Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 250437
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1137 PM EST MON NOV 24 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 333 PM EST MON NOV 24 2014

A TURN TOWARD WINTER WEATHER SETS BACK IN THIS AFTERNOON AND EVENING
WITH SNOW ONCE AGAIN ACROSS THE ENTIRE AREA. ACCUMULATING SNOW IS
LIKELY ACROSS CENTRAL LOWER MICHIGAN WHERE 4 TO 7 INCHES OF SNOW MAY
FALL. LESSER AMOUNTS WILL BE FOUND FURTHER SOUTH...BUT THE TUESDAY
MORNING COMMUTE WILL BE AFFECTED ACROSS MUCH OF WEST MICHIGAN WITH
FALLING SNOW AND POTENTIALLY SLIPPERY ROADS. THE SNOW WILL TAPER OFF
TUESDAY AFTERNOON AND TUESDAY NIGHT. ANOTHER BURST OF LAKE EFFECT
SNOW WILL COME THROUGH WEDNESDAY NIGHT INTO THANKSGIVING MORNING.
THE WIND SHOULD GRADUALLY SUBSIDE THROUGH THE COURSE OF THE NIGHT
WITH THE STRONGEST WINDS ENDING BY AROUND 1100PM THIS EVENING.

&&

.UPDATE...
ISSUED AT 848 PM EST MON NOV 24 2014

THE FCST CONTINUES TO BE ON TRACK THIS EVENING...AND NO CHANGES ARE
PLANNED TO THE HEADLINES THIS EVENING. THE WINTER WEATHER ADVISORY
WILL REMAIN AS IS THROUGH THE NIGHT. THE WIND ADVISORY CONTINUES
FOR NOW...AND WE EXPECT THAT WE WILL BE ABLE TO DROP IT ON
SCHEDULE THIS EVENING BY 10 PM EST/03Z.

RADAR INDICATES THAT THE SNOW HAS MIGRATED INTO ITS POSITION THAT
SHOULD HOLD INTO TOMORROW MORNING. THE POSITION IT HAS MIGRATED
INTO LINES UP VERY WELL WITH THE WINTER WEATHER ADVISORY THAT IS
IN EFFECT. NO SIGNIFICANT SNOW RATES HAVE OCCURRED YET...AND
ACCUMULATIONS HAVE BEEN SOMEWHAT LIMITED WITH TEMPS REMAINING A
NOTCH ABOVE FREEZING.

SNOW WILL CONTINUE THROUGH TONIGHT AS WE SEE THE GENERAL
DEFORMATION CONTINUE WITH INTERVALS OF ENHANCEMENT AS SHORT WAVES
RIDE THROUGH THE AREA. SOME LAKE ENHANCEMENT CONTINUES TO BE
EXPECTED WITH DELTA T/S IN THE TEENS.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 333 PM EST MON NOV 24 2014

DECIDED NOT TO MAKE ANY CHANGES TO THE GOING FORECAST AS IT STILL
LOOKS ON TRACK. COLD AIR IS SWEEPING INTO THE FORECAST AREA AT THIS
TIME...WITH GRR ALREADY SWITCHING OVER TO SNOW. THE DEEPER MOISTURE
IS SHIFTING NORTH WITH THE LOW HOWEVER...AND EXPECT THE DEFORMATION
ZONE TO SET UP ACROSS CENTRAL LOWER MICHIGAN THIS EVENING/TONIGHT.
HEAVIEST SNOWS SHOULD FALL ACROSS OUR FAR NORTHWEST COUNTIES...OR
ROUGHLY NORTHWEST OF A MUSKEGON TO CLARE LINE. THESE AREAS COULD SEE
4 TO 7 INCHES OF SNOW BEFORE IT TAPERS OFF ON TUESDAY. WOULD NOT BE
SURPRISED TO SEE A FEW HIGHER REPORTS...ESPECIALLY IF THE
DEFORMATION ZONE REMAINS SOMEWHAT STATIONARY ACROSS THIS AREA VERSUS
IT PIVOTING AROUND A BIT. UPSLOPE FLOW WILL AID IN SNOW TOTALS AS
WELL...WITH ABOUT A 1000 FOOT RISE FROM THE LAKE SURFACE TO THE HIGH
GROUND IN OSCEOLA COUNTY.

A LAKE EFFECT COMPONENT KICKS IN AS WELL...WITH DELTA T/S INCREASING
TO ABOVE 13 DEGREES C AROUND 01Z THIS EVENING. THE COMBINATION OF
DEEPEST MOISTURE...DEFORMATION ZONE AND BEST LIFT/CONVERGENCE ALL
SETS UP ACROSS THE NORTHWEST CWA...INCLUDING LUDINGTON...
PENTWATER...BALDWIN...BIG RAPIDS...REED CITY AND CLARE.

FURTHER SOUTH...EXPECTING A BURST OF SNOW TO SWEEP NORTH LATE THIS
AFTERNOON AND EVENING ASSOCIATED WITH THE DEFORMATION ZONE WITH LAKE
SNOWS KICKING IN AFTER DARK. LIGHTER ACCUMULATIONS ARE EXPECTED IN
THE SOUTHERN PORTION OF THE WINTER WEATHER ADVISORY MORE ON THE
ORDER OF 2 TO 5 INCHES.

WE MAY NEED TO EXPAND THE WINTER WEATHER ADVISORY INTO ALLEGAN AND
POSSIBLY VAN BUREN AND BARRY COUNTIES...BUT WILL NOT DO THAT YET.
WILL LET THE WIND ADVISORY COME DOWN LATER THIS EVENING AND THE
EVENING SHIFT COULD ADD ANY ADDITIONAL COUNTIES AS THEY SEE FIT. NOT
A SLAM DUNK BY ANY MEANS THAT THESE COUNTIES WILL NEED A WINTER
HEADLINE...BUT ALLEGAN WOULD SEEM MOST LIKELY.

THE LAKE SNOWS TAPER OFF ON TUESDAY AS THE DGZ BECOMES UNSATURATED
AND THE DEEPER MOISTURE PEELS OFF TO THE NORTH AND EAST WITH THE
DEPARTING LOW.

NEXT CHANCE FOR SENSIBLE WEATHER WILL OCCUR WEDNESDAY NIGHT WHEN
LAKE EFFECT BEGINS TO RAMP UP ONCE AGAIN. DEEPER MOISTURE SPREADS IN
WITH A SHORTWAVE ALONG WITH SURGE OF COLDER AIR AT 850MB/S.

WIND ADVISORY AREA SEEMS TO BE WORKING OUT OK...WITH THE HIGHEST
GUSTS OCCURRING ACROSS THE SOUTHERN THIRD OF THE FORECAST AREA.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 333 PM EST MON NOV 24 2014

WE/LL BE TRANSITIONING FROM A HIGH AMPLITUDE FLOW TO A ZONAL FLOW
PATTERN DURING THE LONG TERM PERIOD. THAT USUALLY MEANS A COUPLE OF
THINGS. THE FIRST IS THAT THE ARCTIC AIR WILL RETREAT AND STAY WELL
NORTH OF THE CWA.  THE SECOND THING THAT USUALLY HAPPENS IS THAT
SYSTEMS MOVE QUICKLY AND REGULARLY THROUGH THE GREAT LAKES. BOTH OF
THOSE LOOK TO OCCUR.

THE UPPER TROUGH WILL LIFT OUT THURSDAY NIGHT AND FRIDAY. THE AIR
WILL STILL BE COLD THURSDAY AND FRIDAY AND LAKE EFFECT SNOW SHOWERS
ARE EXPECTED...ESPECIALLY WEST OF US-131 ON THANKSGIVING. THE LAKE
EFFECT WILL WIND DOWN FRIDAY AS THE CORE OF THE COLD AIR MOVES EAST.
WARMER AIR WILL DEVELOP SATURDAY AS LOW PRESSURE MOVES FROM THE
PLAINS TOWARD THE GREAT LAKES. THAT WILL LEAD TO SOME RAIN SATURDAY
BEFORE COLDER AIR MOVES SOUTH AGAIN BEHIND THE FRONT AND PCPN
CHANGES BACK TO SNOW. THE CORE OF COLD AIR BEHIND THE FRONT HOWEVER
WILL STAY IN CANADA DUE TO ANOTHER DEVELOPING LOW IN THE PLAINS
WHICH WILL PUSH WARMER AIR NORTH AGAIN BY TUESDAY.

SO...VERY CHANGEABLE CONDITIONS ARE EXPECTED THROUGH THE
PERIOD...WHICH IS TYPICAL FOR THIS TIME OF YEAR.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1128 PM EST MON NOV 24 2014

IFR AND LOWER CONDITIONS WILL BE POSSIBLE AS THE IMPACTS OF THE
LOW PRESSURE SYSTEM TRACKING THROUGH THE REGION CONTINUE TO BE FELT.
KGRR AND KMKG ARE MOST LIKELY TO SEE THE LOWEST CONDITIONS GIVEN
THE WEST TO SOUTHWEST FLOW AND ADDED LAKE MOISTURE. ELSEWHERE IT
LOOKS LIKE PRIM ARLY AN MVFR NIGHT.

THE RISK FOR FREEZING RAIN OR SLEET HAS DIMINISHED AS COLDER CLOUD
TOPS WERE ARRIVING FROM THE SOUTHWEST.

CONDITIONS WILL IMPROVE FOR MOST LOCATIONS TUESDAY AFTERNOON AS
THE LAKE EFFECT GRADUALLY WEAKENS. WE WILL NEED TO MONITOR KMKG
CLOSELY AS THE REMAINING LAKE EFFECT WILL BE CLOSEST TO THAT AIRPORT.


&&

.MARINE...
ISSUED AT 333 PM EST MON NOV 24 2014

CONTINUED THE GALE WARNING IN THE SOUTHERN 5 ZONES (SOUTH OF
PENTWATER) AND THE SMALL CRAFT ADVISORY IN THE FAR NORTHERN ZONE
(NORTH OF PENTWATER). GALES MAY BE A BIT TOUGH TO GET OFF SHORE OF
OCEANA COUNTY...BUT IT WILL BE CLOSE SO LEFT IT AS IS. THE MUSKEGON
GLERL SITE HAS IT 40 KNOTS...WHILE THE PIER OB AT HOLLAND HAS IT 44
KNOTS. GALES SHOULD TONE DOWN OVERNIGHT WITH SMALL CRAFT CONDITIONS
PERSISTING LIKELY INTO TUESDAY EVENING. THE OVERNIGHT SHIFT WILL
LIKELY BE ABLE TO DOWNGRADE THE GALE TO A SMALL CRAFT ADVISORY AND
THEN EXTEND IT OUT INTO TUESDAY EVENING.


&&

.HYDROLOGY...
ISSUED AT 333 PM EST MON NOV 24 2014

STORM TOTAL RAINFALL HAS RANGED FROM 1 TO SLIGHTLY OVER 2 INCHES
ACROSS THE ENTIRE AREA IN COMBINATION WITH A SNOWPACK THAT
COMPLETELY MELTED. RIVER RESPONSES HAVE BEEN NOTABLE TODAY WITH
SHARP RISES ON SMALLER CREEKS AND STREAMS AND STEADY RISES ON MAIN
STEM RIVERS INCLUDING THE GRAND RIVER AND MUSKEGON RIVER. ADDITIONAL
ADVISORIES MAY BE NEEDED YET THIS EVENING FOR EXPECTED CRESTS ABOVE
BANKFULL...CAUSING SOME LOCALIZED IMPACTS TO AREAS IMMEDIATELY
ADJACENT TO THE RIVERS. THIS INCLUDES STANDING WATER ON RIVER EDGES
AND WATER SPILLING ONTO ADJACENT ROADWAYS AND PARKING LOTS.

WE ARE EXPECTING A CREST ON THE MUSKEGON RIVER TO BEGIN WORKING ITS
WAY DOWNSTREAM FROM EVART BY MIDWEEK. THIS MAY AFFECT AREAS ALONG
THE MUSKEGON RIVER DOWNSTREAM OF ROGERS POND AND ALSO CROTON/HARDY
DAMS. RISES BETWEEN BANKFULL AND FLOOD STAGE ARE POSSIBLE AT THESE
LOCATIONS DOWNSTREAM OF EVART. ON THE GRAND...A CREST OF 14.5 FEET
IS FORECAST AT IONIA FOR WEDNESDAY NIGHT...WHICH IS ONE FOOT ABOVE
BANKFULL. THIS CREST WILL WORK ITS WAY INTO KENT COUNTY FOR THE
SECOND HALF OF THE WEEK AND EVENTUALLY OUT TO LAKE MICHIGAN WITH
MINIMAL IMPACTS EXPECTED DOWNSTREAM AT THIS TIME.

ANY ICE THAT WAS PRESENT ON AREA RIVERS AND STREAMS SHOULD HAVE
MELTED OR BLOWN OUT WITH THE HIGH VOLUME OF WATER THE RIVERS ARE
EXPERIENCING. NOT EXPECTING ANY SIGNIFICANT ICE TO FORM FOR THE REST
OF THE WEEK GIVEN THESE HIGH FLOWS AND TEMPERATURES NOT BEING COLD
ENOUGH FOR SUBSTANTIAL ICE FORMATION.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ037>040-
     043>046-050-051-056-057.

LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR LMZ849.

     GALE WARNING UNTIL 7 AM EST TUESDAY FOR LMZ844>848.

&&

$$

UPDATE...NJJ
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...93
AVIATION...MJS
HYDROLOGY...HOVING
MARINE...DUKE





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