Lake-Effect Snow in Wisconsin, January 30 to 31, 2011

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1015 PM CST SUN JAN 30 2011

.UPDATE...
INCREASED SNOW MENTION TO LIKELY FOR LAKESHORE AREAS ALONG THE
WISCONSIN SOUTH SHORE AND THE DOWNTOWN DULUTH/SUPERIOR AREA.

&&

.DISCUSSION...
RADAR ECHOES OFF THE LAKE...MOVING SOUTHWEST...ARE BEGINNING TO
SHOW SNOW IN THE DULUTH AND SUPERIOR AREA...THE CONVECTION HAS YET
TO REACH THE DULUTH AIRPORT. WEB-CAMS SHOW ONLY A MINOR REDUCTION
TO VISIBILITY AND SNOW SHOWERS SEEM MORE ACTIVE IN THE DULUTH AREA
AT THIS TIME...VERY DRY AIR REMAINS FURTHER EAST. WITH NORTHEAST
WINDS CONTINUING...WE EXPECT LIGHT SNOW TO SPREAD RAPIDLY EAST
ALONG THE SOUTH SHORE IN THE NEXT COUPLE OF HOURS.

.PREV DISCUSSION... /ISSUED 745 PM CST SUN JAN 30 2011/

UPDATE...
DE-EMPHASIZED SNOW ACROSS THE SHORELINE COUNTIES OF NORTHWEST
WISCONSIN AND STRESSED SNOW EARLIER AND STRONGER SOUTH OF ROUTE 2
OF NORTEAST MINNESOTA. LOWERED TEMPERATURES ALONG THE CANADIAN
BORDER A DEGREE OR TWO...MOSTLY ALONG THE RAINY RIVER VALLEY.

DISCUSSION...
WITH A 120 KNOT CHANNELED JET AXIS REMAINING OVER THE CENTER OF
OUR AREA...ADVANCING MID AND HIGH CLOUDS ARE NOT CROSSING THE AXIS
OF STRONGEST WINDS AND NOT QUITE REACHING THE CANADIAN BORDER.
GROUND TEMPERATURES ALONG THAT AREA RESEMBLE CIRRUS TOPS AND
TEMPERATURES IN THAT NARROW REGION OF OUR AREA ARE FALLING
RAPIDLY. IN CONTRAST...ACCUMULATING SNOW HAS MOVED INTO THE PARK
RAPIDS AREA AND SNOW IS STARTING TO SPREAD INTO CASS COUNTY...WITH
RADAR ECHOES SPREADING ACROSS AND EAST OF THE UPPER SAINT CROIX
VALLEY. WE BEEFED-UP POPS A LITTLE. DRY AIR IS HAMPERING
CONVECTION OVER AND DOWNWIND OF THE LAKE...NO RADAR ECHOES ARE
APPARENT AND VISIBILITIES ARE UNRESTRICTED UNDER A LOW OVERCAST
THERE. SO...WE KEPT SNOW SHOWERS IN THE CHANCE CATEGORY.

PREV DISCUSSION... /ISSUED 536 PM CST SUN JAN 30 2011/

AVIATION...01/31/00Z ISSUANCE...
VFR CONDITIONS WILL DETERIORATE TO MVFR IN SNOW SOUTH OF DULUTH
LATE TONIGHT AND IFR IN SNOW EARLY MONDAY. ALONG A XVG-DLH-ASX-IWD
LINE...VFR CONDIONS WILL DETERIORATE TO MVFR IN SNOW EARLY MONDAY.
NORTH OF ROUTE 2 IN NORTHEAST MINNESOTA...VFR CONDITIONS UNDER A
SCATTERED TO BROKEN MID-DECK WILL CONTINUE THROUGH MONDAY EVENING.

PREV DISCUSSION... /ISSUED 348 PM CST SUN JAN 30 2011/

DISCUSSION...LARGE ARCTIC SFC HIGH CENTERED OVER NRN/CTRL SASK
THIS AFTERNOON WITH RIDGING EXTENDING SE INTO WRN ONTARIO. LES HAS
DECREASED ACROSS GOGEBIC AS VERY DRY AIR EVIDENT ON SATELLITE
IMAGERY AND RUC13 85/70H ANALYSIS. HAVE CANCELLED ADVISORY SINCE
ADDITIONAL ACCUMULATION WILL NOT BE SIGNIFICANT. TEMPS RANGE FROM
UPPER TEENS IN PRICE COUNTY TO SINGLE DIGITS ALONG INTERNATIONAL
BORDER. VERY DRY AIR IS PUSHING INTO REGION FROM ARCTIC HIGH AS
EVIDENT FROM CLEARING TODAY OVER MOST OF MN CWA. MID LVL CLOUDS
FROM APPROACHING TROF ADVECTING INTO WRN EDGE OF CWA.

TONIGHT...CHANGES UNDERWAY TONIGHT AS MID LVL TROF MOVES INTO ERN
MT AND CLOUDS INCREASE ACROSS MOST OF CWA. CONFLUENCE BETWEEN
HUDSON BAY VORTEX AND FORWARD FLANK OF ERN MT TROF SHOULD MAINTAIN
SFC HIGH RIDGING JUST NORTH OF CWA. FCST IS COUNTING ON THIS DRY
WEDGE TO KEEP CLOUDS SOMEWHAT AT BAY ALONG BORDER OVERNIGHT. THIS
SHOULD ALLOW TEMPS TO DROP MORE SO THAN PREVIOUS NIGHTS. HAVE
ISSUED A WIND CHILL ADV ALONG NORTHERN TIER OF CWA...MAINLY AFTER
MIDNIGHT AS WINDS REMAIN JUST STRONG ENOUGH. CONFIDENCE IS NOT
GREAT DUE TO CLOUD UNCERTAINTY AND POTENTIAL THAT WINDS MAY
DIMINISH ENTIRELY. MEANWHILE...LT SNOW WILL SPREAD ACROSS SRN CWA
IN ZONE OF MID LVL FRONTOGENESIS. MODEL CONSENSUS HAS BEEN CONSISTENT
LAST TWO DAYS. MAY SEE AN INCH BY MORNING ACROSS BRAINERD LAKES
REGION INTO LWR ST CROIX VALLEY.

TOMORROW...WITH BAROCLINIC ZONE LOCATED OVER SRN PLAINS...
THE APPROACHING UPPER TROF WILL ONLY INDUCE A SFC TROF THIS AFR
NORTH. THAT LEAVES MID LVL ISENTROPIC ASCENT AND POTENTIAL LAKE
ENHANCEMENT AS PRIMARY FORCING MECHANISMS. FCST OF BEST
OMEGA/DGZ/MSTR PROFILES SUGGESTS THAT ACCUMULATIONS WILL RANGE
FROM 1 TO 3 INCHES OVER SRN CWA...ISOLATED 4" OVER A 12/18HR
PERIOD. ONE FACTOR THAT MAY ALLOW FOR MORE ACCUMULATION WOULD BE A
HIGHER LSR THAN 20/1. BY AFTN...ORIENTATION OF LOW LVL FLOW MAY
ALLOW FOR SOME ADDITIONAL ACCUMULATION FROM LAKE EFFECT INTO TWIN
PORTS/NWRN WISC. THIS MAY CONTINUE UNTIL TUESDAY MORNING. NEXT
SHIFTS WILL NEED TO NARROW DOWN POTENTIAL FOR MORE SIGNIFICANT
AMOUNTS BASED ON LATER MDL GUIDANCE.

TUES/WED...COLD WX WILL PREVAIL AS AREA BECOMES LOCATED WITHIN A
COL BETWEEN DEPARTING UPPER TROFS AND APPROACHING WRN CANADIAN MID
LVL RIDGE. ALTHOUGH DEEP LAYER RH WILL DROP SIGNIFICANTLY HAVE
MATCHED ADJACENT MQT WFO HIGHER POPS FOR SOME RESIDUAL LAKE EFFECT
SNOW ALONG THE ERN WISC SNOWBELT. CHILLY AIR/STEEPER LL LAPSE
RATES WILL PROVIDE A SHALLOW CLOUD DECK THAT WILL GENERATE LIGHT
SNOW BUT LITTLE ACCUMULATION DUE TO SHALLOW INVERSION. THIS MAY
VERIFY IF MOIST LAYER IS TOO SHALLOW. LEANED HEAVILY ON NAM12
HIGHER RESOLUTION TO BETTER CAPTURE MESOSCALE NATURE OF LOW LEVEL
MOISTURE AND POTENTIAL DGZ...MAINLY TUESDAY/TUESDAY NIGHT. MDLS IN
STRONG AGREEMENT THAT EJECTING MID LVL LOW WILL STAY FAR ENOUGH
SOUTH OF CWA WED TO KEEP MOST OF AREA QUIET.

WED NITE THRU SUN...
HIGH PRESS IN CONTROL WED NITE/THU...THEN S/WV SWEEPS DOWN FROM
CN...AFFECTING MAINLY NERN HALF OF OUR CWA THU NITE/FRI. ANOTHER
SHORT BREAK FRI NITE UNDER ACYC FLOW ALOFT. MODELS IN BTR AGMT FOR
NEXT WEEKEND BUT STILL SOME SIG DIFFS. IT APPEARS THAT A BROAD UPR
TROF WILL BE ACCOMPANIED BY STRONG SFC LOW...ALTHO THE MODELS DIFFER
IN PLACEMENT AND TRACK. IN ANY CASE...IT SEEMS THAT AT LEAST SLGT OR
LOW CHC POPS ARE WARRANTED FOR THE SAT/SUN TIMEFRAME.

&&

.POINT TEMPS/POPS...
DLH  -2  12  -5  10 /  60  60  50  10
INL -23   2 -20   2 /  10   0  10   0
BRD   2   9  -6   8 /  90  90  50  10
HYR   3  16   2  15 /  60  80  60  20
ASX   5  13   2  15 /  60  60  60  40

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL 9 AM CST MONDAY FOR MNZ010>012-021.

WI...NONE.
&&

SHORT TERM...EOM

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
312 PM CST SUN JAN 30 2011

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-311130-
KOOCHICHING-NORTHERN ST. LOUIS-NORTHERN COOK/NORTHERN LAKE-
NORTHERN ITASCA-CENTRAL ST. LOUIS-SOUTHERN LAKE/LAKESHORE-
SOUTHERN COOK/LAKESHORE-NORTHERN CASS-SOUTHERN ITASCA-
SOUTHERN CASS-CROW WING-NORTHERN AITKIN-SOUTHERN AITKIN-
CARLTON/SOUTHERN ST. LOUIS-PINE-DOUGLAS-BAYFIELD-ASHLAND-IRON-
BURNETT-WASHBURN-SAWYER-PRICE-
312 PM CST SUN JAN 30 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A COMBINATION OF COLD AIR AND LIGHT WIND WILL PRODUCE DANGEROUS
WINDCHILL VALUES TONIGHT ACROSS THE BORDERLAND AND THE ARROWHEAD
OF MINNESOTA. PLEASE REFER TO THE LATEST WINTER WEATHER MESSAGE
FROM THE NATIONAL WEATHER SERVICE OFFICE IN DULUTH FOR ADDITIONAL
INFORMATION.

LIGHT SNOW IS EXPECTED ACROSS THE BRAINERD LAKES REGION EAST TO
NORTHWEST WISCONSIN AFTER MIDNIGHT SUNDAY.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

SNOW WILL CONTINUE SOUTH OF A CASS LAKE TO TWO HARBORS TO ASHLAND
LINE. ACCUMULATIONS MAY REACH 2 TO 3 INCHES FROM THE BRAINERD
LAKES TO THE LOWER ST CROIX VALLEY TO THE HAYWARD LAKES BY EARLY
MONDAY EVENING. SNOW WILL LINGER OVER NORTHWEST WISCONSIN THROUGH
TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SNOW REPORTS FROM OUR SNOW SPOTTER NETWORK WILL BE GREATLY
APPRECIATED.

CANNON

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB ADDRESS:
HTTP://WWW.WEATHER.GOV/DULUTH (ALL LOWER CASE)