FXUS63 KDLH 250204 AAB
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
804 PM CST THU DEC 24 2009
.UPDATE...
PUT FREEZING RAIN AND SNOW ACROSS MORE NORTHERN PARTS OF NORTHWEST
WISCONSIN AND PUT RAIN AND FREEZING RAIN THROUGHOUT THE SAND HILLS
AND GOGEBIC RANGE AREAS...ON SOUTH IN THAT PART OF WISCONSIN
THROUGHOUT TONIGHT. INCREASED WINDS ALONG THE LAKESHORE.
&&
.DISCUSSION...
RAIN...FREEZING RAIN AND SLEET HAVE OVERSPREAD ALL OF NORTHWEST
WISCONSIN EXCEPT FOR BURNETT COUNTY. FOR COUNTIES ADJACENT TO
BURNETT COUNTY AND NORTHEAST MINNESOTA...WE EXPECT PRECIPITATION
TO MIX OR CHANGE BACK TO SNOW FROM TIME TO TIME. WARM AIR AT 850
MB IS MORE APPARENT ON THE NAM WHILE THE OTHER MODELS STRETCH THE
COLUMN TO THE POINT THAT SNOW IS IMPLIED. ON THE MAP...A TROUGH
LIES JUST TO THE WEST OF OUR FORECAST AREA...WITH COLD ADVECTION
ACROSS WESTERN AND SOUTHERN MN...WARM ADVECTION COVERS ALL OF
NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN AS WELL AS WESTERN
ONTARIO. WE ANTICIPATE THAT A STRONG GRADIENT FLOW WILL CAUSE
ENOUGH UPSLOPE FORCING UP THE NORTH-SHORE ESCARPMENT...ALONG WITH
COLUMN STRETCHING...THAT ALL SNOW WILL CONTINUE ACROSS ALL OF
NORTHEAST MN. WE WILL INCLUDE SOME WORDING OF...MAY MIX WITH SLEET
OR FREEZING RAIN AT TIMES...FOR THE DULUTH AREA...BUT ESPECIALLY
ALONG THE HIGHER ELEVATIONS WE DO NOT EXPECT A CHANGE-OVER. OF
COURSE...THE MIXED BAG OF PRECIPITATION WILL REDUCE SNOWFALL
AMOUNTS ACROSS MOST OF NORTHWEST WISCONSIN BOTH TONIGHT AND MUCH
OF CHRISTMAS DAY.
&&
.PREV DISCUSSION... /ISSUED 614 PM CST THU DEC 24 2009/
AVIATION.../00Z TAF ISSUANCE/
ANOTHER WAVE OF SNOW WILL MOVE ACROSS NORTHWESTERN WI/NERN MN THIS
AFT AND CONTINUE AT LEAST THROUGH MUCH OF FRI...AS THE MAIN STORM
SYSTEM IN THE SRN PLAINS MAKES ITS WAY NORTHWARD AND STRENGTHENS.
THE OVERALL TREND WILL BE DETERIORATING CONDITIONS...WITH WINDS
STRENGTHENING BY LATE TONIGHT. WIDESPREAD LIFR CONDS CAN BE
EXPECTED. WINDS WILL GUST UPWARDS OF 25 TO 35 KT...WITH 40 KT OR
MORE AT KDLH WITH BLOWING AND DRIFTING SNOW FRI.
LONKA
PREV DISCUSSION... /ISSUED 534 PM CST THU DEC 24 2009/
UPDATE...
SPREAD FREEZING RAIN AND SNOW ACROSS ALL OF NORTHWEST WI EXCEPT
DOUGLAS COUNTY THIS EVENING AND ALL BUT WESTERN BURNETT COUNTY
LATE TONIGHT. SOUTH OF THE GOGEBIC RANGE...WE CHANGED
PRECIPITATION TO ALL FREEZING RAIN AND RAIN. WE ALSO ARE UPDATING
THE LAKE FORECAST TO DROP A MENTION OF SMALL CRAFT ADVISORY...GALE
WINDS WILL DEVELOP AS TIME GOES ON LATER TONIGHT AND FRIDAY.
DISCUSSION...
THE GRID MODEL MAY BE OVERDOING WARMING AT THE 850 MB LEVEL...BUT
A CHANGEOVER FROM SNOW TO FREEZING RAIN IS SPREADING NORTHWEST
THROUGH NORTHWEST WISCONSIN. THE WARM AIR...AT 850 MB AND NOT AS
MUCH AT THE SURFACE...IS SPREADING NORTHWESTWARD. AT THIS TIME
MECHANICAL FORCING CAUSED BY UPSLOPE FLOW OVER THE NORTH SHORE
ALONG WITH COLUMN STRETCHING WILL LIKELY KEEP PRECIPITATION ALL
SNOW ACROSS ALL OF NORTHEAST MN THROUGH TONIGHT AND FRIDAY.
HOWEVER...WARMING WILL LIKELY CAUSE A CHANGE TO A MIXED BAG IN
SOME OF SOUTHWESTERN ONTARIO.
PREV DISCUSSION... /ISSUED 329 PM CST THU DEC 24 2009/
SHORT TERM...TONIGHT THROUGH SATURDAY...
ROBUST PHASING PROCESS HAS BEGUN THIS AFTERNOON AS INTENSE SRN
STREAM IMPULSE IN NE TEXAS BEGINS TO LIFT NNEWD IN ADVANCE OF NORTHERN
STREAM UPPER LOW OVER THE WRN DAKOTAS WHICH IS SLOWLY TRANSLATING
SEWD. VERY IMPRESSIVE PV ANOMALIES ARE NOTED WITH EACH OF THESE
FEATURES..WITH DEVELOPMENT OF A VERY STRONG AND DEEP CIRCULATION
CENTERED OVER IOWA BY THIS TIME TOMORROW. AHEAD OF THE MAIN UPPER
SYSTEM LIFTING NWD..VERY STRONG WARM/MOIST ADVECTION PATTERN
PERSISTS AND COMPOSITE OF KDLH/KMPX/KARX/KDMX/KDVN RADARS NOW SHOW
NEW ECHOES BLOSSOMING IN COVERAGE/INTENSITY TO OUR SOUTH. THE
CURRENT LULL IN THE PRECIP ACTIVITY IS EXPECTED TO END DURING THE
NEXT 4-6 HOURS FROM SOUTH TO NORTH AS THIS LARGE AREA OF PRECIP
MOVES BACK NWD ACROSS THE AREA.
OVERALL..THERE ARE FEW SIGNIFICANT CHANGES TO THE OVERALL THEME OF
MESSAGE THIS AFTERNOON. SNOW WILL INCREASE IN COVERAGE/INTENSITY
THIS EVENING AND WINDS WILL ALSO INCREASE..ESPECIALLY IN AREAS
ADJACENT TO LAKE SUEPRIOR. THE PEAK OF THE STORM IS EXPECTED TO BE
FROM ROUGHLY 8 PM THIS EVENING THROUGH SOMETIME AROUND MIDDAY ON
CHRISTMAS..ALTHOUGH HEAVIER SNOWFALL RATES MAY PERSIST WELL INTO
THE AFTERNOON ACROSS THE WRN CWA.
ONE INCREASING CONCERN IS THE PROGRESSIVELY FARTHER WEST PLACEMENT
OF THE WRN PERIPHERY OF THE WARM NOSE ALOFT PUSHING INTO NW WI
TONIGHT AND CHRISTMAS MORNING. THE LATEST NAM RUN PLACES A 75 KT
SERLY LLJ ACROSS NRN WI LATE TONITE..WITH A WARM NOSE ABOVE ZERO
NOW AS FAR WEST AS DULUTH AND THE MN ARROWHEAD. THIS MAY ACT TO
BRING MIXED PRECIP FARTHER WEST THAN WHERE WE CURRENTLY HAVE IT
INDICATED. HOWEVER..IF HEAVY PRECIP IS ONGOING /AS EXPECTED/ AS
WARM NOSE TRIES TO PUSH IN..DIABATIC COOLING EFFECTS WILL LIKELY
KEEP PRECIP AS ALL SNOW IN MINNESOTA. IT SEEMS A MORE SURE BET
THAT SNOW WILL MIX WITH OR CHANGE TO SLEET AND/OR FREEZING RAIN
FOR A WHILE IN NW WI..SO WE HAVE TONED DOWN ACCUMS A BIT MORE IN
OUR FAR ERN CWA..AND TIGHTENED UP THE SNOWFALL GRADIENT EXTENDING
FROM ROUGHLY SPOONER AND HAYWARD NEWD TO THE BAYFIELD PENINSULA.
SNOW/WIND SHUD BEGIN A SLOW DECREASE CHRISTMAS AFTERNOON/EVENING
AS LOW BECOMES VERTICALLY STACKED OVER IOWA AND THEN SLOWLY
STARTS TO FILL WHILE DRIFTING EWD. WE STILL EXPECT LIGHT SNOWS TO
PERSIST ACROSS A LARGE PART OF THE THE AREA FRIDAY NITE/SATURDAY
AND INTO SATURDAY NIGHT IN BROAD WRAP AROUND PRECIP AREA..BUT
PRECIP RATES AND SNOW AMOUNTS SHUD BE MUCH LESS DURING THIS TIME
FRAME.
LONG TERM...SATURDAY NIGHT THROUGH THRUSDAY...
LOW PRESSURE WILL GRADUALLY LOSE ITS HOLD ON THE REGION AS IT SLOWLY
FILLS AND MOVES NEWRD. BY 00Z MONDAY LOW FORECAST BY MODELS TO BE
OVR LOWER MI...WITH LINGERING FLURRIES. RIDGING BUILDS OVR THE WRN
1/2 OF THE NATION...PUTTING THE NORTHLAND UNDER FAST NORTHWEST FLOW.
THIS WILL MEAN A BIT COOLER TEMPS WITH PASSING SLIGHT CHANCES OF
VERY LIGHT SNOW.
&&
.POINT TEMPS/POPS...
DLH 29 29 27 29 / 100 100 100 70
INL 24 24 18 21 / 100 100 100 70
BRD 26 28 25 27 / 100 100 100 70
HYR 30 32 28 29 / 100 100 100 60
ASX 30 32 28 30 / 100 100 100 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR MNZ010>012-018-
019-021-025-026-033>036-038.
BLIZZARD WARNING UNTIL 6 AM CST SATURDAY FOR MNZ020-037.
WI...WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR WIZ002>004-
006>009.
BLIZZARD WARNING UNTIL 6 AM CST SATURDAY FOR WIZ001.
LS...GALE WARNING UNTIL 6 PM CST FRIDAY FOR LSZ121-140>148.
&&
$$
EOM/LONKA
