Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 231146
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
746 AM EDT THU APR 23 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT THU APR 23 2015

AFTER A FEW LIGHT SNOW SHOWERS/FLURRIES THIS MORNING...THE AREA WILL
SEE CONDITIONS DRY OUT FOR THE REST OF THE WORK WEEK. TEMPERATURES
WILL REMAIN QUITE A BIT BELOW AVERAGE TODAY WITH HIGHS ONLY IN THE
40S. TEMPERATURES WILL THEN MODERATE A BIT BEGINNING ON FRIDAY. WE
ARE LOOKING AT ANOTHER ROUND OF FREEZING TEMPERATURES FOR TONIGHT
ACROSS THE AREA.

A SYSTEM WILL TRY TO MOVE IN ACROSS THE AREA DURING THE DAY ON
SATURDAY. IT LOOKS LIKE THAT ONLY LOCATIONS ALONG I-94 WILL SEE SOME
LIGHT RAIN...WHILE A CHANCE WILL BE POSSIBLE UP TO ALMOST I-96.
CONDITIONS WILL THEN DRY OUT ONCE AGAIN FOR THE SECOND HALF OF THE
WEEKEND AND EARLY NEXT WEEK ALONG WITH SOMEWHAT MILDER TEMPERATURES.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT THU APR 23 2015

OUR MAIN CHALLENGES IN THE SHORT TERM REVOLVE AROUND FROST/FREEZE
HEADLINES FOR TONIGHT...AND RAIN CHANCES FOR SATURDAY.

SNOW SHOWERS THAT HAD PERKED UP A BIT LATE LAST EVENING ACROSS THE
AREA HAVE SINCE DIMINISHED IN COVERAGE AND INTENSITY OVER THE PAST
COUPLE OF HOURS. WE EXPECT THAT TREND TO CONTINUE THIS MORNING AS
THE SHORT WAVE RESPONSIBLE IS NOW MOVING OFF TO OUR S AND E. WE WILL
RETAIN A LOW CHC OF SNOW SHOWERS/FLURRIES IN THE FCST THIS MORNING
AS THE SHEAR ZONE WITH THE UPPER JET CORE WILL BE COMING THROUGH.
SOME MOISTURE IN THE DGZ WILL HOLD ON UNTIL ABOUT 18Z...KEEPING THE
CHC OF FLURRIES IN THROUGH THEN.

WE THEN EXPECT A BREAK IN THE WEATHER FROM LATER THIS AFTERNOON
THROUGH MOST OF FRI NIGHT. THE UPPER FLOW WILL TRANSITION TO BECOME
ANTI-CYCLONIC AND THE SFC RIDGE WILL MOVE ACROSS THE STATE. THIS
QUIET WEATHER...CLEAR SKIES...AND LIGHT WINDS WILL ALLOW FOR TEMPS
ACROSS THE ENTIRE AREA TO DROP DOWN BELOW FREEZING TONIGHT. WE ARE
LOOKING AT ANOTHER FREEZE WARNING FOR TONIGHT FOR THE COUNTIES THAT
HAVE OFFICIALLY STARTED THEIR GROWING SEASON. THIS COULD BE SOMEWHAT
OF A HARD FREEZE AS TEMPS ARE FCST TO DROP DOWN INTO THE UPPER 20S.

CLOUDS WILL BE ON THE INCREASE FROM LATE FRI THROUGH FRI NIGHT
ACROSS THE AREA...WITH THE CHC OF RAIN INCREASING ACROSS THE SRN
PORTION OF THE AREA TOWARD DAYBREAK ON SAT AND DURING THE DAY. THERE
IS AN UPPER TROUGH THAT WILL EMERGE FROM THE DESERT SW AND TRY TO
MOVE NE TOWARD THE AREA. THERE ARE SOME DIFFERENT SCENARIOS IN HOW
FAR NORTH THE RAIN GETS.

WE ARE THINKING THAT THE MODEL WITH A FARTHER NORTH SOLUTION WITH
THE RAIN IS HAVING ISSUES WITH SHORT WAVE ENERGY. WE BELIEVE THAT
THE RAIN WILL TRY TO SNEAK ACROSS I-94. HOWEVER A DRY NE FLOW IN THE
LOWER LEVELS AND AN UPPER TROUGH DRIVING SOUTH OUT OF CANADA WILL
LIKELY SUPPRESS MOST OF THE RAIN SOUTH OF THE CWFA...WITH SOME LIGHT
RAIN LIKELY ALONG I-94. IT IS POSSIBLE NRN AREAS WILL KEEP A DECENT
AMOUNT OF SUNSHINE ON SAT. TEMPS WILL LIKELY BE A LITTLE WARMER
FURTHER NORTH WITH THE SUNSHINE.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT THU APR 23 2015

UPPER LOW IN THE SHORT TERM OVER THE GREAT LAKES...LINGERS OVER THE
NORTHEAST PORTION OF THE CONUS INTO MUCH OF THE LONG TERM. BY THE
END OF THE PERIOD...WEDNESDAY...THE UPPER PATTERN IS TRANSITIONING
TO MORE OF A ZONAL FLOW ACROSS THE CONUS. HAVE LEANED TOWARD THE
ECMWF WITH THIS FORECAST PACKAGE. IN GENERAL...EXPECTING MAINLY DRY
CONDITIONS AND SLOWLY MODERATING TEMPERATURES.

IN REGARD TO PRECIPITATION...HAVE A LITTLE BIT OF LIGHT RAIN
LINGERING INTO SATURDAY EVENING ACROSS THE I-94 ROW OF COUNTIES.
ONLY HAVE A 30 POP IN THE FORECAST SATURDAY EVENING AND ITS
DEBATABLE IF WE WILL SEE ANYTHING.

OTHERWISE...HAVE A DRY FORECAST SUNDAY THROUGH WEDNESDAY AS THERE IS
LITTLE IN THE WAY OF SIGNIFICANT FEATURES. SURFACE PATTERN IS ONE OF
MAINLY HIGH PRESSURE. ALOFT...SUNDAY INTO MONDAY A CASE COULD BE
MADE FOR SOME LIGHT SHOWERS ON THE BACK EDGE OF THE UPPER LOW
CIRCULATION...BUT DID NOT FEEL CONFIDENT ENOUGH TO CARRY POPS AT
THIS POINT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 746 AM EDT THU APR 23 2015

VFR WEATHER IS EXPECTED FOR THE MOST PART THE NEXT 24 HOURS. THE
EXCEPTION WILL BE BRIEF PERIODS OF MVFR CEILINGS THROUGH ABOUT 15Z
THIS MORNING. A FEW OB SITES HAVE MVFR CEILINGS AT 12Z...BUT THINK
THEY WILL REMAIN SPORADIC AND COME TO AN END THROUGH THE COURSE OF
THE MORNING. OTHERWISE VFR CEILINGS OF 4000-6000FT WILL REMAIN IN
PLACE A GOOD DEAL OF THE DAY. SKIES SHOULD CLEAR TONIGHT.

WINDS WILL BE GUSTY FROM THE NORTHWEST TODAY IN THE 10-20 KNOT
RANGE WITH A FEW HIGHEST GUSTS AT TIMES.


&&

.MARINE...
ISSUED AT 330 AM EDT THU APR 23 2015

CONDITIONS OUT ON THE NEARSHORE WATERS WILL BE A BIT BETTER THAN
THEY HAVE BEEN THE PAST FEW DAYS. WE ARE NOT EXPECTING TO NEED ANY
HEADLINES UNTIL POTENTIALLY ON SATURDAY. WINDS WILL REMAIN IN THE 10
TO 20 KNOT RANGE TODAY WITH A POSSIBLE GUST OR TWO AROUND SCA
CRITERIA LATER THIS AFTERNOON. THIS SHOULD NOT BE SIGNIFICANT ENOUGH
TO NEED A HEADLINE.


&&

.HYDROLOGY...
ISSUED AT 1245 PM EDT WED APR 22 2015

AS MUCH AS 0.20 TO 0.30 INCHES OF PRECIP FELL ACROSS CENTRAL LOWER
MICHIGAN IN A 24-HOUR PERIOD THROUGH 8 AM THIS MORNING...IN THE
FORM OF BOTH RAIN AND SNOW AT TIMES. A SIGNIFICANT RESPONSE IN
RIVER LEVELS IS CERTAINLY NOT EXPECTED...BUT GRADUAL RISES ARE
ONGOING ON THE PERE MARQUETTE AT SCOTTVILLE. THE WHITE RIVER AT
WHITEHALL IS CURRENTLY ENTERING A CREST.

GOING FORWARD...HYDRO IMPACTS WILL BE MINIMAL. THERE WILL BE A
MUCH LOWER CHANCE FOR ANY PRECIP ON THURSDAY DUE TO LIMITED
MOISTURE. RIDGING BUILDS IN...ALLOWING FOR DRY WEATHER ON FRIDAY.
THERE IS A SLIGHT CHANCE FOR A MIX OF RAIN AND SNOW ACROSS FAR
SOUTHERN LOWER MICHIGAN FRIDAY NIGHT INTO SATURDAY.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR MIZ050-056>058-
     064>066-071>073.

LM...NONE.
&&

$$

SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...EBW
MARINE...NJJ






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