Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 122348
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
648 PM CDT SAT APR 12 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 357 PM CDT SAT APR 12 2014

MAIN OUTFLOW AND SFC FRONT IS NEAR THE IA/MN BORDER WITH A
PERSISTENT E/ESE FLOW ACROSS MOST OF SOUTHERN/CENTRAL MN/WC WI. THIS
WILL MEAN THAT NEARLY ALL OF THE SHRA/TSRA WILL BE SOUTH OF THE IA
BORDER WITH ONLY A CHC ALONG THE I-90 CORRIDOR. IN ADDITION...
SBCAPES/SBCINS ARE FAR ENOUGH SOUTH OF THE IA/MN TO KEEP SVR CHC
NIL IN OUR CWA.

A SECONDARY SHRTWV MOVING ACROSS THE ROCKIES AND INTO THE PLAINS
OVERNIGHT WILL ENHANCE THE LIFT ACROSS NEBRASKA/IA AND FAR SE SD TO
CONTINUE CHC/LIKELY POPS ALONG THE MN/IA BORDER. THICKNESS VALUES
ARE HIGH ENOUGH FOR ALL RAIN AT THIS TIME. TEMPS WILL BE MUCH COOLER
WITH CAA AND NORTH/NW FLOW WILL KEEP HIGHS IN THE 40S.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 357 PM CDT SAT APR 12 2014

LIGHT RAIN WILL END ACROSS WEST CENTRAL WISCONSIN THROUGH SOUTH
CENTRAL MINNESOTA SUNDAY EVENING AS A WAVE OF LOW PRESSURE OVER
IOWA SCOOTS EAST. HIGH PRESSURE ALONG WITH A DRY BUT COOL
NORTHWEST FLOW WILL BUILD OVER THE UPPER MISSISSIPPI VALLEY REGION
FROM MONDAY AND TUESDAY. IT WILL BE BREEZY ON MONDAY WITH A RATHER
TIGHT PRESSURE GRADIENT IN PLACE. WIND SPEEDS OF 15 TO 20 MPH ARE
LIKELY WITH GUSTS REACHING THE MIDDLE TO UPPER 20 MPH RANGE.
LOWS/HIGHS FROM SUNDAY NIGHT THROUGH TUESDAY WILL AVERAGE SOME 10
TO 15 DEGREES BELOW NORMAL.

THE WEDNESDAY THROUGH FRIDAY PERIOD OFFERS A LARGE MODEL SPREAD
BETWEEN THE GFS/GEM AND THE ECMWF. THE GFS AND GEM FORMER WOULD
DEVELOP A VERY WET PATTERN OVER US WEDNESDAY AND THURSDAY ALONG
WITH ACCUMULATING SNOW WHILE THE ECMWF WOULD HAVE A MUCH LIGHTER
PRECIPITATION PATTERN WITH THE MOST SIGNIFICANT PRECIPITATION
ACROSS NORTHERN AREAS OF MINNESOTA AND WISCONSIN. LOOKING AT DP/DT
OF THE SOLUTIONS OVER THE PAST FEW DAYS SHOW THAT BOTH SETS OF
SOLUTIONS HOLDING FIRM. IN FACT...THE GFS FOR WEDNESDAY/THURSDAY
HAS HAD ACCUMULATING SNOW FOR MSP IN BUFKIT FOR 7 RUNS IN A ROW.
OF THOSE 7 RUNS...FIVE HAVE HAD 6 OR MORE INCHES OF ACCUMULATION.
HENCE... THIS IS SOMETHING THAT NEEDS TO BE WATCHED CLOSELY...
ESPECIALLY AFTER THE COLD SEASON WE HAVE BEEN EXPERIENCING. IT
MAY NOT BE OVER YET.

THE CULPRIT TO THIS CHAOS IN THE MID TO LATE WEEK PERIOD IS TIED TO
A SHORT WAVE OVER CENTRAL CANADA MOVING SOUTH...A SHORT WAVE IN
THE NORTHERN STREAM COMING IN THROUGH THE PACIFIC NORTHWEST AND A
SOUTHERN STREAM SHORT WAVE MOVING THROUGH THE SOUTHWEST. THE
GFS PHASES THE CANADIAN AND NORTHERN STREAM SHORT WAVE ENERGY
ACROSS THE NORTHERN PLAINS AND THEN WORKS ON PHASING THIS TO THE
SOUTHERN STREAM BY FRIDAY ACROSS OUR AREA. THE GEM IS A LITTLE FARTHER
WEST WITH THIS IDEA BUT VERY SIMILAR IN TIMING. THE ECMWF ON THE
OTHER HAND ALLOWS THE NORTHERN STREAM ENERGY TO PASS BY WITH THE
CANADIAN SHORT WAVE FOLLOWING IN BEHIND. THE PHASING OF THE
NORTHERN AND SOUTHERN STREAMS DON/T OCCUR UNTIL THESE FEATURES REACH
THE APPALACHIANS. KNOWING THE DIFFICULTY THAT THERE IS WITH
PHASING...A BLENDED SOLUTION BETWEEN THE TWO EXTREMES YIELDED CHANCE
POPS WEDNESDAY AND THURSDAY WITH MUCH OF THE PRECIPITATION BEGIN
RAIN. SMALL POPS LINGER FOR FRIDAY AND SATURDAY TO CLOSE OUT THE
EXTENDED.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 601 PM CDT SAT APR 12 2014

A COLD FRONT EXTENDS FROM NORTHWEST MINNESOTA TO LOW PRESSURE IN
CENTRAL KANSAS. MAIN CONCERN IN THE FIRST 7 HRS WILL BE THE
DEVELOPMENT OF LOW CLOUDS AND WIND SHIFT-SPEEDS AS THE COLD FRONT
PUSHES SOUTHEAST. GUIDANCE REALLY WANTS TO GET CIGS DOWN TO IFR
FROM KMSP EAST WHICH IS SOMEWHAT OVERKILL. THINKING IS WE WILL
SEE MVFR AT OUR MINNESOTA TAF SITES. WHEREAS WE EXPECT IFR AT KRNH
AND KEAU. THERE IS NO SHORTAGE OF LOW LEVEL MOISTURE AVAILABLE SO
WILL HAVE TO MONITOR CIGS TO ENSURE WE DO NOT SLIP INTO IFR RANGE
ESPECIALLY AT KSTC AND KMSP. WILL SEE GUSTY WINDS BEHIND THE FRONT
LATE TONIGHT ACROSS THE NORTHWEST PART OF OUR AREA AND REALLY
GUSTY WINDS SUNDAY AFTERNOON ALONG WITH CIGS IN THE VFR RANGE
...EXCEPT FOR THE WI TAF SITES. ON SUNDAY LOW PRESSURE IN THE
SOUTHERN PLAINS MOVES NORTHEAST TOWARD CHICAGO. DO NOT EXPECT ANY
PRECIPITATION CHANCES UNTIL AFTER 00Z. WOULD NOT BE SURPRISED IF
PRECIPITATION STAYED SOUTH AND EAST OF ALL OF OUR TAF SITES. WINDS
WILL REMAIN FAIRLY STRONG THROUGH MONDAY MORNING DUE TO THE TIGHT
PRESSURE GRADIENT OVER THE AREA.



KMSP...
EAST WINDS WILL BECOME MORE NNE LATE THIS EVENING AND DECREASE TO LESS
THAN 7 KTS. THEN AFT 6Z WINDS BECOME MORE N/NNW AND INCREASE
TOWARD MORNING. SATELLITE INDICATES WE MAY LOSE THE CEILING FOR A
COUPLE OF HOURS BEFORE MVFR CONDITIONS RETURN BUT WILL NOT
INDICATE THAT IN THE TAF SINCE CONFIDENCE IS LACKING. EXPECT LOW END MVFR
CIGS TO DEVELOP AFTER 08Z SUNDAY AND LIFT SLIGHTLY A COUPLE OF
HOURS AFTER DAYBREAK. WINDS WILL GUST TO 30KTS IN THE AFTERNOON.
NO RAIN/SNOW IS EXPECTED THRU 00Z/14. INTRODUCED A TEMPO FOR A
RAIN SNOW MIX AFTER 00Z MONDAY BUT DO NOT HAVE VERY GOOD
CONFIDENCE IN THAT ACTUALLY OCCURRING.

/OUTLOOK FOR KMSP/

MON...VFR. WINDS NW 10-15 KT.
TUE...VFR. WINDS W 5 TO 10 KT...BECG E/NE BY EVENING.
WED...MVFR. WINDS E 10 TO 20 KTS...BECOMING N-NE.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ025-026-028.

&&

$$

SHORT TERM...JLT
LONG TERM...RAH
AVIATION...DRL






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