Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 191523 AAA
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1023 AM CDT TUE AUG 19 2014

.UPDATE...
ISSUED AT 1023 AM CDT TUE AUG 19 2014

UPDATED THE FORECAST TO REMOVE MENTION OF FOG THIS MORNING AS MOST
OF THE FOG HAS MIXED OUT OR LIFTED. LOW CLOUDS AND DZ/-RA STILL
REMAIN AND WILL LIKELY PERSIST THROUGH THE DAY. CONVECTIVE SHOWERS
AND ISOLATED STORMS STILL EXPECTED TO DEVELOP THIS AFTERNOON.
OTHERWISE THE REST OF THE FORECAST LOOKS ON TRACK.

UPDATE ISSUED AT 654 AM CDT TUE AUG 19 2014

UPDATED FOR NEW AVIATION FORECAST DISCUSSION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM CDT TUE AUG 19 2014

A SURFACE LOW OVER WESTERN UPPER MICHIGAN IS ASSOCIATED WITH A LARGE
AREA OF CYCLONIC FLOW OVER THE NORTHLAND...WITH STRATUS AND RAIN
SHOWERS/DRIZZLE AND FOG OVER MUCH OF THE FORECAST AREA.  IN
FACT...FOG WAS SO DENSE AROUND THE TWIN PORTS AND SOUTH ALONG AND
EAST OF THE INTERSTATE THAT I HAVE ISSUED A DENSE FOG ADVISORY.
THIS IS KIND OF A NEAT ADVECTIVE/CONVERGENT PROCESS FOG INSTEAD OF
RADIATIVE PROCESSES...SO IT IS EVEN FORMING UNDER THE STRATUS INSTEAD
OF OUT IN THE CLEAR.  AREAS TO THE WEST ARE UNDER CLOUD COVER AS
WELL...BUT BETWEEN THE VERY LOW DEWPOINT DEPRESSIONS THEY MAY HAVE
ENOUGH LOCAL CONVERGENCE TO GENERATE FOG THERE AS WELL.  IT HAS
ALREADY FORMED FARTHER WEST...SO EXPECT IT THERE TOO.  SAME GOES FOR
PORTIONS OF NORTHWEST WISCONSIN.

THE SURFACE LOW IS ASSOCIATED WITH A SLOW MOVING UPPER LOW OVER THE
REGION.  THIS UPPER LOW IS EXPECTED TO SLOWLY MOVE EAST TODAY
THROUGH TOMORROW...CONTINUING THE CYCLONIC FLOW OVER THE AREA ALONG
WITH COOLER TEMPERATURES. TODAY...THE THE FOG SHOULD DISSIPATE
ENOUGH TO ALLOW THE DENSE FOG ADVISORY TO EXPIRE AROUND 8
AM...THOUGH I EXPECT WE WILL HAVE SOME MVFR CONDITIONS LINGERING
WELL INTO MID MORNING.  WITH THE SURFACE AND UPPER LOW STILL CLOSE
BY...EXPECT THE CLOUDS TO LINGER OVER THE AREA TODAY...ALONG WITH A
DIURNAL UPSURGE IN SHOWERS AND EVEN THUNDERSTORMS.  MODELS ARE
INDICATING A CONVERGENCE AREA FROM AROUND SIREN EXTENDING
NORTH-NORTHWEST UP TO AROUND KHIB...WHICH SHOULD HAVE A HIGHER
COVERAGE OF SHOWERS AND MORE POTENTIAL FOR THUNDER TODAY.  HIGHS
TODAY TO BE WARMER THAN YESTERDAY WITH A LITTLE LESS CLOUD COVER AND
A MODERATION OF THE AIRMASS.  TONIGHT THE SHOWERS SHOULD DIMINISH
BEFORE SUNSET...AND EXPECT SOME CLEARING TO ALLOW RADIATIVE FOG TO
FORM TONIGHT.  WEDNESDAY THE LOW WILL HAVE MOVED FAR ENOUGH EAST
THAT WE SHOULD STAY DRY OR MOSTLY DRY...AND WITH SOME CLEARING OF
THE CLOUD COVER.  HIGHS SHOULD BOUNCE WELL UP INTO THE 70S TO NEAR
80 ONCE AGAIN.


.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 421 AM CDT TUE AUG 19 2014

WE WILL DEFINITELY BE IN A FAIRLY ACTIVE PATTERN THROUGHOUT THE
EXTENDED TIME PERIOD. THE NIGHT WILL LIKELY START OUT DRY ACROSS THE
NORTHLAND...BUT THE NEXT UPPER LEVEL SHORTWAVE AND ASSOCIATED
SURFACE LOW PRESSURE WILL MOVE NORTHEASTWARD INTO THE AREA DURING
THE NIGHT. A NW TO SE BAND OF PRECIPITATION SHOULD HAVE REACHED ALL
BUT THE ARROWHEAD OF MN BY 12Z THURSDAY AND A FAIR PORTION OF NW WI.
THERE ARE SOME MODEL DIFFERENCES IN TIMING...BUT WILL INCREASE POPS
TO LIKELY RANGE FOR THE BRAINERD LAKES AREA WITH SLIGHT TO CHANCE
POPS FOR MUCH OF THE REST OF THE AREA. WILL GO WITH LIKELY POPS FOR
MUCH OF THE AREA ON THURSDAY...AS THE SHORTWAVE LIFTS NORTHEAST
THROUGH THE AREA. THE ECMWF AND GEM ARE BOTH FAIRLY HEAVY WITH
PRECIPITATION ACROSS THE CWA.  UPPER LEVEL RIDGING WILL TRY TO DRY
THINGS OUT BUT THERE WILL LIKELY STILL BE SOME SHOWERS LINGERING
INTO THURSDAY NIGHT. THE SOUTHWEST FLOW AND UNSETTLED PATTERN WILL
KEEP THE CHANCE OF SHOWERS AND THUNDERSTORMS GOING INTO THE WEEKEND
AND EARLY NEXT WEEK...ALTHOUGH THE MODELS ARE EXHIBITING QUITE A FEW
DIFFERENCES FURTHER OUT IN THE EXTENDED TIME PERIOD. HIGHS WILL
LARGELY BE IN THE 70S...BUT TEMPS SHOULD COOL TO THE 60S FOR THE
MOST PART EARLY NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 654 AM CDT TUE AUG 19 2014

WIDESPREAD MVFR TO IFR/LIFR CONDITIONS WILL BE FOUND ACROSS THE
AREA THIS MORNING BUT SOME MVFR TO IFR CONDITIONS ARE THEN
EXPECTED BY AFTERNOON. FOG WILL ONCE AGAIN DEVELOP OVERNIGHT WITH
SOME IFR/LIFR CONDITIONS DEVELOPING.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  68  56  72  58 /  50  20  10  30
INL  72  54  78  58 /  20  10  10  20
BRD  75  58  80  64 /  20  10  10  70
HYR  71  56  77  61 /  50  30  10  30
ASX  69  55  73  57 /  50  30  10  20

&&

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

$$

UPDATE...BJT
SHORT TERM...LE
LONG TERM...DAP
AVIATION...DAP





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