687  
FXUS63 KGRB 190839  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
339 AM CDT TUE MAR 19 2024  
 
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE  
   
KEY MESSAGES
 
 
- COLDER TONIGHT AND WEDNESDAY WITH HIGHS ON WEDNESDAY 10 TO 15  
DEGREES BELOW NORMAL. LIGHT LAKE EFFECT SNOW TONIGHT INTO  
WEDNESDAY MORNING FAR NORTH WITH AN INCH OR LESS OF SNOW,  
MAINLY NORTHERN VILAS COUNTY.  
 
- WIDESPREAD SNOWFALL IS FORECAST TO IMPACT THE AREA FROM  
THURSDAY NIGHT THROUGH FRIDAY AFTERNOON. PROBABILITIES OF 3  
INCHES OR GREATER OF SNOW HAVE INCREASED TO THE 60-90% RANGE.  
CENTRAL TO EAST-CENTRAL WI HAVE THE HIGHEST CHANCES OF MINOR  
IMPACTS.  
 
- ANOTHER STRONG SYSTEM COULD PROVIDE WINTRY WEATHER LATE IN THE  
WEEKEND.  
 

 
   
DISCUSSION
 
 
ISSUED AT 337 AM CDT TUE MAR 19 2024  
 
SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY  
 
RELATIVELY QUIET IN THE SHORT TERM. MAIN WEATHER ISSUE WILL BE  
SOME LIGHT LAKE EFFECT SNOW THIS EVENING INTO WEDNESDAY MORNING OVER  
NORTH-CENTRAL WISCONSIN.  
 
SHEARED OUT SHORTWAVE DIGS INTO WESTERN PORTION OF MEAN TROUGHING  
PRESENT FROM CENTRAL CANADA TO THE GREAT LAKES. SURFACE LOW OVER  
NORTHWEST ONTARIO EARLY TODAY WILL DEEPEN A BIT DOWN TO 995MB AS  
IT SHIFTS TO EAST OF LAKE SUPERIOR THIS AFTERNOON. COLD FRONT TIED  
TO THE LOW SWEEPS ACROSS WISCONSIN LATER THIS MORNING THROUGH THE  
AFTERNOON. TEMPS MAY STILL REACH THE MID TO UPPER 40S NEAR AROUND  
50 FROM CENTRAL INTO EAST-CENTRAL WISCONSIN WHILE NW FLOW BEHIND  
THE COLD FRONT WILL KEEP THE FAR NORTH MAINLY STUCK IN THE MID TO  
UPPER 30S.  
 
THE COLD FRONT WILL BE LACKING MOISTURE FOR MOST PART, BUT DEVELOPING  
COLDER AND BLUSTERY NW FLOW (GUSTS TO 30 MPH LATER TODAY) WILL  
ADVECT LOW-LEVEL MOISTURE ACROSS NORTHERN WISCONSIN LATE TODAY  
THROUGH TONIGHT. THOUGH FAR FROM IDEAL IN TERMS OF WIND DIRECTION,  
THE CHILLING NW FLOW (H85 TEMPS DOWN TO LESS THAN -15C TONIGHT)  
CROSSING WESTERN LAKE SUPERIOR (WATER TEMPS 36F/2C) COMBINED WITH  
UPSLOPE LIFT WILL BRING SCATTERED SNOW SHOWERS TO NORTHERN  
PORTIONS OF VILAS AND FOREST COUNTIES. NOT LOOKING AT MUCH SNOW  
ACCUMULATION THOUGH, MAINLY LESS THAN AN INCH THROUGH WEDNESDAY  
MORNING BEFORE SNOW SHOWERS END LATER ON WEDNESDAY. TEMPS WILL  
DROP BACK BELOW NORMAL TONIGHT WITH LOWS AS CHILLY AS AROUND 10  
ABOVE IN THE NORTHWOODS. BELOW NORMAL ON WEDNESDAY WITH READINGS  
IN THE LOW 20S NORTH AND ONLY AS WARM AS THE LOWER 30S FOR EAST-  
CENTRAL AREAS.  
 
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY  
 
THE LATEST ENSEMBLE MEANS INDICATE A RATHER AMPLIFIED UPPER AIR  
PATTERN WILL BE PRESENT ACROSS NORTH AMERICA OVER THE NEXT WEEK. IT  
WILL CONSIST OF RIDGING OVER ALASKA AND DOWNSTREAM TROUGHING  
CENTERED OVER WESTERN HUDSON BAY. THIS WILL BE A COLDER PATTERN  
THAN HAS BEEN TYPICAL THIS COLD SEASON. THE COLDER TEMPS WILL SET  
THE STAGE FOR THE POTENTIAL OF A COUPLE WINTER SYSTEMS TO IMPACT THE  
REGION, NAMELY FROM THURSDAY NIGHT INTO FRIDAY AND ALSO LATE IN THE  
UPCOMING WEEKEND.  
 
THURSDAY NIGHT INTO FRIDAY...NORTHERN STREAM SHORTWAVE ENERGY WILL  
BE DIGGING SOUTHEAST ACROSS SOUTH-CENTRAL CANADA AND THE FAR  
NORTHERN PLAINS DURING THIS PERIOD. BACKING FLOW AHEAD OF THE  
SHORTWAVE IN CONJUNCTION WITH THE RIGHT REAR QUAD OF AN UPPER JET  
WILL PROVIDE THE FORCING FOR AN OVER-RUNNING/FRONTOGENESIS EVENT  
ACROSS WISCONSIN. FORCING ISN'T PARTICULARLY STRONG CONSIDERING THE  
10 TO 15 KTS OF FLOW ALOFT, BUT COULD BRIEFLY BECOME STRONG WHEN  
UPPER AND LOWER LEVEL FORCING MECHANISMS OVERLAP. TEMPS WILL ALSO  
BE SUFFICIENTLY COLD FOR MINOR LAKE ENHANCEMENT ALONG THE LAKE  
MICHIGAN SHORELINE, BUT 1000-850MB FLOW OF 5-10 KTS WILL PROBABLY  
LIMIT ANY ENHANCEMENT TO ONE ROW OF COUNTIES INLAND.  
 
IN GENERAL OVER THE PAST 24 TO 48 HOURS, THERE HAS BEEN AN UPWARD  
TREND IN THE QPF OVER CENTRAL TO EAST-CENTRAL WISCONSIN IN ALL OF  
THE ENSEMBLE MEANS. THE GFS ENSEMBLE PAINTS THE HIGHEST QPF, MOSTLY  
DUE TO A MORE AMPLIFIED SOLUTION AND GENERATES UPWARDS OF A HALF  
INCH OF LIQUID EQUIVALENT. THAT SEEMS RATHER EXCESSIVE GIVEN  
MOISTURE WILL BE OF PACIFIC ORIGIN AND THE LOW AMPLITUDE NATURE OF  
THE SHORTWAVE. SNOW RATIOS OF 12 TO 15 TO 1 SEEM POSSIBLE GIVEN THE  
COLD AIRMASS OF THIS SYSTEM.  
 
PUTTING IT ALL TOGETHER, A 3 TO 5 INCH SNOWFALL LOOKS POSSIBLE FROM  
AFTER MIDNIGHT ON FRIDAY THROUGH FRIDAY AFTERNOON. THE FRIDAY  
MORNING COMMUTE LOOKS TO HAVE SIGNIFICANT IMPACTS FROM THE SNOW.  
SINCE THE REGION HAS NOT RECEIVED SIGNIFICANT SNOW IN A LONG WHILE,  
WONDER IF IMPACTS WILL BE HIGHER AND MORE EQUIVALENT TO THE FIRST  
SNOWFALL OF THE SEASON.  
 
LATE IN THE WEEKEND...A LARGE, SLOW MOVING TROUGH WILL BE WORKING  
EAST ACROSS THE WESTERN HALF OF THE CONUS. THIS TROUGH WILL BRING  
PRECIP BACK INTO WISCONSIN FROM SUNDAY INTO EARLY IN THE FOLLOWING  
WEEK. SIGNIFICANT PRECIP LOOKS POSSIBLE, BUT THERMAL PROFILES  
SUGGESTS PTYPES WILL BE QUITE COMPLICATED TO PIN DOWN OVER  
SUBSEQUENT DAYS.  
 

 
   
AVIATION
 
FOR 06Z TAF ISSUANCE  
ISSUED AT 1008 PM CDT MON MAR 18 2024  
 
A QUICK-HITTING BAND OF LIGHT SNOW WILL IMPACT THE NORTHEAST PART  
OF THE FORECAST AREA THROUGH THE EARLY OVERNIGHT HOURS. THE SNOW  
WILL ONLY LAST FOR 2 OR 3 HOURS AT ANY GIVEN LOCATION, BUT VSBYS  
WILL DROP TO MVFR/IFR AT TIMES. A COLD FRONT WILL SWEEP ACROSS THE  
REGION TUESDAY MORNING, BRINGING GUSTY NORTHWEST WINDS AND  
STRATOCUMULUS CLOUDS WITH BASES MAINLY BETWEEN 3500-5000 FT AGL.  
THE EXCEPTION WILL BE IN FAR NORTH CENTRAL WI, WHERE MVFR CEILINGS  
AND A FEW FLURRIES MAY OCCUR TUESDAY MORNING. AT LEAST PARTIAL  
CLEARING WILL OCCUR LATER TUESDAY AFTERNOON AND EVENING, THOUGH  
BKN-OVC STRATOCUMULUS CLOUDS AND PATCHY LIGHT LAKE-EFFECT SNOW  
SHOWERS OR FLURRIES WILL PERSIST ACROSS NC WI.  
 
LLWS WILL DEVELOP AHEAD OF THE COLD FRONT OVERNIGHT, THEN END AS  
THE COLD FRONT MOVES THROUGH THE REGION TUESDAY MORNING.  
 

 
   
GRB WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
DISCUSSION.....JLA/MPC  
AVIATION.......KIECKBUSCH  
 
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