FXUS63 KDLH 151144
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
544 AM CST TUE DEC 15 2009

.AVIATION...
LINGERING -SHSN OR FLURRIES WILL BE FOUND NEAR KHYR EARLY THIS
MORNING...ENDING BY 15Z. VFR CIGS WILL BE FOUND TODAY...WITH
INCREASING MID LVL CLOUDS OVERNIGHT WITH A LIGHT SN SHOWER POSSIBLE
NEAR KBRD LATE IN THE PERIOD. WEST WINDS MAY BECOME GUSTY TO 20 KT
THIS AFTERNOON...MAINLY NEAR KDLH/LAKE SUPERIOR.

&&

.PREV DISCUSSION... /ISSUED 317 AM CST TUE DEC 15 2009/ 

DISCUSSION...A WEAK SFC TROF WAS BISECTING WESTERN LAKE SUPERIOR
FROM SW TO NE WHILE A VORT MAX WAS CRUISING ALONG THE
INTERNATIONAL BORDER ATTM. CLOUDS COVERED MUCH OF THE FA IN
RESPONSE WITH SOME -SHSN AFFECTING THE SOUTHERN HALF. LITTLE
ACCUMULATION EXPECTED WITH THIS FAST MOVING SYSTEM. THE VORT MAX
WILL CLEAR THE AREA THIS MORNING AS SFC/UPPER LEVEL RIDGING BUILD
IN. MAY SEE SOME LES ALONG THE SNOW BELT OF NW WI AHEAD OF THE
BUILDING HIGH WITH A NW FLOW AND CAA. WINDOW OF OPPORTUNITY FOR
ANY ACCUMULATION IS SMALL WITH DRIER AIR ARRIVING AND THE FLOW
BECOMING MORE WESTERLY. NO CHANGE TO HEADLINE AS WIND WILL STAY UP
AND TEMPS WILL DROP AFTER CLOUDS DEPART.

SFC RIDGE AXIS WILL BE OVERHEAD BY 12Z WEDNESDAY. HOWEVER...A FAST 
MOVING UPPER LEVEL SHORTWAVE WILL BE ENCROACHING THE FA BETWEEN 
06-12Z. CLOUDS WILL BE ON THE INCREASE AND SOME -SN MAY FALL IN THE 
WESTERN TIER OF THE FA LATE TONIGHT AND SPREAD OVER MUCH OF THE AREA 
WEDNESDAY MORNING. THE CLOUDS...WAA ALOFT AND LIGHT WIND WILL KEEP 
WIND CHILL HEADLINES FROM BEING NEEDED TONIGHT. IN FACT...SFC TEMPS 
WILL BE ON THE RISE AFTER MIDNIGHT. MAX TEMPS WILL BE A BIT WARMER 
ON WEDNESDAY AS FA BECOMES UNDER THE INFLUENCE OF A SW FLOW.

EXTENDED...THURSDAY THROUGH SATURDAY.
A FASTING MOVING SHORT WAVE WILL BRING SCT SHSN TO THE FA LATE WED 
NIGHT/THURSDAY. ALTHOUGH TIMING AND PLACEMENT OF AN INCH OR TWO OF 
SNOWFALL IS DIFFICULT...MDLS IN GOOD AGREEMENT THAT THE BEST FORCING 
ASSOCIATED WITH THE VORT MOVES INTO THE WRN CWA AFT 06Z 
THURS...DEPARTING THURS AFTRN. THE 00Z NAM IS THE MOST AGGRESSIVE 
WITH THIS FEATURE AND SUGGESTS CORRIDOR OF STRONG 2D FGEN ALONG A
BAROCLINIC ZONE AHEAD OF THE WAVE. NAM BUFR SOUNDINGS AND BUFKIT
PTYPE SUGGEST THE LO LVLS BECOME SATURATED AS THE TOP OF THE LAYER
REMAINS A FEW DEGREES BLO ZERO...BRINGING A SMALL POTENTIAL FOR A
BRIEF WINDOW OF -FZDZ WED EVENING. CONFIDENCE NOT HIGH ENOUGH TO
MENTION ANY FZDZ IN FCST ATTM DUE TO RUN TO RUN
DISCREPANCIES...BUT LATER SHIFTS WILL NEED TO MONITOR.

GOOD AGREEMENT THAT BOUNDARY LAYER WINDS BECOME S TO SE WED NIGHT 
AHEAD OF THE APPROACHING SHORT WAVE. THIS WILL RESULT IN A FAVORABLE 
FETCH FOR A FEW INCHES OF LK EFFECT/ENHANCED SNOW ALONG THE NORTH 
SHORE OF LAKE SUPERIOR WED NIGHT/THURS...MAINLY IN THE GRAND MARAIS 
TO GRAND PORTAGE AREA. THE LIMITING FACTOR WILL BE AVAILABLE 
MOISTURE AHEAD OF THE MAIN WAVE WHILE 850MB TEMPS ARE COLDEST...AND 
THE STRENGTH OF THE WAA TO DECREASE DELTA-T VALUES DURING THE DAY 
THURS. 

&&

.POINT TEMPS/POPS...
DLH   3 -11  13   1 /  10  10  20  20 
INL  -7 -21  10  -2 /  10  10  20  30 
BRD  -1 -13  14   1 /  10  20  10  30 
HYR   4 -12  13  -4 /  10  10  10  20 
ASX   4 -12  15   2 /  10  10  20  20 

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR MNZ010>012-
     018>021-025-026-033>038.

WI...WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR WIZ001.

LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ121-
     146>148.

&&

$$

GRANING