Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 122058
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
358 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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1205 PM CDT SAT APR 12 2014

MAIN CONCERN IN THE FIRST 6 HRS WILL BE MVFR CIGS
CONTINUING/DEVELOPING FROM THE RESIDUAL MOISTURE FROM MORNING
CONVECTION IN S MN. MVFR CIGS HAVE FORMED IN PORTIONS OF EC MN/WC
WI IN THE PAST HR. AS DWPTS REMAIN IN THE 40S...AND AND SOME
FILTERED SUNSHINE THIS AFTN...THERE COULD BE A PERIOD OF AN HR OR
TWO OF MVFR CIGS FOR KSTC/KRNH/KEAU. UNTIL TEMPS BEGIN TO RISE
INTO THE MID TO UPPER 50S... OR LOWER 60S...MIXING AND LCL/S WILL
BE LOW ENOUGH TO GENERATE THE MVFR CIGS. WILL LIKELY ADJUST TAFS
BASED ON CURRENT CONDS BY 1730Z...WITH AN HR OR TWO OF CIGS ARND
1.5 TO 2.0K. ELSEWHERE...ENOUGH DRIER AIR AT LOW LEVELS SHOULD
PRECLUDE CIGS BLW 3K. MOST OF THE CONVECTION WILL REMAIN SOUTH OF
MPX TAF SITES...ONLY HOLDING NEAR THE IA/MN BORDER...ESPECIALLY
EAST/SE OF KAEL. ONCE WINDS SHIFT TO THE NE/N THIS EVENING LOWER
CIGS WILL LIKELY DEVELOP...ESPECIALLY AFT 6Z WITH GUSTY N WINDS
DEVELOPING ALONG WITH ABUNDANT MOISTURE BLW 2K.

KMSP...

FIRST CONCERN IS MVFR CIGS AS CLDS HAVE BEEN TO INCREASE IN EC/SE
MN ARND 1.2 TO 1.5K. WILL HOLD ONTO THIS CIGS THRU 19-20Z...WITH
CIGS DISSIPATING OR RISING ABV 3.0K AS LCL/S INCREASE. CONFIDENCE
REMAINS LOW FOR MVFR CIGS CONTINUING THIS AFTN. EAST WINDS WILL
BECOME MORE NE THIS EVENING AND DECREASE TO LESS THAN 7 KTS. THEN
AFT 6Z WINDS BECOME MORE N/NNW AND INCREASE TOWARD MORNING. CIGS
WILL REDEVELOP AND CONTINUE THRU THE SUNDAY AFTN. NO RAIN/SNOW IS
EXPECTED THRU 00Z/14.

/OUTLOOK FOR KMSP/

SUN EVENING...CHC OF -RA/-SN WITH MVFR CIGS. WINDS N 10-15 KT.
MON...VFR. WINDS NW 10-15 KT.
TUE...VFR. WINDS W 5 TO 10 KT...BECG E/NE BY EVENING.

&&

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

&&

$$

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






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