000
FXUS63 KDLH 032101
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
301 PM CST WED DEC 3 2008
.DISCUSSION...MAIN FORECAST CHALLENGE IS ONGOING LAKE EFFECT
SNOW. LATEST WATER VAPOR LOOP SHOWS LARGE CANADIAN TROUGH
CONTINUING TO SINK SOUTH ACROSS THE NORTHERN PLAINS THIS
AFTERNOON. MULTIPLE SHORT WAVES WILL CONTINUE TO ROTATE AROUND
THIS TROUGH...BRINGING ROUNDS OF INSTABILITY SNOW SHOWERS AND COLD
AIR ADVECTION. FIRST VORT MAX WILL DIVE SOUTH ACROSS THE FA
TONIGHT INTO THURSDAY...AS H85 TEMPS FALL TO -17 TO -20C. MODERATE
TO HEAVY LES BANDS CONTINUE ACROSS THE HIGHER TERRAIN OF NORTHERN
IRON/ASHLAND COUNTIES THIS AFTERNOON DESPITE LESS THAN FAVORABLE
FETCH AND WIND DIRECTION. FORECAST SOUNDINGS SHOW FAVORABLE
INVERSION HEIGHTS AND DELTA T`S CONTINUING THROUGH
TONIGHT...ALTHOUGH LOW LEVEL WINDS WILL CONTINUE TO SLOWLY BACK AS
THE SHORT WAVE PUSHES SOUTHEAST. HAVE POSTED WRNG WITH A REPORT OF
5 INCHES AT GILE. AN ADDITIONAL 2 TO 4 IN THE FAVORED HIGHER
TERRAIN AREAS LOOKS POSSIBLE THROUGH TONIGHT. IF BACKING WINDS
RESULT IN LES BANDS MIGRATING EASTWARD TONIGHT...WARNING MAY NEED
TO BE CANCELLED EARLY. SECONDARY SHORT WAVE WILL PUSH SOUTHEAST
ACROSS THE NORTHERN GREAT LAKES THURSDAY...AS WINDS SHIFT
WESTERLY. RELATIVE COLD POOL ALOFT WILL RESULT IN SCT
FLURRIES/SHSN THROUGH THE DAY THURSDAY...WITH DAYTIME HIGHS ONLY IN
THE TEENS...AROUND 10 DEGREES BELOW NORMAL. ONE MORE SHORT WAVE
TROUGH PUSHES THROUGH ON FRIDAY...AS DEEP TROUGH CONTINUES ITS
EASTWARD PROGRESSION. BUILDING RIDGE SHOULD END SHSN AND ALLOW
TEMPERATURES TO MODERATE JUST A BIT FRIDAY AFTERNOON BEFORE NEXT
APPROACHING TROUGH.
.SAT THRU WED...THE PD WILL BE DOMINATED BY L/WV TROFING WITH
EMBEDDED SMALLER IMPULSES KEEPING SOME MENTION OF SNOW IN THE FCST
EVERY DAY. SUN LOOKS TO BE MAINLY DRY DUE TO A BRIEF PD OF UPR LVL
RIDGING...ALTHO NW LOLVL WINDS WILL KEEP SOME LES OVR NWRN WI...AT
LEAST IN THE MRNG. OTHW THE BEST CHCS OF PRECIP WILL BE WITH A
DEPARTING SYSTEM ON SAT AND WITH A NEW SYSTEM ON MON. ANOTHER
SYSTEM WILL BE IN THE MIX ON WED...BUT LONG RANGE MODELS ARE STILL
AT VARIANCE WITH EACH OTHER...SO WILL STICK WITH BROAD BRUSH SLGT
OR LOW CHC POPS FOR NOW.
&&
.AVIATION...A SHORT PD OF VFR CIG/VSBY THIS AFTN WILL GIVE WAY TO
PREDOMINANTLY MVFR CIGS TNGT INTO THU. VSBY SHUD BE MAINLY VFR IN
-SN/FLURRIES...DIMINISHING ONLY BRIEFLY TO MVFR IN HEAVIER SHSN.
&&
POINT TEMPS/POPS...
DLH 5 15 3 18 / 20 20 20 20
INL 3 13 2 14 / 30 20 10 20
BRD 5 17 4 19 / 20 20 10 10
HYR 5 16 1 17 / 20 20 20 10
ASX 7 17 3 17 / 30 40 40 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...LAKE EFFECT SNOW WARNING UNTIL 6 AM CST THURSDAY FOR ASHLAND-
IRON.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CST THURSDAY FOR LSZ121-LSZ146-
LSZ147-LSZ148.
$$
LILES/04
