Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 291733
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
133 PM EDT SAT AUG 29 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 328 AM EDT SAT AUG 29 2015

SHOWERS AND A FEW THUNDERSTORMS WILL MOVE THROUGH TODAY AND
TONIGHT...THEN FAIR AND WARMER WEATHER WILL MOVE IN FOR SUNDAY AND
MUCH OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1116 AM EDT SAT AUG 29 2015

LOWERED MAX TEMPS GIVEN THE PERSISTENT CLOUDS AND RAIN. GENERALLY
UPPER 60S NW TO MID 70S SE.

THE SHOWERS WILL GRADUALLY DIMINISH FROM NW TO SE THROUGH THE
AFTERNOON AND EVENING. MOST AREAS SHOULD SEE AROUND A QUARTER INCH
OF RAIN BY EVENING.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EDT SAT AUG 29 2015

BUMPED UP POPS FOR TODAY BASED ON RADAR AND MODEL TRENDS THAT
BRING THE AXIS OF STEADIER RAIN THROUGH LOWER MICHIGAN. THE RAIN
IS ASSOCIATED WITH AREA OF LOW LEVEL CONVERGENCE ALONG A STATIONARY
FRONT EXTENDING NORTHEAST OF A SFC LOW CENTERED IN IOWA. THE FRONT
SLOWLY DISSIPATES TONIGHT AS THE UPPER TROUGH AXIS MOVES EAST WITH
SHOWERS GRADUALLY WINDING DOWN BY SUNDAY MORNING ACROSS SOUTHERN
LOWER MICHIGAN. WENT WITH ONLY SLIGHT CHANCE FOR THUNDER TODAY AND
TONIGHT AS CONVECTION IS LIMITED BY WEAK INSTABILITY AND SHEAR.

HEIGHTS BUILD ON SUNDAY AND MONDAY BUT MOIST AIRMASS IS EXPECTED
TO RESULT IN DIURNALLY ENHANCED SHOWERS ACROSS THE OHIO VALLEY AND
AS FLOW GOES MORE SOUTHERLY ON MONDAY...WE WILL HAVE TO WATCH FOR
POTENTIAL FOR ISOLATED SHOWERS ACROSS THE FAR SOUTHERN FORECAST
AREA. KEPT THAT AREA DRY FOR NOW.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT AUG 29 2015

CHANCES FOR RAIN DON`T LOOK VERY GOOD NEXT WEEK. HOWEVER CHANCES
FOR ABOVE NORMAL TEMPS DO.

THE UPPER RIDGE AXIS IS PROGD BY THE ECMWF AND GFS TO REMAIN
ANCHORED JUST WEST OF LOWER MICHIGAN THROUGH NEXT WEEK. THAT MEANS A
COUPLE OF THINGS. FIRST...SHORT WAVES AND ASSOCIATED COLD FRONTS
WILL HAVE A VERY DIFFICULT TIME ENCROACHING ON LOWER MICHIGAN. IT
ALSO MEANS THAT HEIGHT RISES UNDER THE RIDGE WILL LEAD TO WARMER
TEMPS AS THE WEEK PROGRESSES. H8 TEMPS WARM FROM AROUND 16C TO 18C
WHICH PUTS HIGHS IN THE UPPER 80S BY THE END OF THE WEEK.

THE MODELS SHOW ONE SHORT WAVE MAKING AN ATTEMPT AT PLOWING THROUGH
THE RIDGE WEDNESDAY AND THURSDAY. WE/LL INCLUDE LOW CHC POPS FOR
THIS BUT NOT REAL EXCITED ABOUT THIS. OTHERWISE HIGH PRESSURE IS
PRETTY MUCH IN CONTROL OF SW LWR MI.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 133 PM EDT SAT AUG 29 2015

WIDESPREAD RAIN IS MOVING AWAY FROM THE TERMINALS EARLY THIS
AFTERNOON. EVEN AS THIS OCCURS...CIGS ARE LOWERING AS LOW LEVEL
MOISTURE ACROSS WI IS STARTING TO MAKE ITS WAY TOWARD THE AREA.
THERE WILL BE A FEW SCATTERED SHOWERS POPPING UP THIS AFTERNOON AS
A WAVE MOVES INTO THE AREA.

SHOWERS WILL CONTINUE INTO AT LEAST THE EVENING HOURS BEFORE
DISSIPATING ACROSS THE AREA. WE ARE EXPECTING CIGS TO CONTINUE TO
LOWER...AND SOME FOG TO EVENTUALLY DEVELOP WITH LIGHTER WINDS
EXPECTED AND PLENTY OF LOW LEVEL MOISTURE AROUND. IFR AND LOWER
CONDITIONS ARE LIKELY AT ALL SITES AFTER 06Z TONIGHT AND WILL LAST
THROUGH SUNRISE SUN MORNING. CONDITIONS SHOULD GRADUALLY IMPROVE
INTO SUN AFTERNOON.

&&

.MARINE...
ISSUED AT 328 AM EDT SAT AUG 29 2015

WINDS AND WAVES WILL REMAIN LIGHT OVER THE WEEKEND. THE LIGHT
WINDS AND HIGHER HUMIDITY COULD RESULT IN AREAS OF FOG TONIGHT.


&&

.HYDROLOGY...
ISSUED AT 325 PM EDT FRI AUG 28 2015

A QUARTER TO ONE HALF INCH OF RAIN IS EXPECTED TONIGHT INTO SUNDAY
MORNING.  THIS SHOULD NOT CAUSE HYDRO CONCERNS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...JK
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...04
AVIATION...NJJ
HYDROLOGY...JK
MARINE...OSTUNO


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