483  
FXUS63 KARX 031214  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
614 AM CST SUN MAR 3 2024  
   
KEY MESSAGES
 
 
- RECORD BREAKING TEMPERATURES & INCREASED WINDS REMAIN ON TRACK  
TODAY  
 
- FIRE WEATHER CONCERNS REMAIN ELEVATED PRIMARILY IN NORTHEAST  
IOWA AND SOUTHEAST MINNESOTA THIS AFTERNOON  
 
- INITIAL LIGHT PRECIPITATION CHANCES THIS EVENING FOR SOME  
BECOME MORE WIDESPREAD THROUGH MONDAY  
 

 
   
DISCUSSION
 
 
ISSUED AT 421 AM CST SUN MAR 3 2024  
 
EARLY MORNING OBSERVATIONS:  
 
THE ONGOING WARMING TREND REACHES ITS CRESCENDO TODAY FROM  
INTENSIFYING LOW LEVEL WARM AIR ADVECTION. THE DRIVING,  
ASSOCAITED SURFACE LOW HAS SHOWN A NORTH-NORTHEASTERLY JOG IN  
LATEST EARLY MORNING OBSERVATIONS, PUSHING INTO NE. GOES 16  
UPPER LEVEL WATER VAPOR IMAGERY ALSO SHOWS THE UPPER LEVEL  
TROUGH UNDERGOING A MORE NORTHERLY JAUNT EARLY THIS MORNING,  
PHASING INCREASINGLY POSITIVE.  
 
TEMPERATURES & WINDS TODAY:  
 
AS THIS PHASING AND LIFTING CONTINUES, BECOMING NEARLY ZONAL,  
THE SURFACE LOW MOVES THROUGH THE RED RIVER VALLEY. THE  
ASSOCIATED LOW LEVEL THETA E LOBE TIGHTENS AND INTENSIFIES  
ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. AS A RESULT, SIMILAR  
TO PREVIOUS FORECASTS, DAYTIME HIGHS WELL ABOVE RECORDS EXPECTED  
WITH THE 70 DEGREE ISOTHERM DRAPED INTO CENTRAL WISCONSIN. THE  
TIGHTENED PRESSURE GRADIENT WILL ALSO INCREASE WINDS, SUSTAINED  
FROM UP TO 30 KTS WITH GUSTS NEAR 35 KTS PRIMARILY WEST OF THE  
MISSISSIPPI RIVER.  
 
RELATIVE HUMIDITY & PRECIPITATION TODAY/TONIGHT:  
 
WHILE CONFIDENCE FOR WIND VALUES REMAIN MODERATE (~80%;  
HREF), TIMING OF A SUBSEQUENT DRY LINE PASSAGE IS RESULTING IN  
MODEL DISAGREEMENT FOR PRECIPITATION AND RHS. THE EARLIEST  
SOLUTION DURING THE EARLY EVENING HOURS ADVECTS A THIN FILAMENT  
OF VERY DRY AIR THROUGH FROM WEST TO EAST. THIS EARLIER RESULT  
WOULD ALLOW DEEPER DAYTIME MIXING OF THIS MOST INTENSE DRY AIR,  
PROVIDING RHS BOTTOMING OUT IN THE TEENS. HOWEVER, THE RECENT  
GENERAL SLOWING TREND PASSES THE DRIER AIR LATER INTO THE  
EVENING, KEEPING RHS INTO 20S FROM NORTHEAST IOWA INTO SOUTHEAST  
MINNESOTA. WILL BE IMPORTANT DETAIL TO KEEP AN EYE ON, AS  
HIGHEST CONFIDENCE HAS ABATED ISSUING FIRE WEATHER HEADLINES AT  
THE CURRENT FORECAST HOUR.  
 
PRECIPITATION CHANCES WITHIN THE AREA OF INCREASED CONFLUENCE  
PROGRESSES FROM WEST- CENTRAL WISCONSIN INTO CENTRAL WISCONSIN  
THROUGH THE EVENING HOURS. WHILE THUNDER RUMBLES CANNOT BE RULED  
OUT WITHIN THE TRANSIENT FORCING, CONFIDENCE REMAINS VERY LOW  
GIVEN DAMPENING MID LEVEL LAPSE RATES. RAINFALL AMOUNTS WILL BE  
LOW.  
 
FRONTAL BOUNDARY & FORCING OVERNIGHT THROUGH MONDAY:  
 
OTHERWISE, THE PERSISTENT UPPER LEVEL PATTERN ABANDONS THE  
SURFACE BOUNDARY ACROSS THE FORECAST AREA OVERNIGHT. THE PASSAGE  
OF THE ACCOMPANYING UPPER LEVEL JET STREAK AXIS AND ATTENDANT  
UPPER LEVEL CONVERGENCE WILL PROVIDE MEAGER RETURN FLOW  
OVERNIGHT, SOLIDIFYING AND PROGRESSING THE MOISTURE BOUNDARY  
NORTHWEST. ADEQUATE FORCING WITHIN ENTRANCE REGION OF JET  
STREAK LIFTS THROUGH THE CENTRAL PLAINS INTO MONDAY MORNING  
ALLOWING A SURFACE LOW TO FORM ALONG THE ACCOMPANYING LOW LEVEL  
BAROCLINIC ZONE. AS THE LOW LIFTS, THE AREA OF STRONGEST  
STRETCHING INTENSIFIES LOW LEVEL FRONTOGENESIS, PROVIDING NARROW  
BANDING OF PRECIPITATION CHANCES ALONG THE STRANDED FRONTAL  
BOUNDARY.  
 
PRECIPITATION AMOUNTS THROUGH MONDAY:  
 
THIS STRETCHING PROVIDES HIGHEST PRECIPITATION CHANCES LOCALLY  
THROUGH MONDAY. HOWEVER, GIVEN THE NARROW FGEN FORCING AS WELL  
AS DEPENDENCY OF EXACT LOCATION OF SURFACE FRONT, THERE IS MUCH  
DISAGREEMENT FOR PRECIPITATION AMOUNTS LOCALLY. HREF VARIES  
LOCALLY FROM A MEAN OF 0.25" AND MAX OF 1.25". THEREFORE, HAVE  
BLENDED SHORT TERM MODELS IN WITH NATIONAL BLEND, BROAD BRUSHING  
THE 0.25" RAINFALL ISOHYET FROM FAR SOUTHWEST WISCONSIN THROUGH  
CENTRAL WISCONSIN.  
 
LATE WEEK TEMPERATURES & PRECIPITATION CHANCES:  
 
EVENTUALLY, THE SYNOPTIC PATTERN STABILIZES WITH MODERATE CONFIDENCE  
IN GLOBAL ENSEMBLES (EPS/GEFS) FOR MID-LEVEL SOUTHWESTERLY FLOW  
FLIRTING THE 50 DEGREE ISOTHERM ALONG OUR SOUTHERN PERIPHERY.  
PRECIPITATION CHANCES RETURN FOR THE LATTER HALF OF THE WORK WEEK AS  
A TROUGH PHASES AND DEEPENS. HIGHEST CONFIDENCE IN LONG TERM  
GLOBAL ENSEMBLES PLACES THE 0.1" + RAINFALL ISOHYET BIFURCATING  
OUR SOUTHERN HALF FROM NORTHEAST IOWA INTO SOUTHWEST WISCONSIN.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
 
 
ISSUED AT 555 AM CST SUN MAR 3 2024  
 
VFR CONDITIONS TODAY WITH STRONG WINDS THE MAIN AVIATION CONCERN.  
HAVE BEEN MONITORING LOW CLOUD DEVELOPMENT WITH INFLUX OF HIGHER  
LOW LEVEL DEWPOINTS. NATIONAL BLEND NBH GUIDANCE CONTINUES TO  
SHOW SOME LOW 10 TO 25% PROBABILITIES FOR MVFR CEILINGS THIS  
MORNING. NIGHTTIME MICROPHYSICS SATELLITE IMAGERY DOES SHOW AND  
AREA OF IFR/MVFR CEILING DEVELOPING. COULD STILL SEE SOME  
DEVELOPMENT BACK TOWARD KLSE. DUE TO LOW CONFIDENCE ON COVERAGE,  
DID INCLUDE A SCT DECK OF LOW CLOUDS.  
 
STRONG SOUTHEAST WINDS DEVELOP TODAY 10 TO 20KTS INCREASING 20  
TO 30KTS WITH GUSTS 20 TO 30KTS INCREASING TO 30 TO 40KTS.  
INCLUDED LOW LEVEL WIND SHEAR AT KLSE AND AT KRST DUE TO THE  
DIRECTIONAL SHEAR FOR A FEW HOURS EARLY IN THE TAF PERIOD. WINDS  
SHIFT TO THE WEST AND INCREASE, THEN DIMINISH DURING THE  
EVENING.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 405 AM CST SUN MAR 2 2024  
 
ELEVATED TO NEAR-CRITICAL FIRE WEATHER CONDITIONS EXPECTED  
TODAY. THIS IS DUE THE COMBINATION OF RECORD WARM TEMPERATURES,  
DRY RELATIVE HUMIDITIES, AND STRONG SOUTHERLY WINDS. HIGH  
TEMPERATURES WILL BE IN THE 60S NORTH OF INTERSTATE 94 AND IN  
THE LOWER TO MID-70S ELSEWHERE. AFTERNOON RELATIVE HUMIDITIES  
WEST OF THE MISSISSIPPI RIVER FALLING INTO THE 25 TO 40 PERCENT  
RANGE WITH 30 TO 50 PERCENT ELSEWHERE IN WISCONSIN.  
STRENGTHENING SOUTHERLY WINDS WILL RANGE FROM 25 TO 35 MPH WITH  
WIDESPREAD GUSTS FROM 35 TO 45 MPH, POTENTIALLY HIGHER IN WIND  
PRONE AREAS WEST OF THE MISSISSIPPI RIVER. THE GFDI CLIMBS UP  
INTO EXTREME RANGE ACROSS COUNTIES IN NORTHEAST IOWA.  
 

 
   
CLIMATE
 
 
ISSUED AT 405 AM CST SUN MAR 3 2024  
 
WITH NAEFS 850 MB TEMPERATURES ANOMALIES FROM 2 TO 2.5 STANDARD  
DEVIATIONS TODAY, RECORD HIGH TEMPERATURES ARE EXPECTED. ALSO,  
OVERNIGHT LOW TEMPERATURES EARLY THIS MORNING HAVE REMAINED WARM  
ENOUGH TO POTENTIALLY BREAK OVERNIGHT WARM MINIMUMS. ALTHOUGH,  
THESE OVERNIGHT WARM LOW RECORDS WILL ALSO BE DEPENDENT ON  
TEMPERATURES TONIGHT.  
 
ROCHESTER MN FORECAST RECORD/YEAR  
 
TODAY 72 56/1946  
 
LA CROSSE WI FORECAST RECORD/YEAR  
 
TODAY 74 66/1894  
45 44/1880  
 

 
   
ARX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MN...NONE.  
IA...NONE.  
 

 
 

 
 
DISCUSSION...JAR  
AVIATION...ZAPOTOCNY  
FIRE WEATHER...JAR  
CLIMATE...JAR/ZAPOTOCNY  
 
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