000
FXUS63 KGRR 072350
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
650 PM EST SAT DEC 7 2013

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EST SAT DEC 7 2013

LAKE EFFECT SNOW SHOWERS WILL WIND DOWN TONIGHT AND MOVE OFFSHORE.
ADDITIONAL SNOWFALL AMOUNTS WILL BE LIMITED TOWARD THE
LAKESHORE...BUT ANOTHER INCH OR SO MAY FALL THROUGH THE EVENING.
LATE TONIGHT AND SUNDAY MORNING WILL BRING QUIET WEATHER AS HIGH
PRESSURE SLIPS THROUGH THE REGION. A WIDESPREAD SNOW IS EXPECTED
BEGINNING SUNDAY AFTERNOON AND LASTING INTO SUNDAY NIGHT. THE SNOW
WILL BE ASSOCIATED WITH A WEAK AREA OF LOW PRESSURE LIFTING THROUGH
THE GREAT LAKES. A SET UP WILL EXIST THAT SOME FREEZING DRIZZLE MAY
OCCUR AFTER DARK SUNDAY NIGHT LASTING INTO MONDAY
MORNING...ESPECIALLY ALONG AND SOUTH OF THE INTERSTATE 96 CORRIDOR.
THE SNOW AND THE FREEZING DRIZZLE MAY MAKE FOR A SLIPPERY MONDAY
MORNING COMMUTE. SNOWFALL TOTALS FROM THE EVENT WILL RANGE FROM
AROUND AN INCH IS FAR SOUTHERN LOWER MICHIGAN TO NEAR 3 INCHES UP
TOWARDS U.S. 10. THE MIDDLE OF THE WORK WEEK WILL FEATURE COLD
READINGS AND ACCUMULATING LAKE EFFECT SNOW.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 258 PM EST SAT DEC 7 2013

MAIN ITEM OF CONCERN IN THE SHORT TERM IS THE SYNOPTIC SNOW EVENT
SUNDAY AFTERNOON INTO SUNDAY NIGHT. MODELS LIFT A LOW NEAR OR
THROUGH THE NORTHWEST PORTION OF THE FORECAST AREA NEAR LUDINGTON
SUNDAY NIGHT. THIS LOW IS ASSOCIATED WITH THE CURRENT UPPER WAVE
SEEN MOVING THROUGH THE GREAT BASIN OUT WEST. THE SHORTWAVE RAPIDLY
TAKES AIM ON THE AREA MOVING TO NEAR KANSAS CITY TOMORROW AND THEN
THROUGH THE NORTHWEST CWA TOMORROW NIGHT. A BURST OF WARM AIR
ADVECTION SNOW WILL MOVE THROUGH THE AREA BEGINNING LATE AFTERNOON
ON SUNDAY LIFTING NORTH WITH TIME. THE HEAVIEST SNOW WILL LIKELY
OCCUR SUNDAY EVENING ASSOCIATED WITH THE WARM AIR ADVECTION BURST.
THE NORTHERN CWA SEEMS PRIME TO SEE THE HEAVIER SNOW AS IT WILL SEE
BOTH THE WARM AIR ADVECTION SURGE AND SOME SNOW ASSOCIATED WITH THE
MID LEVEL WAVE ITSELF. A 1-3 INCH FORECAST LOOKS LIKE THE WAY TO GO
WITH AROUND AND INCH SOUTH AND AROUND 3 INCHES NEAR U.S. 10 FROM
LUDINGTON TO CLARE. FREEZING DRIZZLE ALSO LOOKS LIKE A PLAYER AS THE
DGZ BECOMES UNSATURATED OVERNIGHT. AT THIS POINT HAVE THE FZDZ
MENTIONED ACROSS THE SOUTHERN COUPLE TIERS OF COUNTIES AND EVEN A
BIT INTO THE OTTAWA...KENT...IONIA AND CLINTON ROW. COULD SEE
NEEDING TO EXPAND THE FZDZ MENTION NORTH WITH TIME.

OTHERWISE...LAKE EFFECT SNOW WILL FOLLOW THE PASSAGE OF THE LOW FOR
MONDAY AND MONDAY NIGHT. THE MOISTURE DEPTH DOES NOT LOOK IMPRESSIVE
DURING THIS TIME FRAME...5000FT OR LESS. EXPECT SOME LIGHT
ACCUMULATIONS ALONG AND WEST OF HIGHWAY 131 AGAIN.

AS FOR TONIGHT...LAKE SNOWS SHOULD GRADUALLY MIGRATE OUT OVER THE
LAKE WITH TIME AS THE FLOW BECOMES LIGHT. ANOTHER INCH OR SO OF
ACCUMULATION THIS EVENING TOWARDS THE LAKESHORE. THE SNOW RATIOS ARE
ON THE ORDER OF 20-25 TO 1. SO...OUTSIDE OF SOME SLIPPERY SPOTS
WHERE THE SNOW HAS BEEN COMPACTED OR REFROZE DUE TO MELTING FROM
SALT NOT EXPECTING MUCH IMPACT.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 258 PM EST SAT DEC 7 2013

A VERY COLD AND SNOWY MID WEEK HIGHLIGHTS THE LONG TERM PERIOD.

A HEALTHY LOOKING SHORT WAVE SHOULD DROP OUT OF THE UPPER
MIDWEST AND INTO THE GREAT LAKES TUESDAY AFTERNOON.  THIS SHOULD
INTENSIFY THE LAKE EFFECT SNOW.  THEN ANOTHER WAVE IS SHOWN FOR LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING.  UP TO SIX INCHES OF SNOW
COULD BE POSSIBLE...WITH AROUND TWO INCHES INLAND...WITH THESE TWO
EVENTS.  IT APPEARS THE MEAN FLOW WILL BE WEST OR WEST SOUTHWEST...
FAVORING AREAS ALONG I-96 FOR THE HEAVIEST SNOW.

BEHIND THE SECOND WAVE WILL COME THE COLDEST AIR OF WEEK.  WEDNESDAY
SHOULD START OUT AROUND 20...WITH TEMPS FALLING THROUGH THE TEENS
DURING THE DAY.  WIND CHILLS SHOULD BE BELOW ZERO BY WEDNESDAY
AFTERNOON THROUGH MUCH OF WEDNESDAY NIGHT.

THE LAKE EFFECT SHOULD GRADUALLY WEAKEN INTO THURSDAY AS TEMPS WARM
AND HIGH PRESSURE MOVES INTO THE OH VALLEY.  TEMPS SHOULD WARM TO A
HIGH AROUND THE FREEZING MARK BY FRIDAY.  THEN A NORTHERN STREAM
SYSTEM IS SHOWN TO MOVE ACROSS THE U.S./CANADIAN BORDER FRI/SAT.
LOOKS AS THOUGH THIS SYSTEM COULD BRING LIGHT SNOW TO THE NORTHERN
CWA.  THEN IT TURNS COLDER AGAIN ON SATURDAY WITH MORE LAKE EFFECT
POTENTIAL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 650 PM EST SAT DEC 7 2013

LIGHT LAKE EFFECT SNOW SHOWERS AND MVFR CEILINGS WILL CONTINUE
THIS EVENING WITH CEILINGS 2500 TO 3000 FET AGL FROM MKG TO GRR
AND SOUTH TO BTL AND AZO. VFR FURTHER INLAND AT LAN AND JXN.
EXPECT VFR AFTER MIDNIGHT AS THE LAKE EFFECT CLOUDS DECREASE.
MOSTLY VFR FOR SUNDAY UNTIL LATER IN THE AFTERNOON WHEN SOME SNOW
MAY MOVE IN ACROSS WESTERN LOWER MICHIGAN.

&&

.MARINE...
ISSUED AT 258 PM EST SAT DEC 7 2013

WEBCAMS CONTINUE TO SHOW SOME WHITE CAPS...BUT IT LOOKS MORE OF THE
2-4 FOOT VARIETY. WIND GUSTS AT ALL OF THE LAKESHORE SITES CONFIRM
THIS WITH CURRENT VALUES ALL AT 18 KNOTS OR LESS. AS HIGH PRESSURE
BUILDS IN...THE WINDS AND WAVES SHOULD CONTINUE TO SETTLE DOWN
TONIGHT.

WINDS WILL INCREASE OUT OF THE EAST-SOUTHEAST ON SUNDAY...WITH THE
HIGHEST WAVES REMAINING WELL OFF SHORE OF THE WEST COAST OF LOWER
MICHIGAN. THE NEXT TIME FRAME OF CONCERN FOR OUR NEARSHORE AREA WILL
BE SUNDAY NIGHT AFTER DARK AS WINDS RAMP UP OUT OF THE SOUTHWEST.
WIND SPEEDS WILL APPROACH 30 KNOTS AND CONTINUE INTO MONDAY. WINDS
MONDAY WILL BE MORE WESTERLY. A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR SUNDAY NIGHT INTO MONDAY. WAVES SUNDAY NIGHT WILL PUSH
REACH THE 3-6 FOOT RANGE AND BUILD INTO THE 5 TO 8 FOOT RANGE ON
MONDAY.


&&

.HYDROLOGY...
ISSUED AT 258 PM EST SAT DEC 7 2013

TEMPERATURES ARE FORECAST TO REMAIN BELOW FREEZING AT LEAST INTO THE
MIDDLE OF NEXT WEEK IF NOT ALL THE WAY THROUGH IT. THEREFORE...ICE
FORMATION ON AREA RIVERS IS LIKELY. RIVER WATER TEMPERATURES AROUND
THE AREA RANGE FROM 0C TO +4C. CONCERN REMAINS FOR ICE JAM ISSUES ON
AREA RIVERS. NIGHT TIME TEMPERATURES ARE FORECAST TO DROP INTO THE
SINGLE DIGITS ACROSS MUCH OF THE MUSKEGON RIVER BASIN THE NEXT 4 TO
5 NIGHTS. READINGS THIS COLD COMBINED WITH RIVER WATER TEMPS
HOVERING AROUND OR JUST ABOVE FREEZING WILL MAKE PLACES LIKE ROGERS
HEIGHTS ON THE MUSKEGON RIVER A PRIME LOCATION FOR RIVER ICE
FORMATION AND POSSIBLE ICE JAMS. WE WILL CONTINUE TO MONITOR AREA
RIVER LEVELS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...DUKE
MARINE...DUKE