT AND ANY CONVECTION WHICH DOES DEVELOP SHOULD EXIT FA SOON
AFTER MIDNIGHT. DEW POINTS UPSTREAM BEHIND BOUNDARY SIMILAR TO CURRENT
VALUES SO OVERNIGHT LOWS SHOULD RANGE THROUGH THE 50S.

COLUMN DRIES NICELY BEHIND BOUNDARY AS SURFACE HIGH PRESSURE.
SOLAR AND SURFACE WESTERLY FLOW SHOULD ALLOW TEMPERATURES TO
RECOVER TO SEASONAL AVERAGES.

QUIET SATURDAY NIGHT WITH SEASONAL MINIMUMS TO CONTINUE.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 PM CDT FRI JUN 14 2013

RESPECTABLE COLD FRONT DROPS THROUGH FA ON SUNDAY. MODEST
INSTABILITY AHEAD OF BOUNDARY COULD LEAD TO SOME AFTERNOON
CONVECTION AND MAINTAINED POPS ACROSS ROUGHLY NORTH HALF OF FA.
COOLER TEMPERATURES WILL BE FELT MOST ACROSS NORTHERN FA IN
STRONGER COLD ADVECTION DURING THE DAY. FAR SOUTH MAY STILL SEE
TEMPERATURES NEAR AVERAGE.

UPPER LEVEL RIDGE WILL KEEP FIRST PART OF THE WORK WEEK
DRY...HOWEVER THIS FEATURE WILL BEGIN TO SHIFT EAST FOR THE SECOND
HALF OF THE WEEK AND BRING AN INCREASED CHANCE FOR TSTMS THU AND
FRI. STRONGEST SOUTHERLY FLOW AND THERMAL RIDGE SHOULD BE WEST OF
REGION...AND NEAR OR SLIGHTLY ABOVE NORMAL TEMPS ARE EXPECTED.
WARMEST DAYS SHOULD BE IN THE MIDDLE OF THE WEEK...RIGHT AROUND THE
80 MARK FOR MOST OF THE AREA.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 650 PM CDT FRI JUN 14 2013

VFR CIGS THROUGH THE EVENING WITH CLEAR SKIES MOVING INTO THE
REGION FROM WEST TO EAST BY SATURDAY MORNING. THE MAIN CONCERN WILL
BE THUNDER CHANCES. COVERAGE IS UNCERTAIN...AND ATTEMPTED TO LIMIT
THE TEMPO GROUPS TO THE MOST LIKELY TIME PERIOD.

&&

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

$$

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