Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 202357
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
757 PM EDT MON OCT 20 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 314 PM EDT MON OCT 20 2014

LOW PRESSURE OVER LAKE HURON WILL GRADUALLY LOSE IT/S GRIP OVER
SOUTHWEST LOWER MICHIGAN. CLOUDY SKIES TONIGHT WILL BECOME PARTLY
SUNNY TUESDAY. WE LOOKING AT SEVERAL DAYS OF DRY WEATHER WITH
MODERATING TEMPERATURES AS WE HEAD TOWARD THE WEEKEND.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 314 PM EDT MON OCT 20 2014

FORECAST CONCERNS ARE MINIMAL TODAY. THE MAIN STORY IS THE UPPER LOW
MOVING OVER LAKE HURON. THIS LOW WILL TAKE ANOTHER DAY TO MOVE OUT
OF THE PICTURE. TONIGHT WILL BE CLOUDY AS SATELLITE IMAGERY SHOWS
EXTENSIVE CLOUD COVER WEST THROUGH MANITOBA. ANOTHER SHORT WAVE WILL
ROTATE SOUTHWARD THROUGH THE FLOW AND ACROSS EASTERN LOWER MICHIGAN.
WE MAY SEE A FEW SPRINKLES EAST OF US-127 AFTER MIDNIGHT...BUT MOST
LOCATIONS WILL BE DRY.

UPPER RIDGING PUSHES INTO THE GREAT LAKES TUESDAY AND WE/LL SEE
DECREASING CLOUDINESS BY TUESDAY AFTERNOON. THAT WILL SET THE STAGE
FOR A CHILLY TUESDAY NIGHT AS LIGHT WINDS ENCOURAGE TEMPERATURES
FALL INTO THE UPPER 20S TO LOWER 30S. WEDNESDAY AND WEDNESDAY NIGHT
ALSO LOOK FAIR AT THIS TIME.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 314 PM EDT MON OCT 20 2014

THE MAIN CHALLENGE IN THE LONG TERM DEALS WITH HOW WARM TEMPERATURES
WILL GO.  I SUSPECT WE WILL SEE SOME 70S AT SOME POINT...MOST LIKELY
MONDAY.

TRENDS IN THE MODELS SUPPORT WARMER TEMPERATURES FOR SUNDAY INTO
MONDAY.  WARM AIR ADVECTION IS SHOWN TO INCREASE CONSIDERABLY AS A
LOW LEVEL JET DEVELOPS OVER THE PLAINS ON SUNDAY AND TRACKS INTO
MICHIGAN ON MONDAY.  925 MB TEMPERATURES CLIMB INTO THE TEENS...WITH
THE HIGHEST VALUES MONDAY.  ASSUMING WE MIX TO THAT LEVEL...WE WOULD
LIKELY REACH 70.  FOR NOW I BUMPED UP TEMPERATURES
CONSIDERABLY...TAKING THEM INTO THE 60S.

I DID ADD THUNDER TO THE FORECAST FOR MONDAY.  THE COMBINATION OF
INSTABILITY AND THE ARRIVAL OF A COLD FRONT SUPPORTS THIS SCENARIO.
MODELS ARE IN GOOD AGREEMENT ON THE THUNDER RISK.

THERE IS A SMALL CHANCE FOR SOME SHOWERS THURSDAY OR THURSDAY
NIGHT.  A WEAKENING MID LEVEL WAVE TRACKS THROUGH THE GREAT LAKES
REGION.  TRENDS SHOWS THIS FEATURE ARRIVING SOONER...SO IF IT DID
PRECIPITATE...THURSDAY APPEARS TO BE THE DAY.  THE MOISTURE IN THE
DGZ IS DECREASING AS THIS WAVE PASSES THROUGH.  WILL KEEP IT DRY FOR
NOW...BUT WILL NEED TO MONITOR TRENDS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 757 PM EDT MON OCT 20 2014

THERE ARE TWO MAIN CONCERNS WITH THIS PACKAGE...LOWERING CEILINGS
AND WIND GUSTS. LOW AND MID LEVEL MOISTURE STAYS PRETTY THICK IN
THE OVERNIGHT HOURS. THE LOWER CEILINGS WILL MAKE A SLOW SOUTHWARD
TREND AS THE MAIN SYSTEM CONTINUES TO ROTATE EAST OF THE AREA. THE
TOUGHEST PART WAS THE CALL ON WHETHER TO BRIEFLY GO IFR IN THE
LATE NIGHT AND PRE DAWN HOURS. THAT CONFIDENCE IS STILL RATHER
LOW...SO I STUCK WITH LOWER MVFR VALUES FOR CONSISTENCY. SOME
DRIZZLE WILL BE POSSIBLE JUST ABOUT ANYWHERE TONIGHT IN THIS
PATTERN. WIND GUSTS OF 15 TO 20KTS ARE POSSIBLE THROUGH THE LATE
EVENING BEFORE RELAXING A BIT LATER TONIGHT. ALTHOUGH GUSTS FALL
OUT OF THE PICTURE...BREEZING CONDITIONS ARE STILL EXPECTED
THROUGHOUT THE PERIOD. WINDS GRADUALLY BECOME NORTHERLY TOMORROW
WHICH HELPS TO BRING IN SOME DRY AIR AS THE SYSTEM DEPARTS.
CONDITIONS WILL LIKELY IMPROVE THROUGH THE MORNING AND AFTERNOON
GETTING BACK TO VFR BY THE AFTERNOON.

&&

.MARINE...
ISSUED AT 314 PM EDT MON OCT 20 2014

NO CHANGES TO THE HEADLINE. WAVES WILL BEGIN TO SUBSIDE TUESDAY
NIGHT AS HIGH PRESSURE MOVES OVERHEAD.


&&

.HYDROLOGY...
ISSUED AT 314 PM EDT MON OCT 20 2014

MAINLY DRY WEATHER IS EXPECTED FOR THE NEXT SEVERAL DAYS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...93
SHORT TERM...93
LONG TERM...MJS
AVIATION...JAM
HYDROLOGY...93
MARINE...93





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