Ice Storm in Michigan, April 3 to 5, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
445 AM EST THU APR 3 2003

EXTREMELY COMPLICATED FORECAST SETTING UP. SURFACE FRONT HAS SLIPPED
SOUTH OF THE STATE AND SHALLOW COLD AIR MASS HAS REALLY POURED IN
ACROSS THE CWFA. THE COLD AIR FEED FROM THE NORTHEAST AROUND THE
SURFACE HIGH IN SRN CANADA IS QUITE IMPRESSIVE AS TEMPERATURES NORTH
OF LAKE HURON ARE IN THE SINGLE DIGITS. MEANWHILE THE H8 WARM FRONT
IS STILL SITUATED MUCH FARTHER NORTH ACROSS CENTRAL LWR MI WITH
TEMPS AROUND 10C OVER SRN LWR MI. THIS CREATES SOME REALLY
INTERESTING LOOKING THERMAL PROFILES ACROSS THE CWFA...WITH A
SHALLOW STABLE LAYER NEAR THE SURFACE...A STRONG INVERSION FROM THE
SURFACE TO 3K FEET...THEN A RATHER UNSTABLE LOOKING PROFILE ABOVE 3K
FT. SURFACE BASED INSTABILITY WILL LIKELY BE NON-EXISTENT
TODAY AND TONIGHT WITH THE SURFACE FRONT REMAINING JUST TO OUR
SOUTH. HOWEVER...850 MB LIFTED INDICES ARE PROGGED TO BE FROM ZERO
TO -3 AND TSTMS WILL STILL BE A PRETTY GOOD BET.

SHORTWAVE MOVING NORTHEAST FROM IOWA WILL AFFECT SW MI BY THIS
AFTERNOON. WILL START WITH CHANCE POPS THIS MORNING...THEN LIKELY BY
AFTERNOON. AM CONCERNED ABOUT THE POSSIBILITY OF FREEZING RAIN IN
THE NRN PORTION OF THE CWFA WHERE SFC TEMPS ARE CURRENTLY AROUND 30.
HOWEVER WILL COUNT ON A RISE OF A FEW DEGREES BY THE TIME THE BULK
OF THE PCPN ARRIVES AND HOLD OFF ON ANY ADVISORIES FOR NOW. SVR WX
WILL ALSO BE A CONCERN THIS AFTERNOON IN THE SRN CWFA JUST NORTH OF
THE SURFACE BOUNDARY AS H5 JET STREAK OF 60 KNOTS PULLS THROUGH.

SUB-FREEZING SURFACE TEMPERATURES ARE PROGGED TONIGHT OVER THE
NORTHEAST HALF OF THE CWFA AS BANDS OF CONVECTIVE PCPN CONTINUE TO
AFFECT THE AREA. THE H8 JET STRENGTHENS TO 40-50 KNOTS WITH
ADDITIONAL SHORTWAVES PROGGED TO RIDE THROUGH THE AREA. PRECIPITABLE
WATERS RISE TO ABOUT 1.25 WITH SOUTHWEST FLOW... SO MOISTURE NOT A
PROBLEM AT ALL. THERE IS CERTAINLY A POTENTIAL FOR MORE THAN A
QUARTER INCH OF ICE ACCUMULATION SO WILL POST A WATCH NORTH OF
INTERSTATE 96.

MORE WINTER WEATHER EXPECTED FRIDAY AND FRIDAY NIGHT AS SHALLOW COLD
AIR REMAINS IN PLACE AND ADDITIONAL WAVES RIDE ALONG THE FRONT. THE
GFS AND ECMWF ARE SLOWER THAN THE ETA IN BRINGING THE MAIN AND FINAL
WAVE THROUGH ON FRIDAY NIGHT VS FRIDAY. SHOULD THIS SOLUTION
VERIFY...SOME SIGNIFICANT SNOW ACCUMULATIONS ARE POSSIBLE FRIDAY
NIGHT AND MAY NEED TO EXTEND THE WATCH.

MEADE

EXTENDED FORECAST DISCUSSION...
NEGATIVE TILTED TROF WILL EXIT THE REGION ON SATURDAY.  WILL KEEP
THE MENTION OF SOME SNOW OR MIXED RAIN AND SNOW FOR EARLY
SATURDAY...BUT WILL KEEP POPS LOW.  CLEARING SHOULD FINALLY OCCUR
OVERNIGHT AS A SURFACE RIDGE SLIDES IN.  FEB-LIKE TEMPS COULD RESULT
IN AREAS THAT RECEIVED A FRESH COAT OF SNOW.

BY SUNDAY A WARM FRONT SETS UP OVER THE OHIO VALLEY.  STRONG OVER
RUNNING WILL SPREAD CLOUDS ACROSS THE CWA FROM SOUTH TO NORTH.  THE
MOISTURE SHOULD CONTINUE TO INCREASE WITH SNOW MOVING BACK INTO THE
REGION LATE SUNDAY.  MUCH OF THE PCPN SHOULD CHANGE OVER THE RAIN ON
MONDAY WITH TEMPS RISING INTO THE LOWER 40S.

INTO MID WEEK MUCH OF THE EASTERN U.S. SHOULD BE UNDER A LARGE
SURFACE RIDGE WITH A WARM FRONT DRIFTING ACROSS THE U.S/CANADIAN
BORDER.  WILL GO WITH DRY CONDITIONS AND INDICATE A GRADUAL WARMING
TREND...BACK TO NEAR NORMAL TEMPS BY WEDNESDAY.

JK

.GRR...WINTER STORM WATCH TONIGHT AND FRIDAY FOR THE POSSIBILITY OF
       SIGNIFICANT ICE ACCUMULATIONS...COUNTIES NORTH OF INTERSTATE
       96.

MIZ037>040-043>046-050>052-056>059-064>067-071>074-041100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
655 AM EST THU APR 3 2003

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

.DAY ONE...TODAY AND TONIGHT

A SLIGHT RISK OF SEVERE THUNDERSTORMS EXISTS TODAY AND TONIGHT SOUTH
OF INTERSTATE 96. THE PRIMARY THREAT WILL BE LARGE HAIL OF THREE
QUARTERS OF AN INCH IN DIAMETER OR GREATER. STORM MOVEMENT WILL BE
TO THE EAST AT AROUND 40 MPH.

A WINTER STORM WATCH IS IN EFFECT TONIGHT FOR AREAS NORTH OF
INTERSTATE 96. A SHALLOW LAYER OF BELOW FREEZING TEMPERATURES WILL
BE TRAPPED NEAR THE SURFACE...WHILE WARMER AIR REMAINS IN PLACE
ALOFT.  SIGNIFICANT ICE ACCUMULATIONS ARE POSSIBLE AND SOME
THUNDER AND LIGHTNING COULD EVEN ACCOMPANY SOME OF THE HEAVIER
FREEZING RAIN SHOWERS TONIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE SHALLOW COLD AIR IS EXPECTED TO STAY IN PLACE THROUGH FRIDAY
WHICH COULD RESULT IN A PROLONGED PERIOD OF FREEZING RAIN.  ICE
ACCUMULATIONS COULD EXCEED ONE QUARTER OF AN INCH IN THE WATCH AREA
BY FRIDAY EVENING. HAZARDOUS WINTER WEATHER MAY CONTINUE INTO FRIDAY
NIGHT AS WELL. THE POTENTIAL EXISTS FOR ADDITIONAL SNOW AND ICE
ACCUMULATIONS AS YET ANOTHER ROUND OF HEAVIER PRECIPITATION MOVES
THROUGH SOUTHWEST MICHIGAN.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT.

MEADE