Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 290829
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
328 AM EST SAT NOV 29 2014

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

.SYNOPSIS...
ISSUED AT 328 AM EST SAT NOV 29 2014

LIGHT SNOW/FREEZING RAIN WILL CHANGE TO LIGHT RAIN AND DIMINISH
TODAY AS A WARM FRONT PUSHES NORTH THROUGH THE STATE. A MILD DAY IS
EXPECTED TODAY AND MUCH OF SUNDAY BEFORE A STRONG COLD FRONT MOVES
THROUGH AND DROPS HIGHS INTO THE MID 20S BY MONDAY. TEMPERATURES
WILL CLIMB TO THE MID 30S BY THE MIDDLE OF NEXT WEEK. SOME DRIZZLE
IS POSSIBLE TONIGHT AND SUNDAY AND THEN LIGHT SNOW MONDAY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EST SAT NOV 29 2014

FORECAST CONCERNS DEAL WITH PCPN TRENDS THROUGH THE PERIOD.

THE ONGOING WARM AIR ADVECTION PCPN HAS UNDERPERFORMED SO FAR AND
HAS
DECREASED IN COVERAGE AND INTENSITY SINCE IT MOVED ACROSS THE LAKE
FROM WISCONSIN. MOST OF THE PCPN HAS BEEN LIGHT SNOW BUT THERE HAVE
BEEN PATCHES OF LIGHT FZRA AND SLEET. LATEST HRRR SHOWS THE PCPN
MOVING EAST OF THE CWA PRIOR TO 6AM. DECIDED TO CANCEL THE WINTER WX
ADVISORY EARLY AS IMPACT FROM WHAT/S LEFT OF THE PCPN SHOULD BE
MINIMAL.

MODELS SHOW A WEAK DISTURBANCE MOVING THROUGH THIS AFTERNOON IN
ZONAL FLOW. NOT MUCH TOO IT BUT WILL KEEP A 20 POP FOR LIGHT RAIN IN
THE GRIDS. BUFKIT SHOWS SOME LIFT IN THE CLOUD LAYER TONIGHT IN
SOUTH FLOW. ADDED SOME DRIZZLE/LIGHT RAIN TO THE GRIDS FOR THIS.
TEMPS WILL REMAIN ABOVE FREEZING TONIGHT SO ANY PCPN THAT FALLS WILL
BE LIQUID.

SUNDAY WILL ALSO BE MILD WITH HIGHS IN THE 40S. HOWEVER...A STRONG
COLD FRONT WILL MOVE ACROSS THE CWA DURING THE AFTERNOON. H8 TEMPS
FALL FROM +8C TO -5C BY LATE IN THE DAY. MOISTURE IS VERY SHALLOW
THOUGH...LESS THAN 4K FT. THUS LAKE EFFECT SNOW WILL BE MINIMAL
SUNDAY
NIGHT/MONDAY.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EST SAT NOV 29 2014

EXTENDED PERIOD WILL BE RELATIVELY TRANQUIL WITH NO BIG STORMS AND
ONLY A FEW BOUTS OF LIGHT PRECIPITATION. SFC HIGH BRINGS FAIR
WEATHER THROUGH TUESDAY THEN MOVES EAST WITH A COLD FRONT COMING
THROUGH TUESDAY NIGHT. ANY PRECIP SHOULD BE LIGHT WITH ONLY LIGHT
LAKE EFFECT SNOW SHOWERS TO FOLLOW AS INVERSION HEIGHTS FALL BELOW
5000 FEET.

THURSDAY AND FRIDAY ARE QUESTION MARKS AS AN AREA OF ISENTROPIC
UPGLIDE NORTH OF A SFC WARM FRONT ACROSS THE OHIO VALLEY MAY FOCUS
SOME SNOW OR MIXED PRECIP REACHING THE SOUTHERN FORECAST AREA. WILL
GO WITH SLIGHT CHANCE POPS TO COVER THIS FOR NOW AS MODELS ARE
SHOWING LOTS OF TIMING/LOCATION INCONSISTENCY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM EST SAT NOV 29 2014

A BATCH OF MIXED PRECIPITATION IS STILL FORECAST TO SWING THROUGH
THE TAF SITES BEFORE DAYBREAK. SNOW SHOULD MIX WITH A BIT OF SLEET
AND LIGHT FREEZING RAIN BEFORE ENDING BY 10Z TO 11Z THIS MORNING.
NOT EXPECTING BIG REDUCTIONS TO VISIBILITY OR LONG PERIODS OF
PRECIPITATION...AS IT WILL BE SOMEWHAT SHOWERY IN NATURE.

CEILINGS HAVE TRENDED UP THIS EVENING WITH KMKG AND KGRR THE ONLY
TAF SITES STILL REPORTING A MVFR CEILING. EXPECTING CEILINGS TO
CONTINUE TO RISE TONIGHT WITH ALL SITES BECOMING VFR BY DAYBREAK.
SATURDAY MORNING SHOULD BE VFR AT ALL SITES BEFORE TRENDING BACK TO
MVFR IN THE AFTERNOON AND EVENING WITH SOME LIGHT DRIZZLE.

WINDS WILL BE SOUTHERLY THE NEXT 24 HOURS...BECOMING A BIT GUSTY
SATURDAY AFTERNOON. GUSTS SATURDAY AFTERNOON AROUND 20 KNOTS ARE
POSSIBLE.


&&

.MARINE...
ISSUED AT 328 AM EST SAT NOV 29 2014

EXTENDED THE SCA THROUGH SUNDAY NIGHT. SOUTH WINDS WILL GUST TO 20
TO 25 KNOTS TODAY/TONIGHT AND THEN SHIFT TO THE NORTHWEST SUNDAY AS
A STRONG COLD FRONT MOVES THROUGH.

&&

.HYDROLOGY...
ISSUED AT 328 AM EST SAT NOV 29 2014

RIVER LEVELS ARE RECEDING AND WILL CONTINUE TO DO SO OVER THE
WEEKEND AS LITTLE APPRECIABLE PCPN IS EXPECTED.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...DUKE
HYDROLOGY...93
MARINE...93








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