489  
FXUS63 KMKX 181042  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
442 AM CST SAT JAN 18 2025  
   
KEY MESSAGES  
 
- ARCTIC AIR ARRIVES INTO SOUTHERN WISCONSIN TODAY, BRINGING  
FRIGID TEMPERATURES AND BITTERLY COLD WIND CHILLS THROUGH THE  
FIRST HALF OF NEXT WEEK.  
 
- COLD WEATHER ADVISORIES HAVE BEEN ISSUED FROM TONIGHT THROUGH MONDAY  
EVENING IN ADVANCE OF THE ARRIVING ARCTIC AIR MASS.  
ADDITIONAL COLD WEATHER HEADLINES ARE LIKELY FROM MONDAY NIGHT  
INTO TUESDAY.  
 
- HEAVY FREEZING SPRAY IS EXPECTED SUNDAY AFTERNOON THROUGH  
TUESDAY, PARTICULARLY OVER SOUTHERN LAKE MICHIGAN.  
 
- TEMPERATURES GRADUALLY TREND BACK TOWARD NORMAL MID TO LATE  
NEXT WEEK.  
 
 
   
SHORT TERM  
 
ISSUED 442 AM CST SAT JAN 18 2025  
 
TODAY THROUGH WEDNESDAY:  
 
SYNOPSIS/MESOANALYSIS: BREEZY NORTHWEST WINDS AND COLD ADVECTION ARE  
ONGOING EARLY THIS MORNING ACROSS SOUTHERN WISCONSIN, WITH  
YESTERDAY'S ARCTIC COLD FRONT NOW WELL SOUTHEAST OF THE AREA. SAID  
WINDS WILL ALLOW AN ARCTIC AIR MASS TO SETTLE INTO THE REGION  
THROUGH SUNDAY, WITH FRIGID TEMPERATURES AND BREEZY NORTHWEST WINDS  
SUPPORTING A PROLONGED PERIOD OF WIND CHILLS AT AND BELOW -10. THE  
ARCTIC AIR MASS WILL REMAIN ENTRENCHED THROUGH THE DAY ON MONDAY,  
ULTIMATELY BEING REINFORCED BY AN EVEN CHILLIER PULL OF ARCTIC AIR  
MONDAY NIGHT INTO TUESDAY. COLD WEATHER HEADLINES HAVE BEEN ISSUED  
INTO MONDAY EVENING IN THIS FORECAST PACKAGE, WITH ADDITIONAL  
HEADLINES COVERING MONDAY NIGHT AND TUESDAY MORNING BECOMING  
NECESSARY IN LATER FORECASTS. WINDS WILL TURN SOUTHWESTERLY DURING  
THE DAY ON WEDNESDAY, ALLOWING THE ENTRENCHED ARCTIC AIR MASS TO  
BEGIN BREAKING DOWN. DRESS WARM IF HEADING OUTDOORS THROUGH THE  
BEGINNING OF THE UPCOMING WORK WEEK.  
 
REST OF OVERNIGHT: GIVEN OBS AND RADAR TRENDS OVER WEST-CENTRAL  
WISCONSIN, CAN'T ENTIRELY RULE OUT A FEW FLURRIES TO THE NORTH AND  
WEST OF MADISON THROUGH SUNRISE. ANY SUCH ACTIVITY WILL BE NON-  
IMPACTFUL, WITH DRYING CONDITIONS IN THE LOW LEVEL SHUTTING OFF ANY  
FLURRY POTENTIAL BY SUNRISE.  
 
TONIGHT THROUGH MONDAY: THE CORE OF THE INCOMING ARCTIC AIR MASS  
WILL SETTLE INTO SOUTHERN WISCONSIN AMID CONTINUED POST-FRONTAL CAA.  
THE ARRIVAL OF SAID AIR MASS WILL SUPPORT OVERNIGHT LOWS AT OR BELOW  
ZERO OUTSIDE OF FAR SOUTHEASTERN WISCONSIN TONIGHT, AND AREAWIDE  
SUNDAY NIGHT INTO MONDAY. DAYTIME HIGH TEMPERATURES IN THE SINGLE  
DIGITS ARE EXPECTED BOTH SUNDAY AND MONDAY. THE FRIGID AIR WILL BE  
ACCOMPANIED BY PERSISTENT, BREEZY NORTHWEST SURFACE FLOW, WHICH WILL  
HOLD WIND CHILLS IN THE -10S AND -20S THROUGH THE ENTIRETY OF THIS  
TIME PERIOD. WIND CHILL READINGS WILL BE AT THEIR COLDEST---AND WELL  
INTO THE RANGE OF COLD WEATHER ADVISORY CRITERIA---DURING THE  
OVERNIGHT AND MORNING PERIODS, WITH BRIEF "RISES" ABOVE ADVISORY  
THRESHOLDS OCCURRING DURING THE AFTERNOON HOURS EACH DAY. RATHER  
THAN CHASING THE PERIODS OF -20 TO -29 WIND CHILLS WITH MULTIPLE  
HEADLINES, ULTIMATELY ELECTED TO ISSUE A LONG-FUSED COLD WEATHER  
ADVISORY FROM AS EARLY AS 3 AM SUNDAY THROUGH 9 PM MONDAY, WITH THE  
UNDERSTANDING THAT THERE WILL BE BRIEF PERIODS OF SUB-ADVISORY LEVEL  
WIND CHILLS DURING THE AFTERNOON PERIODS. DID SEPARATE THE ADVISORY  
INTO TWO DIFFERENT SEGMENTS, GIVEN THAT SUB -20 WIND CHILLS AREN'T  
FORECAST TO REACH FAR SOUTHEASTERN WISCONSIN UNTIL SUNDAY EVENING.  
COLD WEATHER ADVISORY THUS RUNS BETWEEN 3 AM SUNDAY AND 9 PM MONDAY  
OUTSIDE OF MILWAUKEE, RACINE, AND KENOSHA COUNTIES, AND BETWEEN 9 PM  
SUNDAY AND 9 PM MONDAY IN MILWAUKEE, RACINE, AND KENOSHA COUNTIES.  
 
MONDAY NIGHT THROUGH TUESDAY: EVEN COLDER TEMPERATURES WILL ARRIVE  
INTO SOUTHERN WISCONSIN, RESULTING IN THE CHILLIEST LOWS OF THE  
PERIOD ON TUESDAY MORNING. EXPECT WIDESPREAD LOWS IN THE DOUBLE  
DIGITS BELOW ZERO ALONG/NORTH OF I-94 AND US-18, WITH READINGS  
APPROACHING -10 FURTHER SOUTH. THE EVEN CHILLIER AIR MASS WILL  
COMBINE WITH STILL BREEZY NORTHWEST WINDS SO SUPPORT THE COLDEST  
WIND CHILLS OF THE UPCOMING ARCTIC OUTBREAK. COLD WEATHER HEADLINES  
WILL THUS CONTINUE DURING THIS TIMEFRAME, WITH EXTREME COLD WARNING  
LEVEL WIND CHILLS IN THE -30 TO -35 RANGE POSSIBLE OVER CENTRAL AND  
EAST-CENTRAL WISCONSIN ON TUESDAY MORNING. SHOULD TRENDS SUPPORTING  
SUCH WIND CHILLS CONTINUE TO HOLD, A MIXTURE OF EXTREME COLD  
WARNINGS AND COLD WEATHER ADVISORIES WILL LIKELY BECOME NECESSARY  
DURING THIS PORTION OF THE PERIOD. WILL MONITOR TRENDS OVER THE  
COMING FORECASTS, WITH HEADLINE DECISIONS BEING MADE AS THIS PORTION  
OF THE PERIOD DRAWS CLOSER.  
 
TUESDAY NIGHT THROUGH WEDNESDAY MORNING: ONE MORE OVERNIGHT PERIOD  
OF -10 TO -20 WIND CHILLS IS ANTICIPATED. LOCALLY COLDER READINGS  
ARE POSSIBLE, PARTICULARLY IN EAST-CENTRAL WISCONSIN. WHETHER OR NOT  
ADDITIONAL HEADLINES WILL BE NECESSARY DURING THIS PORTION OF THE  
PERIOD REMAINS UNCERTAIN, WITH TRENDS BEING MONITORED OVER THE  
COMING FORECAST CYCLES.  
 
QUIGLEY  
 
 
   
LONG TERM  
 
ISSUED 442 AM CST SAT JAN 18 2025  
 
WEDNESDAY NIGHT THROUGH FRIDAY:  
 
SYNOPSIS: TEMPERATURES WILL GRADUALLY MODERATE TOWARD NORMAL THANKS  
TO WEST-SOUTHWEST SURFACE WINDS. AN UPPER DISTURBANCE IS FORECAST TO  
TRACK ACROSS THE WESTERN GREAT LAKES THURSDAY NIGHT INTO FRIDAY.  
WHILE PRECIPITATION IS NOT CURRENTLY EXPECTED WITH THIS DISTURBANCE,  
TRENDS WILL CONTINUE TO BE MONITORED OVER THE COMING FORECASTS.  
 
QUIGLEY  
 
 
   
AVIATION  
 
ISSUED 442 AM CST SAT JAN 18 2025  
 
PREDOMINANTLY VFR FLIGHT CATEGORIES PREVAIL EARLY THIS MORNING IN  
THE WAKE OF A DEPARTED ARCTIC COLD FRONT. THE LONE EXCEPTION IS AT  
KUES, WHERE CIGS BETWEEN FL025 AND FL030 HAVE BEEN REPORTED OVER THE  
LAST 60 MINUTES. HAVE INSERTED A TEMPO GROUP THROUGH 11Z TO ACCOUNT  
FOR SAID OBS, AND WILL MONITOR TRENDS FOR ANY POTENTIAL TEMPO  
INSERTIONS DOWNSTREAM AT KMKE AND KENW. POST-FRONTAL NORTHWEST WINDS  
AND GUSTS WILL CONTINUE TO INCREASE THROUGH THIS MORNING, ALLOWING A  
MUCH DRIER AIR MASS TO MOVE INTO SOUTHERN WISCONSIN. THE ARRIVAL OF  
DRIER LOW LEVEL AIR WILL SCOUR OUT LOW LEVEL CLOUD COVER BY EARLY  
AFTERNOON, WITH ONLY FEW-SCT BASED NEAR FL200 REMAINING BY THIS  
AFTERNOON. NORTHWEST WINDS & GUSTS WILL DECREASE SLIGHTLY THIS  
EVENING AS HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS.  
 
QUIGLEY  
 
 
   
MARINE  
 
ISSUED 442 AM CST SAT JAN 18 2025  
 
GUSTY NORTHWEST WINDS ARE IN-PROGRESS ACROSS THE OPEN WATERS THIS  
MORNING IN THE WAKE OF AN ARCTIC COLD FRONT PASSAGE. GUSTS AT OR  
SLIGHTLY ABOVE 30 KTS WILL CONTINUE THROUGH DAYBREAK, WITH A FEW  
GALE-FORCE GUSTS POSSIBLE OVER THE NORTHERN HALF OF THE LAKE.  
NORTHWEST GUSTS WILL WEAKEN SLIGHTLY THROUGH TODAY AS 988 MB LOW  
PRESSURE MOVES INTO NORTHERN QUEBEC AND HIGH PRESSURE OF 1040 MB  
MOVES INTO THE NORTHERN GREAT PLAINS. NORTHWEST GUSTS WILL INCREASE  
TO OR JUST ABOVE 25 KTS SUNDAY AFTERNOON, COMBINING WITH ELEVATED  
WAVE HEIGHTS AND A FRIGID ARCTIC AIR MASS TO SUPPORT FREEZING SPRAY,  
WITH MODERATE TO HEAVY FREEZING SPRAY EXPECTED OVER THE SOUTHERN  
HALF OF THE OPEN WATERS. THE AFOREMENTIONED FREEZING SPRAY POTENTIAL  
WILL CONTINUE INTO THE BEGINNING OF NEXT WEEK AS A SECOND, STRONGER  
AREA OF HIGH PRESSURE NEAR 1048 MB PROGRESSES INTO THE NORTHERN  
GREAT PLAINS. A HEAVY FREEZING SPRAY WATCH HAS THUS BEEN ISSUED FROM  
SUNDAY AFTERNOON THROUGH TUESDAY AFTERNOON, WITH TRENDS BEING  
MONITORED FOR A POSSIBLE UPGRADES TO HEAVY FREEZING SPRAY WARNINGS  
OVER THE COMING FORECAST CYCLES.  
 
IN NEARSHORE ZONES, GUSTY NORTHWEST WINDS AND ELEVATED WAVE HEIGHTS  
WILL CONTINUE THROUGH THIS AFTERNOON IN THE WAKE OF THE DEPARTED  
ARCTIC COLD FRONT. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM  
SHEBOYGAN SOUTH TO WINTHROP HARBOR THROUGH 5 PM CST THIS AFTERNOON.  
GUSTS AND WAVE HEIGHTS ARE EXPECTED TO WEAKEN SLIGHTLY BELOW  
ADVISORY THRESHOLDS THIS EVENING, THOUGH THEY WILL CONTINUE TO HOVER  
JUST BELOW ADVISORY LEVELS INTO SUNDAY. WILL THUS MONITOR WIND/WAVE  
TRENDS CLOSELY OVER THE COMING FORECAST CYCLES, MAKING ANY SMALL  
CRAFT ADVISORY EXTENSIONS IF NECESSARY.  
 
QUIGLEY  
 
 
   
MKX WATCHES/WARNINGS/ADVISORIES  
 
WI...COLD WEATHER ADVISORY...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-  
WIZ057-WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-  
WIZ067-WIZ068-WIZ069-WIZ070...3 AM SUNDAY TO 9 PM MONDAY.  
 
COLD WEATHER ADVISORY...WIZ066-WIZ071-WIZ072...9 PM SUNDAY TO  
9 PM MONDAY.  
 
LM...HEAVY FREEZING SPRAY WATCH...LMZ080-LMZ567-LMZ669-LMZ671-  
LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-  
LMZ876-LMZ878...NOON SUNDAY TO 3 PM TUESDAY.  
 
SMALL CRAFT ADVISORY...LMZ643-LMZ644-LMZ645-LMZ646 UNTIL 5 PM  
SATURDAY.  
 
 
 
 
 
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