Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 300908
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
408 AM CDT TUE JUN 30 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE JUN 30 2015

TODAY AND TONIGHT...SFC ANALYSIS SHOWS A CDFNT DRAPED FROM NEAR KGRB
TO THE IA/MN BORDER THEN SNAKING BACK NWWD INTO THE CENTRAL-WRN
DAKOTAS. THE UPR LVL LOW RESPONSIBLE FOR NUDGING THE SFC FRONT SWD
IS SHIFTING EWD THRU THE NRN GRT LKS AND AWAY FROM THE AREA. ANY
LINGERING PRECIP ACTIVITY HAS LONG SINCE DIMINISHED EARLY THIS
MRNG...AND WITH SFC HIGH PRES COMBINED WITH SLIGHT H5 AND H7 HEIGHT
RISES...INDICATING MINOR UPR LVL RIDGING...PLUS DRIER AIR MOVG INTO
THE REGION BEHIND THE FRONT...TUE WILL BE DEVOID OF PRECIPITATION.

THE ONLY REAL CONCERN IS FOR FOG DEVELOPMENT IN WRN WI INTO ERN MN
WHERE WINDS ARE NEARLY CALM AND DECOUPLING FROM 15-20KT WINDS WITHIN
THE BLYR HAS BEEN BETTER ESTABLISHED. METARS HAVE GENERALLY REPORTED
2-4SM VSBY WITH THE OCNL 1/2SM-1/2SM REPORT. SINCE DENSE FOG ONLY
HAS SPOTTY COVERAGE THIS MRNG...HAVE OPTED TO HOLD OFF ISSUING A
DENSE FOG ADVY. WILL MONITOR TRENDS THRU THIS MRNG...BUT AM THINKING
ONLY AREA FOG MENTION SHOULD SUFFICE.

OTHERWISE...A MIX OF CLOUDS SUN AND CLOUDS WILL PREVAIL THRU THE DAY
TDA...WITH PTLY CLDY SKIES CONTINUING INTO TNGT AS MODEST UPR LVL
RIDGING PLUS WEAK SFC HIGH PRES WILL KEEP PRECIP STREAMS OFF TO THE
W AND S OF THE WFO MPX CWFA.

SLIGHTLY COOLER AND LESS HUMID CONDS CAN BE EXPECTED TDA BEHIND THE
FRONT WITH HIGHS RANGING 70-80 DEGREES AND DEWPOINTS DROPPING INTO
THE 50S. AS SUCH...THIS WILL LEAD TO COOLER TEMPS TUE NIGHT WITH
LOWS FROM THE UPR 40S IN WRN WI TO THE UPR 50S IN WRN MN.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE JUN 30 2015

THE MAIN CHANGES TO THE FORECAST IN THE LONG TERM WAS TO TRIM MUCH
OF THE LOW END POPS ACROSS WESTERN WI AND EASTERN MN FURTHER
WEST...SO THE FORECAST READS QUITE A BIT DRIER IN THESE AREAS
THROUGH SATURDAY.

HIGH PRESSURE OVER ONTARIO THIS MORNING WILL DRIFT SOUTH INTO THE
WESTERN GREAT LAKES.  THE LOW LEVEL DRY AIR INTRUSION WILL SPREAD
FURTHER EAST BY TOMORROW.  THE NEWEST RUNS OF THE GFS/EC/NAM/SREF
ALL PUSH THE QPF FURTHER WEST...AND THE REFLECTIVITY FORECAST OFF
THE ARW AND NMM INDICATE ALL ACTIVITY TO REMAIN ACROSS WESTERN MN AN
THE EASTERN DAKOTAS...WHICH MAKES SENSE GIVEN THE SHORTWAVE WILL
MAINLY PASS OVER THE EASTERN DAKOTAS WITH THE PV ADVECTION AND Q-
VECTOR CONVERGENCE FOCUSED THERE.  THIS WAVE WILL DEPART WEDNESDAY
NIGHT...AS POPS AGAIN ARE PULLED BACK TO THE WEST AHEAD OF THE NEXT
WAVE.

THE WAVE ON THURSDAY LOOKS A BIT STRONGER...BUT WILL FOLLOW A
SIMILAR PATH THROUGH THE EASTERN DAKOTAS. STRONGER AND DEEPER
FORCING LOOKS LIKELY...WITH STRONG DIFFERENTIAL DIVERGENCE MOVING
FROM NEAR ABERDEEN...THROUGH SIOUX FALLS AND CONTINUING SOUTHEAST OF
THERE...SO A GLANCING BLOW FOR OUR FORECAST AREA. THE ECMWF HAD BEEN
AN OUTLIER IN CONTINUING TO SHOW PRECIP POTENTIAL THURSDAY NIGHT
ACROSS EASTERN MN AND WESTERN WI...BUT THE 00Z RUN CAME IN MORE IN
LINE WITH A DRY FORECAST FOR THIS AREA AND LOOKS TO BE IN GOOD
AGREEMENT WITH THE NAM/GFS/SREF WHICH ALL INDICATE A FRY FORECAST
FOR EASTERN MN AND WESTERN WI THURSDAY AND THURSDAY NIGHT.

DAILY TEMPERATURES THROUGH FRIDAY WILL BE VERY CONSISTENT AS THE
THERMAL FIELD STAYS MAINLY STAGNANT AS WE REMAIN BETWEEN THE WESTERN
RIDGE...AND THE UPPER TROUGH TO OUR EAST.

FOR THIS WEEKEND...THE SURFACE HIGH OVER THE GREAT LAKES WILL BE
PULLING AWAY...MOVING EAST.  SOUTHERLY LOW LEVEL FLOW WILL
INCREASE...AND THE TEMPERATURES WILL BEGIN INCREASING OVER THE
PREVIOUS FEW DAYS.  THE FOCUS FOR THIS PERIOD WILL BE A STRONGER
SYSTEM DEVELOPING IN CANADA AND PUSHING A COLD FRONT ACROSS OUR
AREA...WHICH LOOKS TO BE LATE IN THE WEEKEND.  CONTINUED A DRY
FORECAST FOR INDEPENDENCE DAY...BUT IN THE SOUTHERLY FLOW WE MAY SEE
SOME INSTABILITY DEVELOP BY THE AFTERNOON. AT THIS POINT
HOWEVER...THE GFS AND ECMWF INDICATE THAT ANY CONVECTIVE DEVELOPMENT
WILL BE NORTH OF OUR AREA DURING THAT TIME...SO I FELT OK LEAVING A
DRY FORECAST IN PLACE BUT AGAIN LATER FORECASTS WILL NEED TO EVALUATE
THIS PERIOD AND POSSIBLY ADD LOW POPS DEPENDING ON THE TIMING OF THE
APPROACHING SYSTEM.

THE GFS/EC AGREE ON THE COLD FRONT SWEEPING THROUGH THE UPPER
MIDWEST...BUT DISAGREE ON TIMING.  THE EC IS ABOUT 12 HOURS FASTER
AND BRINGS THE FRONT....AND THUNDERSTORMS ALONG IT...THROUGH THE
AREA SUNDAY...WHERE THE GFS DOES SO SUNDAY NIGHT INTO MONDAY. SO
WE`LL LIKELY BE DEALING WITH THUNDERSTORMS AT THE END OF THE
WEEKEND...BUT THE EXACT TIMING WILL NEED TO BE SORTED OUT.
TEMPERATURES COULD WARM WELL INTO THE 80S AHEAD OF THE COLD FRONT ON
SUNDAY.

ON THE HEELS OF THIS SYSTEM...NORTHWEST FLOW WILL DRIVE COOLER
TEMPERATURES AND A CANADIAN SURFACE HIGH DOWN INTO THE UPPER MIDWEST
BY TUESDAY...SO EXPECT A COOLING TREND TOWARD THE MIDDLE OF NEXT
WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1151 PM CDT MON JUN 29 2015

MAIN CONCERN IS FOG DEVELOPMENT ACROSS WESTERN WI THROUGH EARLY
TUESDAY MORNING. BOTH WI SITES AND ALSO KMSP HAD RAIN BEFORE
SUNSET...AND WITH LIGHT WINDS AND CLEAR SKIES SHOULD SEE FOG
DEVELOP AGAIN TONIGHT. THIS IS WHERE THE HOPWRF HIGHEST
PROBABILITIES ARE FOR VISIBILITY LESS THAN A HALF MILE. DO NOT
THINK THAT KMSP WILL DROP THAT LOW...BUT THE WI SITES SHOULD
UNLESS THE SYNOPTIC WINDS PICK UP BEFORE SUNRISE.

KMSP...
SHOULD SEE MVFR CONDITIONS DUE TO FOG THROUGH THE MORNING HOURS.
THEN EXPECTING VFR WITH LIGHT NORTHEAST WINDS.

/OUTLOOK FOR KMSP/
WED...VFR. WINDS ENE AT 5-10 KTS.
THU...VFR WITH SLGT CHC MVFR -TSRA. WINDS SE AT 5-10 KTS.
FRI...VFR WITH SLGT CHC MVFR -TSRA. WINDS WSW 5-10 KTS.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...JPC
LONG TERM...SPD
AVIATION...JRB



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