000
FXUS63 KDLH 100421
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1021 PM CST MON DEC 9 2013

.UPDATE...
ISSUED AT 1019 PM CST MON DEC 9 2013

HAVE MADE SOME MINOR CHANGES TO THE GRIDS TONIGHT. HAVE HIT POPS
HARDER IN THE SOUTHERN PORTIONS OF THE CWA WITH UP TO AN INCH OF
SNOW POSSIBLE IN SOUTHERN SECTIONS OF THE CWA OVERNIGHT. HAVE ALSO
ADDED THE ONE COUNTY WE DID NOT HAVE IN THE WIND CHILL ADVISORY AS
IT LOOKS AS IF THEY WILL BRIEFLY HIT WIND CHILL ADVISORY CRITERIA.
OTHER THAN THAT...THINGS ARE IN GOOD SHAPE OVERNIGHT.

UPDATE ISSUED AT 555 PM CST MON DEC 9 2013

UPDATED FOR NEW AVIATION FORECAST DISCUSSION BELOW.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 259 PM CST MON DEC 9 2013

SFC ANALYSIS AT 19Z PLACED A WEAK TROF OVER WESTERN LAKE SUPERIOR
WITH A RIDGE AXIS OVER THE EASTERN DAKOTAS/MN BORDER. A TIGHT
PRESSURE GRADIENT OVER THE FA ATTM HAS PRODUCED PERIODIC GUSTY WINDS
AND SOME PATCHES OF BLSN. THE BLSN HAS OCCASIONALLY REDUCED
VSBYS...BUT NOT PROLONGED ENOUGH TO MENTION IN THE FORECAST/GRIDS.
SOME LES BANDS WERE MOVING FROM SW TO NE OVER WESTERN LAKE SUPERIOR
WITH ONE BAND FROM SUPERIOR WI TO THE BAYFIELD PENINSULA AND THE
APOSTLE ISLANDS. CLOUDS ARE THIN SO JUST EXPECTING SOME VERY LIGHT
SNOW OR FLURRIES. EXPECTING THE LES BAND TO WEAKEN/MOVE OFF TO THE
NE AS DRIER AIR FROM THE RIDGE AXIS BEGINS TO WORK ALONG THE SOUTH
SHORE. WILL CONTINUE TO MENTION A SMALL POP FOR ANY LINGERING LES
ALONG THE BAYFIELD PENINSULA.

THE RIDGE AXIS MOVES OVER THE FA THIS EVENING WITH THE PRESSURE
GRADIENT SLACKENING...HAVE LOWERED THE WINDS A BIT. WAA CLOUD COVER
IS QUICKLY SPREADING TOWARD THE FA AHEAD OF THE CLIPPER THAT IS
PROGGED TO AFFECT THE AREA TONIGHT THROUGH TUESDAY MORNING. MODELS
ARE IN GOOD AGREEMENT THE SNOW SHOULD HOLD OFF UNTIL AFTER 03Z
TONIGHT HAVE ADJUSTED POPS ACCORDINGLY. IT APPEARS THAT THE BULK OF
THE LIGHT SNOW WILL FALL ALONG AND SOUTH OF THE IRON RANGE. NOT
EXPECTING THE TYPICAL CLIPPER AMOUNTS OF SNOW AND GENERALLY
EXPECTING AROUND ONE INCH. HAVE MADE SOME ADJUSTMENTS TO ACCOUNT FOR
WIND SPEED AND APPARENT T AND SUBSEQUENT HEADLINES. WILL HAVE ALL
BUT PINE COUNTY MN IN THE WIND CHILL ADVISORY FOR TONIGHT.

THE CLIPPER DEPARTS BY TUESDAY AFTERNOON AND MORE ARCTIC AIR IS
USHERED INTO THE AREA. HAVE POPS OVER THE NW WI FA TUESDAY MORNING
DIMINISHING BY AFTERNOON...THEN SWITCH TO NW FLOW OVER LAKE SUPERIOR
AND ANTICIPATE LES SHOWERS ALONG THE HIGHER TERRAIN OF THE SOUTH
SHORE IN THE AFTERNOON. HAVE LOW POPS AS THERE IS SOME UNCERTAINTY
ON THE AMOUNT OF DRY AIR UNDERCUTTING THE LES AS A SFC RIDGE MOVES
INTO THE FA IN THE AFTERNOON.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 259 PM CST MON DEC 9 2013

THE VERY COLD WEATHER PATTERN WILL CONTINUE FOR THE MIDDLE OF THE
WEEK...BUT THERE SHOULD BE A TEMPORARY PERIOD OF SOME MODERATION
LATER THIS WEEK WHICH WILL BRING A POOR EXCUSE FOR RELIEF FROM THE
COLD TO THE NORTHLAND. FOR THE MOST PART...NO SIGNIFICANT SNOWFALL
AMOUNTS ARE LIKELY FOR THE NORTHLAND THROUGH THIS WEEKEND...WITH THE
EXCEPTION OF LAKE EFFECT FOR NW WISCONSIN OVER THE WEEKEND WHERE
MODERATE TO HEAVY SNOWFALL AMOUNTS ARE POSSIBLE. HOWEVER...THERE
COULD BE SEVERAL DISTURBANCES THAT COULD BRING LIGHT SNOW TO PARTS
OF THE NORTHLAND THROUGH THE REST OF THE WEEK. I TRENDED ON THE
COLDER SIDE OF GUIDANCE FOR MY FORECAST. IT APPEARS THE COLDER AIR
WILL BEGIN TO POUR BACK INTO THE NORTHLAND OVER THE WEEKEND AFTER A
COUPLE DAYS OF SLIGHTLY MORE MODERATE TEMPERATURES.

TUESDAY NIGHT SHOULD BE VERY COLD. LIGHT WINDS OVER LAND...PARTIAL
CLEARING...AND 850 HPA TEMPERATURES OF -24 TO -27 DEGREES CELSIUS
SUGGESTED PLUMMETING TEMPERATURES OVERNIGHT. I FORECASTED WIDESPREAD
LOW TEMPERATURES OF -20 TO -25 DEGREES FAHRENHEIT...AND I WOULD NOT
BE SURPRISED IF SOME AREAS APPROACH -35. HOWEVER...BEFORE WE
FORECAST THAT COLD...WE NEED A BETTER IDEA OF WHAT THE CLOUD COVER
WILL BE THAT NIGHT.

WEDNESDAY AND WEDNESDAY NIGHT DO NOT LOOK MUCH BETTER. HIGH
TEMPERATURES ON WEDNESDAY WILL STRUGGLE TO APPROACH 0 DEGREES. THE
MODEL AND MOS GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH WIDESPREAD
HIGH TEMPERATURES BELOW ZERO. I LOWERED TEMPERATURES WEDNESDAY NIGHT
ACROSS FAR NORTHERN MINNESOTA...INCLUDING THE ARROWHEAD AND IRON
RANGE...SINCE IT APPEARS THE SKIES WILL BE FAIRLY CLEAR FOR A TIME
UP THERE OVERNIGHT.

THIS COLD PERIOD THROUGH WEDNESDAY NIGHT WILL LIKELY NEED ADDITIONAL
WIND CHILL HEADLINES.

THERE WILL BE A PROLONGED PERIOD OF LIGHT LAKE EFFECT SNOW FOR AREAS
NEAR LAKE SUPERIOR IN NW WISCONSIN...MAINLY NORTHERN
BAYFIELD/ASHLAND/IRON COUNTIES...TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT DUE TO THE COLD WESTERLY FLOW OVER WESTERN LAKE SUPERIOR. THE
WIND DIRECTION DOES NOT FAVOR SIGNIFICANT SNOWFALL FOR NW WISCONSIN.

A WEAK CLIPPER SYSTEM COULD BRING LIGHT SNOW TO THE SOUTHERN
FORECAST AREA WEDNESDAY NIGHT AND THURSDAY MORNING. AMOUNTS WILL
LIKELY BE UNDER AN INCH.

TEMPERATURES WILL LIKELY MODERATE BIT TO HIGH TEMPERATURES WELL INTO
THE SINGLE DIGITS AND MAYBE LOW TEENS THURSDAY AS A FRONT LIFTS
NORTH TOWARDS THE NORTHLAND. THE MODELS ARE INDICATING SOME LIGHT
SNOW COULD DEVELOP NEAR AND NORTH OF THE BAROCLINIC ZONE THURSDAY
NIGHT AND FRIDAY...WHICH COULD BRING ANOTHER ROUND OF LIGHT SNOW TO
MUCH OF THE NORTHLAND.

THE MODELS ARE SUGGESTING THE REALLY COLD AIR WILL BEGIN TO POUR
BACK OUT OF CANADA INTO THE NORTHLAND OVER THE WEEKEND. THE
NORTHERLY FLOW OVER WESTERN LAKE SUPERIOR COULD BRING MODERATE TO
HEAVY LAKE EFFECT SNOW TO PARTS OF NW WISCONSIN...WITH THE HIGHEST
CHANCES AND AMOUNTS LIKELY ALONG AND NEAR THE GOGEBIC RANGE IN IRON
AND ASHLAND COUNTIES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 555 PM CST MON DEC 9 2013

SKIES WILL BE CLEAR FOR MOST AREAS TONIGHT...BUT CLOUDS WILL BE ON
THE INCREASE LATER IN THE NIGHT...AS A WEAK LOW PRESSURE SYSTEM
MOVES INTO THE REGION. SOME MVFR/LIFR CIGS/VSBYS WILL BE POSSIBLE
WITH SOME LIGHT SNOW.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH -13   2 -20  -4 /  40  20  10   0
INL -19  -3 -23  -5 /  10  10  10   0
BRD -14   2 -20  -2 /  80  10  10   0
HYR -13   3 -18  -1 /  70  70  10   0
ASX  -8   7 -10   1 /  60  70  40  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL 4 AM CST TUESDAY FOR MNZ010>012-
     018>021-025-026-033>038.

WI...WIND CHILL ADVISORY UNTIL 4 AM CST TUESDAY FOR WIZ001>004-
     006>009.

LS...SMALL CRAFT ADVISORY UNTIL 4 AM CST THURSDAY FOR LSZ121-140>148.

&&

$$

UPDATE...DAP
SHORT TERM...GSF
AVIATION...DAP