Area Forecast Discussion
Issued by NWS Twin Cities, MN

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685
FXUS63 KMPX 051008
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
408 AM CST FRI FEB 5 2016

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CST FRI FEB 5 2016

ANOTHER ROUND OF LIGHT SNOW IS EXPECTED TODAY...BUT ACCUMULATIONS
SHOULD BE LESS THAN THURSDAY/S SNOW. TEMPERATURES WILL BE NEAR
THE SEASONAL AVERAGE FOR EARLY FEBRUARY.

A WEAK CLIPPER SYSTEM WILL MOVE ACROSS THE REGION TODAY. THERE ARE
TWO AREAS OF ENHANCED VORTICITY. ONE IS LOCATED OVER THE WESTERN
DAKOTAS...AND IS PRODUCING LIGHT SNOW ACROSS THE DAKOTAS. THE
OTHER ONE IS LOCATED IN SOUTHERN MANITOBA...AND IS ALSO PRODUCING
LIGHT SNOW.

TODAY THESE TWO PV ANOMALIES WILL WEAKEN AS THEY MOVE INTO A
REGION OF CONFLUENT UPPER LEVEL FLOW...BUT THERE SHOULD STILL BE
ENOUGH ISENTROPIC ASCENT ON THE WARM SIDE OF THE LOW LEVEL
CYCLONIC CIRCULATION TO PRODUCE SATURATION...AND SNOWFLAKES.
EXPECT PRECIPITATION TOTALS TO BE EQUAL TO OR LESS THAN THURSDAY/S
LIGHT SNOW. THIS SYSTEM WILL EXIT THE REGION TONIGHT...BUT
LINGERING CLOUDS WILL KEEP OVERNIGHT LOWS IN THE TEENS.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM CST FRI FEB 5 2016

SATURDAY-MONDAY...SAT WILL START OUT WITH WEAK SFC HIGH PRES MOVG
THRU THE AREA ALONG WITH AN INCOMING SW-NE ORIENTED RIDGE AXIS
TRAVERSING THE CENTRAL CONUS. THIS COMBINATION WILL ALLOW FOR A
MIX OF SUN AND CLOUDS WHILE ALSO PROMOTING WAA. SLY FLOW IN
ADVANCE OF THE NEXT STORM SYSTEM COMBINED WITH THE RIDGE AXIS
PRODUCING INCRD H5 HEIGHTS THEN DRIFTING EWD AND ALLOWING BRIEF
W-SW FLOW ALOFT WILL MAKE FOR WARMER TEMPERATURES SAT INTO SUN.
HIGHS WILL HIT THE LOW-MID 30S ON SAT. HOWEVER...CLOUDS WILL BE ON
THE INCRS AS A POTENT LOW PRES CENTER DROPS INTO THE REGION FROM
NWRN CANADA WHILE BEING PICKED UP BY A PACIFIC-ORIGIN UPR LVL
TROF. THE TROF WILL BE QUITE PROGRESSIVE BUT WILL SLOW ITS MOTION
DUE TO PICKING UP THE SFC FEATURE. THE SFC LOW WILL THEN DEEPEN
SIGNIFICANTLY...PARTICULARLY ONCE E OF THE UPR MISS RIVER VALLEY
SUN NIGHT INTO MON. THE TROF WILL DRAG ALONG A FAIR AMOUNT OF
PACIFIC MOISTURE AND THE PHASING OF THE UPR TROF WITH THE SFC LOW
WILL ENABLED HEIGHTENED OMEGA LIFT FOR PRECIP GENERATION SUN-MON.
BECAUSE OF THE WARMER BLYR...THERE MAY BE SOME P-TYPE ISSUES LATE
SAT NIGHT THRU SUN AFTN OVER WRN AND CENTRAL MN. HOWEVER...ONCE
THE SYSTEM MOVES TO THE E OF THE AREA AND COLDER AIR IS DRAGGED
DOWN ON ITS BACKSIDE...ALL PRECIP SUN NIGHT THRU MON WILL LIKELY
BE -SN. IN FACT...AS SNOW RATIOS INCRS WITH THE STRONG CAA ON THE
BACKSIDE...SNOWFALL AMOUNTS WILL INCRS TO THE 1-4 INCH RANGE...
WITH THE HIGHER AMOUNTS ALONG AND N OF THE I-94 CORRIDOR. THE
OTHER CONCERN IS THE VERY TIGHT PRES GRADIENT DEVELOPING ON THE
WRN FRINGES OF THE DEVELOPING LOW. AS THE LOW DEEPENS AND SPREADS
OUT...ITS INFLUENCE WILL REMAIN IN PLACE MON AND MON NIGHT IN
TERMS OF VERY STRONG WINDS OVER WRN AND SRN MN...A LITTLE LESS
GOING EWD. TEMPERATURES DURING THE BRIEF PERIOD OF WAA DO NOT
APPEAR TO WARM UP ENOUGH TO CREATE ANY CRUSTING OF THE TOP LAYER
OF EXISTING SNOWPACK. IN ADDITION...THE SYSTEM ITSELF WILL PRODUCE
NEW SNOW. THUS...THERE DOES APPEAR TO BE PLENTY OF LOOSE TOP SNOW
FOR BLOWING/DRIFTING SNOW ISSUES SUN NIGHT THRU MON NIGHT...
POTENTIALLY CREATING BLIZZARD CONDITIONS SINCE WINDS MAY WELL
INCREASE TO AROUND 35MPH WITH GUSTS TO NEAR 50MPH AT TIMES. WILL
CONTINUE TO MENTION THIS POSSIBILITY IN THE HAZARDOUS WX OUTLOOK
/HWO/ AS TRAVEL COULD BECOME HAZARDOUS SHOULD ALL OF THIS COME
TOGETHER. THE OTHER ASPECT WITH THIS PASSING STORM SYSTEM WILL BE
NOTICEABLY COOLER TEMPERATURES FOR THE START OF THE NEXT WORK
WEEK. WHEN WAA PEAKS SUN AFTN...HIGHS WILL REACH THE MID 30S CWFA-
WIDE. FOR MON...WITH CAA TAKING OVER...HIGHS WILL ONLY HIT THE UPR
TEENS TO LWR 20S.

TUESDAY-THURSDAY...THE LARGE SCALE PATTERN WILL DEVELOP INTO A
LARGE RIDGE OVER WRN NOAM WHILE THE ERN PORTION WILL BE ENVELOPED
BY THE DEEP LOW PRES AREA. HIGH PRES WILL ARRIVE FROM THE W TUE
AND DRIFT SEWD THRU WED WHILE THE UPR LVL PATTERN HOLDS IN PLACE.
THIS WILL CONTINUE TO PROMOTE CAA ACRS THE AREA. HIGHS TUE AND WED
WILL DROP TO THE MID TEENS TO LWR 20S WHILE LOWS BOTTOM OUT IN THE
SINGLE DIGITS. BY THU...THE UPR LVL RIDGE WILL FLATTEN SOMEWHAT AS
A CANADIAN AREA OF LOW PRES DRIVES SEWD. IT LOOKS TO BE FAIRLY
STRETCHED OUT WHICH WILL HELP LOSE ITS INFLUENCE FOR PRECIP
GENERATION. NEVERTHELESS...WITH SUCH COLD AIR IN PLACE...IT WOULD
NOT TAKE MUCH FROM A PASSING UPR LVL DISTURBANCE TO PRODUCE
PRECIP. BEST TIMING LOOKS TO BE THU INTO THU NIGHT...BUT NOTHING
ALL THAT IMPRESSIVE ATTM.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1159 PM CST THU FEB 4 2016

VFR CONDS GENERALLY EXPECTED UNTIL THE SNOW ARRIVES
FRIDAY AFTERNOON. PATCHY IFR FZFG HAVE DEVELOPED ACROSS WEST
CENTRAL WI. THIS SHOULD IMPROVE LATE TONIGHT AS HIGH CLOUDS
INCREASE.

KMSP...VFR EXPECTED UNTIL THE SNOW ARRIVES FRIDAY AFTERNOON.

/OUTLOOK FOR KMSP/
SAT...MAINLY VFR. WIND SW/S 5 TO 10 KTS.
SUN...CHC MVFR-IFR/-SN. WIND SW 5-10 KTS...BECOMING NW LATE AT
25G35KT.
MON...CHC MVFR-IFR/-SN. CHC BLSN. WIND NW 25G35KT.


&&

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

$$

SHORT TERM...JRB
LONG TERM...JPC
AVIATION...BORGHOFF



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