Area Forecast Discussion Issued by NWS Grand Forks, ND
000
FXUS63 KFGF 181427
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
927 AM CDT TUE JUN 18 2013
.UPDATE...
ISSUED AT 925 AM CDT TUE JUN 18 2013
NOT ENOUGH CHANGES IN THE GRIDS TO WARRANT AN UPDATE THIS PERIOD.
WILL BE MONITORING TO SEE HOW MUCH CLOUD COVER DEVELOPS WITHIN THE
VALLEY REGION WHICH WILL BE ADDRESSED AT THE 1PM UPDATE. CURRENTLY
ONLY CLOUDS IS MID LEVEL CLUSTER ACROSS FAR NORTHERN FA. ONCE
CONVECTIVE TEMPERATURES IN THE LOWER 70S REACHED WILL SEE HOW MUCH
ADDITIONAL CLOUD COVER DEVELOPS.
UPDATE ISSUED AT 635 AM CDT TUE JUN 18 2013
PATCHY DENSE FOG HAS DEVELOPED WITHIN THE DEVILS LAKE BASIN...BUT
SHOULD DISSIPATE QUICKLY WITH HEATING. MID-LEVEL CLOUDS ARE
DEVELOPING ACROSS THE VALLEY WITHIN THE WEAK INVERTED TROUGH WHERE
CONVECTIVE TEMPS ARE LOWER. THERE WILL LIKELY BE BROKEN CU ACROSS
THE CENTRAL FA INTO THE EARLY AFTERNOON HOURS AND THEN SCATTERING
CLOUDS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 345 AM CDT TUE JUN 18 2013
SHOULD BE A MOSTLY QUIET PERIOD WITH THUNDER POSSIBLE ACROSS THE
SOUTHERN FA LATER WEDNESDAY AFTERNOON. MODELS DIVERGE WITH THE
UPPER LOW ACROSS THE NW CONUS...WITH THE GFS/ECMWF SLOWER THAN
OTHER GUIDANCE. GIVEN THE HIGH AMPLITUDE WAVE PATTERN CLOSED LOWS
USUALLY MOVE SLOWLY...AND WILL FOLLOW THE GFS/ECMWF FOR DETAILS.
THE MAIN AFFECT IS THAT LOW LEVEL MOISTURE AND RESULTANT
INSTABILITY WILL BE SLOWER TO ADVECT INTO THE FA. THIS WILL LEAD
TO MOSTLY DRY AND WARM WEATHER FOR TODAY AND WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE JUN 18 2013
WEDNESDAY NIGHT-THURSDAY NIGHT...IT IS POSSIBLE THAT THERE WILL BE
ISOLATED TO SCATTERED THUNDER ACROSS THE SOUTHERN FA WED NIGHT
WITH A WEAK LOW LEVEL JET...POSSIBLE UPPER WAVES EJECTING FROM THE
UPPER LOW...AND INSTABILITY IN PLACE. THE POTENTIAL FOR STRONG
STORMS FOR WED NIGHT IS EXTREMELY LIMITED CONSIDERING EXPECTED WEAK
INSTABILITY AND DEEP LAYER SHEAR. THE NEXT BEST SEVERE THREAT WILL
BE THURSDAY INTO THURSDAY NIGHT. MODEL GUIDANCE SUGGESTS THAT
THERE WILL BE AN MCS ONGOING NEAR NORTHWEST NORTH DAKOTA 12Z THUR.
SOUTHERLY LOW LEVEL FLOW WILL HAVE BEEN ONGOING FOR A COUPLE
DAYS...AND DEW POINT VALUES SHOULD AT LEAST BE ABLE TO APPROACH
THE MID TO UPPER 60S BY THUR AFTERNOON WITHIN MUCH OF THE FA.
DEPENDING ON HOW CLEAR AND WARM TEMP ARE ABLE TO REACH...MLCAPE
VALUES COULD EXCEED 2000 J/KG BY THE TIME ACTIVITY FROM THE WEST
MOVES INTO THE FA...AND REDEVELOPS AND/OR INTENSIFIES. DEEP LAYER
SHEAR WILL BE SUFFICIENT FOR SEVERE STORMS...BUT EXTENT OF
INSTABILITY IS VERY UNCERTAIN.
FRIDAY-MONDAY...LONG WAVE TROUGH OVER THE WEST COAST AND LONG
WAVE RIDGE OVER THE NORTHERN PLAINS WEAKENS THROUGH THE PERIOD.
SERIES OF UPPER LEVEL DISTURBANCES TO MOVE THROUGH THE REGION THIS
PERIOD WILL MAKE FOR AN ACTIVE PERIOD.
THE ECMWF AND THE GFS WERE SIMILAR AT 84 HOURS. THE ECMWF BECOMES
FASTER THAN THE GFS BY THE END OF THE PERIOD. LITTLE CHANGE TO
TEMPERATURES THIS PERIOD. A DEGREE HIGHER FOR FRI AND MON. NO
CHANGE FOR SAT AND SUN FROM YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 635 AM CDT TUE JUN 18 2013
ANY FOG AND LOWER VSBY AFFECTING KDVL WILL QUICKLY DISSIPATE.
ANTICIPATE BROKEN CU (AROUND 5000 KFT) INTO THE EARLY AFTERNOON
HOURS ACROSS THE VALLEY...WITH A CLEARING TREND THROUGH THE
AFTERNOON HOURS. WINDS WILL BE LIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...TG
LONG TERM...TG/HOPPES
AVIATION...TG