765  
FXUS63 KDLH 291438 AAA  
AFDDLH  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE DULUTH MN  
938 AM CDT WED MAR 29 2017  
   
UPDATE
 
 
ISSUED AT 935 AM CDT WED MAR 29 2017  
 
UPDATED TO INCLUDE WORDING OF MUCH COOLER TEMPERATURES NEAR LAKE  
SUPERIOR. WITH BRISK OFF-LAKE WINDS, TEMPERATURES WILL NOT RISE  
MUCH BEYOND WHERE THEY ARE CURRENTLY AT, IN THE MID 30S, TODAY.  
 

 
   
SHORT TERM
 
(TODAY THROUGH THURSDAY)  
ISSUED AT 458 AM CDT WED MAR 29 2017  
 
INCREASING CLOUD COVER WITH COOLER TEMPERATURES ARE EXPECTED  
TODAY ACROSS THE NORTHLAND. A FEW SHOWERS MAY NOSE INTO OUR  
SOUTHERN WISCONSIN ZONES TONIGHT AND WEDNESDAY, WITH A WINTRY MIX  
POSSIBLE.  
 
SPLIT FLOW WILL CONTINUE ACROSS THE UPPER MIDWEST TODAY AND  
THURSDAY. SURFACE HIGH PRESSURE OVER NORTHERN ONTARIO AND THE  
WESTERN GREAT LAKES THIS MORNING WILL SHIFT FARTHER EASTWARD  
TODAY. A CLOSED UPPER LOW WILL ADVANCE SLOWLY EASTWARD FROM THE  
TEXAS PANHANDLE THIS MORNING TO THE MIDDLE MISSISSIPPI VALLEY BY  
THURSDAY EVENING. MEANWHILE A PROGRESSIVE, AND WEAKER SHORTWAVE  
TROUGH WILL DIG ACROSS THE CANADIAN PRAIRIES AND UPPER MIDWEST,  
MOVING INTO NORTHERN ONTARIO BY THURSDAY EVENING. BEING BETWEEN  
THESE UPPER- LEVEL FEATURES WILL KEEP CONDITIONS FAIRLY QUIET  
ACROSS THE NORTHLAND DURING THE PERIOD. MID- AND UPPER-LEVEL  
STRATUS WILL SPREAD ACROSS THE AREA THIS MORNING AND LINGER  
THROUGH THURSDAY AFTERNOON RESULTING IN PARTLY TO MOSTLY CLOUDY  
SKIES ACROSS THE AREA. TEMPERATURES WILL TREND A LITTLE COOLER DUE  
TO THE CLOUD COVER. WITH THE SURFACE RIDGE SHIFTING EASTWARD, AND  
LOW PRESSURE APPROACHING FROM THE WEST AND SOUTHWEST, WINDS WILL  
BE STRONG AT THE HEAD OF THE LAKE AND FOR PORTIONS OF IRON AND  
ASHLAND COUNTIES. THE WINDS WILL BE STRONGEST ALONG THE NORTH  
SHORE WHERE THE PRESSURE GRADIENT IS EXPECTED TO INCREASE SHARPLY.  
HIGHS TODAY WILL BE IN THE MIDDLE 50S WEST TO AROUND 50 DEGREES  
SOUTHEAST, WITH UPPER 40S ALONG THE LAKE SUPERIOR SHORE AND IN THE  
ARROWHEAD.  
 
SKIES MAY CLEAR FOR CENTRAL PORTIONS OF THE FORECAST AREA, WHILE  
OVERCAST SKIES ARE FAVORED SOUTHEAST AND PORTIONS OF THE  
NORTHWEST. TEMPERATURES WILL REMAIN ELEVATED OVERNIGHT DUE TO THE  
CLOUD COVER WITH LOWS IN THE MIDDLE 20S TO LOW 30S. MOST MODELS  
BRING A SLIGHT CHANCE OF SHOWERS INTO OUR SOUTHERN WISCONSIN  
ZONES, GENERALLY SOUTH OF WISCONSIN STATE HIGHWAY 70 FROM SPOONER  
TO WINTER TO PARK FALLS. TEMPERATURE PROFILES WOULD SUGGEST A MIX  
OF RAIN, FREEZING RAIN, OR SNOW. DO NOT EXPECT NOTEWORTHY  
ACCUMULATIONS OF SNOW OR ICE AS OF THIS FORECAST PACKAGE, BUT A  
FEW SECONDARY ROADS MAY BE SLIPPERY FOR THE THURSDAY MORNING  
COMMUTE. THE CHANCE FOR PRECIPITATION SHIFTS EASTWARD DURING THE  
DAY AND KEPT POPS LIMITED TO PRICE COUNTY AFTER 12Z. SKIES WILL  
GRADUALLY CLEAR ACROSS THE NORTH ON THURSDAY AS THE NORTHERN  
STREAM TROUGH SHIFTS EAST OF THE NORTHLAND. TEMPERATURES WILL  
CLIMB INTO THE LOW 50S WEST WITH 40S OVER THE REMAINDER OF THE  
AREA.  
   
LONG TERM
 
(THURSDAY NIGHT THROUGH TUESDAY)  
ISSUED AT 458 AM CDT WED MAR 29 2017  
 
LATEST GUIDANCE CONTINUES THE TREND OF A FAIRLY QUIET LONG-TERM  
FORECAST PERIOD. THURSDAY NIGHT/FRIDAY MORNING LOOKS TO BE DRY  
ACROSS MOST, IF NOT ALL, OF THE NORTHLAND. A CLOSED AREA OF LOW  
PRESSURE IS BEING PROGGED TO ADVANCE THROUGH THE MID MISSISSIPPI  
RIVER VALLEY REGION DURING THIS TIME. THE 29.00Z GFS WANTS TO  
BRING QPF AS FAR NORTH AS SAWYER, ASHLAND, AND IRON COUNTIES IN NW  
WI, BUT THE CMC/NAM MODELS KEEP THIS AREA DRY. CONSENSUS BLENDS  
CONTINUE THE DRY FORECAST THAT WAS INHERITED, SO WILL KEEP THIS  
TREND GOING. NORTHEAST FLOW DUE TO THE PROXIMITY OF THIS LOW WILL  
KEEP TEMPERATURES A BIT COOLER DURING THE DAY FRIDAY ALONG LAKE  
SUPERIOR.  
 
A MID-LEVEL SHORTWAVE TROUGH IS THEN PROGGED TO DIVE SOUTHEAST  
ACROSS THE REGION DURING THE DAY SATURDAY, WHICH LOOKS TO BRING  
CHANCES OF PRECIPITATION WITH IT. HOWEVER, THERE IS SOME  
UNCERTAINTY REGARDING THE SPATIAL EXTENT OF THE PRECIPITATION AS  
THE GFS/ECMWF/CMC MODELS DISAGREE ON HOW FAR SOUTH PRECIPITATION  
REACHES. THE GFS SOUNDINGS SHOW A BRIEF PERIOD OF DEEPER MOISTURE  
DEVELOPING BEFORE DRYING ABOVE THE 800 MB LEVEL. CONSENSUS BLENDS  
HAVE CUT BACK ON POPS QUITE A BIT FROM THE PREVIOUS FORECAST,  
WHICH SEEMS REASONABLE DUE TO THIS UNCERTAINTY. BEST CHANCES LOOK  
TO BE ALONG THE INTERNATIONAL BORDER AND IRON RANGE REGIONS  
THROUGH SATURDAY.  
 
SUNDAY LOOKS DRY AND VERY WARM DUE TO SOUTHERLY RETURN FLOW FROM  
SFC HIGH PRESSURE. HIGH TEMPERATURES SUNDAY LOOK TO REACH INTO THE  
50S FOR ALL LOCATIONS EXCEPT FOR THE TIP OF THE MN ARROWHEAD.  
THEN, CHANCES OF PRECIPITATION LINGER FROM MONDAY MORNING THROUGH  
WEDNESDAY AS ANOTHER SYSTEM MAKES ITS WAY INTO THE REGION.  
UNCERTAINTY IN THE SPATIAL EXTENT DOES EXIST BETWEEN THE  
GFS/CMC/ECWMF MODELS AT THIS TIME, SO ONLY KEPT CHANCE POPS FOR  
NOW. HIGH TEMPERATURES IN THE UPPER 40S AND INTO THE 50S SHOULD  
CONTINUE THROUGH THE PERIOD.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)  
ISSUED AT 626 AM CDT WED MAR 29 2017  
 
HIGH CIRRUS CLOUDS WILL CONTINUE TO BUILD INTO THE REGION TODAY,  
WITH SOME SCT TO BKN CLOUD DECKS POSSIBLE. THE BAND OF STRATUS  
THAT DEVELOPED THIS MORNING NEAR THE HEAD OF LAKE SUPERIOR  
REMAINED NEARLY STATIONARY DESPITE WINDS HAVING A SLIGHT WESTERLY  
COMPONENT. NOT CONFIDENT THAT IT WILL PROPAGATE TO THE NORTH OVER  
THE DLH TAF SITE. SO, DECIDED TO REMOVE THE BKN008 TEMPO GROUP  
FOR DLH.  
 
AS AN AREA OF LOW PRESSURE APPROACHES THE REGION FROM THE SOUTH,  
EXPECT A LOW-LEVEL STRATUS DECK TO DEVELOP, WITH CEILINGS BETWEEN  
1 TO 5 KFT FOR ALL TAF SITES EXCEPT FOR INL. DLH AND HIB ARE  
EXPECTED TO SEE MVFR CIGS, WHILE THE OTHER SITES LOOK TO REMAIN  
VFR THROUGH THE TAF PERIOD. SOME MVFR FOG LOOKS TO DEVELOP OVER  
DLH TONIGHT AS WELL AS A LOW-LEVEL INVERSION DEVELOPS, WHICH SHOULD  
HELP TO TRAP BOUNDARY LAYER MOISTURE NEAR THE SURFACE.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
DLH 46 29 45 29 / 0 0 0 0  
INL 53 30 51 29 / 0 0 0 0  
BRD 54 31 51 30 / 0 0 0 0  
HYR 51 32 47 28 / 0 10 10 0  
ASX 48 28 44 28 / 0 0 10 0  
 

 
   
DLH WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MN...NONE.  
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ142>145.  
 

 
 

 
 
UPDATE...CLC  
SHORT TERM...HUYCK  
LONG TERM...JTS  
AVIATION...JTS  
 
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