Area Forecast Discussion Issued by NWS Grand Forks, ND
000
FXUS63 KFGF 171154
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
654 AM CDT MON JUN 17 2013
.UPDATE...
ISSUED AT 653 AM CDT MON JUN 17 2013
NO CHANGES PLANNED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT MON JUN 17 2013
CHALLENGE FOR THE FORECAST THIS MORNING WILL BE PLACEMENT OF
SHOWER ACTIVITY THIS AFTERNOON AND TEMPERATURES WITH CLOUDS TODAY.
MODELS IN GOOD AGREEMENT AND WILL CONTINUE TO USE A BLEND FOR THE
FORECAST.
TODAY...500MB SHEAR AXIS AND COLD POOL WILL MOVE OVER THE CWFA
LOWERING CONVECTIVE TEMPS A GOOD 5 TO 10 DEGREES FROM YESTERDAY.
THIS WILL ALLOW SHOWERS AND...GIVEN AFOREMENTIONED COLD POOL
ALOFT...ENOUGH INSTABILITY FOR ISOLATED THUNDERSTORMS TO DEVELOP.
THIS CONVECTIVE ACTIVITY WILL SLOWLY SAG TO THE SOUTH AND EAST
DIMINISHING SHORTLY AFTER SUNSET AS A SFC HIGH BUILDS INTO THE
AREA.
SFC HIGH WILL TRAVERSE THE CWFA TUESDAY MORNING WITH SOME COOLER
MIN TEMPS POSSIBLE...MID TO UPPER 40S ACROSS THE MN TREES. RETURN
FLOW BEGINS ACROSS THE RRV AND DVL BSN KEEPING TEMPS UP INTO THE
LOW 50S. LIGHT SE WINDS TUESDAY WITH TEMPS GREATLY INFLUENCED BY
CLOUD COVER IF ANY...HIGHS IN THE MID TO UPPER 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON JUN 17 2013
TUESDAY NIGHT TO WEDNESDAY NIGHT...SFC HIGH CONTINUES TO TRACK TO
THE SOUTHEAST WITH RETURN FLOW SETTING UP AS 500MB RIDING
OCCURS...LIFTING THE 500MB NW FLOW TO THE NE THROUGH OUT THE DAY
WEDNESDAY. AS A RESULT INCREASING MOISTURE ON THE SOUTHERLY 850MB
WINDS AND POTENTIAL FOR WEAK SW ENERGY TO PULSE OUT OF UPPER LOW
OVER PAC-NW...WILL KEEP MENTION OF CHC POPS WEDNESDAY NIGHT AS
850MB CONVERGENCE MAY PROVIDE ENOUGH LIFT FOR SOME CONVECTIVE
ACTIVITY.
THURSDAY-SUNDAY...MODELS IN GOOD AGREEMENT INDICATING AN UPPER LOW
ACROSS THE NORTHWEST CONUS TO BEGIN THE PERIOD. THIS FEATURE WILL
SLOWLY PROPAGATE EASTWARD AND SHOULD BE LOCATED JUST NORTH OF THE FA
ON SUNDAY. ANTICIPATE MULTIPLE WAVES EJECTING FROM THIS UPPER LOW
AND MOVING THROUGH THE FA. LOW LEVEL SOUTHERLY FLOW WILL ADVECT
HIGHER MOISTURE INTO THE REGION...SETTING THE STAGE FOR AN UNSETTLED
PERIOD. THE POTENTIAL WILL EXIST FOR STRONG TO SEVERE STORMS...BUT
THERE IS STILL SOME UNCERTAINTY AS TO THE DEGREE OF MOISTURE AND
INSTABILITY THAT WILL BE IN PLACE DURING THIS PERIOD. MODELS
DISAGREE WITH TIMING OF POSSIBLE THUNDER COMPLEXES...AND WILL STICK
WITH THE BLENDED SOLUTION. TEMPERATURES WILL BE NEAR NORMAL VALUES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 653 AM CDT MON JUN 17 2013
MVFR CIGS AT DVL THIS MORNING WILL SLOWLY IMPROVE WITH DAYTIME
HEATING. ALSO THIS MORNING 1500FT DECK OF CU APPROACHING BJI AND POSSIBLY
TVF. TEMPO AT BJI LEFT OUT OF TVF FOR UNCERTAINTY. SHOWERS ARE
POSSIBLE AT ALL TAF SITES THIS AFTN W/ MVFR CIGS AROUND 2500 TO
3000FT. NORTH WINDS TODAY BECOMING LIGHT AND VRB OVERNIGHT AS HIGH
PRESSURE MOVES INTO THE NORTHERN PLAINS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JK
SHORT TERM...JK
LONG TERM...TG/JK
AVIATION...JK