Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 281928
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 PM EDT TUE OCT 28 2014

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT TUE OCT 28 2014

A COOLER AIRMASS WILL CONTINUE TO MOVE IN TONIGHT THROUGH MIDWEEK
WITH TEMPERATURES WEDNESDAY AND THURSDAY AVERAGING CLOSE TO NORMAL
FOR THIS TIME OF YEAR. SCATTERED LIGHT LAKE EFFECT RAIN SHOWERS
AND SPRINKLES ARE ANTICIPATED WEDNESDAY. AN UNSEASONABLY COOL
AIRMASS WILL MOVE IN FOR HALLOWEEN WHEN HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE MIDDLE 30S UP NORTH TO LOWER 40S NEAR TO SOUTH
OF INTERSTATE 96. THE FIRST SNOWFLAKES OF THE SEASON ARE ANTICIPATED
FRIDAY ALONG WITH GUSTY NORTH TO NORTHEAST WINDS. THE UNSEASONABLY
COOL AIR WILL STICK AROUND SATURDAY BEFORE TEMPERATURES UNDERGO A
GRADUAL MODERATING TREND LATE IN THE WEEKEND INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM EDT TUE OCT 28 2014

WSW TO WEST WINDS WILL CONTINUE TO GUST TO AROUND 30 MPH THROUGH
THE EARLY EVENING HOURS BEFORE SUBSIDING OVERNIGHT. EXTENSIVE LOW
CLOUD COVER OFF TO THE WNW ACROSS WI WILL GRADUALLY MOVE IN
TONIGHT.

SCATTERED LIGHT LAKE EFFECT RAIN SHOWERS WILL DEVELOP DURING THE
EARLY MORNING HOURS WEDNESDAY AND CONTINUE THROUGH THE DAY. THIS
AS AN UPPER TROUGH MOVES OVERHEAD WEDNESDAY AFTERNOON AND WITH
CYCLONIC FLOW/DEEP LOW TO MID LEVEL MOISTURE IN PLACE AND WITH H8
TEMPS OF -3 TO -4 C LEADING TO NW FLOW LAKE EFFECT SHOWERS.

A FEW SPRINKLES MAY LINGER WEDNESDAY EVENING WITH DRY WX
ANTICIPATED WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON AS A WEAK
HIGH PRESSURE RIDGE BUILDS IN. THE NEXT LOW PRESSURE SYSTEM AND
STRONG COLD FRONT WILL DROP DOWN FROM THE NW AND BRING AN
INCREASING CHANCE OF RAIN SHOWERS THURSDAY NIGHT.

THE BEST CHANCE FOR RAIN THURSDAY NIGHT WILL COME AFTER MIDNIGHT.
RAISED POPS TO LIKELY ACROSS OUR NORTHERN FCST AREA TO ACCOUNT FOR
THIS. THERE IS ALSO POTENTIAL FOR SOME WET SNOW FLAKES TO MIX IN
WITH HEAVIER RAIN SHOWERS OVER OUR NORTHERN FCST AREA TOWARD 12Z
FRIDAY.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 PM EDT TUE OCT 28 2014

MAIN IMPACTS IN THE LONG TERM ARE STILL EXPECTED TO BE ON HALLOWEEN.
THE MOST SIGNIFICANT HAZARD WILL BE GUSTY WINDS OUT OF THE
NORTH...WHICH WILL LIKELY AFFECT HALLOWEEN DECORATIONS AND TRICK OR
TREATING. WE COULD SEE SNOW MIX IN WITH RAIN ON HALLOWEEN... BUT
THIS IS STILL UNCERTAIN. THE BEST CHANCE FOR SNOW WOULD BE IN THE
LATE AFTERNOON AND EVENING. TEMPERATURES IN THE UPPER 30S AND LOWER
40S DURING THE DAYTIME WITH DEWPOINTS ONLY IN THE MID 20S TO MID 30S
ARE LIMITING FACTORS. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED.
RAIN OR SNOW ASIDE...EXPECT NASTY TRICK OR TREATING CONDITIONS WITH
WIND CHILLS PLUMMETING INTO THE 20S BY FRIDAY EVENING.

THERE HAS BEEN DECENT MODEL AGREEMENT AND RUN TO RUN CONSISTENCY FOR
THE HALLOWEEN SYSTEM. A STRONG PV ANOMALY WILL DIVE SOUTH OUT OF
CANADA AND MOVE ACROSS THE GREAT LAKES. RIDGING QUICKLY TAKES HOLD
OVER THE WEEKEND WITH FAIR SKIES...BUT STILL QUITE COOL WITH HIGHS
IN THE LOWER 40S. TEMPERATURES WILL MODERATE BACK INTO THE 50S EARLY
NEXT WEEK...AND THE NEXT CHANCE FOR RAIN ARRIVES MONDAY NIGHT INTO
TUESDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 145 PM EDT TUE OCT 28 2014

WE ARE FAIRLY CONFIDENT ABOUT VFR CONDITIONS THROUGH 00Z THIS
EVENING. SOME SCATTERED CLOUDS AROUND 3000-4000 FT AGL ARE EXPECTED
TO DEVELOP THIS AFTERNOON. WE ALREADY SEE CEILINGS AROUND 3000 FT
AGL OVER WI BASED ON SATELLITE AND METAR OBSERVATIONS. THIS SHOULD
SPREAD EAST OVER LOWER MICHIGAN THIS EVENING. CEILINGS SHOULD REMAIN
AT OR ABOVE 3000 FT AGL WITH A LOW PROBABILITY OF DROPPING BELOW FUEL
ALTERNATES OF 2000 FT. HAVE LOWERED WIND SPEEDS AND REMOVED GUSTS
TONIGHT BASED ON LATEST MODEL GUIDANCE.

&&

.MARINE...
ISSUED AT 330 PM EDT TUE OCT 28 2014

A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH WEDNESDAY
AFTERNOON. BRISK WEST WINDS LATE THIS AFTERNOON INTO THIS EVENING
AND COOLER AIR MOVING OVER THE LAKE WATERS WILL CAUSE WAVE HEIGHTS
TO CONTINUE TO BUILD TO AS HIGH AS 5 TO 8 FEET THIS EVENING AND
OVERNIGHT. WAVE HEIGHTS WILL REMAIN HAZARDOUS TO SMALL CRAFT
THROUGH WEDNESDAY AFTERNOON AS SUGGESTED BY 12Z GLERL WAVE MODEL
GUIDANCE BEFORE FINALLY SUBSIDING LATE WEDNESDAY AFTERNOON/WEDNESDAY
EVENING.

&&

.HYDROLOGY...
ISSUED AT 330 PM EDT TUE OCT 28 2014

RAINFALL LAST NIGHT WAS NOT SIGNIFICANT ENOUGH TO CAUSE HYDRO
ISSUES AND NO HYDRO ISSUES ARE ANTICIPATED FOR THE REST OF THE
WEEK WITH MAINLY DRY WX ANTICIPATED TONIGHT THROUGH THURSDAY. PCPN
THURSDAY NIGHT AND FRIDAY WILL NOT BE SIGNIFICANT ENOUGHT TO CAUSE
HYDRO ISSUES SINCE BASIN AVG QFP AMOUNTS OF ONLY UNDER A HALF OF
AN INCH ARE ANTICIPATED THEN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...EBW
AVIATION...TJT
HYDROLOGY...LAURENS
MARINE...LAURENS







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