FXUS63 KDLH 010333
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
933 PM CST MON NOV 30 2009

.UPDATE...ZONES/GRIDS STILL IN GOOD SHAPE THIS EVENING. CLOUDS
HANGING ON ACROSS THE NE HALF OF THE CWA...WITH CLOUDS THINNING
ACROSS THE SW HALF. CLOUDS WILL GRADUALLY INCREASE FROM THE WEST
IN AREAS THAT CLEARED OUT...WITH THICKENING CLOUDS LATER IN THE
NIGHT AND ON TUESDAY. COULD BE SOME LIGHT SNOW ADVANCING INTO THE
CWA LATER IN THE NIGHT...AND WOULD LIKE TO LOOK AT ALL THE EVENING
GUIDANCE BEFORE MAKING ANY WHOLESALE CHANGES. 

&&

.AVIATION...00Z TAF ISSUANCE
THE NORTHEASTERN PORTION OF THE NORTHLAND WILL EXPERIENCE MAINLY
MVFR CONDITIONS FOR MUCH OF THE TAF PERIOD...WHILE THE SOUTHWEST
HALF WILL EXPERIENCE VFR CONDITIONS FOR MUCH OF THE NIGHT. THE
SOUTHWESTERN AREAS WILL SEE CLOUD HEIGHTS GRADUALLY LOWER ON
TUESDAY...REACHING INTO THE MVFR RANGE AT TIMES. THE NORTHERN
AREAS WILL SEE GRADUALLY LOWERING CIGS AND VSBYS DUE TO SNOW
ADVANCING INTO THAT AREA...ESPECIALLY DURING THE AFTERNOON. SOME
PATCHY FOG WILL BE POSSIBLE OVERNIGHT WITH A PERIOD OF CLEAR TO
PARTLY CLOUDY SKIES IN ADVANCE OF THE WAA CLOUDS LATER TONIGHT.

&&

.PREV DISCUSSION... /ISSUED 334 PM CST MON NOV 30 2009/ 

DISCUSSION...SFC LOW CENTER AT 20Z WAS LOCATED IN SW ONTARIO JUST
N OF CYQT WITH A WEAK SFC TROF TRAILING THROUGH NE MN. MODELS HAVE
PERFORMED POORLY WITH THE HANDLING OF THIS FEATURE AND THE AMOUNT
OF PCPN/CLEARING. BULK OF THE -SN IN NW WI/TIP OF THE ARROWHEAD
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. CANADIAN GEM HI-RES
REGIONAL HAD THE BEST HANDLE INITIALLY...BUT APPEARS TOO FAR N
WITH THE NEXT SFC LOW AT AFFECT THE AREA.

THIS NEXT SYSTEM WILL WILL SEND A SFC LOW CENTER RIGHT THROUGH THE
HEART OF THE FA TUESDAY. MODELS OFFERING VARIOUS SOLUTIONS ON THE
IMPACT OF THIS SYSTEM AND JUST THE SLIGHTEST DEVIATION WITH THE
SFC LOW TRACK WILL AFFECT THE SNOW TOTALS. HAVE FOLLOWED A BLEND
WHILE LEANING TOWARD THE HPC QPF AND ITS SNOW TO LIQUID RATIO. 

AS A RESULT...GREATEST SWATH OF SNOW WILL BE JUST N OF THE SFC
LOW CENTER WITH THE LARGEST IMPACT SEEN ALONG THE INTERNATIONAL
BORDER. EXPECT 2 TO 4 INCHES ON TUESDAY WITH LOWER AMOUNTS FURTHER
S. THE LIGHT SNOW WILL CONTINUE TUESDAY NIGHT...BUT DIMINISH. SOME
ACCUMULATION IS EXPECTED PRIMARILY NEAR THE PERIPHERY OF LAKE
SUPERIOR AS SFC WIND CHANGES FROM SE COMPONENT TO NNW AND CAA
BECOMES ESTABLISHED. 

SNOW CHANCES LINGER OVER THE FA AS A LARGE CUT OFF UPPER LOW
MEANDERS AROUND THE UPPER MIDWEST. GREATEST POTENTIAL FOR
ACCUMULATION IS ALONG THE SOUTH SHORE OF LAKE SUPERIOR WHERE THE
FLOW WILL BE NORTHERLY...GOOD CAA/FETCH COME INTO PLAY.

EXTENDED...THURSDAY NIGHT THROUGH MONDAY...
A LARGE AMPLITUDE MID LVL TROF WILL BEGIN TO EXIT OFF TO THE EAST. 
CYCLONIC FLOW WILL WILL ALLOW FOR INDIVIDUAL SHORTWAVES TO
CONTINUE TO ROTATE SOUTH THROUGH THE NORTHLAND ON FRIDAY AND
SATURDAY. MOISTURE BEGIN TO FADE AS HIGH PRESSURE TRIES TO SHOVE
IN FROM THE WEST WITH LIMITED SUCCESS. THE GFS/GEM TAPER THINGS
OFF TO FLURRIES SATURDAY WHILE THE ECMWF KEEPS ENOUGH MOISTURE
AROUND FOR LIGHT SNOW SHOWERS SATURDAY. SUNDAY WILL BE GENERALLY
DRY WITH WEAK HIGH PRESSURE IN CONTROL BEFORE THE UNSETTLED
PATTERN CONTINUES INTO MONDAY. TEMPERATURES WILL BE MUCH COOLER
WITH NORTHWEST WINDS MUCH OF THE PERIOD.

WITH PROGRESSION OF COLDER AIR SOUTH FROM PLAINS OF CANADA EXPECT 
SNSH CONTINUE ALONG THE SOUTH SHORE OF LAKE SUPERIOR...PARTICULARLY
THE WI SNOWBELT. BUFKIT LAKE EFFECT PARAMETERS CONTINUE TO
INDICATE A MAXIMUM INSTABILITY PERIOD WITH LAKE INDUCED CAPE ABOVE
500J/KG LINGERING INTO SATURDAY...WITH PLENTY OF DEEP LAYER
SATURATION...GOOD WIND TRAJECTORY...AND HIGH INVERSION HEIGHTS. FLOW
BECOMES MORE W TO NW ON SATURDAY AFTERNOON...AND SO WE TAPER POPS
FROM LIKELY ON FRIDAY TO HIGH AND THEN LOWER CHANCE SATURDAY.

AVIATION...18Z TAFS.
MVFR CIGS WITH OCCASIONAL IFR VSBYS WILL AFFECT KINL
AND KHIB FOR A FEW HOURS IN -SN...WITH MVFR AT KDLH AND KHYR.
EXPECT -SN TO PASS THROUGH KDLH BETWEEN 18-21Z...20-23Z AT KHYR.
EXPECT MVFR TO LINGER A BIT BEFORE A DRY SLOT AND SURFACE HIGH
BUILD IN OVERNIGHT. POTENT UPPER LEVEL DISTURBANCE WILL IMPACT
KINL AND KHIB DURING THE 12Z-18Z TIME FRAME...WITH MVFR
EXPECTED...IFR IN MODERATE SN IS EXPECTED AT KINL NEAR THE END OF
THE PERIOD WHEN THE BEST UPPER FORCING AND FGEN IS COINCIDENT.

&&

.POINT TEMPS/POPS...
DLH  27  35  23  29 /  10  30  40  10 
INL  21  30  18  25 /  10  80  70  10 
BRD  25  38  24  30 /  10  10  30  10 
HYR  25  42  26  31 /  10  10  30  10 
ASX  26  41  28  30 /  10  30  30  40 

&&

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

$$

DAP/BERDES/BERDES