Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 260827
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EST WED NOV 26 2014

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

.SYNOPSIS...
ISSUED AT 330 AM EST WED NOV 26 2014

FAIR WEATHER IS ANTICIPATED TODAY BEFORE AN UPPER LEVEL SYSTEM
MOVES IN FROM THE NORTHWEST AND BRINGS A LITTLE LIGHT SNOW VERY
LATE TONIGHT THROUGH THURSDAY AFTERNOON. SNOW ACCUMULATIONS NEAR
TO EAST OF US-131 THURSDAY WILL BE QUITE LIGHT BUT LOCATIONS
CLOSER TO THE LAKE MICHIGAN SHORELINE WILL SEE ONE TO AS MUCH AS
THREE INCHES OF SNOW FROM THIS SYSTEM. HIGH PRESSURE WILL BRING
DRY WEATHER THURSDAY NIGHT BUT ANOTHER SYSTEM WILL BRING POTENTIAL
FOR A LITTLE MORE LIGHT SNOW FOR FRIDAY.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EST WED NOV 26 2014

DRY WX WILL CONTINUE TODAY AND IT WILL REMAIN SEASONABLY COLD WITH
MAX TEMPS STRUGGLING TO REACH THE LOWER TO PERHAPS MIDDLE 30S. DRY
WX WILL CONTINUE THIS EVENING BEFORE THE UPPER LEVEL SYSTEM
APPROACHING FROM THE NW BRINGS LIGHT SNOW BEGINNING VERY LATE
TONIGHT THROUGH THURSDAY AFTERNOON.

VERY LIGHT SNOW ACCUMULATIONS OF ONLY AROUND AN INCH OR LESS ARE
ANTICIPATED WITH THIS SYSTEM NEAR TO EAST OF US-131. LIGHT SNOW
ACCUMULATIONS OF 1 TO 3 INCHES ARE ANTICIPATED MAINLY WEST OF
US-131 IN AN AREA OF DEEPER LOW TO MID LEVEL MOISTURE AND 1000-850
MB CONVERGENCE. HIGHER END SNOW ACCUMULATIONS WITHIN THAT 1 TO 3
INCH RANGE THURSDAY ARE MOST PROBABLE NEAR TO NW OF A LINE FROM
KMKG TO KRQB... THOUGH MOST AMOUNTS SHOULD END UP IN THE 1-2 RATHER
THAN 1-3 INCH RANGE EVEN NEAR THE LAKE MI SHORELINE.

HIGH PRESSURE WILL BRING FAIR WEATHER WITH PARTLY CLOUDY SKIES
THURSDAY EVENING. HOWEVER THE NEXT SYSTEM WILL QUICKLY MOVE IN FOR
FRIDAY AND BRING SOME MORE LIGHT SNOW. SOME LARGE SHORT RANGE
GUIDANCE DISCREPANCIES ARISE FOR FRIDAY WITH THE 00Z NAM SHOWING
VIRTUALLY ALL ACCUMULATING SNOW WOULD STAY NORTH OF OUR FCST AREA.
HOWEVER THE 00Z GFS SUGGESTS ONE TO TWO INCHES OF SNOW COULD FALL
ACROSS MOST OF OUR AREA.

THE 00Z ECMWF SUGGESTS POTENTIAL FOR AROUND AN INCH OR LESS OF
SNOW FRIDAY. THEREFORE WE WILL STAY CLOSE TO OUR PREVIOUS FORECAST
FOR FRIDAY THAT IS ALSO IN LINE WITH THE 00Z ECMWF WHICH FEATURES
LIGHT SNOW WITH ACCUMULATIONS OF AROUND AN INCH OR LESS. THIS WILL
BE FINE TUNED ACCORDINGLY AS GUIDANCE COMES INTO BETTER AGREEMENT.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EST WED NOV 26 2014

ZONAL FLOW REGIME WILL DOMINATE THE EXTENDED PERIOD WITH A FEW FAST
MOVING RIPPLES IN THE FLOW BRINGING GENERALLY LIGHT PRECIPITATION
ALONG WITH SOME GENERALLY LIGHT LAKE EFFECT SNOW SHOWERS AT TIMES.
TEMPERATURES WILL VARY FROM ABOVE NORMAL SATURDAY AND SUNDAY TO
BELOW NORMAL MONDAY...THEN NEAR NORMAL AFTER THAT.

A BURST OF LIGHT WARM ADVECTION SNOW IS EXPECTED FRIDAY NIGHT WHICH
SHOULD EITHER END OR CHANGEOVER TO LIGHT RAIN BY SATURDAY. A SFC LOW
TRACKS WELL NORTH OF LOWER MICHIGAN SATURDAY AND SUNDAY AND THERE
DOES NOT APPEAR TO BE ANY REAL FORCING MECHANISM FOR PRECIPITATION.
MOISTURE IS RATHER SHALLOW...SO SLIGHT CHANCE POPS OR NO POPS SEEMS
THE WAY TO GO. SINCE SLIGHT CHANCE POPS WERE ALREADY IN THE FORECAST
THEY WERE LEFT THERE. PRECIP TYPE WOULD BE LIQUID FOR ALL BUT THE
NORTHERN ZONES WHERE A MIX IS POSSIBLE SUNDAY.

A COLD FRONT MOVES THROUGH SUNDAY NIGHT AND MAY BE ABLE TO FOCUS
SOME LIGHT SNOW OR MIXED PRECIPITATION. ANY PRECIP SHOULD ONCE AGAIN
BE LIGHT WITH MOISTURE REMAINING SHALLOW. SOME LIGHT LAKE EFFECT
SNOW IS POSSIBLE MONDAY AS AN ARCTIC HIGH BEGINS TO BUILD IN. SNOW
SHOWERS SHOULD END BY TUESDAY AS SUBSIDENCE AND SFC RIDGING ARE OVER
LOWER MICHIGAN.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1143 PM EST TUE NOV 25 2014

CONDITIONS WILL NOT REALLY CHANGE FOR THIS TAF PERIOD...AS WE ARE
EXPECTING VFR TO PERSIST. SOME LIGHT SNOW WILL BE MOVING IN TOWARD
MKG AROUND OR SHORTLY AFTER 06Z THURSDAY...SO TRENDED CIGS DOWN AS
THAT OCCURS. COULD SEE IFR CIGS AND/OR VISIBILITIES DEVELOP AT MKG
AND GRR BY 12Z THURSDAY...JUST BEYOND THIS FORECAST PERIOD.


&&

.MARINE...
ISSUED AT 330 AM EST WED NOV 26 2014

RATHER MINIMAL WIND AND WAVE ACTION IS ANTICIPATED TODAY THROUGH
TONIGHT. HOWEVER WINDS WILL BECOME NNW AND INCREASE THURSDAY
LEADING TO INCREASING WAVE HEIGHTS THAT WILL BECOME HAZARDOUS TO
SMALL CRAFT BY LATE THURSDAY MORNING WHEN AN SCA WILL LIKELY
BE NEEDED.

&&

.HYDROLOGY...
ISSUED AT 330 AM EST WED NOV 26 2014

SEVERAL RIVER FLOOD ADVISORIES CONTINUE IN EFFECT. MANY LOCATIONS
HAVE REACHED THEIR PEAK BUT SOME RIVER LEVELS WILL NOT CREST UNTIL
TONIGHT. ANY PCPN TONIGHT THROUGH LATE IN THE WEEK WOULD BE IN THE
FORM OF SNOW AND QUITE LIGHT. THIS WILL HAVE LITTLE TO NO AFFECT ON
AREA RIVER LEVELS.

&&

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

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...HOVING
HYDROLOGY...LAURENS
MARINE...LAURENS








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