011  
FXUS63 KDLH 260512  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
1212 AM CDT WED JUL 26 2017  
   
SHORT TERM
 
(THIS EVENING THROUGH WEDNESDAY)  
ISSUED AT 334 PM CDT TUE JUL 25 2017  
 
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF  
A COLD FRONT TONIGHT ACROSS PORTIONS OF EAST CENTRAL MINNESOTA INTO  
NORTHWEST WISCONSIN, SOME OF WHICH COULD BE STRONG TO SEVERE.  
PRECIPITATION MAY LINGER INTO WEDNESDAY MORNING AS THE COLD FRONT  
EXITS NORTHWEST WISCONSIN WITH SKIES CLEARING OUT IN THE WAKE OF THE  
FRONT WEDNESDAY AFTERNOON. FOR AREAS OF NORTH-CENTRAL MINNESOTA INTO  
PORTIONS OF NORTHEAST MN - AREAS SUCH AS THE BRAINERD LAKES, IRON  
RANGE, AND POINTS NORTH - THE OVERALL CHANCE FOR PRECIPITATION IS  
LOW TONIGHT WITH DECREASING OVERNIGHT. HIGHS TODAY AND TOMORROW  
SEASONABLE IN THE MID 70S TO LOW 80S, WITH LOWS TONIGHT FALLING TO  
THE MID/UPPER 50S WHERE SKIES CLEAR OUT, MID 60S UNDER THE CLOUDS IN  
EAST-CENTRAL MN AND NORTHWEST WISCONSIN.  
 
ON THE SYNOPTIC SCALE A MID-LEVEL LOW OVER CENTRAL MANITOBA WILL  
TRACK EAST INTO NORTHWEST ONTARIO TONIGHT WITH A RESULTING SURFACE  
LOW TO ITS NORTHEAST NEAR HUDSON BAY. EXTENDING FROM THIS LOW IS A  
COLD FRONT EXTENDED ALL THE WAY SOUTH INTO THE EASTERN GREAT PLAINS.  
A WARM SECTOR AHEAD OF THIS COLD FRONT IS ACROSS THE UPPER MIDWEST  
TODAY, AND AS EXPECTED MUCH OF THE REGION IS DRAPED WITHIN STRATUS  
LIMITING SURFACE HEATING. A FEW SHOWERS AND STORMS HAVE DEVELOPED AT  
TIMES THROUGH THE MORNING AND AFTERNOON ALONG THE WARM FRONT  
TRACKING EAST INTO NORTHWEST WISCONSIN, BUT THESE HAVE REMAINED SUB-  
SEVERE WITH JUST A FEW STORMS CAPABLE OF PRODUCING SMALL HAIL. IN  
ADDITION, ALONG THE INTERNATIONAL BORDER REGION A FEW STORMS HAVE  
DEVELOPED AT TIMES ALONG THE COLD FRONT, BUT THESE STORMS HAVE BEEN  
SHORT-LIVED.  
 
THE COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT INTO  
WEDNESDAY. IN THE WARM SECTOR ELEVATED INSTABILITY IS AN 1500-2000  
J/KG OVER NORTHERN MINNESOTA, APPROACHING 3000-4000 J/KG IN EASTERN  
SOUTH DAKOTA AND SOUTHWESTERN MINNESOTA. IT IS IN THIS AREA TOWARDS  
CENTRAL MINNESOTA WHERE LATE-DAY CONVECTION IS EXPECTED TO DEVELOP  
AND SPREAD EASTWARD. WHILE EARLIER GUIDANCE HAD SOLUTIONS WHICH  
FAVORED SOME OF THESE STORMS TRACKING TOWARDS SOUTHERN PARTS OF THE  
CWA - AREAS LIKE THE I-35 CORRIDOR EAST ACROSS NORTHWEST WISCONSIN -  
MODELS HAVE BEEN TRENDING AWAY FROM THIS IDEA AS THE DEEP-LAYER WIND  
SHEAR DOES NOT SEEM TO BE ENOUGH TO SUSTAIN STRONG TO SEVERE STORMS  
THIS FAR NORTH. A FEW STRONG TO SEVERE UPDRAFTS CANNOT BE RULED OUT  
GIVEN THE VERY IMPRESSIVE MID-LEVEL LAPSE RATES ADVECTING IN, BUT  
THUNDERSTORMS WILL STRUGGLE TO SUSTAIN THEMSELVES GIVEN THE WIND  
FIELD. THE COLD FRONT WILL SWEEP EAST TONIGHT WHICH IN ADDITION TO  
ISOLATED/SCATTERED STORMS OVER EAST-CENTRAL MN AND NORTHWEST WI MAY  
RESULT IN CONTINUED ISOLATED STORMS DEVELOPING ALONG THE  
INTERNATIONAL BORDER REGION, BUT THESE WILL LIKELY REMAIN SUB-  
SEVERE. GIVEN THE SHORT-LIVED STORMS, DAMAGING WINDS MAY BE A THREAT  
FOR A BIT THIS EVENING AS STORMS COLLAPSE, OTHERWISE AN ISOLATED  
LARGE HAIL THREAT WILL EXIST THROUGH THIS EVENING. WITH PRECIPITABLE  
WATER VALUES APPROACHING 2" IN EAST-CENTRAL MN AND NORTHWEST  
WISCONSIN, ALL STORMS WILL BE PRODUCING HEAVY RAIN RATES WHICH COULD  
LEAD TO MINOR FLOODING, THOUGH STORMS SHOULD BE PROGRESSIVE ENOUGH  
AND ISOLATED TO SCATTERED IN NATURE, LIMITING THE POSSIBILITY OF ANY  
FLASH FLOODING. BEHIND THE COLD FRONT OVERNIGHT SOME PATCHY FOG MAY  
DEVELOP AS SKIES CLEAR OUT AND TEMPERATURES FALL.  
 
WEDNESDAY A FEW SHOWERS AND STORMS MAY CONTINUE AHEAD OF THE COLD  
FRONT IN NORTHWEST WISCONSIN DURING THE MORNING, BUT BY THE  
AFTERNOON MOSTLY SUNNY SKIES SHOULD PREVAIL OVER THE NORTHLAND. WITH  
DIURNAL HEATING SOME AFTERNOON STRATOCU IS POSSIBLE ALONG WITH  
NORTHWEST WINDS AROUND 5-10 MPH.  
   
LONG TERM
 
(WEDNESDAY NIGHT THROUGH TUESDAY)  
ISSUED AT 334 PM CDT TUE JUL 25 2017  
 
WEDNESDAY EVENING A FEW SHOWERS MAY BE LINGERING OVER PRICE COUNTY  
ACCORDING TO SOME OF THE MODEL QPF, BUT IT APPEARS ALL THE FORCING  
IS WELL TO OUR SOUTHEAST, AND HAVE LEFT THE EVENING FORECAST DRY  
WITH GRADUALLY DECREASING CLOUDS.  
 
A FAIRLY STRONG SURFACE RIDGE BUILDS INTO THE AREA FOR THURSDAY AND  
FRIDAY, WHICH IS EXPECTED TO BRING SOME COOLER TEMPERATURES FOR BOTH  
DAYS. USUALLY A RIDGE WOULD BRING DRY WEATHER AS WELL, BUT IT LOOKS  
LIKE WE MAY DEVELOP SOME AFTERNOON SHOWERS THURSDAY AND HAVE SOME  
SLIGHT CHANCE POPS THERE FOR THE AFTERNOON HOURS. OTHERWISE WE ARE  
LOOKING AT DRY CONDITIONS THROUGH AT LEAST FRIDAY NIGHT.  
 
SATURDAY OUR RIDGE SHIFTS OFF TO THE EAST AND ALLOWS RETURN FLOW TO  
SET UP OVER THE AREA. THE GFS IS BRINGING A SHORTWAVE THROUGH THE  
WESTERLY FLOW ALOFT, WHICH IS NOT DEPICTED IN THE ECMWF WHICH BIGHT  
BRING SHOWERS AND THUNDERSTORMS INTO THE AREA AS EARLY AS SATURDAY  
AFTERNOON. HOWEVER, THIS IS DAY 5 AND AM NOT TERRIBLY CONFIDENT IN  
IT, SO HAVE KEPT POPS IN THE SLIGHT TO LOW END CHANCE RANGE SATURDAY  
NIGHT AND SUNDAY. HIGHS PUSH BACK UP INTO THE UPPER 70S TO LOW 80S  
BOTH DAYS.  
 
EARLY NEXT WEEK WE START SEEING SOME SIGNIFICANT DIFFERENCES IN THE  
MODELS THAT AFFECT THE FORECAST AREA. THE GFS HAS A STRONG UPPER  
LOW OVER THE HUDSON BAY AND MORE AMPLIFIED RIDGE OVER WESTERN NORTH  
AMERICA THAN IS DEPICTED ON THE ECMWF. THE GFS SOLUTION BRING  
COOLER TEMPERATURES AND SOME PRECIPITATION CHANCES ACROSS THE AREA.  
THE ECMWF ALSO HAS SOME PRECIPITATION CHANCES AND IS WARMER THAN THE  
GFS, THOUGH STILL BELOW NORMAL. HAVE LOW CONFIDENCE FOR NOW, BUT  
HAVE SLIGHT CHANCE POPS WITH NEAR TO BELOW NORMAL TEMPERATURES FOR  
THE FIRST HALF OF NEXT WEEK.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)  
ISSUED AT 1212 AM CDT WED JUL 26 2017  
 
A FRONTAL BOUNDARY WILL LINGER ACROSS THE SOUTHERN  
PORTIONS OF THE NORTHLAND OVERNIGHT, AND WILL BE THE FOCUS FOR  
SHOWERS AND THUNDERSTORMS. NORTH OF THE KDLH AREA, WE SHOULD  
GENERALLY SEE DRY CONDITIONS WITH SOME AREAS OF FOG. CIG'S AND  
VSBY'S WILL VARY CONSIDERABLY OVERNIGHT, RANGING FROM VFR TO IFR  
DUE TO FOG AND ALSO SHOWERS AND STORMS. CONDITIONS WILL QUICKLY  
BECOME VFR EVERYWHERE ON WEDNESDAY.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
DLH 62 79 58 76 / 50 10 0 20  
INL 57 77 56 79 / 30 10 0 0  
BRD 64 80 59 79 / 50 10 0 0  
HYR 65 80 58 79 / 90 30 0 10  
ASX 65 82 59 76 / 80 20 0 10  
 

 
   
DLH WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MN...NONE.  
LS...NONE.  

 
 

 
 
SHORT TERM...JJM  
LONG TERM...LE  
AVIATION...DAP  
 
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