Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 261722
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1222 PM EST MON JAN 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 325 AM EST MON JAN 26 2015

THE FIRST HALF OF THIS WEEK WILL REMAIN COLDER THAN NORMAL...BUT
LITTLE TO NO PRECIPITATION IS EXPECTED.  THERE WILL BE THE CHANCE
FOR LITTLE SNOW ALONG THE LAKESHORE TONIGHT...AND ANOTHER CHANCE
ACROSS CENTRAL LOWER MICHIGAN ON WEDNESDAY.  HOWEVER ANY
ACCUMULATIONS WILL BE MINIMAL.

THE SECOND HALF OF THE WEEK STILL LOOKS COLDER THAN NORMAL...WITH
HIGHS MAINLY IN THE 20S.  THERE APPEARS TO BE A GOOD CHANCE OF SNOW
BY WEDNESDAY NIGHT AND THURSDAY.  ANOTHER SYSTEM MAY GIVE US SNOW
AGAIN LATE IN THE WEEKEND.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EST MON JAN 26 2015

RELATIVELY QUIET THROUGH MUCH OF THE SHORT TERM WITH ONLY LOW
CHANCES FOR LIGHT SNOW TONIGHT AND AGAIN WEDNESDAY AFTERNOON.  IT
WILL REMAIN SLIGHTLY COLDER THAN NORMAL AS THE STORM ON THE EAST
COAST KEEPS NW FLOW ACROSS THE GREAT LAKES.

QUIET TODAY AS WE FIND OURSELVES IN BETWEEN SYSTEMS...WITH A BIG
EAST COAST STORM AND ANOTHER SYSTEM MOVING ACROSS THE UPPER
MIDWEST.  WE SHOULD BE ABLE TO SQUEEZE OUT A LITTLE SUNSHINE
EARLY...THEN MID/HI CLOUDS WILL INCREASE THROUGH THE AFTERNOON AHEAD
OF THE UPPER MIDWEST SYSTEM.  LOW TO MID 20S FOR HIGHS.

THE UPPER MIDWEST SYSTEM WEAKENS CONSIDERABLY TONIGHT AS IT CROSSES
WISCONSIN.  THE LOW LEVELS REMAIN QUITE DRY HERE AND ANY PCPN THAT
TRIES TO CROSS THE LAKE SHOULD GRADUALLY DIMINISH.  AREAS WEST OF
U.S. 131 MAY SEE A BRIEF PERIOD OF LIGHT SNOW THIS EVENING BEFORE
THE SYSTEM COMPLETELY WEAKENS LATE TONIGHT.  LITTLE TO NO
ACCUMULATION IS EXPECTED.

HIGH PRESSURE FILLS BACK IN ON TUESDAY.  THIS APPEARS TO BE OUR BEST
CHANCE OF SEEING A FAIR AMOUNT OF SUNSHINE.  TEMPS SHOULD BE A TOUCH
WARMER WITH THE SUN...MAINLY UPPER 20S.  HOWEVER TRIMMED MINS COLDER
TUESDAY NIGHT AS THE CENTER OF THE HIGH PRESSURE WILL STILL BE
NEARBY PRODUCING PARTLY CLOUDY SKIES AND LIGHT WINDS.

WEDNESDAY WILL SEE THICKENING CLOUDS AS WE GET ON THE BACKSIDE OF
THE HIGH AND WARM ADVECTION KICKS IN.  FAVORABLE ISENTROPIC LIFT
DEVELOPS LATER IN THE DAY AND ALTHOUGH MOISTURE IS A BIT LACKING...
WE COULD SEE SOME LIGHT SNOW DEVELOP INTO THE AFTERNOON/EVENING
ACROSS CENTRAL LOWER.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EST MON JAN 26 2015

FOCUS CONTINUES TO BE ON SOME LIGHT SNOW ACCUMULATIONS WEDNESDAY
NIGHT AND THURSDAY WITH A CLIPPER MOVING THROUGH...AS WELL AS A PUSH
OF ARCTIC AIR THAT MAY ARRIVE BY SUNDAY BUT DETAILS ARE SKETCHY.
SLICK TRAVEL IS ANTICIPATED FOR THE THURSDAY MORNING COMMUTE AND
LIKELY THE THURSDAY EVENING COMMUTE AS WELL ALTHOUGH SIGNIFICANT
SNOWFALL IS NOT IN THE FORECAST.

MODEL AGREEMENT GENERALLY HAS BEEN GOOD WITH THIS CLIPPER
CONSIDERING PART OF ITS ORIGIN WILL BE A CLOSED LOW ACROSS THE
SOUTHERN PACIFIC AT THIS TIME WHICH MERGES WITH A H500 SHORTWAVE
ACROSS WESTERN CANADA. THAT SAID...THE GFS HAS CONSISTENTLY BEEN A
BIT QUICKER WITH THIS SYSTEM (LIKE THE GEM) WHILE THE ECMWF IS A BIT
SLOWER WITH THE SHORTWAVE. THE MAIN CHALLENGE THEN IS DETERMINING
WHICH COMMUTE ON THURSDAY WILL HAVE WORSE CONDITIONS...THE MORNING
OR EVENING. RIGHT NOW IT APPEARS THE MORNING COMMUTE MAY BE
TRICKIER...WITH PERHAPS AN INCH OF SNOW OR SO HAVING FALLEN BY THAT
POINT WITH ANOTHER INCH OR TWO DURING THE DAY THURSDAY. LITTLE HAS
CHANGED WITH OUR STORM TOTAL SNOW FORECAST WITH THIS SYSTEM...WITH
ALL AREAS EXPECTED TO PICK UP 1-3 INCHES BY THURSDAY NIGHT.

I HAVE SEEN TOO MUCH MODEL RUN TO RUN INCONSISTENCY WITH REGARD TO
THE ARRIVAL OF ARCTIC AIR THIS WEEKEND AND EARLY NEXT WEEK TO BE
ABLE TO PINPOINT WHEN IT ARRIVES AND HOW LONG IT WILL LAST. THE
ECMWF HAS GONE FROM EXTREMELY COLD H850 TEMPS (-25C TO -30C) ACROSS
LOWER MICHIGAN LASTING FOR A FEW DAYS...TO ONE SOLID DAY OF REALLY
COLD WEATHER...AND THEN BACK AGAIN TO SEVERAL DAYS OF REALLY COLD
TEMPS. THE 00Z GFS DOES NOT BRING IN SUB -20C UNTIL 12Z TUESDAY. AND
THE DIFFERENCES ARE STARK ON 12Z MONDAY...WITH THE GFS SHOWING -8C
AT H850 FOR GRR WHILE THE ECMWF HAS -24C. AT THIS POINT WE ARE NOT
HANGING OUR HAT ON ANYTHING TOO TERRIBLY COLD. WILL CONTINUE TO
WATCH MODEL TRENDS TO SEE IF THEY LOCK ONTO A SOLUTION...AS THAT
WILL ALSO HAVE IMPLICATIONS ON SNOW CHANCES ALONG THE ARCTIC FRONT
AND POSSIBLE LAKE ENHANCEMENT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1222 PM EST MON JAN 26 2015

QUIET WEATHER WITH LITTLE IMPACTS TO AVIATION EXPECTED OVER THE
NEXT 24 HOURS. A SYSTEM DIVING SOUTH THROUGH WI IS PUSHING IN SOME
MID LEVEL CLOUD COVER OVER THE AREA. THESE MID LEVEL CLOUDS WILL
BE BASED AROUND 7-10K FEET WITH THE LOWEST CONDITIONS EXPECTED
FURTHER WEST. ONCE THE CLOUDS MOVE IN...THEY SHOULD REMAIN IN
PLACE UNTIL ABOUT THE END OF THE FCST PERIOD. WE EXPECT THE LOW
LEVELS WILL REMAIN DRY ENOUGH WITH A E/NE LOW LEVEL FLOW THAT
PCPN IS NOT EXPECTED OVER THE AREA.

&&

.HYDROLOGY...
ISSUED AT 328 PM EST SUN JAN 25 2015

MOST RIVERS ARE HOLDING STEADY OR DROPPING. COLD TEMPERATURES
FOR THE COMING WEEK WILL KEEP THE ICE LOCKED UP. CURRENTLY NO
SUSPECTED ICE JAMS IN THE AREA... BUT WILL CONTINUE MONITORING FOR
ANY THAT DO DEVELOP. SERIOUS ICE JAMS AND FLOODING CONCERNS ARE
UNLIKELY UNTIL A SIGNIFICANT WARM UP AND RAINFALL.

&&

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

$$

SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...HOVING
AVIATION...NJJ
HYDROLOGY...CAS






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