Heavy Snow in Michigan, December 24 to 25, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
328 PM EST TUE DEC 24 2002

PRETTY INTERESTING SCENARIO PLAYING OUT TO OUR SOUTH THIS AFTERNOON
AND ACROSS THE SRN 1/2 OF THE CWA OVERNIGHT AND EARLY CHRISTMAS.
WITH THE ONGOING EARLY FLOW SET UP LOW LEVELS START OUT FAIRLY DRY
AND WILL TAKE AWHILE TO MOISTEN UP OVERNIGHT. LOOKS LIKE THINGS
COULD START UP IN THE SRN ZONES AROUND MIDNIGHT AND GRADUALLY WORK
ITS WAY TO THE NORTH OVERNIGHT. SE AREAS COULD SEE 2-4 OVERNIGHT AND
ANOTHER INCH OR SO IN THE MORNING AS THE DOMINANT EAST COAST LOW
TAKES OVER AND FOCUSES THE ENERGY OF THE COUPLED JET STRUCTURE ALONG
THE CENTRAL ATLANTIC COAST. INITIAL THINKING WAS THAT THE SYSTEM
WOULD BE PRETTY WELL STARVED FOR MOISTURE DUE TO THE INTENSE
CONVECTION OVER THE SERN US ATTM BUT WITH 1 FOOT SNOWFALL BEING
REPORTED UPSTREAM IN MISSOURI I WILL BUMP OUR AMOUNTS FOR OVERNIGHT
AND GO CATEGORICAL IN EXTREME SE AND LIKELY ACROSS THE CENTRAL SWATH
AND CHANCE UP NORTH.  AFTER LOW MOVES OUT THERE MAY BE A CHANCE FOR
SNOW ALONG THE LAKESHORE CHRISTMAS AFTERNOON AND EVENING. THEN
FAIRLY TRANQUIL WITH SEASONAL TEMPERATURES THROUGH THURSDAY.

MWH

EXTENDED FORECAST DISCUSSION...
THE EXTENDED PERIOD STILL LOOKS QUIET FROM FRI THROUGH MOST OF SAT.
WITH THE 12Z AVN...THE SHORTWAVE WILL MOVE OUT OF THE NORTHERN
PLAINS EARLY SAT...AND ENTER MY CWA LATE SAT EARLY SUN. THINKING IS
THAT ENOUGH DRY AIR AT THE SFC WILL REMAIN IN PLACE...SO WILL HOLD
OFF PRECIP UNTIL SUN...BUT WILL ADJUST THE TIMING TO EARLY/MID SUN
AS IT APPEARS TO HAVE CLIPPER CHARACTERISTICS. AT THIS TIME IT
DOESN/T APPEAR TO BE ANYTHING HEAVY...BUT A FEW LAKE EFFECT SNSH
POSSIBLY MIXED WITH LGT RA AT TIMES WITH TEMPS AROUND TO JUST ABOVE
FREEZING. ONCE SYSTEM PUSHES THROUGH GRT LKS...DRY AIR WILL SLIDE
INTO CWA AS A SPLIT JET DEVLPS ACROSS THE PLAINS. IT IS THIS SPLIT
JET THAT NEEDS MONITORING. AS THE WEEKEND ENDS...A NEW VORT IS
PROGGED TO MOVE OUT OF THE CENTRAL ROCKIES AND MOVE EASTWARD ON MON.
THIS VORT APPEARS FROM THE AVN/ECMWF TO SPIN UP A LOW AT THE MID
LVLS...AND RIDE ALONG A FRONT LATE MON. THICKNESS VALUES STILL LOOK
GOOD ENOUGH TO PRODUCE SN...BUT A RA SN MIX IS NOT OUT OF THE
QUESTION AS THE SYSTEM GETS MORE DEVELOPED THROUGH TUE.

ENSEMBLES ARE BEGINNING TO INDICATE THAT AFTER THE MON/TUE
SYSTEM...A MORE ACTIVE PATTERN TAKES SHAPE TOWARDS MID TO LATE WEEK.
BUT THIS IS BEYOND MY EXTENDED TIME FRAME SO WILL LEAVE MONITORING
TO LATER RUNS.

BEACH

.GRR...NONE.

MWH

MIZ037>040-043>046-050>052-056>059-064>067-071>074-251100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
530 AM EST TUE DEC 24 2002

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SOUTHWEST QUARTER OF LOWER
MICHIGAN.

.DAY ONE...TODAY AND TONIGHT
1 TO 4 INCHES OF SNOW IS EXPECTED TONIGHT SOUTH AND EAST OF A LINE
FROM SOUTH HAVEN TO ST JOHNS AS A STORM SYSTEM TRACKS INTO THE OHIO
VALLEY.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY
AN ADDITIONAL INCH OF SNOW ACCUMULATION IS POSSIBLE CHRISTMAS
MORNING SOUTH AND EAST OF A SOUTH HAVEN TO ST JOHNS LINE. OTHERWISE
NO HAZARDOUS WEATHER IS EXPECTED IN THE OUTLOOK PERIOD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH THE PERIOD.

MEADE