Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 231743
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1243 PM CDT MON MAR 23 2015

.UPDATE FOR 18Z TAF...

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 432 AM CDT MON MAR 23 2015

SNOW OVER THE EASTERN HALF OF THE FORECAST AREA WILL CONTINUE
WINDING DOWN AS LIFT ASSOCIATED WITH THE HEALTHY SHORTWAVE OVER
SOUTHERN MN/NORTHERN IOWA SHIFTS AWAY...AND THE ASSOCIATED INVERTED
TROUGH SLIDES SOUTH. ADDITIONAL SNOWFALL ACCUMULATIONS SHOULD BE
AROUND ONE HALF INCH OR LESS. COULD ALSO SEE SPOTTY LIGHT FREEZING
DRIZZLE REPORTS THIS MORNING AS THE ICE CRYSTAL LAYER DRIES OUT AND
LIFT WANES. ANOTHER SHORTWAVE IN THE NORTHWEST FLOW WILL PIGGYBACK
ON LAST NIGHTS WAVE...AND DIVE FROM NORTHERN MINNESOTA TO SOUTHERN
LAKE MICHIGAN TODAY. HOWEVER...THE ASSOCIATED UPGLIDE PASSES NORTH
OF THE FORECAST AREA...SO EXPECT ANY RELATED PRECIP TO STAY NORTH OF
THE AREA.

CLOUDS WILL STRUGGLE TO CLEAR OUT TODAY...WITH ONLY PEEKS OF
SUNSHINE EXPECTED THIS AFTERNOON. HAVE THEREFORE LOWERED HIGH TEMPS
FOR TODAY...ESPECIALLY GIVEN THE FRESH SNOW ACROSS MUCH OF THE AREA.
GENERALLY EXPECT HIGHS IN THE MID 30S TO LOWER 40S. PERSISTENT CLOUD
COVER ACROSS MUCH OF THE AREA WILL KEEP LOWS TONIGHT FROM TANKING
TOO FAR...WITH POSSIBLY THE EXCEPTION OF WEST CENTRAL WI...WHERE
SOME CLEARING IS EXPECTED TO ALLOW TEMPS TO FALL TO AROUND 20
DEGREES. OTHERWISE...MID TO UPPER 20S ARE EXPECTED.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 432 AM CDT MON MAR 23 2015

MAIN CONCERN IN THE LONG TERM SURROUNDS THE MID WEEK SYSTEM THAT
CAN ONLY BE BEST DESCRIBED AS A MESS TUESDAY NIGHT...FOLLOWED BY
WHAT WILL THE SRN EXTENT OF WRAP AROUND PRECIP BE GOING THROUGH
WEDNESDAY. AFTER THIS SYSTEM THOUGH...WE LOOK TO LAPSE BACK INTO A
DRY WEATHER PATTERN...WITH NOTHING MORE FOR PRECIPITATION EXPECTED
OUTSIDE OF A GLANCING BLOW FROM A CLIPPER SATURDAY NIGHT.

FOR THE MID WEEK SYSTEM...MODELS CONTINUE TO LACK CONSISTENCY AS
THEY TRY TO DETERMINE THE DEGREE OF PHASING WE WILL SEE BETWEEN AN
UPPER LOW GOING ACROSS THE CANADIAN BORDER AND A STRONG
NEGATIVELY TITLED SHORTWAVE ROTATING AROUND IT FROM CO/NM TOWARD THE
GREAT LAKES. THE SHIFT WE HAVE SEEN WITH THE 00Z MODELS IS MORE
SEPARATION WITH THIS TWO WAVES. THIS SEPARATION OF THE UPPER WAVES
MEANS WE ARE LIKELY TO KEEP TWO DISTINCT SFC LOWS...WITH ONE LOW
MORE OR LESS GOING ACROSS THE CANADIAN BORDER...WITH THE STRONGER
SRN WAVE SENDING A DEEPER LOW FROM THE TX PANHANDLE TO THE STRAITS
OF MACKINAC. THIS GREATER SEPARATION MEANS THE SRN LOW AND ITS
ASSOCIATED GULF MOISTURE WILL BE GOING FARTHER SOUTHEAST AS WELL.
ONE BIG IMPACT WITH THE SRN LOW GOING FARTHER SOUTH IS QPF AMOUNTS
HAVE COME DOWN A BIT...WITH IT EVEN NOW IN QUESTION IF OUR NW CWA
WILL SEE MUCH OF ANYTHING WITH THIS WAVE. THE BIGGER ISSUE THOUGH IS
STILL WITH WHAT TYPE OF PRECIP WILL WE SEE. THE COLD AIR WILL BE
LOCKED UP WITH THE NORTHERN LOW...WHILE THE WARM AIR WILL BE LARGELY
LOCKED UP WITH THE SRN LOW. THIS LEAVES US STUCK IN BETWEEN ON THE
CUT OFF BETWEEN EVERY PRECIPITATION TYPE. LOOKING AT THE 1540 M 850-
700 THICKNESS /CRITICAL RAIN/SNOW THICKNESS FOR THAT LAYER/...THE
SREF SHOWS THIS LINE SETTING UP FROM ABOUT A NEW ULM...TO ST.
PAUL...TO CUMBERLAND LINE. NORTH OF THIS LINE...NEAR SFC
TEMPERATURES WILL LARGELY DETERMINE WHETHER ITS RAIN OR SNOW
TUESDAY NIGHT...WHILE SOUTHEAST OF THIS LINE...THE NEAR SFC TEMPS
MAY END UP DETERMINING WHETHER ITS RAIN OR FREEZING RAIN. THIS IS
IN GENERAL WHAT THE 23.00 HI-RES NAM NEST REFLECTIVITY/P-TYPE
SHOWED. GIVEN THE HIGH DEGREE OF UNCERTAINTY THOUGH WITH EXACTLY HOW
STRONG/EXTENSIVE THE MELTING WARM NOSE WILL BE...ALONG WITH HOW COLD
THE SFC TEMPS WILL BE...THE GRIDS ARE LIKELY A BIT OVERSIMPLIFIED
BUT CONVEY THE GENERAL THEME WE WANTED WITH P-TYPE FOR TUESDAY
NIGHT...A MIX. FOR SNOW TOTALS...GENERALLY HAVE 1-3 INCHES FROM WRN
MN ACROSS CENTRAL MN INTO NW MN...THOUGH SNOW AMOUNTS HAVE CERTAINLY
TRENDED DOWN FROM WHAT THE 22.12 MODELS HAD.

THIS GREATER SEPARATION IN THE UPPER WAVE WILL CONTINUE TO HAVE
RAMIFICATIONS WITH POPS GOING INTO WEDNESDAY...AS THE INVERTED
TROUGH AND ASSOCIATED DEFORMATION PRECIP HAVE SHIFTED
NORTH...WITH ALL BUT THE GEM KEEPING THE BULK OF THIS PRECIP WED/WED
NIGHT NORTH OF THE MPX AREA. AS A RESULT...CUT BACK ON POPS QUITE A
BIT FOR THIS PERIOD...HOLDING CHANCE POPS TO MAINLY NORTH OF I-94...
WITH NOTHING NOW BY THE TIME YOU GET TO THE IOWA BORDER.

EVENTUALLY THIS WHOLE SYSTEM WILL MOVE OFF TO OUR EAST AS THE UPPER
FLOW BECOMES HIGHLY AMPLIFIED TO END THE WEEK...WITH NORTHERLY FLOW
SETTING UP FOR FRIDAY. THIS WILL SEND A 1035MB HIGH DOWN ACROSS THE
STATE...WITH HIGHS THU/FRI REMAINING 10-15 DEGREES BELOW
NORMAL...WITH LOWS FRIDAY MORNING MAKING A RUN FOR THE SINGLE
DIGITS...ESPECIALLY WHERE WE PICKED UP SNOW OVERNIGHT.

FOR THE WEEKEND CLIPPER...GUIDANCE HAS SHIFTED NE QUITE A BIT WITH
THE TRACK OF THE SFC LOW...WITH MUCH OF ITS PRECIPITATION NOW
REMAINING NE OF THE MPX AREA. WE STILL LOOK TO GET INTO A HEALTHY
WARM SECTOR AHEAD OF THIS CLIPPERS COLD FRONT...WITH H85 TEMPS
PUSHING UP TO AROUND +12C. UNFORTUNATELY THOUGH...THIS WARM NOSE
LOOKS TO BE COMING ACROSS THE AREA DURING THE OVERNIGHT HOURS
SATURDAY NIGHT...SO WE WILL BE MISSING OUT ON THE POTENTIAL TO SEE
HIGHS PUSH INTO THE 60S THIS WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON MAR 23 2015

EXPECT LOW END MVFR TO LIFT DURING THE AFTERNOON...PERHAPS
SCATTERING OUT LATER THIS EVENING MAINLY OVER THE EAST. THERE
REMAINS SOME THREAT OF STRATUS DEVELOPMENT OR LOWER CIGS MOVING
BACK NORTH AND EAST DURING THE EVENING AHEAD OF THE NEXT SYSTEM
FOR TUESDAY. MAY SEE SOME FOG/BR AS WELL...BUT NOT CONFIDENT
ENOUGH TO MENTION MVFR VSBYS RIGHT NOW. WILL KEEP TAFS DRY
THROUGH 18Z WED ALTHOUGH PRECIPITATION MAY COME CLOSE TO KRWF BY
18Z. SOUTHEAST TO SOUTH WINDS DURING THE PERIOD. A BIT GUSTY TO
THE WEST AND ACROSS THE MN PORTION OF THE AREA FOR WED.

KMSP...
EXPECT LOW END MVFR TO LIFT DURING THE AFTERNOON...PERHAPS
SCATTERING OUT LATER THIS EVENING. SOME THREAT OF STRATUS
DEVELOPMENT OR LOWER CIGS MOVING IN FROM THE WEST OR SOUTH THIS
EVENING AHEAD OF THE NEXT SYSTEM FOR TUESDAY. WILL KEEP TAF DRY
FOR THE MOMENT AND BRING IN LOWER MVFR CIGS AFTER 22Z WED. SURFACE
WINDS WILL BE SOUTHEAST LESS THAN 10KTS UNTIL 15Z WED WHEN SOME
GUSTS TO 20KTS WILL BECOME POSSIBLE.

/OUTLOOK FOR KMSP/
TUE NITE...MVFR/IFR WITH -RA/-SN. POSSIBLY MIXED WITH SLEET
EARLY. WINDS SE 15G20 KTS.
WED...MVFR/IFR WITH -RA/-SN. WINDS W 15G25 KTS.
THU...MVFR AND -RASN POSSIBLE EARLY. WINDS NNW 15G25 KTS.

&&

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

$$

SHORT TERM...LS
LONG TERM...MPG
AVIATION...DWE


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