FXUS63 KDLH 251022
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
422 AM CST FRI DEC 25 2009
.DISCUSSION...MAJOR WINTER STORM IS THE MAIN FOCUS TODAY.
SNOW CONTINUED ACROSS THE ENTIRE NORTHLAND EARLY THIS MORNING...
WITH HEAVY SNOW ACROSS THE HEAD OF THE LAKES REGION. SNOWFALL
REPORTS HAVE BEEN SPORADICALLY COMING IN. THE HIGHEST TOTAL SO FAR
IS AT THE DULUTH AIRPORT...WITH 16.2 INCHES AS OF 4 AM. STRONG NE
WINDS WERE CAUSING LAKE AND OROGRAPHIC ENHANCEMENT OF THE SNOW IN
THE VICINITY OF THE WESTERN TIP OF LAKE SUPERIOR. WAVES OF SNOW
CONTINUE TO LIFT NORTHWARD AS THE INTENSE LOW PRESSURE SYSTEM IN
NE MISSOURI CONTINUES TO EVOLVE. SOME SLEET...FREEZING RAIN OR
RAIN HAD DEVELOPED ACROSS PORTIONS OF NW WI...AS WARMER AIR LIFTS
INTO THAT AREA FROM THE SOUTHEAST. THE PRECIPITATION IS MAINLY IN
THE FORM OF RAIN ACROSS MUCH OF NW WI.
THE BIG STORY TODAY REMAINS THE BLIZZARD CONDITIONS AT THE HEAD OF
THE LAKES REGION. AFTER A LULL IN THE PRECIPITATION YESTERDAY
AFTERNOON AND EARLY EVENING...SNOW AND WINDS HAVE BEEN INCREASING
IN INTENSITY OVERNIGHT. LOCALLY HEAVY SNOWFALL WILL CONTINUE
THROUGH AT LEAST THE MORNING HOURS...AS WINDS OF 30 TO 40 MPH WITH
GUSTS TO 50 MPH CONTINUE. HAVE KEPT MOST SNOW TOTALS FOR THIS
EVENT THE SAME AS WE HAVE BEEN GOING. FOR THE HEAD OF THE LAKES
AREA...ROUGHLY FROM SILVER BAY...TO DULUTH AND SUPERIOR...WE ARE
EXPECTING AROUND 2 FEET OF SNOW. SNOWFALL RATES OF 1 TO 2 INCHES AN
HOUR HAVE BEEN COMMON OVERNIGHT. THERE COULD BE LOCALLY HIGHER
STORM TOTAL AMOUNTS AS WELL...AS LONG AS THE PRECIPITATION DOES
NOT APPRECIABLY MIX WITH FREEZING RAIN...SLEET OR RAIN. THE 00Z
NAM WAS MUCH WARMER THAN PREVIOUS RUNS...AND ACTUALLY CHANGED THE
PRECIPITATION TO A LIQUID FORM FOR THE DULUTH AREA AS WELL FROM
LATE MORNING INTO AFTERNOON. THE 06Z NAM HAS BACKED OFF A BIT ON
THIS...AND THE GFS KEEPS MOST PRECIPITATION IN THE FORM OF SNOW.
WITH STRONG UPWARD VERTICAL MOTION...MOST OF THE PRECIPITATION HAS
REMAINED IN THE FORM OF SNOW...BUT IF THE PRECIPITATION LETS UP
SOMEWHAT...WE COULD SEE A BIT MORE MIX OR CHANGEOVER. THIS WILL
HAVE TO BE WATCHED CAREFULLY.
SEVERAL ROUNDS OF PRECIPITATION WILL CONTINUE TO ROTATE AROUND THE
DEVELOPING SURFACE AND UPPER LOW PRESSURE SYSTEM AS IT TAKES ON
A STRONG NEGATIVE TILT AND CLOSES OFF DUE TO THE PHASING OF THE
NORTHERN AND SOUTHERN STREAM SYSTEMS OVER IOWA/ILLINOIS BY TONIGHT.
A DEEP MOISTURE STREAM WILL CONTINUE TO FEED INTO THE MASSIVE
STORM SYSTEM FROM THE GULF OF MEXICO...PROVIDING A CONVEYOR BELT
OF MOISTURE WRAPPING AROUND THE DEVELOPING UPPER LOW.
MODEL QPF HAS DONE A FAIRLY POOR JOB OF LATE WITH THIS SYSTEM...
AND HAS BEEN GENERALLY UNDERDONE. THE AMOUNTS HAVE LIKELY BEEN
CLOSER TO THE NAM THAN THE ECMWF/GFS. AS A RESULT...WILL REMAIN ON
THE HIGH SIDE OF QPF...AND EVEN A BIT HIGHER THAN MODEL QPF.
THE HEAVIEST SNOW SHOULD OCCUR THIS MORNING...AND POSSIBLY INTO
THE AFTERNOON. THERE SHOULD THEN BE A GRADUAL DIMINISHING TREND TO
THE SNOW TONIGHT AND INTO SATURDAY. THE WINDS WILL REMAIN STRONG
TODAY AND INTO THE NIGHT...ESPECIALLY AT THE HEAD OF THE LAKES.
THE FORTUNATE THING IS THAT DESPITE THE STRONG WINDS...THE SNOW IS
HEAVY AND WET...MINIMIZING SOME OF THE MOST EXTREME BLOWING SNOW.
SUNDAY THROUGH THURSDAY...THE STORM SYSTEM WILL LOSE INTENSITY AS
IT SLOWLY EXITS TO THE EAST OVER MICHIGAN AND THE ERN GRT LKS
SUNDAY NIGHT. A SHORT WAVE WILL BREAK FREE FROM THE HUDSON BAY LOW
AND DROP SOUTH OVER ONTARIO AND INTO THE WRN GRT LKS REGION SUN
NIGHT/MONDAY. ATTM...THIS WAVE WILL MAINLY AFFECT THE TIP OF THE
MN ARROWHEAD AND BRING LK EFFECT SN SHOWERS TO THE SOUTH SHORE OF
LK SUPERIOR AS 850 MB TEMPS FALL INTO THE UPR TEENS BELOW ZERO AND
WINDS BECOME GUSTY OUT OF THE N. INCREASED POPS ALONG THE GOGEBIC
RANGE DURING THIS TIME FRAME WHERE A FEW INCHES OF SNOW WILL BE
POSSIBLE. A BRIEF BREAK IN THE ACTIVE PATTERN WILL BE FOUND MON
NIGHT/TUESDAY AS SFC HIGH PRESSURE TAKES CONTROL OF THE UPPER
MIDWEST AHEAD OF THE NEXT FAST MOVING WAVE THAT WILL BRING A SMALL
CHANCE FOR SNOW TO PORTIONS OF THE FA TUES NIGHT/WED.
&&
.AVIATION.../06Z TAF ISSUANCE/
ANOTHER WAVE OF SNOW HAS MADE ITS WAY INTO NE MN AND NW WI THIS
EVENING...AND WILL CONTINUE AT LEAST THROUGH MUCH OF FRI...AS THE
MAIN STORM SYSTEM IN THE SRN PLAINS MAKES ITS WAY NORTHWARD INTO
IOWA. THE OVERALL TREND WILL BE DETERIORATING CONDITIONS...WITH
WINDS STRENGTHENING BY LATE TONIGHT. WIDESPREAD IFR...WITH LIFR
CONDS IN HEAVIER SNOW BANDS CAN BE EXPECTED. WINDS WILL GUST
UPWARDS OF 20 TO 30 KT...WITH GUSTS APPROACHING 40 KT AT KDLH
WITH BLOWING AND DRIFTING SNOW FRI.
&&
.POINT TEMPS/POPS...
DLH 33 30 32 19 / 100 100 70 40
INL 30 26 27 20 / 100 100 70 30
BRD 33 28 30 18 / 100 100 70 40
HYR 36 29 29 12 / 100 100 60 60
ASX 35 29 32 15 / 100 100 60 50
&&
.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 THIS EVENING FOR LSZ121-140>148.
&&
$$
DAP/GRANING
