933  
FXUS63 KDLH 231745  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
1145 AM CST SUN FEB 23 2020  
   
SHORT TERM
 
(TODAY THROUGH MONDAY)  
ISSUED AT 304 AM CST SUN FEB 23 2020  
 
EARLY MORNING WATER VAPOR IMAGERY SHOWING ZONAL FLOW PREVAILING  
ACROSS THE NORTHERN U.S., WITH A DEEP UPPER TROUGH SLOWLY  
TRANSITIONS ACROSS THE FOUR CORNERS REGION. CLOSER TO OUR AREA,  
SHORTWAVE ENERGY IS SEEN THIS MORNING OVER CENTRAL NORTH DAKOTA,  
WHICH WITH TIME, WILL LEAD TO AN INCREASE IN CLOUDS AND A TREAT  
FOR LIGHT SNOW SHOWER ACTIVITY ACROSS PORTIONS OF OUR AREA EARLY  
THIS AFTERNOON. BEFORE THIS, THE GOES-EAST CHANNEL DIFFERENCE FOG  
PRODUCT IS SHOWING LOW STRATUS AND PATCHY FOG ACROSS PORTIONS OF  
THE REGION THIS MORNING, WITH THE MOST CONCENTRATED ACTIVITY NOTED  
EAST OF THE I-35 CORRIDOR. DEGREE OF EXPANSION REMAINS IN  
QUESTION THIS MORNING AS SOUTHWEST FLOW OF 4-8 KTS ACROSS THE  
REMAINING PORTION OF NORTHEAST MINNESOTA MAY CREATE ENOUGH MIXING  
TO PREVENT FOG FROM BECOMING MORE WIDESPREAD. FOR NOW, HAVE  
MAINTAINED A FOG MENTION FOR MANY AREAS THIS MORNING, BUT WILL  
MAKE ADJUSTMENTS AS NEEDED AS TRENDS BECOMING MORE FIRMLY  
ESTABLISHED.  
 
SHIFTING GEARS TO LATER TODAY, FCST MODELS ARE IN EXCELLENT  
AGREEMENT THAT THE BEST FORCING FOR THE AFOREMENTIONED SHORTWAVE  
WILL REMAIN NORTH OF THE INTERNATIONAL BORDER AS IT SLIDES EAST  
WITH TIME. THAT SAID, THIS FEATURE WILL BE ACCOMPANIED BY A COLD  
FRONT WHICH COMBINED WITH THE MODEST UPPER FORCING, MAY BE ENOUGH  
TO SQUEEZE OUT A LITTLE SNOW SHOWER ACTIVITY ACROSS THE BORDERLAND  
AREA LATER TODAY, HOWEVER NO ACCUMULATION IS EXPECTED AT AT THIS  
TIME. DESPITE THE INCREASING CLOUDS, WARM AIR ADVECTION AND BREEZY  
SOUTHWEST WINDS OF 10-20 MPH WILL ALLOW TEMPERATURES TO AGAIN  
CLIMB INTO THE MIDDLE TO UPPER 30S ACROSS MUCH OF THE AREA, WITH  
LOW 40S POSSIBLE ACROSS PORTIONS OF NORTHWEST WISCONSIN. DRY  
WEATHER WILL THEN CONTINUE INTO MONDAY WITH TEMPERATURES EXPECTED  
TO WARM INTO THE LOWER TO MIDDLE 30S FOR DAYTIME HIGHS.  
   
LONG TERM
 
(MONDAY NIGHT THROUGH SATURDAY)  
ISSUED AT 304 AM CST SUN FEB 23 2020  
 
THE UPPER LEVEL PATTERN EARLY NEXT WEEK SHOWS AN INTERESTING PHASING  
OF A NORTHERN AND SOUTHERN STREAM LOW PRESSURE SYSTEM, ONE OVER THE  
NORTHWEST CONUS, WITH ANOTHER SLOWER MOVING ONE OVER EASTERN CO/NM.  
THESE BEGIN TO PHASE TOGETHER AS THE FASTER NORTHERN STREAM FEATURE  
MOVES ACROSS THE NORTHERN ROCKIES ON MONDAY, AND BY TUESDAY MORNING  
THE SOUTHERN FEATURE IS A WAVE EJECTING OUT OF THE EAST SIDE OF A  
STRONG UPPER LOW OVER NEBRASKA. THE SURFACE LOWS OVER EASTERN MT  
AND ANOTHER OVER EASTERN OK MONDAY MORNING MORPH INTO A STRONGER  
SURFACE LOW OVER THE MID MISSISSIPPI RIVER VALLEY, WITH A STRONG  
INVERTED TROUGH EXTENDING TOWARD SOUTH DAKOTA. THE BULK OF THESE  
SYSTEMS REMAIN SOUTH OF THE FORECAST AREA, AND WE SHOULD REMAIN  
DRY MONDAY NIGHT. HOWEVER, WE WILL HAVE FAIRLY STRONG NORTHEAST  
FLOW OVER THE FORECAST AREA, AND BY TUESDAY WE WILL HAVE SOME LAKE  
EFFECTS GOING ON, AND WHILE I DON'T THINK WE WILL HAVE ENOUGH  
LAKE SURFACE T TO 850MB T DIFFERENCE TO PRODUCE LAKE EFFECT SNOW,  
I DO EXPECT STRATUS AND EITHER FLURRIES/DRIZZLE TO DEVELOP ALONG  
THE SOUTH SHORE LATE MONDAY NIGHT, GRADUALLY INCREASING ON  
TUESDAY. A SECONDARY UPPER LEVEL TROUGH AXIS MOVING ACROSS THE  
AREA ON TUESDAY NIGHT AND WEDNESDAY ALONG WITH COLDER AIR MOVING  
IN ALOFT SHOULD INCREASE OUR PRECIPITATION CHANCES, AND WITH THE  
NORTH-NORTHEAST LOW LEVEL FLOW CONTINUING, LAKE EFFECT SNOW  
CHANCES INCREASE AS WELL. THE MODELS DO NOT HAVE VERY GOOD  
AGREEMENT ON HOW QUICKLY THIS SYSTEM PULLS OFF TO THE EAST, BUT  
SNOW CHANCES SHOULD TAPER OFF EITHER WEDNESDAY NIGHT OR THURSDAY.  
EARLIER IN THE WEEK THE MILDER TEMPERATURES SHOULD CONTINUE WITH  
HIGHS IN THE 20S AND LOWER 30S, AND OVERNIGHT LOWS IN THE SINGLE  
DIGITS AND TEENS. ONCE THIS UPPER LEVEL SYSTEM MOVES OFF TO OUR  
EAST, A POOL OF COLDER AIR MOVES OVER THE AREA FOR THE LATER  
PORTIONS OF THE WORK WEEK, BRINGING ANOTHER PERIOD OF COLDER  
TEMPERATURES WHICH THEN MODERATE THROUGH NEXT WEEKEND. FOR NOW I  
HAVE HIGHS IN THE 20S FOR THURSDAY AND FRIDAY WITH LOWS IN THE  
SINGLE DIGITS, BUT WOULD NOT BE SURPRISED TO NEED TO LOWER THESE  
AS WE GET CLOSER INTO THIS TIME RANGE. TEMPERATURES SHOULD  
MODERATE BACK INTO THE LOWER TO MID 30S FOR HIGHS FOR NEXT  
WEEKEND.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)  
ISSUED AT 1145 AM CST SUN FEB 23 2020  
 
A PATCH OF LOW STRATUS BETWEEN 1500-2100 FEET WAS MOVING TOWARDS  
INL AND BRD AT THE START OF THE FORECAST. VFR ELSEWHERE. LOOK FOR  
THESE LOW CLOUDS WITH MVFR CIGS TO REACH HIB EARLY THIS AFTERNOON  
AND PERSIST TO THE EARLY EVENING BEFORE MOVING EAST OF  
INL/BRD/HIB. NOT EXPECTING THESE LOWER CIGS TO AFFECT DLH OR HYR.  
GUSTY SURFACE WINDS UNTIL SUNSET. AFTER SUNSET, SOME BR IS  
EXPECTED TO FORM NEAR BRD WITH CIGS AND VSBYS INTO THE IFR RANGE  
FROM 08-12Z. CIGS WILL IMPROVE AT BRD TO MVFR BY 15Z AND VFR BY  
16Z. ELSEWHERE, VFR CONDITIONS ARE EXPECTED.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
DLH 38 19 33 22 / 10 0 0 20  
INL 36 16 32 17 / 20 10 0 10  
BRD 39 16 33 22 / 0 0 0 10  
HYR 42 17 37 22 / 0 0 0 0  
ASX 42 20 35 23 / 0 0 0 20  
 

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

 
 

 
 
UPDATE...LE  
SHORT TERM...CG  
LONG TERM...LE  
AVIATION...GSF  
 
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