Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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997
FXUS63 KGRR 091210
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
710 AM EST TUE FEB 9 2016

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 256 AM EST TUE FEB 9 2016

SIGNIFICANT WEATHER CHANGES ARE IN STORE FOR SOUTHWEST MICHIGAN
STARTING THIS AFTERNOON.  COLDER AIR WILL POUR IN OVER THE LAKE
GIVING THE LAKESHORE AREAS A PROLONG PERIOD OF LAKE EFFECT SNOWS.
SEVERAL AREAS WILL SEE OVER SIX INCHES OF SNOW FROM THIS AFTERNOON
THROUGH THURSDAY MORNING. FURTHER INLAND IT WILL ALSO BECOME
COLD...BUT THE SNOWFALL WILL BE LIGHTER...GENERALLY 2 TO 4 INCHES
THROUGH THURSDAY. HIGH TEMPERATURES BOTH WEDNESDAY AND THURSDAY WILL
ONLY BE AROUND 20 ALONG WITH A BRISK WIND.

IT SHOULD STAY COLD FOR THE REST OF THE WEEK BUT THE LAKE EFFECT
SNOWS SHOULD BECOME LIGHTER.  TEMPERATURES SHOULD MODERATE INTO
MONDAY...BUT IT WILL COME WITH ANOTHER CHANCE OF SNOW.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 256 AM EST TUE FEB 9 2016

LAKE EFFECT SNOWS WILL INCREASE TODAY.  THIS APPEARS TO BE A
DOMINATE BAND SET UP WHICH COULD BRING DOUBLE DIGIT SNOWFALL BEFORE
ITS DIMINISHES INTO THURSDAY MORNING.

THE COLDER H8 AIR ARRIVES TOWARD MID DAY TODAY WHEN THE LAKE EFFECT
SNOW WILL RAMP UP.  WILL LEAVE THE HEADLINE AS IS...STARTING AT
4PM...BUT THE STEADIER SNOWS COULD KICK IN SHORTLY AFTER NOON.  THE
MAIN THING IS THAT THE WORD IS OUT.

WITH H8 TEMPS OF -16C MOVING IN THIS AFTERNOON THE LAKE WILL BEGIN
TO LIGHT UP.  MOISTEN DEPTH IS SOLID WITH INVERSION LEVELS AT OR
ABOVE 8K FEET THIS AFTERNOON AND INTO TONIGHT.  THE PEAK OF THE LAKE
EFFECT SHOULD BE FROM ROUGHLY NOON TODAY THROUGH NOON WEDNESDAY WHEN
THERE IS LITTLE TO INHIBIT INTENSE SNOW BANDS.

THE MAIN CONCERN WITH THIS EVENT IS THAT MEAN CLOUD LAYER WINDS
APPEAR TO STAY ROCK SOLID...FROM 330-340 TODAY ALL THE WAY INTO
EARLY THURSDAY. THIS POINTS TOWARD DOMINATE BANDS THAT WON/T WAVER
MUCH. SIX-PLUS INCHES CERTAINLY LIKELY...WITH ISOLATED TWELVE INCH
REPORTS POSSIBLE BY THURSDAY MORNING.

ALONG WITH THIS...WINDS WILL GUST TO AROUND 35 MPH AT TIMES OVER THE
LAKESHORE COUNTIES CREATING BLOWING AND DRIFTING SNOW.  THIS WILL
REDUCE VISIBILITIES TO NEAR ZERO AT TIME.  THE TIMING OF THE
STRONGEST WINDS SHOULD COINCIDE WITH THE STEADIEST SNOWS...ROUGHLY
NOON TODAY THROUGH NOON THURSDAY.  IT IS NOT OUT OF THE QUESTION WE
MAY NEED TO BUMP SOME OF THE LAKESHORE INTO A WINTER STORM
WARNING...BUT WE WILL WAIT TO SEE HOW THIS EVOLVES INTO LATE TODAY.

FURTHER INLAND AREAS WILL ALSO SEE PERIODS OF SNOW THROUGH TONIGHT
AS THE UPPER LOW  OVER NW OHIO KEEPS DEEP MOISTURE OVER THE REGION.
A SHORT WAVE PIVOTING AROUND THE LOW MOVES IN TONIGHT FOR WIDESPREAD
SNOW.  EXPECTING A GENERAL 1-3 INCHES THROUGH TONIGHT.  INLAND SNOWS
SHOULD DIMINISH THROUGH WEDNESDAY...WITH MOST SNOW LINGERING ONLY
OVER THE LAKESHORE INTO WEDNESDAY NIGHT.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 256 AM EST TUE FEB 9 2016

SNOW AND COLD WILL CONTINUE THROUGH THE LONG TERM. THE SNOW WILL
COME FROM A SEVERAL DIFFERENT METHODS...WHILE THE COLD WILL BE
PREVALENT AND LIKELY SOME OF THE COLDEST WE/VE SEEN THIS WINTER.

THURSDAY NIGHT...THE ARCTIC FRONT WILL BE APPROACHING FROM THE
NORTH WHICH WILL SPREAD MOISTURE BACK INTO AN UNSTABLE LAKE
ENVIRONMENT. EXPECT LAKE EFFECT TO PICK BACK UP AGAIN THURSDAY
NIGHT AFTER A LULL ON THURSDAY. SOME LIGHT ACCUMS EXPECTED TOWARDS
THE LAKESHORE.

ON FRIDAY...THE ARCTIC FRONT WILL SWEEP THROUGH THE FORECAST AREA
AND BRING SOME LIGHT SNOW AREA WIDE. ACCUMULATIONS INLAND WILL BE ON
THE LIGHT SIDE...AROUND AN INCH OR LESS. TOWARDS THE LAKE...THE
ACCUMULATIONS WILL BE A BIT MORE ON THE ORDER OF 1-3 INCHES
POTENTIALLY. LAKE EFFECT SNOW WILL CONTINUE ACROSS WESTERN LOWER MI
ON FRIDAY NIGHT AS THE ARCTIC AIR POURS IN. 850MB TEMPS WILL DROP TO
NEAR -26C SATURDAY AT 12Z. TEMPERATURES WILL NOT MAKE IT OUT OF THE
SINGLE DIGITS IN SOME SPOTS FOR HIGHS ON SATURDAY WHICH WILL BE MORE
THAN 20 DEGREES BELOW SEASONAL NORMS. HIGH PRESSURE WILL BRING
MAINLY COLD AND DRY CONDITIONS ON SATURDAY WITH THE LAKE EFFECT
DIMINISHING IN THE LIGHT FLOW.

SUNDAY INTO MONDAY THE MODELS BRING A SURFACE LOW INTO THE GREAT
LAKES REGION. THE GFS AND ECMWF HANDLE THIS SYSTEM DIFFERENTLY. AT
THIS POINT HAVE CHANCE POPS 30-40 PCT TO ACCOUNT FOR THE POSSIBILITY
OF SNOW. NOT CONFIDENT HOW THE SUN/MON LOW WILL PLAY OUT AT THIS
POINT THOUGH.

BOTTOM LINE...COLD WILL BE THE MAIN STORY IN THE EXTENDED WITH POOR
TRAVEL CONDITIONS TOWARDS THE LAKESHORE. SNOW PACKED AND SLIPPERY
ROADS EXPECTED IN THE LAKE SNOW BELTS GIVEN THE VERY COLD
CONDITIONS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 710 AM EST TUE FEB 9 2016

SOME SNOW OVER CENTRAL AND EASTERN PORTIONS OF THE STATE WILL
CONTINUE TO AFFECT KJXN AND KLAN THIS MORNING WITH THE SNOW
TAPERING OFF TOWARDS MIDDAY. IFR CONDITIONS THIS MORNING WILL
IMPROVE TO MVFR BY 18Z.

LAKE EFFECT SNOW WILL ORGANIZE TODAY AND BECOME HEAVY TONIGHT. THE
HEAVIEST BANDS WILL LIKELY MISS THE TAF SITES...AFFECTING THE
LUDINGTON AND SOUTH HAVEN AREAS MORE SO THAN MUSKEGON AND
KALAMAZOO. THE WIND DIRECTION ASSOCIATED WITH THE SNOW WILL BE
FROM 330 DEGREES SO INLAND TAF SITES WILL MOSTLY BE SPARED.

MVFR CONDITIONS WILL BE PREVALENT THIS AFTERNOON AND
TONIGHT...WITH AN OCCASIONAL IFR VISIBILITY POSSIBLE AT KMKG AND
KAZO. WINDS WILL BE GUSTY FROM THE NORTHWEST AT 10-25 KNOTS THIS
AFTERNOON AND EVENING.

&&

.MARINE...
ISSUED AT 330 AM EST TUE FEB 9 2016

WILL BUMP THE AREAS NORTH OF WHITEHALL INTO A GALE WARNING.  THIS IS
A LOW END GALE...BUT WINDS INCREASE TO GALE FORCE LATE THIS
AFTERNOON AND SHOULD CONTINUE INTO WED MORNING.  FREEZING SPRAY WILL
ALSO BE ON THE MODERATE SIDE FOR MUCH OF THE NEARSHORE WATERS THIS
AFTERNOON THROUGH WED EVENING


&&

.HYDROLOGY...
ISSUED AT 1200 PM EST MON FEB 8 2016

COLDER TEMPERATURES (AS OPPOSED TO PRECIPITATION) WILL BE THE
HIGHLIGHT OF THE UPCOMING WEEK. DAYTIME HIGHS WILL CONSISTENTLY BE
BELOW FREEZING WITH NIGHTTIME TEMPERATURES INTO THE TEENS... AND
EVENTUALLY INTO THE SINGLE DIGITS BY THE END OF THE WEEK. STREAMS
AND RIVERS CONTINUE TO RUN HIGH. FORECAST TEMPERATURES AND HIGHER
RIVERS MAY CREATE SOME CONCERNS IN REGARDS TO ICE BUILD UP.
IN THE EVENT OF ICE FORMATION...FLUCTUATIONS COULD RESULT THROUGH
THE NEXT SEVERAL DAYS...POSSIBLY SENDING SOME LOCATIONS NEAR OR
OVER BANKFULL.

THE POSITIVE NOTE IS THAT PRECIPITATION OVER THE NEXT SEVERAL
DAYS WILL COME IN PERIODIC EPISODES. THE GREATEST TOTALS WILL
FAVOR LAKESHORE COUNTIES AND WILL BE IN THE FORM OF SNOW. FREEZING
TEMPERATURES WILL MINIMIZE RISK DUE TO RUNOFF...LIMITING THE RISK
MAINLY TO ICE JAM POTENTIAL.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST
     THURSDAY FOR MIZ037-038-043-050-056-064-071.

LM...GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LMZ848-849.

     SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...JK



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