Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 251955
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
255 PM EST TUE NOV 25 2014

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 323 AM EST TUE NOV 25 2014

COOLER AIR WILL CONTINUE TO SETTLE IN ACROSS THE AREA THROUGH MOST
OF THE REST OF THE WEEK. SOME RESIDUAL SNOW WILL CONTINUE THIS
MORNING...BEFORE IT WILL DIMINISH IN INTENSITY THIS AFTERNOON AND
THIS EVENING. THERE WILL BE A FEW MORE CHANCES OF LIGHT SNOW THIS
WEEK...ESPECIALLY WED NIGHT/THURSDAY...AND AGAIN ON FRIDAY.

&&

.UPDATE...
ISSUED AT 1055 AM EST TUE NOV 25 2014

WILL BE CAN CELLING THE WINTER WEATHER ADVISORY SHORTLY. AREA OF
ENHANCED SNOWFALL CROSSING THE GRAND RAPIDS VICINITY AT THIS TIME
HAS PRODUCED VISIBILITIES JUST UNDER A MILE AND LIGHT ADDITIONAL
ACCUMULATIONS. WATER VAPOR SATELLITE IMAGES SHOW AN UPPER
POTENTIAL VORTICITY MAXIMUM MOVING EAST ACROSS SOUTHERN LAKE
MICHIGAN. THIS FEATURE WILL USHER THE ENHANCED SNOW AREA OUT OF
THE REGION BY EARLY AFTERNOON WITH ONLY LIGHT SNOW SHOWERS
EXPECTED AFTERWARDS. TRAVEL CONDITIONS SHOULD CONTINUE TO IMPROVE
WITH AIR TEMPERATURES CLIMBING TO NEAR FREEZING. ROAD SENSORS AT
LUDINGTON/REED CITY ALREADY INDICATE SURFACE TEMPERATURES JUST
BELOW FREEZING AND CLIMBING.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 323 AM EST TUE NOV 25 2014

THE MAIN FOCUS OF THE SHORT TERM PORTION OF THE FCST IS DETERMINING
THE FATE OF THE EXISTING HEADLINES THIS MORNING. WE WILL BE SHAVING
OFF THE EASTERN PORTION OF THE ADVISORY WHERE SNOW HAS BEEN LIGHT TO
ALMOST NON-EXISTENT OVERNIGHT. ELSEWHERE...WE WILL BE HOLDING ON TO
THE ADVISORY FOR THIS MORNING. THIS WILL BE MORE FOR THE SNOW
IMPACTING THE MORNING COMMUTE VS. AMOUNTS.

LATEST RADAR TRENDS HAVE NOT BEEN IMPRESSIVE WITH THE SNOW THIS
MORNING. IT APPEARS THAT THE DEFORMATION COMPONENT OF THE SNOW IS
DIMINISHING FOR OUR AREA THIS MORNING. WHAT IS LEFT IS A LITTLE
SYNOPTIC FORCING AND LIMITED LAKE EFFECT. WE DO EXPECT ANOTHER
LIMITED BURST OF SNOW THIS MORNING TOWARD 12Z AND THEN DIMINISHING
TOWARD NOON. THIS BURST WILL BE THE RESULT OF ONE MORE SHORT WAVE
ACROSS CENTRAL WI MOVING IN...ALONG WITH A SFC TROUGH THAT WILL BE
SINKING SOUTH TO ABOUT I-96 BEFORE DIMINISHING.

WE CONSIDERED CAN CELLING THE ENTIRE ADVISORY THIS MORNING. HOWEVER
WE DECIDED TO KEEP IT WHERE THERE IS ENOUGH SNOW FALLING SINCE IT
WILL IMPACT THE MORNING COMMUTE ALONG WITH ICY ROADS IN ADDITION TO
THE EXPECTED BRIEF BURST OF SNOW IN THE VICINITY OF RUSH HOUR. IT
LOOKS LIKE IT SHOULD BE ABLE TO BE CANCELLED THIS MORNING ONCE THE
EXPECTED BURST OF SNOW PASSES THROUGH.

WE EXPECT THAT WE WILL TREND TOWARD A DRY FCST BY WED. WE WILL SEE
RIDGING BUILD IN BY WED...AND THE NEXT UPPER SHORT WAVE WILL PASS SW
OF THE AREA. THE MEAN LOW LEVEL FLOW ACTUALLY BECOMES MORE SERLY AS
A SFC LOW MOVES BY TO OUR SW. WE BELIEVE THAT THERE IS A POTENTIAL
FOR SOME CLEARING DURING THE DAY ON WED BEFORE HIGH CLOUDS
EVENTUALLY MOVE BACK IN LATE IN THE DAY AHEAD OF THE NEXT STRONGER
SHORT WAVE POISED TO MOVE THROUGH THE AREA.

LAKE EFFECT WILL BEGIN TO REDEVELOP ON WED NIGHT ACROSS THE NW
SECTION OF THE CWFA AS THE SFC LOW TO OUR SW MOVES AWAY AND THE FLOW
AHEAD OF THE NEXT SYSTEM BECOMES SWRLY. INVERSION HEIGHTS WILL
INITIALLY BE LIMITED...HOWEVER THEY WILL RISE ON THANKSGIVING DAY AS
THE SHORT WAVE PASSES ACROSS THE AREA. THE FLOW WILL BE MAINLY NW ON
THANKSGIVING WITH A BRIEF PERIOD OF WNW FLOW. THIS WILL BRING SOME
RELATIVELY LIGHT ACCUMULATIONS OF SNOW LIKE 1 TO 3 OR 2 TO 4 INCHES
FOR THE FAVORED NW FLOW AREAS. INLAND AREAS COULD SEE A DUSTING OF
SNOW AS THE TROUGH PASSES THROUGH...BUT NO SIGNIFICANT SNOW
ACCUMULATION IS EXPECTED.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 323 AM EST TUE NOV 25 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 LAKE EFFECT SNOW SHOWERS AT TIMES. TEMPERATURES WILL
VARY FROM BELOW NORMAL AT THE START TO NEAR TO ABOVE NORMAL SATURDAY
AND SUNDAY THEN COOLING BACK DOWN AGAIN BY MONDAY.

LAKE EFFECT SNOW SHOWERS SHOULD BE ENDING THURSDAY NIGHT AS WARM
ADVECTION BEGINS. A BURST OF LIGHT WARM ADVECTION SNOW IS POSSIBLE
FRIDAY AND FRIDAY NIGHT. A SFC LOW TRACKS WELL NORTH OF LOWER
MICHIGAN OVER THE WEEKEND. THERE DOES NOT APPEAR TO BE ANY REAL
FORCING MECHANISM FOR PRECIPITATION...SO I WENT WITH A DRY FORECAST
SATURDAY THROUGH SUNDAY.

A COLD FRONT MOVES THROUGH SUNDAY NIGHT AND MAY BE ABLE TO FOCUS
SOME LIGHT SNOW OR MIXED PRECIPITATION. ANY PRECIP SHOULD BE LIGHT
AS FORECAST SOUNDINGS SHOW MOISTURE IS RATHER SHALLOW. THE FRONT
STALLS ACROSS THE OHIO VALLEY BUT IT SHOULD BE FAR ENOUGH SOUTH THAT
PRECIP IS CLEAR OF THE SOUTHERN ZONES. ALTHOUGH IT IS COLD ENOUGH
FOR LAKE EFFECT SNOW...LOW LEVEL FLOW IS NORTHEAST AND INVERSION
HEIGHTS ARE PROGGED TO BE BLO 5 KFT...SO WENT WITH A DRY FORECAST
FOR MONDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1243 PM EST TUE NOV 25 2014

RADAR SHOWS SHSN ACTIVITY DECREASING IN AREAL COVERAGE AND
INTENSITY. FLURRIES WILL CONTINUE THROUGH AT LEAST THE EVENING AT
KMKG/KGRR. OTHER LOCATIONS WILL SEE PCPN END SOONER. CIGS WILL
LIKELY REMAIN IN THE 1500-2500 FT RANGE UNTIL LATE TONIGHT BEFORE
RISING ABOVE 3K FT.


&&

.MARINE...
ISSUED AT 323 AM EST TUE NOV 25 2014

PER COLLABORATION WITH SURROUNDING MARINE OFFICES...WE WILL BE
CAN CELLING THE GALE WARNING A LITTLE EARLY THIS MORNING. IT WILL BE
REPLACED WITH A SMALL CRAFT ADVISORY THAT WILL RUN UNTIL 04Z THIS
EVENING. LATEST OBS ALONG THE COAST ALL HAVE DROPPED BELOW GALE
CRITERIA. WINDS WILL CONTINUE TO SLOWLY DECREASE THROUGH
TODAY...WITH WAVES LAGGING THE DROP IN WIND BY A FEW HOURS.

THE NEXT PERIOD OF CONCERN FOR MARINE WILL BE THE DAY ON THU. A
BRIEF PERIOD OF ADVISORY TYPE WINDS WILL BE POSSIBLE WITH THE
PASSAGE OF A FRONTAL SYSTEM THAT DAY.


&&

.HYDROLOGY...
ISSUED AT 255 PM EST TUE NOV 25 2014

SEVERAL LOCATIONS ON AREA RIVERS REMAIN AT OR ABOVE ADVISORY
CRITERIA. MANY LOCATION HAVE REACHED THEIR PEAK AND ARE BEGINNING
THEIR DECLINE...WHILE A FEW OTHERS WILL SEE CRESTS OVER THE NEXT
48 HOURS OR SO. THERE ARE A FEW CHANCES AT PRECIPITATION THROUGH
THE WEEK BUT IT MOSTLY LOOKS TO BE IN THE FORM OF SNOW AND MAINLY
IN THE LIGHTER VARIETY. PRECIPITATION IS ALSO SPREAD OUT OVER
THE COURSE OF SEVERAL DAYS. THIS IS ANTICIPATED TO HAVE
LITTLE...IF ANY...AFFECT ON AREA RIVERS. WE SHOULD SEE IMPROVING
CONDITIONS AS WE GET LATER INTO THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LMZ844>849.

&&

$$

UPDATE...TJT
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...93
HYDROLOGY...JAM
MARINE...NJJ






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