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 46 47 48 49 50
000
FXUS63 KMPX 180501
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1101 PM CST WED DEC 17 2014

.UPDATE...FOR 06Z AVIATION DISCUSSION BELOW

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 245 PM CST WED DEC 17 2014

A LONG WAVE SHEAR AXIS THAT HAD AN ASSOCIATED AREA OF
CLDS/FLURRIES WAS ACROSS PORTIONS OF EC/CENTRAL MN AND INTO WC WI.
BASICALLY ALONG AND NORTH OF I-94. THERE HAS BEEN A SLOW DECREASE
IN THE CLOUD COVER THIS AFTN...BUT NOT ENOUGH TO WARRANT
CLR/CLEARING SKIES TONIGHT. WHERE THE SKIES HAVE REMAINED CLEAR
TODAY AND WINDS REMAIN LIGHT AND VARIABLE TONIGHT...SFC TEMPS WILL
LIKELY FALL QUICKLY. DEBATED ON SOME OF THE LOCAL MODELS /MPXWRF
AND HOPWRF/ FOR SFC LOWS TONIGHT /-2F TO -8F/...BUT THESE SEEM TO
LOW...ESPECIALLY CONSIDERING DEW PTS ARND 10 DEGREES. HAVE OPTED
TO LOWER TEMPS SLIGHTLY FROM THE PREVIOUS FORECAST...WITH NEAR
ZERO IN WC/SW MN WHERE CLR SKIES/LIGHT WINDS AND HIGHER SNOW PACK
WILL LEAD TO LOWER TEMPS. ELSEWHERE...TEMPS WILL BE A FEW DEGREES
COOLER THAN PREVIOUSLY FORECAST.

A STORM SYSTEM MOVING ACROSS THE CENTRAL/SOUTHERN PLAINS WILL
PROVIDE MORE CLOUD COVER ON THURSDAY AS WINDS SHIFT TO THE SE AS
THE SFC HIGH MOVES OFF TO THE EAST.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 PM CST WED DEC 17 2014

FAIRLY QUIET WEATHER WITH A GRADUAL WARMUP IS EXPECTED THROUGH THE
WEEKEND...WITH MORE ACTIVE AND COOLER WEATHER EXPECTED FOR THE DAYS
HEADING INTO CHRISTMAS.

FOR THE GENERAL PATTERN EVOLUTION...THE BIG HIGHLIGHT FROM BOTH THE
GFS AND ECMWF IS THE DEVELOPMENT OF A MORE AMPLIFIED PATTERN NEXT
WEEK...WITH ERN PAC RIDGING AND NOAM TROUGHING MAKING A RETURN. YOUR
TYPICAL TIMING/STRENGTH DETAILS STILL EXIST...BUT IN
GENERAL...MEDIUM RANGE MODELS SHOW A RATHER BAGGY AND DISORGANIZED
SERIES OF SHORTWAVES WORKING ACROSS THE AREA FRIDAY THROUGH SUNDAY.
ON SUNDAY...THE RIDGE/TROUGH PATTERN WILL START TAKING SHAPE...WITH
A STRONGER WAVE BEGINNING TO IMPACT THE AREA SUNDAY NIGHT. THIS
TROUGH SUNDAY NIGHT LOOKS TO GO THROUGH A PERIOD OF INTENSIFICATION
MON/TUE AS IT MERGES WITH AN UPPER WAVE COMING OUT OF THE SRN
PLAINS...WITH THIS WAVE DEVELOPING INTO A RATHER DEEP CLOSED H5 LOW
OVER THE GREAT LAKES ON WEDNESDAY. THE MAIN DIFFERENCE BETWEEN THE
GFS/ECMWF IS ONE OF TIMING...WITH THE ECMWF BEING SLOWER AND FARTHER
WEST/SOUTH WITH WHERE THIS DEEPENING OCCURS.

MAIN THING EXPECTED TO CHANGE WITH THE WEATHER FRIDAY AND SATURDAY
IS THAT THE BANK OF STRATUS CURRENTLY SPLAYED OUT ACROSS BOTH THE
CANADIAN AND U.S. HIGH PLAINS WILL BE WORKING ACROSS THE UPPER MIS
VALLEY AS THE SFC RIDGE CURRENTLY NUDGING INTO WRN MN MOVES INTO THE
GREAT LAKES. THIS WILL AGAIN LIMIT THE DIURNAL RANGE IN
TEMPERATURES. HAVE ALSO KEPT BOTH DAYS DRY. FRIDAY..THE PRIMARY
UPPER WAVE AND SUPPORT FOR LIFT WILL BE GOING ALONG THE
INTERNATIONAL BORDER. IN ADDITION...WHAT LITTLE LIFT/MOISTURE THERE
IS AROUND THE 290K SFC IS CENTERED IN NE MN...WHERE THE 17.15 SREF
DOES SHOW SOME LOW PROBABILITIES FOR MEASURABLE PRECIP. KEPT
SATURDAY DRY AS WELL...THOUGH CONTINUED SOUTHERLY WINDS AND WAA
COULD LEAD TO THE GENERATION OF LIGHT PRECIP...THOUGH WITH NO DEEP
MOISTURE IT WOULD BE DRIZZLE.

HAVE PRECIP CHANCES RETURNING SUNDAY FOR THE ERN HALF OF THE AREA AS
THIS IS WHEN WE START SEEING DEEPER MOISTURE FROM THE GULF STARTING
TO WORK UP INTO THE AREA...THOUGH UPPER FORCING STILL LOOKS TO BE
LACKING...SO THIS WOULD BE LIGHT AT BEST.

PRECIP CHANCES ARE STARTING TO LOOK BETTER STARTING SUNDAY
NIGHT...LASTING ALL THE WAY OUT INTO WEDNESDAY. COMPARED TO 24 HOURS
AGO...THERE HAS BEEN A SOUTHWARD SHIFT IN THE MODELS...BUT IN THE
LAST 12 HOURS...BOTH THE ECMWF/GFS HAVE BEEN MORE STABLE WITH A SFC
LOW TRACKING ACROSS SRN MN ON MONDAY. IT STILL LOOKS WARM ENOUGH
MONDAY WITH TEMPERATURES/DEWPOINTS UP IN THE MID 30S SOUTH OF I-94
TO LEAD TO A RA/SN MIX ON MONDAY BEFORE THE LOW LEVELS COOL ENOUGH
FOR ALL SNOW BY MONDAY EVENING. GIVEN THE INTENSIFICATION THIS LOW
GOES THROUGH...IT DOES NOT MOVE VERY FAR...WITH BOTH THE ECMWF AND
GFS SHOWING A PROLONGED PERIOD OF LIGHT TO MODERATE SNOW IMPACTING
THE AREA MOST OF MONDAY NIGHT THROUGH TUESDAY NIGHT BEFORE SLOWLY
TAPERING OFF ON WEDNESDAY. BECAUSE IT IS SLOWEST...THE ECMWF IS ALSO
THE MOST BULLISH WITH QPF...WITH A HEALTHY SWATH OF AROUND 0.75"
ROTATING AROUND SE MN...WHICH WOULD TRANSLATE TO 6-8 INCHES OF
SNOW...OF COURSE THIS FALLS OVER THE COURSE OF ABOUT 48 HOURS.
ALTHOUGH THE SNOW MAY TAPER OFF ON WEDNESDAY...IT WILL BE REPLACED
BY BLOWING SNOW ISSUES AS NW WINDS START CRANKING IN RESPONSE TO THE
SFC LOW DIPPING UNDER 970 MB OVER THE GREAT LAKES. AT THIS
POINT...STILL WAY TO EARLY TO GET TOO EXCITED ABOUT POTENTIAL SNOW
TOTALS/IMPACTS...BUT GIVEN INCREASED TRAVEL THE FIRST HALF OF NEXT
WEEK...THIS CERTAINLY IS SOMETHING THAT BEARS WATCHING. WILL ALSO
ADD A MENTION FOR THE POTENTIAL FOR ACCUMULATING SNOW NEXT WEEK IN
THE HWO.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1100 PM CST WED DEC 17 2014

A RATHER MASSIVE AREA OF STRATUS CLOUDS WILL CONTINUE OOZING IN FROM
WI INTO EAST CENTRAL MN OVERNIGHT. KRNH AND KEAU WILL EXPERIENCE
PREVALENT MVFR CONDITIONS...WITH KMSP EVENTUALLY SEEING MVFR
CONDITIONS BECOME PREDOMINANT THROUGH MID MORNING THURSDAY.
MEANWHILE...A MID LEVEL DECK OF SD/NE/IA WILL CONTINUE EXPANDING
NORTH AND EAST TOWARD THE AREA OVERNIGHT AS WELL... WITH KAXN AND
KRWF BECOMING MOSTLY CLOUDY WITH A 7KFT-9KFT DECK. WHILE EASTERN
SITES MAY SEE THE MVFR DECK SCATTER OUT DURING THE MID TO LATE
MORNING...IT WILL BE REPLACED BY MID LEVEL CLOUDS FROM THE WEST.
WINDS WILL BE LIGHT AND VARIABLE THROUGH TONIGHT...THEN LIGHT
SOUTHEAST /UNDER 5 KTS/ ON THURSDAY.


KMSP...
BKN MVFR LEVEL CLOUDS ARE NOW EXPECTED TO SNEAK INTO KMSP
OVERNIGHT...ALTHOUGH EXPECT CIGS TO STAY ABOVE 1700 FT. SHOULD SEE
THE MVFR DECK SCATTER OUT DURING THE MORNING...BUT BE REPLACED BY
A BKN MID LEVEL DECK AROUND 8000FT.

/OUTLOOK FOR KMSP/
FRI...VFR. WINDS SSE 5 KTS.
SAT...VFR. WINDS SSE 5 KTS.
SUN...VFR. SLGT CHANCE -RASN. WINDS SSE 7-10KTS.

&&

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

$$


SHORT TERM...JLT
LONG TERM...MPG
AVIATION...LS





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