621  
FXUS63 KMPX 080422  
AFDMPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN  
1022 PM CST WED DEC 7 2016  
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY)  
ISSUED AT 255 PM CST WED DEC 7 2016  
 
THE MAIN FORECAST CONCERN THROUGH THURSDAY AFTERNOON IS WHETHER ANY  
OF THE SNOWFALL WILL ACCUMULATE AS THE LAST BATCH OF DEEPER MOISTURE  
SHIFTS SOUTHWARD.  
 
THE STORM SYSTEM THAT HAS AFFECTED THE UPPER MIDWEST/NORTHERN PLAINS  
OVER THE PAST TWO DAYS WAS CENTERED NORTH OF THE GREAT LAKES. A  
SURFACE TROUGH WAS NOTED ACROSS NORTHERN MINNESOTA WHICH WILL MOVE  
SOUTH/SOUTHEAST OVERNIGHT. ALTHOUGH QPF AMOUNTS WILL BE EXTREMELY  
LIGHT IN THIS AIR MASS REGIME, EVEN A HUNDREDTH OR TWO WITH CREATE A  
LIGHT DUSTING, OR POSSIBLY AN INCH. THIS TYPE OF SNOW IS VERY DRY,  
FLUFFY, AND WILL BE EASILY BLOWN AROUND. I WOULDN'T BE SURPRISED TO  
SEE SOME BLOWING SNOW PROBLEMS IF AN INCH OF SNOW DEVELOPS. THIS  
SURFACE TROUGH AND ASSOCIATED AREA OF DEEPER MOISTURE WILL MOVE  
SOUTHEAST OF MINNESOTA AND LIMIT ANY ACCUMULATING SNOWFALL BY  
THURSDAY AFTERNOON. THE BEST TIME FRAME IS LATE THIS EVENING,  
THROUGH THURSDAY MORNING FOR ANY ACCUMULATIONS.  
 
TEMPERATURES WILL LIKELY HOLD WITHIN A DEGREE OR TWO OVERNIGHT, AND  
RISE INTO THE 20S THURSDAY AFTERNOON. GUSTY WINDS WILL CONTINUE  
OVERNIGHT, THROUGH THURSDAY MORNING BEFORE TAPERING OFF THURSDAY  
AFTERNOON.  
   
LONG TERM
 
(THURSDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 255 PM CST WED DEC 7 2016  
 
MAIN FORECAST ISSUES THIS PERIOD WOULD BE THE POTENTIAL SNOW STORM  
DEVELOPING SATURDAY INTO SATURDAY NIGHT. THEN THE OVERALL  
AMPLIFIED NORTHWEST FLOW PATTERN DEVELOPING THROUGH THE END OF  
THE FORECAST PERIOD.  
 
WE EXPECT CLOUDS TO LINGER THROUGH AT LEAST THURSDAY NIGHT...WITH  
PERHAPS SOME BREAKS DEVELOPING INTO FRIDAY. CYCLONIC FLOW MAY  
STILL DROP A FEW FLURRIES INTO THURSDAY EVENING OVER THE FAR  
EAST. THE SURFACE HIGH PRESSURE RIDGE MOVES EAST THROUGH  
FRIDAY...WITH A MINOR SHOT OF ARCTIC AIR. TEMPERATURES SHOULD  
RANGE AROUND 10 DEGREES BELOW NORMAL THROUGH SUNDAY.  
 
THE SNOW THREAT INCREASES AGAIN SATURDAY INTO SATURDAY NIGHT OVER  
MUCH OF THE CWA. THE GFS AND NAM ARE MOST AMPLIFIED WITH THE  
SHORT WAVE DROPPING ACROSS THE ROCKIES FROM THE PACIFIC NORTHWEST  
INTO THE NORTHERN PLAINS INTO SATURDAY. THE 12Z ECMWF TROUGHS A  
WRENCH IN THE FORECAST ITS TREND OF WEAKENING THE WAVE AS IT MOVES  
ACROSS THE NORTHERN PLAINS DURING THIS PERIOD. IT PRODUCES ONLY  
LIGHT QPF/SNOW WITH THIS FEATURE AND WAITS FOR ANOTHER STRONGER  
SHORT WAVE DROPPING IN BEHIND THIS SYSTEM SUNDAY AFTERNOON AND  
SUNDAY NIGHT. THERE WERE SOME ISSUES WITH UPPER AIR SOUNDINGS  
GETTING INTO THE 12Z NAM_WRF AND GFS...BUT BELIEVE THIS SHOULD  
HAVE VERY LITTLE IMPACT TOT EH FORECAST OVERALL. WE WILL CONTINUE  
TO PUSH THE CATEGORICAL POPS SPREADING ACROSS THE SOUTHERN HALF  
OF THE AREA THROUGH SATURDAY. 12 HOUR SNOW AMOUNTS FOR SATURDAY  
ARE GENERALLY 3-5 INCHES SOUTH OF A LINE FROM NEAR AXN-STC-MSP. AN  
ADDITIONAL 1 TO 3 INCHES OF ACCUMULATION ARE POSSIBLE OVER THE  
EASTERN AREA INTO SATURDAY NIGHT...AS THE SYSTEM MOVES OUT...AND  
WOULD PUSH TOTALS AROUND 7 INCHES MAINLY ALONG AND SOUTH OF THE  
MINNESOTA RIVER VALLEY. STILL WOULD LIKE TO SEE ANOTHER MODEL RUN  
BEFORE ISSUING ANY HEADLINES...DUE TO THE DISCREPANCY IN THE  
MODELS HANDLING THE POTENTIAL TWO WAVES.  
 
THE REAL ARCTIC PLUNGE FOLLOWS THIS SYSTEM MONDAY THROUGH MUCH OF  
NEXT WEEK. THE ECMWF WAS MORE AMPLIFIED WITH ITS NORTHWEST FLOW  
PATTERN AND WAS DRAWING H85 TEMPERATURES OF MINUS 32C OVER THE  
AREA TUESDAY INTO WEDNESDAY. THE GFS BRINGS IN MINUS 22C AIR OVER  
THE REGION. NOT QUITE AS COLD...BUT WITH FRESH SNOW COVER AND  
LIGHTER WINDS DEVELOPING INTO MIDWEEK...WE MAY STRUGGLE TO REMAIN  
ABOVE ZERO FOR HIGHS...AND LOWS SHOULD BOTTOM OUT CLOSE TO 5 BELOW  
TO 15 BELOW ZERO POSSIBLE. WE WILL TREND SEVERAL DEGREES COLDER  
THAN GUIDANCE FOR THE TUESDAY/WEDNESDAY PERIOD FOR NOW. WIND  
CHILLS WILL BE APPROACHING ADVISORY CRITERIA(MINUS 25F) DURING  
THIS PERIOD AS WELL...BUT WINDS SHOULD BE TRENDING LIGHTER AS THE  
HIGH PRESSURE RIDGE MOVES IN.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)  
ISSUED AT 1020 PM CST WED DEC 7 2016  
 
ASIDE FROM KAXN, WHICH HAS BEEN IFR/LIFR FOR AROUND 36 HOURS DUE  
TO BLOWING SNOW, MOST TAF SITES WILL BE MVFR/VFR FOR CEILINGS WITH  
LIGHT SNOW OR FLURRIES THROUGH THE MORNING. THERE WILL BE A  
SLIGHTLY HEAVIER ROUND OF SNOW LATE TONIGHT THAT COULD RESULT IN  
IFR VISIBILITY. LITTLE IN THE WAY OF ACCUMULATION IS EXPECTED.  
 
KMSP...  
 
MVFR CEILINGS SHOULD HAVE FILLED BACK IN (BUT CEILINGS COULD VARY  
FROM 2500-4000FT FOR MOST OF THE NIGHT. SNOW WILL INCREASE  
SLIGHTLY IN INTENSITY EARLY IN THE MORNING AS A LIGHT BAND OF  
SNOW DROPS SOUTH FROM NORTHERN MN INTO THE TWIN CITIES METRO. A  
DUSTING TO QUARTER OR THIRD OF AN INCH IS POSSIBLE.  
 
/OUTLOOK FOR KMSP/  
FRI...VFR. WNW WIND 5-10 KTS.  
SAT...MVFR WITH SN AND IFR LIKELY. SE WIND 5-10 KTS.  
SUN...IFR/MVFR EARLY WITH SN. VFR BY AFTERNOON. NW WIND 10 KTS.  
 

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

 
 

 
 
SHORT TERM...JLT  
LONG TERM...DWE  
AVIATION...CLF  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MN Page
The Nexlab WI Page Main Text Page