699  
FXUS63 KARX 282306  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
506 PM CST MON NOV 28 2022  
   
DISCUSSION
 
(THIS EVENING THROUGH MONDAY)  
ISSUED AT 230 PM CST MON NOV 28 2022  
 
KEY MESSAGES:  
 
- A MIXTURE OF SNOW AND FREEZING DRIZZLE ALONG AND NORTHWEST OF  
AN AUSTIN TO WABASHA LINE DURING THE DAY ON TUESDAY. SEVERAL  
INCHES OF SNOW AND A GLAZE OF ICE EXPECTED, BUT AMOUNTS HINGE  
ON THE EXACT MIXTURE OF SNOW AND FREEZING DRIZZLE.  
 
- WINTRY MIX SPREADS EASTWARD TUESDAY NIGHT WITH LIGHT SNOW AND  
POSSIBLY A BRIEF PERIOD OF FREEZING DRIZZLE EXPECTED AREA-WIDE.  
COLDER AIR RUSHING IN MAY ALSO TURN WET ROADS SLICK OVERNIGHT  
INTO WEDNESDAY MORNING.  
 
- COLD AND BLUSTERY ON WEDNESDAY, WARMING FOR FRIDAY, WITH A  
PASSING SYSTEM AND COOLER TEMPERATURES FOR THE WEEKEND.  
 
TONIGHT - TUESDAY NIGHT: WINTRY MIX DETAILS  
 
A LEE CYCLONE EJECTS OFF THE FRONT RANGE IN KANSAS TONIGHT AND  
CURVES TO THE EAST/NORTHEAST OVER THE ENSUEING 24 HOURS, TRACKING  
ACROSS SOUTHEAST IOWA AND EASTERN WISCONSIN BEFORE REACHING LAKE  
SUPERIOR BY 06Z WEDNESDAY. A LEADING VORT MAX LIFTING ALONG THE  
EASTERN FLANK OF THE PARENT UPPER LEVEL TROUGH HAS ALREADY PUSHED  
A SURFACE COLD FRONT ACROSS THE MN/DAKOTA BORDER, WHICH MEANDERS  
EASTWARD INTO SOUTHEAST MINNESOTA AFTER MIDNIGHT TONIGHT.  
INCREASING LOW-LEVEL MOISTURE RIDES OVER THE LOW-LEVEL BAROCLINIC  
ZONE TONIGHT AS THE MAIN UPPER WAVE/SURFACE LOW APPROACH FROM THE  
WEST. A SOLID WEDGE OF 280-290K ISENTROPIC ASCENT BECOMES  
ESTABLISHED BY 12-15Z TUESDAY WITH A NARROW, SLOPED FGEN BAND  
PROVING TO BE THE FOCUS FOR THE HIGHEST QPF/SNOW TOTALS. THE  
SURFACE CYCLONE PASSES SOUTHEAST OF THE FORECAST AREA BETWEEN  
21-00Z WEDNESDAY, WITH THE STRONGEST FORCING WANING QUICKLY IN ITS  
WAKE. LIGHT SYNOPTIC LIFT LINGERS FOR ANOTHER 6 HOURS AHEAD OF  
THE UPPER WAVE, WITH THE SNOW CEASING BY 00-06Z FOR MOST LOCALES.  
 
THE GENERAL MODEL CONSENSUS IS LOCKING IN ON THE MAIN SNOW BAND  
TAKING SHAPE TO THE NORTHWEST OF THE FORECAST AREA ALONG THE FGEN  
CORRIDOR, RUNNING THROUGH THE TWIN CITIES METRO AREA FROM SOUTHWEST  
TO NORTHEAST. SNOWFALL AMOUNTS TAPER OFF QUICKLY SOUTH OF THIS  
BAND AS THE COMBINATION OF WARMER SURFACE TEMPERATURES AND AN  
INCREASING RISK OF LOSING ICE INTRODUCTION ALOFT COMPLICATES THE  
FORECAST. ALL OF THE MODELS ARE SHOWING THIS 100-200-MB MID-LEVEL  
DRY WEDGE IMPEDING ON THE SOUTHERN FLANK OF THE SNOW BAND, THE  
QUESTION JUST BECOMES WHERE EXACTLY THIS SETS UP WITH ABOUT 50-100  
MILES OF SPREAD STILL NOTED IN THE DETERMINISTICS/ENSEMBLES. WITH  
MOST DETERMINISTIC PROFILES SHOWING THE COLDER AIR UNDERCUTTING  
THE DRY SLOT, HAVE INTRODUCED FREEZING DRIZZLE/ICE ACCUMULATIONS  
TO THE FORECAST ALONG THIS SNOW/RAIN TRANSITION ZONE FOR MUCH OF  
THE FORECAST AREA.  
 
SNOW AND ICE AMOUNTS WILL BE VERY SENSITIVE OWING TO THE  
PREVIOUSLY DISCUSSED FACTORS AND THEREFORE IT REMAINS TOUGH TO PIN  
DOWN EXACT VALUES FOR ANY ONE LOCATION. HAVE HOISTED A WINTER  
WEATHER ADVISORY FOR PARTS OF SOUTHEAST MINNESOTA WHERE CONFIDENCE  
IS HIGHEST FOR BOTH SNOW AND ICE ACCUMULATIONS THAT COULD IMPACT  
TRAVEL. HOWEVER, THERE IS A MODEST LIKELIHOOD THAT THIS ADVISORY  
WILL NEED AN EASTWARD EXPANSION WITH LATER UPDATES AS WE HONE IN  
ON THE IMPACTS RESULTING FROM THE WINTRY MIX TRANSITION AND  
FREEZING OF WET ROAD SURFACES AS MUCH COLDER AIR ARRIVES TUESDAY  
EVENING/NIGHT.  
 
WEDNESDAY - WED NIGHT: COLD AND BLUSTERY WITH A FEW FLURRIES POSSIBLE  
 
AS TUESDAY'S COLD FRONT AND LOW PRESSURE SYSTEM CONTINUE TO LIFT TO  
THE NE ACROSS LAKE SUPERIOR INTO JAMES BAY, A SURFACE HIGH PRESSURE  
RIDGE SHIFTS IN FROM THE WEST. THE RESULT WILL BE BLUSTERY NW WINDS,  
WITH GUSTS IN THE 25 TO 30 MPH ACROSS MUCH OF THE AREA. WITH COLDER,  
POLAR AIR ACROSS THE AREA BEHIND TUESDAY'S COLD FRONT, WIND CHILL  
VALUES FALL INTO THE SINGLE DIGITS ABOVE ZERO ACROSS MOST OF THE  
AREA--A FEW LOCATIONS IN SW WISCONSIN AND NE IOWA WILL HAVE WIND  
CHILLS IN THE LOW TEENS ABOVE ZERO. SLICK SPOTS ARE EXPECTED ON ANY  
UNTREATED SURFACES WEDNESDAY MORNING. BY WEDNESDAY NIGHT, WINDS  
BEGIN TO SLACKEN AS THE SURFACE RIDGE MOVES FURTHER OVERHEAD -  
WARMER AIR BEGINS TO MOVE IN AS THE RIDGE AXIS SHIFTS EAST OF OUR  
AREA, THOUGH TEMPS REMAIN FAIRLY STEADY THROUGH THE NIGHT WITH WIND  
CHILLS IN THE SINGLE DIGITS ABOVE ZERO.  
 
THURSDAY - FRIDAY: TRENDING TOWARDS NORMAL, COLD FRONT FRIDAY NIGHT  
 
SOUTHWEST WINDS BRING IN WARMER AIR ALOFT THROUGH THE DAY THURSDAY  
INTO FRIDAY. TEMPERATURES THURSDAY RISE TO SLIGHTLY BELOW NORMAL AND  
NEAR NORMAL ON FRIDAY WITH HIGHS IN THE MID-30S ACROSS CENTRAL  
WISCONSIN AND MID-40S TO THE SOUTH ACROSS SW WISCONSIN AND NE IOWA.  
ENOUGH WIND LINGERS THURSDAY FOR WIND CHILLS TO BE IN THE TEENS.  
LATE IN THE DAY ON FRIDAY, A COLD FRONT APPROACHES FROM THE NW.  
PREDICTABILITY ON THE TIMING OF THIS FRONT REMAINS LOW, AS  
TEMPERATURE SPREAD BETWEEN THE NBM 25TH AND 75TH PERCENTILE IS WELL  
INTO THE TEENS FRIDAY EVENING AS GEFS GUIDANCE REMAINS MUCH FASTER  
THAN EPS.  
 
WEEKEND/EARLY NEXT WEEK: ANOTHER SYSTEM SATURDAY, COOLER TEMPS  
 
PREDICTABILITY IN THE DETAILS HEADING INTO THE WEEKEND AND EARLY  
NEXT WEEK REMAINS LOW AT THIS TIME. CLUSTERED ENSEMBLE GUIDANCE  
SUGGESTS GFS, GEM, AND EC ENSEMBLES ARE NOT FAVORING ANY SOLUTION  
OVER ANOTHER - ENSEMBLE MEANS SHOW NEAR-ZONAL FLOW SATURDAY AS A  
POTENTIAL WAVE AND LOW PRESSURE SYSTEM PASS TO OUR NORTH ALONG THE  
US/CANADA BORDER AND LAKE SUPERIOR. SUNDAY INTO MONDAY, ENSEMBLE  
MEANS SUGGEST COOLER AIR ACROSS THE UPPER MIDWEST AS GEFS AND EPS  
SHOW A SIGNAL FOR A LEESIDE LOW PRESSURE SYSTEM DEVELOPING ACROSS  
THE CENTRAL PLAINS AND LIFTING NE INTO THE GREAT LAKES REGION -  
SOMETHING TO MONITOR IN THE DAYS AHEAD.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)  
ISSUED AT 449 PM CST MON NOV 28 2022  
 
STILL ON TRACK FOR WINTER CONDITIONS TO AFFECT BOTH TAF SITES  
TUESDAY MORNING AND LASTING INTO THE AFTERNOON. INITIAL SNOW  
IMPACTS EXPECTED TO REMAIN NORTH AND WEST OF KRST TUESDAY MORNING.  
HOWEVER, MIXED PRECIPITATION INCLUDING FREEZING RAIN IS POSSIBLE  
DURING THE EARLY MORNING/OVERNIGHT HOURS. KLSE PRECIPITATION  
EXPECTED TO START AS RAIN, POTENTIALLY SWITCHING OVER TO FREEZING  
RAIN IN THE EVENING AND THEN SNOW. HAVE NOT INCLUDED FROZEN  
PRECIPITATION AT KLSE AT CURRENT FORECAST HOUR, MAY BE INCLUDED IN  
FUTURE TAF ISSUANCES. HIGH RESOLUTION ENSEMBLE GUIDANCE CONTAINS  
HIGH CONFIDENCE FOR IFR AT BOTH TAF SITES THROUGH TUESDAY. AS THE  
MIXED PRECIPITATION MOVES SOUTHEAST THROUGH TUESDAY MORNING, IFR  
CIGS/VIS WORK TOWARDS KLSE FROM KRST. IFR CONDITIONS EXPECTED TO  
WANE AFTER THE TERMINATION THE 00Z TAF PERIOD.  
 

 
   
ARX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MN...WINTER WEATHER ADVISORY FROM 4 AM TO 9 PM CST TUESDAY FOR MNZ079-  
086-087-094.  
 
IA...NONE.  

 
 

 
 
DISCUSSION...SKOW/JAW  
AVIATION...JAR  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab WI Page
The Nexlab IA Page
The Nexlab MN Page Main Text Page