Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
000
FXUS63 KMPX 132112
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
412 PM CDT SUN APR 13 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 112 PM CDT SUN APR 13 2014

OVER THE PAST FEW HRS...AN EXPANDING AREA OF RAIN HAS MOVED INTO
FAR SC/SE MN. ACROSS NW IA...SOME OF THE RAIN HAS CHANGED OVER
OR MIXED WITH SNOW SINCE NOON. THIS IS ALSO THE AREA WHERE THE
MEAN WET BULB TEMP LAYER FROM THE SFC TO 1KM WAS NEAR ZERO. THESE
WET BULB TEMPS ARE QUITE HIGHER ACROSS SC/SE MN...EXTENDING INTO
WC WI THIS AFTN. ANYWHERE FROM +2C TO +6C WET BULB TEMPS WERE
NOTED IN THOSE AREAS.

THERE HAS BEEN AN ABRUPT/SHARP CUTOFF LINE FROM WHERE THE
EXPANDING AREA OF RAIN/SNOW HAS MOVED INTO SW/SC MN. DUE TO THE
PERSISTENT DRIER AIR BLW 3K FROM THE NORTH...THERE WILL BE A VERY
SHARP CUTOFF FROM WHERE RAIN WILL BE MODERATE TO HEAVY AT
TIMES...TO ONLY SPRINKLES. EVENTUALLY AS WET BULB TEMPS FALL THIS
EVENING...THE CHANGE OVER TO SNOW WILL DEVELOP...ESPECIALLY IN
AREAS WHERE THE PRECIPITATION WILL BE LOCALLY HEAVY AT TIMES.
ALTHOUGH THERE WILL BE PERIODS OF MODERATE...POSSIBLY HEAVY SNOW
AT TIMES...A WARM GROUND AND TEMPS ABV FREEZING THRU THE
EVENING...WILL KEEP SNOWFALL TOTALS LOW. THE BEST CHANCE OF 1 TO 2
INCHES OF WET SNOW WILL OCCUR FROM KAEL TO KRGK TO KEAU. NW OF
THIS LINE...ONLY A SLUSHY ONE HALF INCH OR LESS IS POSSIBLE WHERE
SOME MODERATE SNOW IS POSSIBLE. THE PRECIPITATION SHOULD END
QUICKLY AFTER MIDNIGHT ACROSS SC/SE MN AS WELL AS WC WI. THE WINDS
WILL REMAIN BRISK WITH SUSTAINED WINDS OF 20 TO 30...WITH GUSTS
OVER 40 MPH POSSIBLE THIS EVENING/OVERNIGHT. TEMPS ON MONDAY WILL
LIKELY RISE TO NEAR 40 WHERE SNOW COVER IS POSSIBLE IN SE/SC
MN...TO 40 TO 45 DEGREES ELSEWHERE WITH PARTLY CLOUDY SKIES.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 308 PM CDT SUN APR 13 2014

MON NIGHT THRU TUESDAY...COLD AIR WILL RETURN IN EARNEST MON NIGHT
INTO TUE AS THE AXIS OF AN UPR LVL LONGWAVE TROF SWINGS THRU THE
REGION...RESULTING IN ANOTHER SURGE OF CAA LASTING THRU THE DAY ON
TUE. SKIES LOOK TO PARTIALLY CLEAR OUT DURG THIS TIME AS SFC HIGH
PRES MOVES ACRS THE REGION UNDER THE TROF AXIS. THIS WILL FORCE
TEMPS MON NIGHT TO BOTTOM OUT IN THE MID TEENS TO LWR 20S.
ALTHOUGH THERE LOOKS TO BE MORE SUN THAN CLOUDS ON TUE...CAA WILL
LIKELY WIN OUT DESPITE LACK OF SNOW COVERED GROUND READY TO SOAK
UP THE SUN. HIGHS WILL RANGE FROM THE MID 30S IN WRN WI TO THE MID
40S IN WRN MN.

TUESDAY NIGHT THRU THURSDAY...THE REST OF THE WEEK LOOKS TO BE
RATHER UNSETTLED...STARTING WITH TUE NIGHT. THE UPR LEVEL PATTERN
BECOMES MORE ZONAL AND FLAT TUE NIGHT INTO WED...BUT THIS
FLATTENING IS ON THE FRINGES OF A DIVING INVERTED UPR LVL TROF
OVER CENTRAL-ERN CANADA. IN CONJUNCTION WITH THIS WILL BE A
CLIPPER-TYPE LOW PRES SYSTEM DROPPING SE ACRS THE CENTRAL PLAINS.
THIS LOW BECOMES STRETCHED OUT ALONG A LEADING WMFNT ATTENDANT
FROM A MORE DEVELOPED LOW PRES CENTER ORGANIZING ITSELF OVER THE
CO/KS AREA. STRONG INCREASES IN ISENTROPIC LIFT AHEAD OF THE NRN
PLAINS LOW ALONG WITH DEEPER MOISTURE AHEAD OF THE UPR LVL TROF
WILL ALLOW FOR PRECIP DEVELOPMENT OVER THE AREA TUE NIGHT...
LASTING OCCASIONALLY THRU THU. WED AND WED NIGHT LOOK TO HAVE THE
MOST PERSISTENT PRECIPITATION AS THE DEVOLVING NRN LOW SPREADS OUT
ALONG THE SFC FRONT...THE UPR TROF OVER CANADA DROPS INTO THE GRT
LKS AND FORMS A CUTOFF LOW WITHIN IT...AND THE LOW E OF THE
ROCKIES BECOMES MORE ORGANIZED. THIS COMBINATION PLUS DEEPER
MOISTURE STREAMING UP FROM THE GULF OF MEXICO WILL PRODUCE QPF IN
THE 0.25-0.50 INCH RANGE. COMPLICATING FACTORS WILL BE THE
TEMPERATURES FLOPPING ABOVE AND BELOW FREEZING DURING THE ENTIRE
PERIOD. THIS MEANS THERE MAY WELL BE SOME MINOR WET SNOW
ACCUMULATION OVER NRN PORTIONS OF THE CWFA THRU THU.

FRIDAY THRU SUNDAY...THE LOW OVER THE CENTRAL CONUS LOOKS TO TRACK
NE FROM THE OK/TX PANHANDLES THU NIGHT INTO WI BY LATE SAT WHILE
THE CUTOFF UPR LVL LOW ROTATES OVER THE DAKOTAS AND WRN MN DURING
THIS TIME PERIOD. WITH THE UPR LOW REMAINING IN PLACE...THIS WILL
KEEP THE AXIS OF PRECIPITATION OVER SRN AND ERN PORTIONS OF THE
CWFA FOR THE END OF THE WEEK THRU MUCH OF THE WEEKEND. PRECIP CHCS
ARE LOW DUE TO UNCERTAINTY IN PLACEMENT OF THE SW-NE ORIENTED AXIS
OF PRECIP...BUT THERE IS ENOUGH MODEL AGREEMENT TO MAINTAIN 20-40
PERCENT POPS FOR MOST PERIODS. BOTH THE SFC AND UPR LVL LOWS
BECOME NEARLY STACKED BY MIDDAY SAT AND BECOME CAUGHT UP IN THE
UPR JET TO ALLOW THE SYSTEM TO SHIFT OFF TO THE E FOR THE START OF
NEXT WEEK. INDICATIONS ARE THAT A LARGE DOME OF HIGH PRES...
INCLUDING STRONG H5 HEIGHT RISES...WILL MOVE INTO THE REGION. THIS
COMBINATION MAY WELL MEAN A DRYING OUT PERIOD FOR EARLY NEXT WEEK
ALONG WITH SIGNIFICANT WARMING TO NEAR NORMAL TEMPERATURES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1128 AM CDT SUN APR 13 2014

UPSTREAM OBS/CIGS ACROSS NW/CENTRAL MN HAVE REMAINED BETWEEN 1-2K
FOR MOST OF THE MORNING. ALTHOUGH THE CONTINUED CAA AND DRIER
DWPTS SHOULD SLOWLY LIFT THE CIGS DURING THE AFTN...WILL CONTINUE
ON THE CAUTION SIDE WITH MVFR CIGS FOR MOST AREAS THRU
21-22Z...THEN BECOMING VFR OR CIGS RISING ABV 3K BY THE LATE AFTN.
THIS IS BASED ON THE CONTINUED DRIER AIR ADVECTING SOUTHWARD
ACROSS NORTHERN MN THIS AFTN. KRHN/KEAU WILL LIKELY CONTINUE WITH
THE MVFR CIGS THRU THE EVENING...BEFORE LIFTING TOWARD MONDAY
MORNING. KEAU WILL SEE RAIN/SNOW DEVELOP BY 21-23Z WITH MODERATE
RAIN AT TIMES...MIXING WITH SNOW AND CHANGING OVER TO SNOW BETWEEN
00-03Z. SOME MINOR ACCUMULATIONS WILL BE POSSIBLE BEFORE THE SNOW
ENDS IN KEAU BY 3-6Z. WINDS WILL REMAIN FROM THE N/NW THRU THE TAF
PERIOD...WITH THE CONTINUED GUSTY WINDS...BUT NOT AS STRONG BY
MONDAY LATE MORNING.

KMSP...

MAIN SHORT TERM CONCERN REMAINS THE CIGS RISING ABV 1.7K.
UPSTREAM OBS AND THE CONTINUED EXPANSION OF THE PRECIPITATION TO
THE SOUTH HAS ME WONDER IF 21Z IS TOO FAST...AND WHETHER THE
PRECIPITATION MOVES INTO MSP. BASED ON A DRIER FORECAST BLW
3K...AM LEANING TOWARD CIGS RISING TO 2K BY 21Z WITH VCSH. THIS IS
HIGHLY DEPENDENT ON THE EXPANSION OF THE PRECIPITATION FIELD
ACROSS FAR SOUTHERN MN. BY 3Z...MOST OF THE PRECIPITATION...IF TO
MAKES IT TO KMSP...WILL BE SE OF REGION. THEREFORE...CIGS WILL
BEGIN TO RISE TO VFR...BUT THE GUSTY WINDS WILL CONTINUE THRU THE
FORECAST PERIOD FROM THE N/NW.

/OUTLOOK FOR KMSP/

TUE...VFR. WINDS W 5-10 KT...BCMG E/NE BY EVENING.
WED...MVFR WITH RA/SN POSSIBLE. WINDS E 10-20 KT...BCMG N-NE.
THU...MAINLY VFR. CHC MVFR CIGS WITH RA/SN. WINDS NE 10-15 KT.

&&

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

&&

$$

SHORT TERM...JLT
LONG TERM...JPC
AVIATION...JLT






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.