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000
FXUS63 KGRR 011734
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1234 PM EST SAT MAR 1 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 329 AM EST SAT MAR 1 2014

AREAS OF LIGHT SNOW WILL DIMINISH THIS MORNING...BUT THEN IT WILL
PICK UP AGAIN LATE THIS AFTERNOON AND CONTINUE INTO TONIGHT.  MOST
AREAS WILL ONLY SEE AN INCH OR LESS THROUGH TODAY.  HOWEVER THE SNOW
WILL BECOME STEADIER TONIGHT WITH AN ADDITIONAL 2 TO 4 INCHES EXPECT
SOUTH OF I-96...WHILE 1 TO 3 INCHES SHOULD FALL TO THE NORTH OF I-96.

THE SNOW WILL DIMINISH BY SUNDAY...BUT MORE ARCTIC AIR ARRIVES...
KEEPING DAYTIME TEMPERATES IN THE TEENS FOR SUNDAY AND MONDAY.

TEMPERATURES ARE EXPECTED TO GRADUALLY WARM THROUGH THE WORK WEEK
WITH 30S POSSIBLE BY FRIDAY.  THERE WILL BE MORE CHANCES FOR SNOW
TUESDAY AND WEDNESDAY...AND AGAIN FRIDAY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 329 AM EST SAT MAR 1 2014

THE SNOW THIS MORNING NORTH OF I-96 WILL DRIFT SOUTH AND SLOWLY
DIMINISH.  THEN STEADIER SNOW ARRIVES TONIGHT.  WE MAY NEED AN
ADVISORY FOR THIS EVENT THAT WILL HIT AREAS SOUTH OF I-96 WITH THE
HEAVIEST SNOW.

A WEAK COLD FRONT WAS MAKING IT/S WAY THROUGH THE WESTERN CWA EARLY
THIS MORNING.  THE SNOW WITH IT HAS BEEN RATHER LIGHT AND SHOULD
CONTINUE TO BE SO.  THERE WAS SOME FGEN ASSOCIATED WITH THE FRONT...
SO A QUICK BURST OF SNOW IS POSSIBLE THIS MORNING...BUT FEEL MOST
ACCUMS TODAY WILL BE AN INCH OR LESS.  THE FRONT SLOWLY WEAKENS
AND THE SNOW WILL BECOME LIGHT AND SCATTERED BY LATE MORNING.

DEEPER MOISTURE RETURNS ALONG THE FRONT LATER TODAY AND INTO TONIGHT
AS A WAVE OF LOW PRESSURE FORMS ON THE FRONT OVER THE SOUTHERN
PLAINS.  THE ONSET OF THE INCREASED SNOW IS SOMEWHAT IN QUESTION IN
SW MI AS SOME OF THE MODELS SUGGEST SOME DRY AIR NEEDS TO BE
OVERCOME.  I COULD SEE THE SNOW BREAKING OUT OVER THE FAR SW CWA BY
LATE AFTERNOON...OR IT COULD BE CLOSER TO MIDNIGHT IF THIS DRY AIR
IS MAINTAINED.  FEEL THIS EVENT PROBABLY WILL NEED AN ADVISORY FOR
AREAS ALONG AND SOUTH OF I-96...BUT DUE TO TIMING UNCERTAINTIES WILL
ALLOW THE DAY SHIFT TO FURTHER ANALYSIS.  HOPEFULLY A CLEARER
PICTURE WILL BE REALIZED BY MID DAY TODAY WHEN WE WILL BE ABLE TO
DEFINE THE EVENT BETTER.  WITH THE HEAVILY TRAVELED I-94 CORRIDOR
POSSIBLY SEEING SOME OF THE HEAVIEST ACCUMS AROUND 4
INCHES...IMPACTS COULD BE FAIRLY SIGNIFICANT.

THE SNOW WILL GRADUALLY DIMINISH SUNDAY MORNING AS DRIER AIR ARRIVES
FROM THE NORTH.  THIS WILL PUSH THE STEADIEST SNOW INTO INDIANA AND
OHIO.  HOWEVER INVERSION HEIGHTS WILL BE AROUND 4-5K FT WHICH SHOULD
SUPPORT LIGHT LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT AND MONDAY.  THE
MEAN FLOW IS NNW...SO MOST OF THIS SNOW SHOULD HUG THE COAST.

ALONG WITH THE PUSH OF DRIER COMES MORE ARCTIC AIR TOO.  MAX TEMPS
ON BOTH SUN AND MON SHOULD BE STUCK IN THE TEENS.  FEEL WE WILL HOLD
ON TO A FAIR AMOUNT CLOUDS SUNDAY NIGHT...SO HAVE LOWS IN THE SINGLE
DIGITS ABOVE ZERO.  IF ANY PLACE CLEARS IT WOULD BE THE INTERIOR
NORTH...BIG RAPIDS TO CLARE...WHERE LOWS OF ZERO TO -10F CAN BE
EXPECTED.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 329 AM EST SAT MAR 1 2014

OVERALL THE FORECAST FOR THE LONG TERM LOOKS MAINLY DRY WITH A
GRADUAL MODERATING TREND TO THE SURFACE TEMPERATURES.

THE REASON IT WILL STAY MAINLY DRY IS BECAUSE THE MID LEVEL FLOW
WILL FEATURE PRIMARILY CONFLUENT FLOW.  THIS SUPPORTS SINKING MOTION
WHICH TENDS TO WEAKEN APPROACHING STORMS.  MODELS ARE IN FAIRLY GOOD
AGREEMENT ON THIS AND NO BIG TRENDS ARE NOTED WITH THE 00Z RUN
THROUGH THU.  THERE WILL BE AN UPPER LOW TRACKING SLOWLY EASTWARD
ALONG THE GULF STATES DURING THIS TIME.  FOR OUR AREA...THIS SYSTEM
WILL ACT TO PREVENT GULF WARMTH AND MOISTURE FROM REACHING MI DURING
THIS TIMEFRAME.  THIS IS PROBABLY A GOOD THING GIVEN THE SNOW WATER
EQUIVALENT VALUES SEEN IN OUR CURRENT SNOWPACK ALONG WITH THE AMOUNT
OF ICE IN THE RIVERS.

THE HIGHEST CHANCE FOR PRECIPITATION IS TUESDAY WHEN A WEAK SHORT
WAVE DROPS DOWN FROM THE NORTHWEST.  THE COMBINATION OF SOME MINOR
LIFT AND MOISTURE FROM LAKE MI COULD ALLOW FOR SCATTERED SNOW
SHOWERS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1234 PM EST SAT MAR 1 2014

MAIN CONCERN WITH THE 18Z FCSTS IS THE AREA OF SNOW EXPECTED TO
IMPACT THE AREA THIS EVENING INTO THE OVERNIGHT HOURS. A FEW
FLURRIES/LIGHT SNOW SHOWERS ARE SCATTERED ACROSS THE AREA EARLY
THIS AFTERNOON BEHIND THE DEPARTING FRONT. THESE ARE MAINLY FOUND
IN MVFR CIGS. THERE WAS A LITTLE FZDZ REPORTED NEAR KJXN WITH
IFR...HOWEVER WE EXPECT THAT TO MOVE OUT VERY QUICKLY IN THE NEXT
HOUR.

AFTER 21Z AND MORE TOWARD 23-00Z...WE WILL SEE A BIT MORE
WIDESPREAD SNOW DEVELOP ACROSS THE AREA. THIS SHOULD BREAK OUT
FAIRLY CLOSE IN TIME ACROSS THE ENTIRE AREA. IT WILL LAST MUCH
SHORTER ACROSS NRN AREAS TOWARD KMKG WITH LESS OF A RESTRICTION TO
CIGS AND VSBYS. IT WILL LAST LONGER DOWN SOUTH TOWARD THE I94
CORRIDOR...POTENTIALLY UNTIL 06Z-08Z. LIGHT SNOW MAY CONTINUE
UNTIL AROUND 12Z WHEN THE DEEPER MOISTURE MOVES OUT.

CONDITIONS SHOULD IMPROVE TO MVFR EVERYWHERE AFTER 12Z WITH A HIGH
LIKELIHOOD TO VFR WITH AN OFFSHORE FLOW DEVELOPING.

&&

.HYDROLOGY...
ISSUED AT 329 PM EST FRI FEB 28 2014

STABLE ICE DEVELOPMENT WILL CONTINUE DUE TO COLD WEATHER. THE ICE
JAM THREAT IS LOW AND THERE IS NO CURRENT INDICATIONS OF ANY ICE
JAMS ON THE RIVER NETWORK. RIVERS LEVELS ARE STEADY ACROSS THE AREA.

AT SOME STATIONS... THE SYSTEMS USED TO SENSE WATER STAGE ARE
SUSCEPTIBLE TO ERRONEOUS READINGS DURING PERIODS OF EXTREME COLD
TEMPERATURES.  STAGE HYDROGRAPHS DURING SUCH TIMES SHOW RAPID
FLUCTUATIONS IN WATER LEVELS AND SUBSEQUENT RAPID RETURN TO PREVIOUS
LEVELS WHEN SLIGHTLY WARMER TEMPERATURES RETURN.

&&

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

$$

SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MJS
AVIATION...NJJ
HYDROLOGY...63