Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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690
FXUS63 KGRR 131621
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1121 AM EST SAT FEB 13 2016

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 324 AM EST SAT FEB 13 2016

HIGH PRESSURE WILL MOVE OVER THE GREAT LAKES TODAY AND PROVIDE SOME
SUNSHINE AWAY FROM THE LAKE. LAKE EFFECT SNOW WILL CONTINUE WEST OF
US-131 WHERE A FEW MORE INCHES OF SNOW WILL ACCUMULATE. A COLD DAY
IS EXPECTED WITH HIGHS IN THE TEENS. TONIGHT WILL BE VERY COLD WITH
MANY LOCATIONS BELOW 0. LIGHT SNOW WILL MOVE IN LATE SUNDAY AND
SUNDAY NIGHT AS A CLIPPER MOVES ACROSS ILLINOIS/INDIANA. WARMER
WEATHER WILL RETURN EARLY NEXT WEEK WITH HIGHS IN THE MID 30S.

&&

.UPDATE...
ISSUED AT 1121 AM EST SAT FEB 13 2016

I WILL LET OUR HEADLINES RIDE UNTIL I ISSUE THE NEW FORECAST
AROUND 330 PM THIS AFTERNOON. THE LATEST SURFACE OBSERVATIONS AND
RADAR TRENDS SUPPORT THIS IDEA.

WHILE IT IS TRUE INVERSION HEIGHTS HAVE DECREASED FROM OVER 8000
FT EARLY THIS MORNING TO AROUND 6OOO FT NOW AND ARE EXPECTED TO
DECREASE TO 5000 FT THIS AFTERNOON THERE IS STILL DECENT LIFT IN
THE DGZ AND RADAR SHOWS DOMINANT  BANDING ECHOES CONTINUING OVER
OTTAWA...ALLEGAN AND VAN BUREN COUNTIES LATE THIS MORNING. THE
MODELS (HRRR...RAP AND NAM12) ALL SHOW THE BEST LIFT AND MOISTURE
OVER THE WARNING COUNTIES THROUGH THE AFTERNOON. SO I WOULD EXPECT
WHAT IS HAPPENING NOW TO CONTINUE INTO LATE THIS AFTERNOON. DUE TO
DAY TIME HEATING CONVECTION WILL CONTINUE TO DEVELOP AND THAT MAY
WEAKEN THE SNOW SHOWERS SOME AS WELL AS SPREAD THEM INLAND ACROSS
THE CWA BUT INLAND OF US-131 THEY WILL REMAIN WEAKER THAN THOSE
NEAR THE LAKE SHORE. WE HAVE HAD REPORTS FROM COUNTY ROAD
DEPARTMENTS AND DISPATCH OPERATORS THAT THERE CONTINUE TO BE
SIGNIFICANT TRAVEL ISSUES ON THE ROADS WHERE THE SNOW SHOWERS ARE
OCCURRING. SO FOR ALL THESE REASONS I WILL HOLD OUR CURRENT
COURSE  WITH THE HEADLINES.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 324 AM EST SAT FEB 13 2016

FORECAST CONCERNS DEAL WITH ONGOING LAKE EFFECT AND THE NEXT CLIPPER
MOVING THROUGH SUNDAY AND SUNDAY NIGHT.

LATEST RADAR TRENDS SHOW AREAS WEST OF US-131 RECEIVING MODERATE
SNOW. VISIBILITIES AT HART/HOLLAND/BENTON HARBOR ARE UNDER 2SM -SHSN.
DESPITE LOW INVERSION HEIGHTS...INSTABILITY IS VERY HIGH OVER THE
LAKE AND SNOW SHSN WILL CONTINUE TODAY ACROSS THE WESTERN CWA. NOT
MUCH SNOW IS OCCURRING IN KALAMAZOO AND LAKE COUNTIES AND SO WE
ENDED THE ADVISORY THERE. IT/S POSSIBLE THAT SOME LIGHT SHOW MAY
REDEVELOP AS WINDS BACK A COUPLE OF DEGREES...BUT IMPACTS SHOULD BE
MINIMAL. WE KEPT THE HEADLINES AS IS WITH A WINTER WX ADVISORY ALONG
THE LAKE SHORE EXCEPT FOR THE WINTER STORM WARNING COUNTIES OF
ALLEGAN AND VAN BUREN WHERE ANOTHER 1-4 INCHES MAY FALL TODAY.

DON`T REALLY THINK THE SNOW WILL END AT THE LAKE SHORE BEFORE THE
NEXT CLIPPER ARRIVES LATE SUNDAY. THERE HAS BEEN A SOUTHWARD TREND
IN THE TRACK OF THE LOW BUT WE/LL STILL RECEIVE SOME LIGHT SNOW
SUNDAY AFTERNOON INTO MONDAY. . ACCUMULATIONS OF AN INCH OR TWO
LOOKS POSSIBLE.

TODAY WILL BE VERY COLD WITH HIGHS ONLY REACHING THE MID TEENS. THEN
TEMPS WILL PLUMMET BELOW 0 TONIGHT IN MANY LOCATIONS AWAY FROM THE
LAKE SHORE. WIND CHILLS WON/T GET OUT OF HAND THOUGH DUE TO
DIMINISHING WINDS.


.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM EST SAT FEB 13 2016

AFTER A BRIEF REPRIEVE FROM THE BITTER COLD AIR EARLY NEXT WEEK
ANOTHER ARCTIC FRONT SLIPS SOUTH THROUGH THE AREA ON TUESDAY NIGHT.
WE SHOULD SEE A FEW SNOW SHOWERS WITH THE FRONTAL PASSAGE HOWEVER
NOT MUCH LAKE EFFECT SNOW IS EXPECTED BEHIND THE FRONT ON WEDNESDAY
SINCE SURFACE RIDGING AND SUBSIDENCE IS QUICK TO MOVE IN.

THE MID WEEK BOUT OF COLD AIR DOES NOT STICK AROUND FOR VERY LONG AS
THE NRN BRANCH OF THE JET RETREATS AND AN APPROACHING PACIFIC SYSTEM
INDUCES A STRONG WARM ADVECTION PATTERN THURSDAY AND FRIDAY.
CURRENTLY IT LOOKS LIKE THIS SYSTEM WILL BRING RAIN SHOWERS AND MILD
TEMPS IN THE 40S NEXT FRIDAY... BUT A BRIEF PERIOD OF MIXED
PRECIPITATION INCLUDING FREEZING RAIN IS POSSIBLE THURSDAY NIGHT AND
EARLY FRIDAY MORNING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1105 AM EST SAT FEB 13 2016

MAINLY MVFR TO VFR CONDITIONS WILL CONTINUE AT MOST OF THE
TERMINALS THIS AFTERNOON WITH NOTHING MORE THAN A FEW FLURRIES.
THE EXCEPTION TO THIS IS AT KMKG AND KAZO WHERE CONDITIONS WILL
REMAIN MAINLY IFR THROUGH MID AFTERNOON DUE TO LAKE EFFECT SNOW
SHOWERS. NW WINDS WILL CONTINUE TO GUST TO AROUND 20 TO 25 KTS
THIS AFTERNOON BEFORE SUBSIDING QUICKLY EARLY THIS EVENING.

CONDITIONS WILL IMPROVE TO VFR AT ALL THE TERMINALS THIS EVENING
AND OVERNIGHT AS SKIES BECOME MOSTLY CLEAR. CONDITIONS WILL THEN
REMAIN VFR THRU 18Z SUN. SE WINDS WILL INCREASE TO AROUND 10 KTS
BY MID TO LATE SUNDAY MORNING.


&&

.MARINE...
ISSUED AT 324 AM EST SAT FEB 13 2016

BASED ON COASTAL OBS...WE DISCONTINUED THE GALE WARNING AND ISSUED A
SMALL CRAFT ADVISORY WHICH IS IN EFFECT THROUGH THIS EVENING.


&&

.HYDROLOGY...
ISSUED AT 301 PM EST FRI FEB 12 2016

RIVER GAUGES THROUGH SOUTHWEST LOWER MICHIGAN CONTINUE TO SHOW SIGNS
OF BEING AFFECTED BY ICE BUILD UP. IT IS ALSO EVIDENT THAT THE GRAND
RIVER AT ROBINSON TWP HAS A BIT MORE ICE FLOWING DOWNSTREAM THAN WAS
THE CASE YESTERDAY. THIS TREND WILL CONTINUE THROUGH THE WEEKEND UP
THROUGH AT LEAST TUESDAY...WHEN WE FINALLY SEE HIGH TEMPERATURES
RISE SLIGHTLY ABOVE FREEZING. LONG TERM FORECASTS SUGGEST WE MAY
EVEN SEE WARMER TEMPERATURES FOR THE FOLLOWING WEEKEND.

FLUCTUATIONS ARE STILL A POSSIBILITY TO MAKE NOTE OF THROUGH THE
SHORT TERM. RIVERS WILL NEED TO BE MONITORED CLOSELY IN THE EVENT
THAT THICKER ICE BEGINS TO DEVELOP.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR MIZ064-
     071.

     WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ037-
     043-050-056.

LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR LMZ844>849.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...04



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