675  
FXUS63 KMPX 222333  
AFDMPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN  
533 PM CST SUN JAN 22 2017  
   
SHORT TERM
 
(THIS EVENING THROUGH MONDAY)  
ISSUED AT 253 PM CST SUN JAN 22 2017  
 
QUITE THE UNEVENTFUL NEXT 24 HOURS OVER THIS REGION AS THERE'S  
DEEP UPPER LEVEL TROUGHS OVER EACH CONUS COAST WITH WEAK RIDGING  
OVER THE CENTRAL STATES ALONG WITH WEAK HIGH PRESSURE MOVING IN  
FROM THE WEST. WITH VERY WEAK ADVECTION BOTH AT THE SURFACE AND  
ALOFT, THE DEEPLY MOIST ATMOSPHERE WILL BE SLOW TO EXIT THE  
REGION. THUS, LOW STRATUS AND FOG WILL AGAIN BE THE PREVAILING  
WEATHER FEATURES OVERNIGHT INTO TOMORROW BUT NOT AT THE EXTENT  
SEEN LAST NIGHT WITH SUCH PREVALENT DENSE FOG. VISIBILITIES WILL  
COMMONLY DROP TO BETWEEN 1-4SM SO, AT THIS POINT, A DENSE FOG  
ADVISORY IS NOT EXPECTED. AFTER DAYBREAK MONDAY, THE RATE OF  
CLEARING WILL IMPROVE AS DRIER AIR WILL BE ADVECTED IN FROM THE  
WEST, AIDING IN VISIBILITY FIRST THEN SCOURING OUT THE LOW CLOUDS.  
TEMPERATURES WILL RUN VERY SIMILAR TO TODAY WITH HIGHS AGAIN IN  
THE MID-UPPER 30S. WITH SOME CLEARING AND DRIER AIR IN WESTERN MN,  
LOWS WILL BE A BIT COOLER, DROPPING TO THE MID 20S TO LOWER 30S.  
THE LACK OF DRIZZLE AND DENSE FOG SHOULD PREVENT ICING ISSUES  
TONIGHT.  
   
LONG TERM
 
(MONDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 253 PM CST SUN JAN 22 2017  
 
A WINTER STORM WATCH HAS BEEN ISSUED FOR ABOUT THE SOUTHERN THIRD  
OF MINNESOTA FOR THE POTENTIAL OF 6"+ SNOW FROM TUESDAY THROUGH  
WEDNESDAY, WITH THE HEAVIEST FALLING TUESDAY NIGHT. IN ADDITION  
THERE WILL BE SOME PATCHY BLOWING AND DRIFTING SNOW ON WEDNESDAY.  
 
WHILE THERE IS STILL PLENTY OF MODEL SPREAD WHEN LOOKING AT THE  
GEM AND NAM SOLUTIONS, THE GFS AND ECMWF CONTINUE TO ADVERTISE  
THE POTENTIAL OF SEVERAL INCHES OF SNOWFALL FROM THE TUESDAY-  
WEDNESDAY STORM. THE GEFS ENSEMBLE HAS INCREASED PROBABILITIES FOR  
TWO CONSECUTIVE RUNS FOR QPF>0.50" LIQUID EQUIVALENT. SNOW RATIOS  
MAY NOT BE ALL THAT IMPRESSIVE AS THE LOWER ATMOSPHERE IS NOT  
VERY COLD. WITH THAT SAID, PLENTY OF MOISTURE WILL BE AVAILABLE  
WITH THIS SYSTEM. WE FELT MORE CONFIDENCE SIDING WITH THE  
GFS/ECMWF AND GEFS MEMBERS WITH A TRACK NORTH OF THE GEM AND NAM.  
NOW, THIS TRACK COULD STILL SHIFT BUT WE STILL FELT CONFIDENT  
ENOUGH TO HOIST A WINTER STORM WATCH FOR SOUTHERN MN. THE FORCING  
IS COMING TOGETHER WITH A DECENTLY STRONG JET STREAK NOSING INTO  
THE MIDWEST PLACING US IN A VERY FAVORABLE DIVERGENCE ZONE, ALONG  
WITH AN IMPRESSIVE PV ANOMALY PUSHING THROUGH, AND PLENTY OF  
THETA-E ADVECTION TO PROVIDE LOW LEVEL LIFT AND MOISTURE.  
 
WHILE THE BEST THREAT AREA OF 6"+ IS IN THE WATCH, FARTHER NORTH  
WILL ALSO SEE ACCUMULATING SNOW INCLUDING THE TWIN CITIES. AT THIS  
TIME 2-4" WITH SOME POCKETS OF 5" LOOKS REASONABLE FROM ACROSS  
SOUTH CENTRAL MN INCLUDING THE METRO, THROUGH MUCH OF WESTERN WI  
INCLUDING MENOMINEE AND EAU CLAIRE. SHIFTS IN THE STORM TRACK  
EITHER NORTH OR SOUTH WOULD EITHER INCREASE OR DECREASE AMOUNTS  
ACROSS THE FORECAST AREA. PLEASE STAY TUNED FOR THE LATEST  
FORECAST DETAILS AS WE GAIN MORE CONFIDENCE WITH THIS STORM.  
 
AFTER THE STORM GOES THROUGH, WRAP AROUND SNOW SHOWERS COULD BE  
SEEN FOR A COUPLE DAYS TO ROUND OUT THE WEEK AND TEMPERATURES  
WILL BE SEASONABLE, BELOW FREEZING EVERY DAY AND NEAR THE AVERAGE  
MAX T WITH HIGHS IN THE 20S GENERALLY EXPECTED. WE DO NOT EXPECT  
ANY BITTER COLD THROUGH THE NEXT WEEK.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)  
ISSUED AT 533 PM CST SUN JAN 22 2017  
 
CEILINGS AND VISIBILITIES ARE ALREADY STARTING TO SLIP LOWER LATE  
THIS AFTERNOON AS LOW LEVEL MOISTURE REMAINS IN ABUNDANCE DUE TO  
SEVERAL DAYS OF SNOWMELT. THERE IS A LITTLE BIT OF A PRESSURE  
GRADIENT ACROSS MN AND WI WITH LOW PRESSURE OVER THE CENTRAL GREAT  
LAKES AND HIGH PRESSURE OVER ND/SD. SHORT TERM GUIDANCE WOULD  
SUGGEST VISIBILITIES IMPROVING SOME IN WESTERN MN THIS EVENING  
WHILE DETERIORATING ACROSS EASTERN MN AND WESTERN WI. NOT BUYING  
THE IMPROVEMENT IN THE WEST AND FEEL LOWER CIGS/VSBYS ARE IN STORE  
FOR THE TWIN CITIES AS WELL AS KRNH AND KEAU ALMOST OUT THE GATE  
IF NOT BY 03Z AND PERSISTING INTO MONDAY MORNING. A LITTLE BIT OF  
LOW LEVEL DRYING IS EXPECTED ON MONDAY AS THE HIGH TO OUR WEST  
SETTLES OVERHEAD. CONTINUED THE TREND OF DRIVING VSBYS TO VFR  
ALONG WITH CEILINGS IN THE 012-022 RANGE. LIGHT WNW WINDS THROUGH  
THE PERIOD.  
 
KMSP...EXPECT CEILINGS BELOW 010 BY THE START OF THE TAF ALONG  
WITH MVFR VISIBILITIES IN BR. THIS WILL LIKELY PERSIST THROUGH  
MONDAY MORNING. CEILINGS IMPROVING TO 020 BY LATE MONDAY AFTERNOON  
ALONG WITH VFR VISIBILITIES.  
 
/OUTLOOK FOR KMSP/  
TUE...MVFR WITH IFR POSSIBLE. CHANCE -SN IN THE MRNG WITH SN IN  
THE AFTN. WINDS E LESS THAN 10 KTS BECOMING NE 10-15 KTS.  
TUE NIGHT...IFR WITH SN. WINDS NE 10-20 KTS BECOMING NW.  
WED...MVFR WITH IFR POSSIBLE. -SN LIKELY EARLY. WINDS NW 15-25 KTS.  
WED NIGHT AND THU...MVFR POSSIBLE. CHANCE -SN. WINDS NW 10-20 KTS.  
 

 
   
MPX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MN...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY  
AFTERNOON FOR MNZ073>078-082>085-091>093.  
 

 
 

 
 
SHORT TERM...SPD  
LONG TERM...JPC  
AVIATION...RAH  
 
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