Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 190213
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
913 PM EST TUE NOV 18 2014

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 259 PM EST TUE NOV 18 2014

THE CURRENT LAKE EFFECT SNOW EVENT WILL CONTINUE TO DIMINISH THIS
EVENING BUT ANOTHER SYSTEM BRINGING ADDITIONAL ARCTIC AIR WILL
BRING SNOW ACROSS THE AREA WEDNESDAY MORNING THAT WILL TRANSITION
INTO LAKE EFFECT SNOW WEDNESDAY EVENING. THAT WILL CONTINUE INTO
THURSDAY...TAPERING TO FLURRIES ON FRIDAY. TEMPERATURES WILL
CONTINUE TO BE WELL BELOW NORMAL THROUGH FRIDAY.

A STRONG STORM SYSTEM FROM THE SOUTHERN PLAINS WILL BRING MUCH
WARMER AIR WITH RAIN OVER THE WEEKEND. THAT WILL LIKELY START AS
FREEZING RAIN LATE FRIDAY NIGHT AND THE FREEZING RAIN WILL
CONTINUE INTO SATURDAY MORNING. RAIN MAY BE HEAVY AT TIMES INTO
SATURDAY NIGHT INTO EARLY MONDAY.

THE COLD AIR RETURNS LATER MONDAY SO THE RAIN CHANGES BACK TO SNOW
SHOWERS. EXPECT COLDER WEATHER INTO THANKSGIVING WITH SOME SNOW
POSSIBLE.

&&

.UPDATE...
ISSUED AT 904 PM EST TUE NOV 18 2014

LAKE EFFECT SNOW SHOWERS WILL CONTINUE LATE THIS EVENING AND
OVERNIGHT. HOWEVER THEY WILL GRADUALLY DIMINISH IN COVERAGE AND
INTENSITY OVERNIGHT AS DUE TO SIGNIFICANTLY LOWERING INVERSION
HEIGHTS AND ALSO A GRADUALLY SHIFT IN LOW LEVEL WIND DIRECTION
BACK TO THE SW THEN SSW TO SOUTH OVERNIGHT. THIS WILL CAUSE THE
LAKE EFFECT SNOW BANDS TO SHIFT IN ORIENTATION SUCH THAT THEY WILL
BE MOST FOCUSED AND PREVALENT ACROSS THE LAKESHORE COUNTIES BY
EARLY WEDNESDAY MORNING.

THE WARNING HEADLINES WERE ALL ALLOWED TO EXPIRE AS SCHEDULED AT 9
PM. THE WINTER WX ADVISORY HEADLINE IS IN EFFECT FOR ALL OUR
LAKESHORE COUNTIES THROUGH 7 AM THURSDAY. WE HAVE ALSO ISSUED A
WINTER WX ADVISORY HEADLINE THAT IS IN EFFECT FROM NOW THROUGH 3
AM WEDNESDAY FOR NEWAYGO... KENT... BARRY... KALAMAZOO AND
MONTCALM COUNTIES. THIS SINCE LAKE EFFECT SNOW SHOWERS AND
HAZARDOUS TRAVEL CONDITIONS WILL LINGER TONIGHT ACROSS PORTIONS OF
THOSE COUNTIES UNTIL THE WINDS FINALLY BACK MORE TO THE SSW DURING
THE EARLY MORNING HOURS WEDNESDAY AT WHICH POINT THE SNOW SHOWERS
WILL BE MAINLY WEST OF US-131 ACROSS OUR LAKESHORE COUNTIES.

&&

.SHORT TERM...(WEDNESDAY THROUGH FRIDAY NIGHT) ISSUED AT 259 PM
EST TUE NOV 18 2014

THE GREATEST IMPACT TO TRAVEL IN THE SHORT TERM PERIOD WILL LIKELY
BE DURING THE DAY WEDNESDAY ESPECIALLY FROM HOLLAND TOWARD LUDINGTON
WITH HEAVY SNOW SHOWERS AT TIMES AND SNOW COVERED ROADS. WINDS PICK
UP LATER WEDNESDAY AND SHIFT MORE WESTERLY...BRINGING STEADIER SNOW
SHOWERS ONCE AGAIN INTO THE GRAND RAPIDS AREA AND LOCATIONS
NEAR/WEST OF US 131. BLOWING SNOW WILL BE POSSIBLE WEDNESDAY
AFTERNOON THROUGH THURSDAY AFTERNOON IN THESE SAME AREAS.

BY 12Z WEDNESDAY...WAA WILL BE ON OUR DOORSTEP AS WINDS SHOULD
BECOME DUE SOUTH OR EVEN SSE FROM MUSKEGON NORTHWARD ALONG THE LAKE
SHORE. A COLD FRONT WILL BE APPROACHING THE SHORELINE AROUND 18Z
WEDNESDAY AND IT IS AROUND THIS TIME FRAME THAT THINGS COULD GET
RATHER INTERESTING. HI RES MODELS SUCH AS THE WRF ARW AND NAMDNG5
SUGGEST A DOMINANT BAND OR EVEN A MESOLOW WILL LIKELY DEVELOP NEAR
BIG AND LITTLE SABLE POINTS IN THE PRESENCE OF VERY STRONG SFC
CONVERGENCE AS WINDS GO WESTERLY OVER THE LAKE BUT STAY SSE OVER THE
LAKESHORE REGION. THAT BEING SAID...NAM BUFKIT SOUNDINGS INDICATE A
BULLSEYE OF OMEGAS AT MKG AND LDM BELOW THE DGZ BY 18Z
WEDNESDAY...THANKS TO WAA BUMPING UP THE DGZ A FEW THOUSAND FEET
HIGHER DURING THE DAY...SO THIS COULD MITIGATE MORE SUBSTANTIAL
ACCUMULATIONS.

I WOULD ENVISION A DOMINANT LAKE BAND THAT MOVES PARTICULARLY INTO
MASON AND OCEANA COUNTIES BUT COULD EXTEND FURTHER SOUTH INTO
MUSKEGON AND OTTAWA COUNTIES DURING THE LATE MORNING/EARLY AFTERNOON
BEFORE WEAKENING AS IT HEADS EAST. DURING THE 15Z TO 21Z TIME
FRAME...IT COULD GET RATHER DICEY ANYWHERE ALONG THE LAKESHORE BUT
PARTICULARLY FROM HOLLAND TO LUDINGTON AS THIS BAND MOVES ON SHORE.
BRIEFLY VERY HEAVY SNOWFALL RATES ARE POSSIBLE AS THIS OCCURS...WITH
1"-2" PER HOUR POSSIBLE. DOMINANT BANDS AND MESOLOWS CAN PRODUCE
VERY SIGNIFICANT SNOWFALL AMOUNTS IN A SHORT AMOUNT OF
TIME...LEADING TO VERY POOR TRAVEL CONDITIONS. BUT SINCE THIS BAND
WILL BE SHIFTING EAST WITH TIME...THE LOWER RESIDENCE TIME MAY KEEP
ACCUMULATIONS IN CHECK.

AS WINDS TURN WESTERLY WEDNESDAY EVENING...ANY DOMINANT BAND WILL
COME TO AN END AS MULTI-BAND SNOW SHOWERS SET UP ALONG WITH GUSTY
WINDS ONCE AGAIN. INLAND...WE ARE LOOKING AT GUSTS AROUND 25 MPH
WHILE CLOSER TO THE LAKESHORE THOSE GUSTS COULD BE 30-35 MPH. THE
DGZ WILL BE FULLY SATURATED WEDNESDAY AND THURSDAY THOUGH LIFT WILL
BE WANING A BIT ON THURSDAY. THAT BEING SAID THE 1000MB-700MB LAPSE
RATES DO STEEPEN FROM 5-6C/KM ON WEDNESDAY TO 6-7C/KM ON THURSDAY.
0-2KM THETA E LAPSE RATES DO GO NEGATIVE BY LATE WEDNESDAY NIGHT AND
THIS CONTINUES THROUGH THURSDAY NIGHT. THE BOTTOM LINE IS THE SNOW
WILL CONTINUE AS ADVERTISED WITH TOTALS BY THURSDAY EVENING AROUND
4"-7" OR A BIT HIGHER NEAR/WEST OF US 131.

AFTER A QUIETER FRIDAY...RAPID WAA ENSUES LATE FRIDAY NIGHT/EARLY
SATURDAY MORNING AHEAD OF A DEEPENING WAVE ACROSS THE SOUTHERN
PLAINS. MODEL SOUNDINGS DO SUPPORT A PERIOD OF FREEZING RAIN OR
FREEZING DRIZZLE AS THIS OCCURS. COULD BE SOME IMPACTS TO TRAVEL FOR
A BRIEF TIME.

.LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 259 PM EST TUE
NOV 18 2014

THE LONG TERM PORTION OF THE FCST WILL FEATURE A TEMPORARY PATTERN
SHIFT FOR THE AREA BRINGING WARMER AND WETTER CONDITIONS FOR THE
WEEKEND INTO MON. IT DOES LOOK LIKE WE WILL THEN SETTLE BACK INTO A
COOLER PATTERN WITH LAKE EFFECT SNOW POSSIBLE THEN BY THE END OF THE
PERIOD ON TUE.

THE TRANSITION TO THE TEMPORARY WARMER AND WETTER PATTERN COULD BE A
BIT TRICKY FOR A SHORT TIME WITH SOME FREEZING RAIN POSSIBLE EARLY
SAT. WE WILL SEE A STRONG SHORT WAVE COMING ONSHORE OVER THE WEST
COAST ON THU EVENTUALLY LIFT NE TOWARD SAT AS ANOTHER LONGER WAVE
TROUGH MOVES INTO THE ROCKIES AND ABSORBS IT. THE AIR ALOFT WILL BE
PLENTY WARM ENOUGH FOR RAIN...BUT THE COLDER AIR AT THE SFC WILL
TAKE A LITTLE WHILE TO BE USHERED OUT. THE WARMER AIR WILL
EVENTUALLY WIN OUT AS A DEEP SRLY FLOW MOVES IN.

THERE WILL THEN BE A GOOD CHANCE OF RAIN FOR THE WEEKEND AND INTO
MON AS THE UPPER WAVE APPROACHES AND ADVECTS WARM AND MOIST AIR
NORTH OUT OF THE GULF OF MEXICO. THIS COMBINED WITH TEMPS AND DEW
POINTS REMAINING ABOVE FREEZING WILL HELP TO MELT A GOOD DEAL OF THE
RECENT SNOW ACROSS THE AREA. PLEASE SEE THE HYDRO SECTION BELOW FOR
MORE DETAILS ON THIS.

COLDER AIR WILL THEN MAKE A RETURN ON MON AND CONTINUE INTO
TUE...ALONG WITH THE THREAT OF LAKE EFFECT SNOW SHOWERS. THE WEEKEND
WAVE WILL MOVE NORTHEAST...AND THE LONG WAVE TROUGH OVER THE ROCKIES
WILL MOVE OVERHEAD ONCE AGAIN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 647 PM EST TUE NOV 18 2014

LAKE EFFECT SNOW SHOWERS WILL SLOWLY DIMINISH THIS EVENING.
CONDITIONS WILL BE MOSTLY MVFR...WITH SOME IFR FROM MKG TO GRR.
EXPECT VFR THIS EVENING AND OVERNIGHT FROM BTL TO JXN AND NORTH
TO LAN. SOUTHWEST WINDS WILL GUST TO 20 KNOTS AT TIMES TONIGHT AND
BECOME SOUTHERLY ON WEDNESDAY.


&&

.MARINE...
ISSUED AT 259 PM EST TUE NOV 18 2014

NONE OF OUR REPORTING STATIONS HAVE BEEN SHOWING GALES THIS
AFTERNOON SO I CANCELED THE GALE WARNING AND ISSUED A SMALL CRAFT
ADVISORY FROM NOW THROUGH THURSDAY EVENING. WE WILL HAVE A SHORT
WINDOW OF GALES WEDNESDAY EVENING BUT TO KEEP HEADLINES SIMPLE FOR
NOW WE WENT WITH THE DOMINATE WIND SPEED WHICH IS BELOW GALE
FORCE. LATER SHIFTS MAY WELL UPGRADE TO GALES SO WHAT FOR POSSIBLE
UPDATES TO THIS WITH LATER FORECASTS.


&&

.HYDROLOGY...
ISSUED AT 259 PM EST TUE NOV 18 2014

I AM RATHER CONCERNED ABOUT THE FLOOD POTENTIAL FOR THE WEEKEND AS
STRONG STORM MOVES THROUGH THE GREAT LAKES BRINGING HEAVY RAIN
OVER THE CURRENT SNOW PACK WITH FROZEN GROUND. AFTER COORDINATION
WITH THE NORTH CENTRAL RIVER FORECAST CENTER... WE DECIDED THERE
IS POTENTIAL FOR SOME FLOODING IS THIS WEEKEND. AT THIS POINT IT
IS MINOR BUT WE WILL HAVE TO STAY ON TOP OF THIS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ037-043-
     050-056-064-071.

     WINTER WEATHER ADVISORY UNTIL 3 AM EST WEDNESDAY FOR MIZ044-051-
     057-065-072.

LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR LMZ844>849.

&&

$$

UPDATE...LAURENS
SYNOPSIS...WDM
SHORT TERM...HOVING
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM





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