Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 160821
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
321 AM EST TUE DEC 16 2014

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE

.SYNOPSIS...
ISSUED AT 321 AM EST TUE DEC 16 2014

LOW PRESSURE WILL MOVE ACROSS LOWER MICHIGAN TODAY SPREADING RAIN
SHOWERS AS IT GOES. COLDER AIR WILL WRAP INTO THE SYSTEM LATER THIS
EVENING AND THE RAIN WILL MIX WITH AND THEN CHANGE TO LIGHT SNOW.
THIS WILL BEGIN A PERIOD OF NEAR NORMAL TEMPERATURES...ALTHOUGH MUCH
COLDER THAN WHAT WE`VE SEEN LATELY...THAT WILL LAST THROUGH THE
WEEKEND. LIGHT LAKE EFFECT SNOW SHOWERS ARE POSSIBLE WEDNESDAY INTO
THURSDAY WITH LIGHT ACCUMULATIONS POSSIBLE MAINLY WEST OF US-131.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM EST TUE DEC 16 2014

FORECAST CONCERNS DEAL WITH THE EVOLUTION OF THE LOW CURRENTLY
MOVING THROUGH NORTHWEST ILLINOIS.

REGIONAL RADAR AND IR LOOP SHOWS A WELL DEFINED LOW JUST CROSSING
THE MISSISSIPPI. LIGHT RAIN SHOWERS CONTINUE TO PIVOT NORTHWARD FROM
INDIANA AND WE/LL BE LOOKING AT SHOWERS THROUGHOUT THE DAY AS THE
LOW MOVES ACROSS LOWER MICHIGAN. HEAVY RAIN ISN/T ANTICIPATED.
HOWEVER...THERE HAS BEEN SOME LIGHTNING OVER SOUTHERN INDIANA.
MODELS SHOW SOME ELEVATED INSTABILITY DEVELOPING OVER FAR WESTERN
LAKE ERIE THIS MORNING BUT IT PROBABLY TOO FAR AWAY TO RESULT IN
THUNDER IN OUR CWA.

COLDER AIR WILL WRAP INTO THE SYSTEM TONIGHT AND TURN THE LINGERING
PCPN TO LIGHT SNOW SHOWERS. H8 TEMPS FALL TO -12C WEDNESDAY AND THIS
NORMALLY CREATES SUFFICIENT OVER-LAKE INSTABILITY TO GENERATE SNOW
SHOWERS. THE ISSUE THIS TIME THOUGH IS THE SHALLOW MOISTURE. THE
DGZ IS VERY SMALL AND RESIDES AT THE TOP OF THE SHALLOW MOISTURE
AROUND 4K FT. IT/S PROBABLY ENOUGH TO SEE SOME SNOW SHOWERS...AND
LIGHT ACCUMS WEST OF US-131 BUT NOT MUCH MORE THAN THAT. THE SHSN
WILL GRADUALLY DIMINISH WEDNESDAY NIGHT.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 321 AM EST TUE DEC 16 2014

MORE QUIET WEATHER IS IN STORE IN THE LONG TERM PERIOD AS THE SPLIT
FLOW ALOFT CONTINUES AND SURFACE HIGH PRESSURE DOMINATES. THE POLAR
JET STAYS WELL TO OUR NORTH AND THE SRN STREAM BRANCH REMAINS
SOUTH... SO STILL NO MAJOR WINTER SYSTEMS OR ARCTIC AIR IN OUR
FUTURE.

THE MAIN CONCERN WILL BE CLOUD COVER AS STRATUS/FOG/DRIZZLE COULD BE
AN ISSUE AGAIN UNDER THE SFC HIGH. FOR NOW WILL BE OPTIMISTIC WITH
PARTLY SUNNY WORDING BUT THIS COULD CHANGE IN LATER FORECASTS.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL WITH HIGHS IN THE LOWER
TO MID 30S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1204 AM EST TUE DEC 16 2014

EXPECT IFR CONDITIONS OVERNIGHT AND INTO TUESDAY AFTERNOON. WINDS
WILL BE SOUTHEAST TONIGHT AOB 10 KNOTS THEN TURN SOUTHWEST TO WEST
DURING TUESDAY AROUND 10 KNOTS.


&&

.MARINE...
ISSUED AT 321 AM EST TUE DEC 16 2014

WINDS WILL INCREASE AS THE LOW MOVES BY THIS AFTERNOON. ISSUED A SCA
TO COVER INCREASED WINDS AND WAVES FROM THIS AFTERNOON THROUGH
THURSDAY MORNING.

&&

.HYDROLOGY...
ISSUED AT 321 AM EST TUE DEC 16 2014

NO HYDRO ISSUES.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM NOON TODAY TO NOON EST THURSDAY FOR
     LMZ844>849.

&&

$$

SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...OSTUNO
HYDROLOGY...93
MARINE...93








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