Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 261143
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
743 AM EDT SUN OCT 26 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT SUN OCT 26 2014

A WARM FRONT MOVING NORTH THROUGH MICHIGAN LATE TONIGHT AND EARLY
MONDAY WILL TRIGGER A FEW SCATTERED SHOWERS AND THUNDERSTORMS...
MAINLY NORTH OF INTERSTATE 96. MONDAY WILL BE UNSEASONABLY WARM WITH
HIGH TEMPERATURES 10 TO 20 DEGREES ABOVE NORMAL.

A COLD FRONT SWEEPING IN FROM THE WEST LATE MONDAY NIGHT AND EARLY
TUESDAY WILL BRING A PERIOD OF SHOWERS AND THUNDERSTORMS FOLLOWED BY
A RETURN TO MORE NORMAL TEMPERATURES FOR THIS TIME OF YEAR. A VERY
CHILLY AIR MASS IS EXPECTED TO ARRIVE ON HALLOWEEN WITH A CHANCE OF
MIXED RAIN AND SNOW SHOWERS.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 330 AM EDT SUN OCT 26 2014

OVERALL THIS DOES NOT LOOK LIKE A SIGNIFICANT CONVECTIVE EVENT FOR
SOUTHWEST MICHIGAN. MOST OF THE FORCING WITH THE WARM FRONT LATE
TONIGHT AND EARLY MONDAY IS FOCUSED TO OUR NORTH AND THE LATE NIGHT
ARRIVAL OF THE COLD FRONT MONDAY NIGHT DOES NOT REALLY FAVOR ROBUST
CONVECTION. THE OTHER POTENTIAL NEGATIVE FACTOR WITH THIS SYSTEM IS
THE CURRENT LACK OF MOISTURE AS NOTED BY CLOUD FREE SKIES AT THIS
HOUR COVERING A LARGE PART OF THE CONUS. THIS MAY LIMIT THE COVERAGE
OF SHOWERS AND THUNDERSTORMS.

DESPITE DEEP LAYER SHEAR IN EXCESS OF 30 KTS... STRONG TO SEVERE
STORMS ARE UNLIKELY SINCE THE CONVECTION WILL BE MOSTLY ROOTED ABOVE
THE BOUNDARY LAYER WITH LITTLE TO NO SFC INSTABILITY PROGGED. H8-H5
THETA E LAPSE RATES ARE PROGGED TO BE NEGATIVE AND THIS DOES
SUPPORT THE RISK OF ELEVATED STORMS WITH PERHAPS SOME SMALL HAIL.
SHOWERS AND STORMS SHOULD END BY NOON TUESDAY AS THE MID LEVEL DRY
SLOT ARRIVES RAPIDLY FROM THE SOUTHWEST BEHIND THE EXITING COLD
FRONT.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM EDT SUN OCT 26 2014

THE COLDER AIR SHOULD CONTINUE TO POUR INTO SW MI TO START THE LONG
TERM PERIOD.  H8 TEMPS OF -2C TO -3C SUPPORT AT LEAST SOME WEAK LAKE
EFFECT WITH INVERSION HEIGHTS AROUND 5K FT.  I BUMPED POPS UP A BIT
TUESDAY NIGHT AS THE FLOW SHOULD BE WESTERLY...CARRYING THE RAIN
SHOWERS INLAND.  ANY LAKE EFFECT SHOULD WIND DOWN ON WED AS
ANTICYCLONIC FLOW DEVELOPS.

ANOTHER SHORT WAVE IS PROGGED OVER THE REGION BY THURSDAY NIGHT.  IT
IS THIS WAVE THAT DROPS OUT OF CENTRAL CANADA THAT SHOULD GIVE US A
BRIEF SHOT OF WINTRY WEATHER.  THE SYNOPTIC WAVE SHOULD GIVE US
ANOTHER CHANCE FOR RAIN SHOWERS THURSDAY AFTERNOON INTO THURSDAY
NIGHT.  THEN THE THERMAL TROUGH WILL BE OVER THE AREA FOR FRIDAY AND
HALLOWEEN NIGHT.  THIS SHOULD SPARK MORE LAKE EFFECT WHICH SHOULD
MIX OR CHANGE TO SNOW AT TIMES... MAINLY ALONG AND NORTH OF I-96.
THERE SHOULD ALSO BE A DECENT AMOUNT OF WIND...WHICH COULD BRING
WINDS CHILLS AS LOW AS THE LOWER 20S FOR TRICK OR TREAT NIGHT.  THE
FLOW BECOMES MORE NORTHERLY INTO FRIDAY NIGHT...SO MOST OF THE LAKE
EFFECT BY THEN SHOULD BE HUGGING THE COAST.  HIGH PRESSURE APPEARS
TO BUILD IN BY SATURDAY GIVING SW MI DRY WEATHER AS THE COLDEST OF
THE AIR BEGINS TO MOVE OUT OF THE REGION.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 743 AM EDT SUN OCT 26 2014

CONFIDENCE IS HIGH THAT VFR CONDITIONS WILL CONTINUE TODAY AND
TONIGHT. THE RISK OF TSTMS LATE TONIGHT IS NOT HIGH ENOUGH TO
MENTION IN ANY OF THE TAFS ALTHOUGH DID INCLUDE A VCSH REMARK IN
THE MKG TAF AS A CLOUD DECK WITH BASES OF 5000-8000 FT MOVES IN
FROM THE SOUTHWEST LATE TONIGHT.

&&

.MARINE...
ISSUED AT 330 AM EDT SUN OCT 26 2014

SMALL CRAFT ADVISORIES CONTINUE BUT WINDS WILL BE DECREASING TODAY
WITH THE ARRIVAL OF THE SFC RIDGE. WE MAY BE ABLE TO CANCEL THE
CURRENT HEADLINE A BIT EARLY. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED AGAIN ON TUESDAY IN THE WESTERLY FLOW COLD ADVECTION BEHIND
THE COLD FRONT.


&&

.HYDROLOGY...
ISSUED AT 1157 AM EDT SAT OCT 25 2014

DRY CONDITIONS WILL HOLD THROUGH MUCH OF THE WEEKEND WHILE THE
UPCOMING WEEK GETS A BIT MORE ACTIVE.

PRECIPITATION CHANCES WILL INCREASE GOING INTO LATE SUNDAY
NIGHT. SHOWERS AND A FEW STORMS MAY DEVELOP WHICH COULD TOTAL ONE
TENTH TO ONE QUARTER OF AN INCH OF RAIN. A BRIEF LULL IS EXPECTED
DURING THE DAY MONDAY...AHEAD OF A STRONG COLD FRONT THAT IS
ANTICIPATED TO MOVE THROUGH LATE MONDAY NIGHT AND TUESDAY MORNING.
THIS SHOULD BRING ADDITIONAL PRECIPITATION TO THE REGION WITH
ANOTHER QUARTER INCH OR SO OF RAIN. PRECIPITATION TOTALS WILL
BE DEPENDENT ON ANY THUNDERSTORM DEVELOPMENT...MEANING THAT
THUNDERSTORM AFFECTED AREAS HAVE A GREATER CHANCE AND EXCEEDING
THE AFOREMENTIONED EXPECTATIONS. THAT SAID...RECENT DRY WEATHER
AND PROBABILITIES OF ANY BIG IMPACT PRECIPITATION IS LOW. NO RIVER
FLOODING IS ANTICIPATED AT THIS TIME.

&&

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

&&

$$

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






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