Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 191002
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
402 AM CST WED NOV 19 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CST WED NOV 19 2014

SHORT TERM CONCERNS INCLUDE TIMING OF SNOW EXITING TO THE EAST THIS
MORNING AND BLOWING SNOW THREAT TODAY.  THEN EXTENT OF CLEARING
OVERNIGHT AND LOW TEMPERATURE POTENTIAL.

WATER VAPOR SATELLITE IMAGERY SHOWING DECENT SHORT WAVE MOVING
ACROSS SOUTHERN MN THIS MORNING.  SURFACE ANALYSIS HAS THE COLD
FRONT PUSHING INTO CENTRAL MN AT 08Z.  THIS FRONT IS PROGGED TO EXIT
INTO WISCONSIN AFTER 12Z.  THE LIGHT SNOW OVER AHEAD OF THE FRONT
SHOULD MOVE INTO WESTERN WISCONSIN THROUGH 12Z AS WELL.  THIS MAY
LINGER THROUGH ABOUT MID MORNING THERE.  HIGH SLR SNOWFALL OVER THE
AREA...HAS YIELDED AROUND 1/2 TO 1 INCH OF FLUFFY SNOW.  THOUGHT NOW
IS THAT THIS WAS MAINLY INTO CENTRAL AND EASTERN MN OVERNIGHT.  THE
STRONGEST WINDS ARE FORECAST TO REMAIN OVER WESTERN INTO SOUTH
CENTRAL MN.  THE GREATEST PRESSURE RISES ARE NOW DROPPING ACROSS
SOUTHWEST MN INTO NORTHWEST IOWA.  THIS SHOULD PROHIBIT SIGNIFICANT
GUST POTENTIAL INTO SOUTHERN MN.  STRONG CAA AND TIGHTENING
PRESSURE GRADIENT WILL STILL GENERATE GUSTS TO AT LEAST 35 MPH INTO
THE DAY.  BLOWING SNOW COULD BECOME A GREATER THREAT IF WINDS BECOME
STRONGER THAN ALREADY FORECAST. WILL HAVE TO MONITOR CONDITIONS INTO
THE MORNING FOR POSSIBLE ADVISORY.

CLOUDS AND FLURRIES WILL REMAIN OVER THE CWA OR MUCH OF THE DAY.  WE
COULD SEE SOME EROSION IN THE CLOUDS TO THE SOUTHWEST...BUT MOSTLY
CLOUDY CONDITIONS ARE ANTICIPATED WITH CAA AND WEAK CYCLONIC FLOW TO
THE EAST.  TEMPERATURES WILL PROBABLY SETTLE OUT AROUND 20 DEGREES FOR
HIGHS OVER MUCH OF THE CWA TODAY.

MODELS SUGGEST LOW LEVEL HUMIDITY TO REMAIN HIGH OVER THE EASTERN
HALF OF THE CWA INTO TONIGHT.  THE SURFACE RIDGE DROPS SOUTHEAST
ACROSS EASTERN SOUTH DAKOTA AND IOWA TONIGHT INTO THURSDAY...SO
WILL TREND CLOUDIER CONDITIONS TO THE EAST.  LOWS TONIGHT WILL BE
DIFFICULT TO FORECAST WITH UNCERTAINTY IN CLOUD COVER.  WILL FOLLOW
MORE OF AN ALL BLEND APPROACH TO TEMPERATURES FOR NOW.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 400 AM CST WED NOV 19 2014

LONG TERM FORECAST CONCENTRATIONS ARE CENTERED AROUND CHANCES FOR
FREEZING PRECIPITATION OVER THE WEEKEND...AND THEN ON A
POTENTIALLY IMPACTFUL WINTER SYSTEM FOR MONDAY.

THE PERIOD STARTS OUT ON A FAIRLY BENIGN NOTE ON THURSDAY...WITH
SURFACE HIGH PRESSURE IN CONTROL. IT WILL BE ANOTHER CHILLY DAY
HOWEVER...WITH 925 MB TEMPS AROUND -14C AND WEAK COLD AIR
ADVECTION CONTRIBUTING TO HIGHS IN THE LOW/MID TEENS. CLEAR SKIES
AND THE CONTINUED INFLUENCE OF SFC HIGH PRESSURE WILL LIKELY YIELD
SUBZERO TEMPS ACROSS MUCH OF THE FORECAST AREA ON THURSDAY
NIGHT...WITH POSSIBLY ONLY A FEW LOCATIONS IN WEST AND SOUTH
CENTRAL MN HOLDING A COUPLE DEGREES ON THE POSITIVE SIDE OF ZERO.

FRIDAY BRINGS THE RETURN TO SOUTHERLY FLOW AS SURFACE HIGH
PRESSURE SLIDES EAST/SOUTHEAST OF THE AREA AND TROUGHING BEGINS TO
APPROACH FROM THE WEST/SOUTHWEST. WEAK WARM AIR ADVECTION DEVELOPS
AHEAD OF AN ADVANCING TROUGH. BOTH 19.00Z GFS AND ECMWF MODELS
CAME IN SLOWER...DRIER AND FARTHER EAST FOR FRIDAY NIGHT...AND
THEREFORE MEASURABLE PRECIP CHANCES WERE REMOVED UNTIL AFTER
DAYBREAK SATURDAY. CHANCES ON SATURDAY INTO SATURDAY NIGHT LOOK TO
BE CONFINED TO AREAS EAST OF THE INTERSTATE 35 CORRIDOR /PRIMARILY
WI/. SURFACE TEMPS SHOULD BE PRIMARILY ABOVE 32 DEGREES THROUGH
MOST OF SATURDAY AND SATURDAY NIGHT GIVEN THE LOW LEVEL WARM AIR
ADVECTION AND CLOUD COVER...SO THE FREEZING RAIN THREAT APPEARS
LIMITED THROUGH THEN. REGARDING HIGH TEMPS...THE WEEKEND WILL BE A
WELCOMED RETURN FOR MANY TO NEAR NORMAL HIGHS IN THE 30S.

ON SUNDAY...THE TROUGH LIFTS TO SOUTHERN LAKE MICHIGAN...AND
DEEPENS TO CIRCA 985 MB. FREEZING/MIXED PRECIPITATION CONCERNS THEN
INCREASE FOR SUNDAY...ALTHOUGH THERE IS A DECENT CHANCE THAT WE
COULD BE DRY SLOTTED FOR MUCH OF THE DAY.

SUNDAY NIGHT AND MONDAY REALLY LOOKS TO BE THE TIME PERIOD OF
UTMOST CONCERN...GIVEN BOTH GFS AND ECMWF MODELS CRANK NORTHWEST
WINDS UP TO 25-35 MPH /SUSTAINED/ IN CONJUNCTION WITH DEFORMATION
SNOW TAKING PLACE AS THE AFOREMENTIONED LOW DEEPENS FURTHER AND
PIVOTS NORTH-NORTHWEST TO LAKE SUPERIOR. WILL DEFINITELY NEED TO
MONITOR FOR THE BLOWING SNOW POTENTIAL...WITH NOTABLE SNOW ACCUMS
ALSO A POSSIBILITY. HOWEVER...MODELS HAVE LACKED RUN TO RUN
CONSISTENCY WITH THEIR HANDLING OF THE KEY PLAYER...THE STRENGTH
OF THE NORTHERN STREAM SHORTWAVE...SO HAVE KEPT SNOW CHANCES IN
THE LOW CHANCE CATEGORY AT THIS POINT.

BY TUESDAY...WEATHER CONDITIONS SHOW IMPROVEMENT...WITH MODELS
INDICATING SURFACE HIGH PRESSURE BUILDING IN.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1107 PM CST TUE NOV 18 2014

SHORT TERM SOLUTIONS SHOW A MORE COMPACT BAND OF SNOW MOVING FROM
CENTRAL MN THROUGH THE TWIN CITIES AND WEST CENTRAL WI IN THE
06Z-10Z TIME FRAME WITH THE ARCTIC FRONT. ADJUSTED THE TIMING IN
THE TAFS. CONFIDENCE IS STILL HIGH ON MVFR CEILINGS IN THE WAKE OF
THE COLD FRONT AND CONTINUING THROUGH MID AFTERNOON ON WEDNESDAY.
A CONCERN FOR THE OVERNIGHT IS THE WIND SPEED BEHIND THE FRONT.
WIND SPEEDS SHOULD JUMP UP TO 20 TO 25 KNOTS WITH FROPA WITH TOP
END GUSTS APPROACHING 35 KNOTS. WINDS WILL CONTINUE TO BLOW STRONG
DURING THE DAY ON WEDNESDAY WITH STEEP LOW LEVEL LAPSE RATES.
THERE WILL ALSO BE A FEW SNOW SHOWERS...MAINLY AT KRNH AND KEAU.
DIMINISHING WIND AND VFR CONDITIONS BY WEDNESDAY EVENING.

KMSP...SNOW THROUGH 08Z THEN DIMINISHING THEREAFTER. ACCUMULATION
LESS THAN 1 INCH. COLD FRONT MOVING THROUGH AROUND 10Z. INCREASED
WIND SPEEDS AND GUSTS IN THE WAKE OF THE FRONT ON THROUGH THE DAY
WEDNESDAY.

/OUTLOOK FOR KMSP/
THU...VFR. WINDS WNW 10 KTS.
FRI...VFR. WINDS SSE 10-15 KTS.
SAT...VFR. CHC MVFR CIGS. WINDS SSW 10 KTS.


&&

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

$$

SHORT TERM...DWE
LONG TERM...LS
AVIATION...RAH





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