958  
FXUS63 KARX 161845  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
145 PM CDT MON SEP 16 2019  
   
SHORT TERM
 
(TONIGHT THROUGH TUESDAY NIGHT)  
ISSUED AT 145 PM CDT MON SEP 16 2019  
 
SURE THIS IS MID-SEPTEMBER? THE WEATHER ON TAP OVER THE NEXT FEW  
DAYS WILL FEEL MORE AUGUST-LIKE AS SOUTHWEST FLOW ALOFT ALLOWS VERY  
WARM AND HUMID AIRMASS TO OVERSPREAD THE REGION. TEMPERATURES THIS  
AFTERNOON AS OF 2 PM WERE IN THE 80S MOST PLACES WITH DEW POINTS IN  
THE MID 60S.  
 
A MID-LEVEL TROUGH ROTATES TOWARD THE UPPER MISSISSIPPI VALLEY  
REGION OVERNIGHT THROUGH TUESDAY. THIS WILL SPREAD SOME MID  
CLOUD/ALTOCUMULUS INTO THE AREA. OTHERWISE, BULK OF 850MB MOISTURE  
TRANSPORT STEERS WEST OF THE AREA OVER MN INTO FAR NORTHWEST WI -OR  
NORTHWEST OF OUR FORECAST AREA. THIS IS WHERE THE DETERMINISTIC AND  
CAMS KEEP QPF/SHOWERS AND STORMS. OTHERWISE, ANOTHER WARM ONE FOR  
TUESDAY WITH HIGHS TOPPING OFF AGAIN WELL INTO THE 80S FOR MUCH OF  
THE AREA.  
 
SHOWER AND STORM CHANCES MOVE INTO PORTIONS OF MN/IA/WESTERN WI  
LATER TUESDAY NIGHT AS A COLD FRONT PUSHES FROM THE DAKOTAS INTO MN.  
BETTER SHEAR AND INSTABILITY STAY WEST OF THE AREA WITH BUFKIT  
SOUNDING SHOWING MAINLY ELEVATED CONVECTION OVER OUR AREA. NOT  
REALLY LOOKING AT ANYTHING SEVERE WITH THIS THEN BUT STORMS COULD  
PRODUCE SOME LOCALLY HEAVIER RAINFALL AS PRECIPITABLE WATER VALUES  
CREEP UP INTO THE 1.25 TO 1.5 INCH RANGE.  
   
LONG TERM
 
(WEDNESDAY THROUGH MONDAY)  
ISSUED AT 145 PM CDT MON SEP 16 2019  
 
COLD FRONT SINKS EVER SO SLOWLY SOUTHEAST INTO THE AREA WEDNESDAY  
INTO THURSDAY WITH INCREASING PRECIPITABLE WATER VALUES AND CAPE.  
HOWEVER, BULK SHEAR REMAINS FAIRLY WEAK -GENERALLY 15-20KT, SO NOT  
EXPECTING ANY WIDESPREAD SEVERE. THAT BEING SAID, RAINFALL COULD BE  
QUITE HEAVY AT TIMES WITH PRECIPITABLE WATER VALUES IN THE 1.5 TO  
2.25" RANGE. WILL HAVE TO KEEP AN EYE OUT FOR SOME LOCALIZED  
FLOODING, ESPECIALLY THOSE AREAS ACROSS SOUTHWEST WI THAT GOT HEAVY  
RAIN THIS LAST WEEK. REMAINING ON THE WARM AND MUGGY SIDE OTHERWISE  
WITH HIGHS IN THE UPPER 70S TO MIDDLE 80S AND DEW POINTS IN THE  
60S/LOWER 70S.  
 
AREA OF LOW PRESSURE ROLLS OUT OF THE ROCKIES INTO THE NORTHERN  
PLAINS FRIDAY, PUSHING ANOTHER/STRONGER COLD FRONT TOWARD THE  
REGION. INCREASING MOISTURE TRANSPORT AHEAD OF THE FRONT WILL  
PRODUCE MORE SHOWER AND THUNDERSTORM CHANCES. COLD FRONT PUSHES INTO  
OUR AREA SATURDAY WITH INCREASING BULK SHEAR VALUES. MAY HAVE TO  
WATCH FOR A FEW STRONGER STORMS THEN ALONG WITH THAT CONTINUED  
THREAT FOR SOME LOCALIZED HEAVIER RAINFALL IN THE WARM/MUGGY  
AIRMASS.  
 
MODELS SHOW MID-LEVEL TROUGH LINGERING ACROSS THE AREA SUNDAY FOR  
PLENTY OF CUMULUS AND PERHAPS A FEW SHOWERS.  
 
RIDGING BUILDS IN FOR MONDAY FOR WHAT LOOKS TO BE A DRIER/PLEASANT  
DAY.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)  
ISSUED AT 1159 AM CDT MON SEP 16 2019  
 
THE MAIN CONCERN IS WHETHER FOG WILL FORM AGAIN TONIGHT. THE AREA OF  
HIGH PRESSURE IS NOT EXPECTED TO MOVE MUCH WHICH WOULD KEEP PART OF  
THE AREA UNDER THE RIDGE AXIS. THIS WOULD PROVIDE MOSTLY CLEAR SKIES  
WITH LIGHT WINDS TO ALLOW THE FOG TO DEVELOP. THE CONCERN IS JUST TO  
THE WEST OF THE RIDGE AXIS, FORECAST SOUNDINGS SHOW STRONG WINDS  
JUST ABOVE THE SURFACE, WHICH WOULD LEAD TO MORE LOW CLOUD  
DEVELOPMENT INSTEAD OF FOG. KLSE LOOKS TO BE RIGHT ON THE EDGE OF  
WHERE THE FOG MAY FORM SO HAVE ONLY INCLUDE A BCFG MENTION BUT DID  
INCLUDE A PERIOD OF MVFR CONDITIONS WITH LOW CLOUDS. KRST LOOKS TO  
BE FAR ENOUGH WEST TO NOT BE IMPACTED BY EITHER FOG OR LOW CLOUD  
DEVELOPMENT WITH VFR CONDITIONS EXPECTED THROUGH TUESDAY MORNING.  
 

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

 
 

 
 
SHORT TERM...DAS  
LONG TERM...DAS  
AVIATION...04  
 
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