Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 272339
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
639 PM EST THU NOV 27 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 323 PM EST THU NOV 27 2014

LAKE EFFECT SNOW SHOWERS WILL DIMINISH TONIGHT BUT WIDESPREAD LIGHT
SNOW IS EXPECTED ON FRIDAY. ACCUMULATIONS WILL BE MOSTLY UNDER THREE
INCHES BUT MAY STILL CREATE SLIPPERY TRAVEL. WARMER TEMPERATURES
WILL ARRIVE FOR SATURDAY AND SUNDAY WITH OCCASIONAL LIGHT RAIN OR
DRIZZLE EXPECTED.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 323 PM EST THU NOV 27 2014

LAKE EFFECT HAS OVERACHIEVED TODAY WITH LOCALIZED REPORTS OF 5 TO 8
INCHES WHERE HEAVIEST BANDS HAVE PERSISTED. SNOW SHOWERS HAVE
RECENTLY DIMINISHED CONSIDERABLY NORTH OF MUSKEGON WITH THE PASSAGE
OF SFC TROUGH SO WILL CANCEL THE NRN PORTION OF THE LAKE EFFECT SNOW
ADVISORY THERE. THE ADVISORY REMAINS IN EFFECT UNTIL 9 PM SOUTHWEST
OF GRAND RAPIDS. HOWEVER EVEN HERE THE TREND SHOULD BE DIMINISHING
WITH TIME WITH LOWERING INVERSION HEIGHTS.

BAND OF ISENTROPIC LIFT SNOW EXPECTED FRIDAY AS WARM FRONT LIFTS
NORTH. AMOUNTS SHOULD BE GENERALLY LIGHT ALTHOUGH SOME 1 TO 3 INCHES
ACCUMS POSSIBLE MAINLY ALONG AND NORTH OF I-96.

WARM ADVECTION PERSISTS FRIDAY NIGHT INTO SATURDAY ALTHOUGH MOISTURE
BECOMES QUITE SHALLOW WITH TIME. THE LIGHT SNOW ON FRIDAY WILL
EVENTUALLY TRANSITION TO OCCASIONAL LIGHT RAIN OR DRIZZLE BY
SATURDAY... WITH PERHAPS A BRIEF THREAT OF SOME LIGHT FREEZING
RAIN/DRIZZLE LATE FRIDAY NIGHT AND EARLY SATURDAY BEFORE SFC TEMPS
WARM ABOVE FREEZING.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 323 PM EST THU NOV 27 2014

LOOKING QUIET AND DRY WITH SEASONABLE TEMPERATURES ON AVERAGE NEXT
WEEK. OVERALL PATTERN WILL BE PROGRESSIVE WITH A BRIEF SHOT OF
ARCTIC AIR ON MONDAY - TUESDAY FOLLOWED BY A SECOND SHOT ON
WEDNESDAY. THERE MAY BE A SYSTEM DEVELOPING SOUTH OF MICHIGAN ON
THURSDAY AS PER GFS/FIM BUT THE ECMWF IS ALL HIGH PRESSURE AT THIS
POINT.

TIMING OF FIRST COLD FRONT STILL LOOKING LIKE LATE SUNDAY
AFTERNOON/EVENING.  CURRENT BLENDED GUIDANCE INDICATING MID 40S FOR
HIGHS BUT WOULD NOT RULE OUR NEAR 50 DEGREE READINGS AT THIS POINT.
THERE WILL BE GOOD FRONTAL CONVERGENCE WITH SOME SHOWER ACTIVITY BUT
DEEPER FRONTOGENETICAL LIFT DOES NOT REALLY COUPLE WITH MOISTURE
CONVERGENCE UNTIL THE FRONT IS SOUTH AND EAST OF MICHIGAN.

OPPORTUNITY FOR LAKE EFFECT SNOW LOOKS VERY LIMITED AS COLD AIR
MOVES BACK SUNDAY NIGHT INTO EARLY MONDAY. SURFACE FLOW WILL BE VERY
DIFFLUENT AS SURFACE HIGH QUICKLY BUILDS OVER THE AREA AND ALOFT WE
REMAIN MORE OR LESS ON ANTICYCLONIC SIDE OF JET AXIS. THIS WILL ALL
RESULT IN VERY SHALLOW CONVECTION AND A LACK OF DEEPER LOW LEVEL
MOISTURE WITH LITTLE IN THE WAY OF LE SNOW SHOWER ACTIVITY.

SECOND SHOT OF COLD AIR ARRIVES EARLY WEDNESDAY. AGAIN NOT MUCH
MOISTURE TO WORK WITH SO NOT EXPECTING MORE THAN A FEW MIXED
RAIN/SNOW SHOWERS AT THIS POINT FOLLOWED BY SUB FREEZING
TEMPERATURES INTO THURSDAY.

PROGRESSIVE PATTERN LOOKING LIKE IT WILL CONTINUE INTO THE SECOND
WEEK OF DECEMBER PER FIM/GFS PARA/ECWMF.  GFS/ECMWF LOOKING WARM THE
WHOLE WEEK BUT FIM BRINGS ANOTHER GLANCING SHOT OF ARCTIC AIR ON
MONDAY (DEC 8TH).  BASED ON CURRENT TRENDS...THAT LOOKS LIKE THE
BEST BET. ALL NWP GUIDANCE LOOKS TO CONTINUE OVERALL DRY PATTERN AS
WELL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 636 PM EST THU NOV 27 2014

THE LAKE EFFECT SNOW WILL CONTINUE TO DIMINISH TONIGHT...BUT IT IS
NOT EXPECTED TO TOTALLY GO AWAY. THUS LIGHT SNOW SHOWERS/FLURRIES
WITH VFR WEATHER HAS BEEN FORECASTED. KMKG WILL NEED TO BE
MONITORED CONSIDERING THEIR PROXIMITY TO THE LAKE.

A BAND OF SNOW WILL MOVE IN FROM THE WEST FRIDAY MORNING INTO
EARLY AFTERNOON. KGRR AND KMKG ALONG WITH KLAN SHOULD SEE THE
GREATEST IMPACT FROM THIS AREA OF SNOW...AND IFR LOOKS LIKELY. THE
EVENT WILL PERSIST THROUGH 00Z SAT.

&&

.MARINE...
ISSUED AT 323 PM EST THU NOV 27 2014

SMALL CRAFT ADVISORIES REMAIN IN EFFECT UNTIL 3 AM FOR NORTHWEST
FLOW OF 15 TO 25 KNOTS. THEN A BRIEF LULL IN WIND AND WAVE ACTIVITY
IS EXPECTED UNTIL SOUTH WINDS INCREASE LATE FRIDAY AND FRIDAY NIGHT.


&&

.HYDROLOGY...
ISSUED AT 323 PM EST THU NOV 27 2014

ONLY TWO ADVISORIES ARE REMAINING...EACH AT SCOTTVILLE AND NEW
RICHMOND. SNOW SHOWERS WILL DEVELOP OVER THE AREA FRIDAY BEFORE
WARMER AIR MOVES IN OVER THE WEEKEND. ANY LEFT OVER MOISTURE COULD
RESULT IN SCATTERED LIGHT RAIN SHOWERS SATURDAY AND SUNDAY. FRIDAYS
EVENT MAY BE GOOD ENOUGH FOR A COUPLE OF INCHES OF ACCUMULATION IN
NORTHERN SECTIONS OF THE FORECAST AREA AND WILL NOT RESULT IN ANY
IMMEDIATE RUNOFF. WEEKEND PRECIPITATION SHOULD BE LIGHT AS WELL. SO
MOISTURE WILL GRADUALLY FIND ITS WAY TO STREAMS AND RIVERS AND
IMPROVEMENT IS EXPECTED TO CONTINUE. WE SHOULD BE CLEAR OF
ADVISORIES IN THE NEXT DAY OR SO WITH NO NOTABLE REASON FOR CONCERN
IN THE NEAR FUTURE.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...LAKE EFFECT SNOW ADVISORY UNTIL 9 PM EST THIS EVENING FOR MIZ056-
     064-071-072.

LM...SMALL CRAFT ADVISORY UNTIL 3 AM EST FRIDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...COBB
AVIATION...MJS
HYDROLOGY...JAM
MARINE...MEADE





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