Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 220017
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
817 PM EDT SUN SEP 21 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 259 PM EDT SUN SEP 21 2014

SHOWERS OVER THE AREA THIS AFTERNOON WILL ROTATE OUT OF THE AREA TO
THE EAST BY EARLY THIS EVENING. SKIES WILL GRADUALLY CLEAR A BIT
INLAND WITH SOME PATCHY FROST POSSIBLE UP NORTH. SOME LAKE EFFECT
CLOUD COVER WILL HOLD ON ALONG THE IMMEDIATE LAKESHORE TONIGHT. ANY
CLOUDS LEFT OVER ON MONDAY MORNING WILL DIMINISH DURING THE DAY.
HIGH PRESSURE WILL BRING QUIET AND MILD WEATHER TO THE AREA THEN FOR
THE REST OF THE WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 259 PM EDT SUN SEP 21 2014

THE ONLY REAL ISSUES IN THE SHORT TERM ARE CLOUD COVER TRENDS FOR
TONIGHT AND FROST POTENTIAL UP NORTH FOR TONIGHT.

THE RAIN SHOWERS IMPACTING THE AREA TODAY WILL STEADILY DIMINISH
THROUGH THE EARLY EVENING HOURS THIS EVENING FROM NW TO SE. UPPER
LOW RESPONSIBLE FOR THE RAIN SHOWERS IS CURRENTLY LOCATED ACROSS THE
SE HALF OF THE CWFA AS OF 1830Z THIS AFTERNOON. IT IS STEADILY
ROTATING TO THE E/SE AND WILL MOVE OUT EARLY THIS EVENING. THE WRAP
AROUND MOISTURE IS ACROSS THE ERN HALF OF THE CWFA AND WILL ROTATE
OUT.

CLOUD COVER SHOULD DIMINISH ACROSS INLAND AREAS THIS EVENING...WITH
SOME CLOUDS HOLDING ON ALONG THE LAKESHORE OVERNIGHT TONIGHT. AS THE
UPPER LOW MOVES EAST AND WE LOSE DIURNAL HEATING...MORE CLEARING
SHOULD TAKE PLACE INLAND. H850 TEMPS OF AROUND 3-6C TONIGHT WILL
ALLOW FOR ENOUGH OVER-LAKE INSTABILITY TO ALLOW FOR SOME CLOUDS TO
REMAIN RIGHT ALONG THE COAST WITH A NNW FLOW EXPECTED. FCST
SOUNDINGS INDICATE A FAIRLY STRONG SUBSIDENCE INVERSION BUILDING IN
OVERNIGHT. THIS WILL LIMIT THE CONVECTIVE CLOUD DEPTH AND KEEP THE
CHANCE OF RAIN SHOWERS LOW ENOUGH TO KEEP IT OUT OF THE FCST.

THE INLAND CLEARING AND WINDS DIMINISHING WILL ALLOW TEMPS TO COOL
OFF QUICKLY TONIGHT. TEMPS HAVE THE POTENTIAL TO COOL OFF ENOUGH FOR
A CHANCE OF FROST UP NORTH. THE UNCERTAINTY WITH FROST TONIGHT LIES
IN THE AMOUNT OF CLOUD COVER AND AMOUNT OF WIND THAT REMAINS UP. IT
SEEMS THAT A WIDESPREAD FROST IS UNLIKELY TONIGHT WITH A FAIRLY
MOIST AIR MASS STILL IN PLACE AND SOME CLOUD COVER POSSIBLE FROM
LAKE EFFECT OVER NRN LOWER. WE CONTINUED THE PATCHY FROST WORDING
FOR NOW...AND WILL MONITOR THE POTENTIAL FOR MORE WIDESPREAD
FROST.

THE REMAINDER OF THE SHORT TERM FROM MON THROUGH TUE NIGHT LOOKS
VERY QUIET AND INCREASINGLY MILD. THE UPPER LOW ACROSS THE GREAT
BASIN TODAY WILL SLOWLY MOVE INTO THE PLAINS STATES THROUGH MID
WEEK. WE WILL SEE THE EFFECTS FROM THE RIDGE DOWNSTREAM OF THIS LOW
SLOWLY BUILD IN OVER THE AREA. WE WILL SEE TEMPS ALOFT RECOVER VERY
NICELY WHICH WILL HELP THE SFC TEMPS FOR THE AREA REBOUND INTO THE
70S.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 259 PM EDT SUN SEP 21 2014

QUIET WEATHER EXPECTED IN THE EXTENDED PERIOD AS THE GREAT LAKES
REGION IS DOMINATED BY STRONG RIDGING AT THE SFC AND ALOFT. WITH DRY
SOUNDINGS AND GENERAL SUBSIDENCE WE SHOULD SEE TEMPERATURE RANGES
GREATER THAN GUIDANCE...WITH MAXES A BIT WARMER AND MINS A BIT
COOLER.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 817 PM EDT SUN SEP 21 2014

CEILINGS ARE MVFR ACROSS MUCH OF THE AREA AT 00Z...BUT THERE ARE
SOME VFR SPOTS SHOWING UP. CLEARING IS EVEN MOVING INTO THE
LAKESHORE. WENT PESSIMISTIC THOUGH IN THE 00Z TAFS AS MODELS SHOW
MOISTURE ROTATING BACK IN FROM THE NORTH THROUGH THE COURSE OF THE
NIGHT. THE WESTERN TAF SITES MAY BE ON THE BACK EDGE OF THIS
MOISTURE THOUGH AND CONFIDENCE IS NOT HIGH OVERALL IN HOW CLOUDS
EVOLVE. THE BOTTOM LINE THOUGH...WE ARE IN CYCLONIC FLOW AND DELTA
T/S OFF THE LAKE EVEN SUPPORT STRATOCUMULUS DEVELOPMENT. ALL OF
THIS POINTS TOWARDS CLOUDS TRYING TO HANG IN. HAVE MVFR CONDITIONS
THROUGH ABOUT SUNRISE THEN GOING VFR FOR THE REMAINDER OF THE TAF
PERIOD.

WINDS WILL GRADUALLY DIMINISH THIS EVENING...WITH MUCH OF THE
GUSTINESS GONE BY MIDNIGHT OR SO. NORTHWEST WINDS OF 6-11 KNOTS
WILL TREND WESTERLY ON MONDAY AFTERNOON.

&&

.MARINE...
ISSUED AT 800 PM EDT SUN SEP 21 2014

ALLOWED THE GALE WARNING TO EXPIRE AND REPLACED WITH A SMALL CRAFT
ADVISORY. WINDS WILL CONTINUE TO TAIL OFF THROUGH THE NIGHT. WAVES
WILL TAKE UNTIL MORNING TO SUBSIDE.


&&

.HYDROLOGY...
ISSUED AT 259 PM EDT SUN SEP 21 2014

OBSERVED RAINFALL FROM YESTERDAY THROUGH THIS MORNING HAS RANGED
FROM A QUARTER INCH TO OVER 1.5 INCHES ACROSS THE AREA. MODEST RISES
ARE ONGOING ON SOME RIVERS BUT ALL ARE STILL WELL BELOW BANKFULL.
SEVERAL GAGES HAVE REPORTED CRESTS IN THE PAST FEW HOURS. ONLY
CONCERN ARE SOME OF THE CREEKS IN SOUTH CENTRAL MI...WHERE GENERALLY
HIGHER RAINFALL TOTALS HAVE BEEN OBSERVED AND WHERE LIGHT TO
MODERATE RAIN WILL CONTINUE FOR A FEW MORE HOURS. HOWEVER...FLOODING
IS NOT EXPECTED. BEYOND TODAY...THE UPCOMING WEEK LOOKS DRY WITH NO
HYDRO CONCERNS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...DUKE
HYDROLOGY...CAS
MARINE...JK






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