Area Forecast Discussion Issued by NWS Twin Cities, MN
000
FXUS63 KMPX 140902
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
402 AM CDT FRI JUN 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM CDT FRI JUN 14 2013
LARGE 50H RIDGE WILL FLATTEN OUT AS A COLD FRONTAL BOUNDARY
MAKES ITS WAY INTO THE EASTERN DAKOTAS BY THIS AFTERNOON.
CURRENTLY 0.5 DEGREE REFLECTIVITY INDICATING SHOWERS AND
ISOLATED THUNDERSTORMS STRETCHING FROM REDWOOD FALLS SOUTHEAST
INTO NORTH CENTRAL IA. USED GFS40 310K ISENTROPIC SURF ANALY
TO PROG PROGRESSION AND INTENSITY OF CONVECTION THROUGH
SATURDAY NIGHT. WARM FRONTAL BOUNDARY ACTIVITY SHOULD REMAIN
MAINLY SHOWERS WITH EMBEDDED T-STORMS INTO AT LEAST THE
EARLY AFTN. ALTHOUGH 850MB LI`S DECREASE MARKEDLY BY 15/06Z
...PRETTY FORMIDABLE 700MB CAP BUILDS OVER MUCH OF SW AND
SOUTH CENTRAL MN DURING THE EVENING HOURS. ANTICIPATE CAP
TO BE PUNCTURED OVER SOUTH CENTRAL MN BY EARLY THIS EVENING.
MOISTURE TRANSPORT OVER MUCH OF MN CWA BEGINS TO RAMP UP
BY MID AFTERNOON AND CONTINUES INTO 15/03Z OVER MUCH OF
THIS REGION...THEN SHIFTS TO SOUTH CENTRAL MN INTO WEST
CENTRAL WI INTO 15/09Z TIME PERIOD. VERY STRONG 35 TO 40KT
850MB LOW LEVEL JET NOTED OVER MUCH OF SOUTHERN THIRD
OF MN FROM 15/00-03Z. SATURATED TO SOMEWHAT SATURATED
GROUND OVER FARIBAULT AND FREEBORN COUNTIES ORIGINATING FROM
2 TO 4 INCHES OF RAINFALL ON WEDNESDAY NIGHT HAS PROMPTED THE
ISSUANCE OF A FLASH FLOOD WATCH FOR THESE COUNTIES LATE THIS
AFTERNOON INTO EARLY SATRUDAY EVENING. ALTHOUGH CONFIDENCE IN
SIGNIFICANT FLOODING IS NOT HIGH...PRESENCE OF SLOW MOVING COLD
FRIDAY NIGHT INTO SATURDAY AFTERNOON...COULD GENERATE A PERIOD OF
TRAINING SHOWERS AND THUNDERSTORMS OVER PORTIONS OF THESE COUNTIES.
HOWEVER ...STILL EXPECT BRUNT OF ANY SIGNFICANT MOISTURE TO FALL
OVER NORTHERN AND CENTRAL IOWA...AND PORTIONS OF SE MN. WITH
THAT SAID...AREA OF MN FLOOD POTENTIAL COULD OBSERVE BETWEEN
ONE AND TWO INCHES OF RAINFALL UNDER HEAVIEST T-STORM ACTIVITY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 403 AM CDT FRI JUN 14 2013
NOCTURNAL COMPLEX OF SHOWERS AND THUNDERSTORMS SHOULD WANE A BIT
ON SATURDAY MORNING AS MOISTURE TRANSPORT VEERS OFF IN TYPICAL
WARM SEASON FASHION...BUT EXPECT STORM REIGNITION BY SATURDAY
AFTERNOON AS A SURFACE COLD FRONT PASSES ACROSS THE FORECAST AREA.
BOTH NAM AND GFS MODELS DEPICT DECENT DESTABILIZATION BY 18Z FROM
SOUTH CENTRAL MN INTO CENTRAL WI ALONG/AHEAD OF THE FRONT. WHILE
THE FRONT SHOULD EXIT THE FORECAST AREA PRIOR TO
STALLING...THUNDERSTORMS COULD QUICKLY PRODUCE A QUICK 1 TO 2 INCH
BURST OF HEAVY RAINFALL...GIVEN FORECAST PWATS OF 1.5 TO 2 INCHES
STRADDLING THE MN/IA BORDER. HAVE THEREFORE MAINTAINED THE FLASH
FLOOD WATCH UNTIL 00Z SUNDAY.
PRECIPITATION SHOULD MOVE OFF STEADILY ON SATURDAY EVENING WITH
THE DEPARTURE OF THE FRONT AND ACCOMPANYING SHORTWAVE. SUNDAY
SHOULD BE A FAIRLY BENIGN AND SEASONAL DAY...IN BETWEEN THE
DEPARTING SYSTEM AND AN ADVANCING STACKED CANADIAN LOW PRESSURE
SYSTEM. THIS FEATURE ARRIVES SUNDAY NIGHT AND MONDAY...AND BRINGS
ANOTHER WINDOW OF SHOWERS AND THUNDERSTORMS.
BROAD HIGH PRESSURE EXPANDS ACROSS THE NORTH CENTRAL CONUS ON MONDAY
NIGHT THROUGH THE MIDDLE OF NEXT WEEK...AS WESTERN TROUGHING
FOSTERS MID LEVEL RIDGING DOWNSTREAM OVER THE NORTH CENTRAL CONUS.
THIS SHOULD FACILITATE DRY AND WARM WEATHER FOR THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1059 PM CDT THU JUN 13 2013
NO BIG CHANGES WITH THE 06Z TAF ISSUANCE MOVED THE TIMING OF THE
SHOWERS UP AN HOUR TO REFLECT THE LATEST TRENDS. THERE HAS BEEN A
COUPLE SMALL SHOWERS AND A LIGHTNING STRIKE IN SD THIS EVENING.
STILL LOOKING AT SHOWERS FROM MID MORNING TO MID AFTERNOON...THEN
A BREAK BEFORE THUNDERSTORMS ROLL IN FRIDAY NIGHT. MVFR CIGS/VIS
POSSIBLE WITH THE DOWNPOURS OF RAIN. JUST HAVE VCTS IN THE
FORECAST NOW GIVEN THE UNCERTAINTY OF PLACEMENT...BUT WE ARE
CONFIDENT IN THUNDERSTORMS ACROSS THE AREA FRIDAY NIGHT.
KMSP...
AS MENTIONED ABOVE...NO BIG CHANGES WITH THE 06Z TAF. ACTIVE
WEATHER ARRIVES FRIDAY NIGHT. STILL THINK THUNDER IS UNLIKELY WITH
ANY SHOWERS DURING THE DAY ON FRIDAY. HEAVY RAIN WITH
THUNDERSTORMS LIKELY FRIDAY NIGHT.
/OUTLOOK FOR KMSP/
SAT...MVFR POSSIBLE EARLY IN THE MORNING. WINDS BECOMING WEST 5-10
KTS.
SUN...VFR. WSW WINDS 5-10KTS.
MON...VFR. NNW WINDS 10KTS.
&&
.HYDROLOGY...
ISSUED AT 403 AM CDT FRI JUN 14 2013
ISSUED FLOOD WATCH OVER SMALL PORTION OF SOUTH CENTRAL MN FROM LATE
THIS AFTN INTO EARLY SATURDAY EVENING DUE ACCUMULATINON OF TWO TO
FOUR INCH SWATH OF RAINFALL OVER PORTIONS OF FARIBAULT AND FREEBORN
COUNTIES ON WEDNESDAY NIGHT...AND POTENTIAL FOR TRAINING SHOWERS
AND THUNDESTORMS LATE THIS AFTERNOON AND INTO SATURDAY. THE
POTENTIAL EXISTS FOR ANOTHER ONE TO TWO INCHES OF RAINFALL OVER
THESE COUNTIES...WITH SOMEWHAT HIGHER LOCAL AMOUNTS ALSO POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH FROM THIS AFTERNOON THROUGH SATURDAY EVENING
FOR MNZ092-093.
WI...NONE.
&&
$$
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...CLF
HYDROLOGY...AJZ