Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 282030
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 PM EST FRI NOV 28 2014

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

.SYNOPSIS...
ISSUED AT 330 PM EST FRI NOV 28 2014

OCCASIONAL LIGHT SNOW WILL CHANGE TO AREAS OF LIGHT FREEZING RAIN
AND SLEET LATE TONIGHT... RESULTING IN SLICK TRAVEL IN SPOTS. ANY
LINGERING PRECIPITATION ON SATURDAY WILL CHANGE TO LIGHT DRIZZLE BY
NOON AS TEMPERATURES WARM ABOVE FREEZING. HIGHS IN THE 40S AND 50S
ARE EXPECTED ON SUNDAY BEFORE TEMPERATURES IN THE 20S RETURN SUNDAY
NIGHT AND MONDAY BEHIND A COLD FRONT. THE WEATHER NEXT WEEK LOOKS
RELATIVELY QUIET WITH NEAR NORMAL TEMPERATURES AND LITTLE SNOW.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EST FRI NOV 28 2014

WARM ADVECTION/ISENTROPIC LIFT SNOW HAS BEEN UNDER-PERFORMING TODAY
DUE LARGELY TO VERY DRY AIR BELOW 600 MB SHOWN ON THE 12Z DTX AND
APX RAOBS. MODELS STILL SHOW SOME LIGHT QPF AROUND A TENTH OF AN
INCH COMING THROUGH TONIGHT SUPPORTING MORE INTERMITTENT LIGHT SNOW
NORTH OF THE WARM FRONT. HOWEVER HAVE BACKED DOWN ON TOTAL SNOW
ACCUMULATIONS AND WILL FCST GENERALLY AN INCH OR LESS.

PERHAPS THE MORE IMPACTFUL ISSUE TONIGHT IS THE LIGHT FREEZING RAIN
AND SLEET POTENTIAL WHICH DEVELOPS TOWARD MIDNIGHT AS WARM AIR
SURGES IN ALOFT. THE COMBINATION OF A DUSTING OF LIGHT SNOW FOLLOWED
BY A LIGHT GLAZE LATE WITH TEMPS IN THE 20S TONIGHT COULD CREATE
SOME SLICK TRAVEL.

MID LEVEL MOISTURE DEPARTS FROM SOUTHWEST TO NORTHEAST ON SATURDAY
LEAVING MAINLY JUST A LIGHT DRIZZLE THREAT FROM SHALLOW STRATUS DECK
THROUGH SATURDAY NIGHT. THE FOG THREAT LOOKS RELATIVELY LOW DUE TO
WIND SPEEDS OF 10 KNOTS OR MORE.

CHALLENGE ON SUNDAY IS HOW WARM IT GETS AHEAD OF THE APPROACHING
COLD FRONT AS MODELS SHOW 10C AIR AT H8 ARRIVING FROM THE SOUTHWEST.
POTENTIAL EXISTS FOR AREAS SOUTH AND EAST OF GRR TO REACH WELL INTO
THE 50S BUT HAVE PLAYED IT CONSERVATIVE FOR NOW WITH HIGHS 50 TO 55.
ANY PRECIPITATION POTENTIAL WITH THE FRONTAL PASSAGE SUNDAY
AFTERNOON IS EXPECTED TO BE VERY LIGHT DUE TO LIMITED/SHALLOW
MOISTURE.


.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EST FRI NOV 28 2014

PRETTY QUIET NEXT WEEK OR SO SHAPING UP WITH FEW OPPORTUNITIES FOR
SNOWFALL AND A PATTERN THAT SHOULD BRING A WEEK OF MOSTLY NEAR
NORMAL HIGH TEMPERATURES. COLDER AIR LOOKS TO REMAIN THROUGH THE END
OF THE FIRST WEEK OF DECEMBER WITH LITTLE CHANGE IN TEMPERATURES
BEING HINTED AT AFTER THAT.

ONLY REAL PRECIPITATION CHANCES IN THE LONG TERM APPEAR TO COME
MONDAY WITH SOME LINGERING LIGHT SNOW POTENTIAL NEAR THE LAKE
SHORE...AND POSSIBLY LATE THURSDAY NIGHT INTO FRIDAY WITH THE
PASSING OF A MORE ORGANIZED WEATHER SYSTEM TO OUR SOUTH.

MODELS CONTINUE TO VARY SLIGHTLY ON THE TRACK OF THE THURSDAY NIGHT
SYSTEM. ALL MODELS HAVE BEEN TRENDING SLOWER AND FURTHER SOUTH IN
RECENT RUNS...WITH THE GFS MOVING MORE IN LINE WITH THE FURTHER
SOUTH TRACK OF THE FIM AND THE EUROPEAN MODEL SLOWLY TRENDING THAT
WAY AS WELL. SHOULD THE SOUTHERN TREND OF THE SYSTEM CONTINUE...MOST
IF NOT ALL OF LOWER MICHIGAN WOULD MISS OUT ON PRECIP FROM THIS LATE
WEEK SYSTEM. THIS WOULD LEAVE OUR NEXT SHOT FOR MORE ORGANIZED
PRECIPITATION COMING SOMETIME MID NEXT WEEK AT THE EARLIEST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1220 PM EST FRI NOV 28 2014

SOME LIGHT SNOW FOR THE FIRST SIX HOURS OF THE TAF PERIOD WITH
SOME LIFR VISIBILITIES LIKELY AT KMKG AND ALONG THE LAKE SHORE.
REMAINDER OF THE TAF LOCATIONS SHOULD REMAIN MOSTLY MVFR IN SNOW
AT TIMES THROUGH 03Z. AFTER 03Z WARMER AIR ALOFT MOVES INTO LOWER
MICHIGAN BRINGING THE CHANCE FOR SOME LIGHT FREEZING RAIN TO OCCUR
BRIEFLY AROUND OR SHORTLY AFTER 06Z. HAVE INCLUDED SOME PROB30S
IN THE TAFS FOR THIS AT THIS TIME AS CONFIDENCE IS FAIRLY LOW FOR
FZRA TO OCCUR. LOOKS LIKE ANY FZRA THREAT WILL END AFTER 12Z WITH
MOSTLY VFR CONDITIONS OCCURRING THROUGH MUCH OF SATURDAY.

&&

.MARINE...
ISSUED AT 330 PM EST FRI NOV 28 2014

SMALL CRAFT ADVISORIES ARE IN EFFECT FOR SOUTHERLY FLOW OF 15 TO 25
KNOTS THROUGH SATURDAY NIGHT.

&&

.HYDROLOGY...
ISSUED AT 330 PM EST FRI NOV 28 2014

ALL RIVERS HAVE CRESTED AND ARE RECEDING. WITH HIGH FLOWS FOR THIS
TIME OF YEAR COMBINED WITH LACK OF PERSISTENT TEMPERATURES BELOW 20
DEGREES...NO ICE FORMATION OF ANY CONSEQUENCE IS EXPECTED FOR SOME
TIME. ALSO...WITH A LACK OF ANY SUBSTANTIAL PRECIPITATION OVER THE
NEXT WEEK OR SO...RIVERS WILL RETURN TO NORMAL FLOWS HEADING INTO
DECEMBER.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...MACZKO
AVIATION...MACZKO
HYDROLOGY...HOVING
MARINE...MEADE









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