Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 291821
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
221 PM EDT MON JUN 29 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 329 AM EDT MON JUN 29 2015

A BIT OF AN UNSETTLED PERIOD IS EXPECTED EARLY THIS WEEK AS WE SEE
SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY. THE SHOWERS AND STORMS
SHOULD BE MOST NUMEROUS IN THE AFTERNOON AND EVENING HOURS AS THEY
WILL BE DRIVEN SOMEWHAT BY THE HEATING OF THE DAY. HIGHS INTO MID
WEEK WILL GENERALLY BE IN THE 70S WHICH WILL BE SLIGHTLY COOLER THAN
NORMAL FOR THIS TIME OF YEAR.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 329 AM EDT MON JUN 29 2015

MAIN FOCUS OF THE SHORT TERM WAS ON SHOWER AND STORM CHANCES THROUGH
THE PERIOD. A SHORTWAVE WILL BE WORKING THROUGH THE REGION TODAY AND
ANOTHER ONE IS FORECAST TO MOVE THROUGH ON TUESDAY. TODAY/S
SHORTWAVE IS SEEN MOVING THROUGH THE AREA EARLY THIS MORNING WHILE
TUESDAY/S IS CLEARLY NOTED OVER MANITOBA IN THE WATER VAPOR IMAGERY.

EACH SHORTWAVE SHOULD ENHANCE PRECIPITATION CHANCES AS IT MOVES
THROUGH...WITH A DIURNAL FLARE TO THE PRECIPITATION EACH DAY. THE
GFS SHOULD CAPE VALUES INCREASING INTO THE 1000-2000 J/KG RANGE
TODAY AND ON TUESDAY AND RISING INTO THE 500-1000 RANGE ON
WEDNESDAY. HAVE HIGHER POPS 30-60 PCT DURING THE DAY TIME HOURS WITH
CHANCES DROPPING TO ZERO-20 PCT OVERNIGHT. RIDGING IS TRYING TO
BUILD IN FOR WEDNESDAY SO THINK CHANCES ARE A LITTLE BIT LESS THEN.

OVERALL NOT EXPECTING WIDESPREAD RAINS...BUT SCATTERED SHOWERS AND
STORMS SHOULD BUBBLE UP EACH DAY. THINKING TUESDAY IS REALLY OUR
BEST CHANCE AS THE SHORTWAVE PASSAGE SHOULD CORRESPOND TO NEAR PEAK
HEATING. WIND FIELDS AND SHEAR VALUES ARE PRETTY LIGHT/LOW...SO NOT
EXPECTING ANY SEVERE WEATHER. LIGHTNING...SMALL HAIL POSSIBLY AND
SOME LOCALLY HEAVY DOWNPOURS SHOULD BE THE MAIN THREATS.

HIGHS WILL BE TEMPERED BY DIURNALLY DRIVEN CLOUD COVER AND SHOULD
MAINLY BE IN THE 70S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 AM EDT MON JUN 29 2015

DRY WEATHER WITH SEASONABLE TEMPERATURES IS ANTICIPATED WEDNESDAY
NIGHT THROUGH THURSDAY AS A SURFACE HIGH PRESSURE RIDGE BUILDS IN. A
LOW PRESSURE SYSTEM AND UPPER LEVEL DISTURBANCE MOVING IN FROM THE
NORTHWEST WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS VERY LATE
IN THE WEEK.

AT THIS TIME AN OVERALL MEDIUM RANGE GUIDANCE CONSENSUS SUGGESTS
THAT MAINLY DRY WX CAN BE ANTICIPATED THIS WEEKEND AS RIDGING AT THE
SFC BUILDS IN AND THE UPPER LEVEL PATTERN BECOMES MORE ZONAL.
TEMPERATURES SHOULD MODERATE A BIT AND REACH THE LOWER 80S BOTH
SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 138 PM EDT MON JUN 29 2015

AS EXPECTED...SCT SHOWERS/STORMS HAVE DEVELOPED EARLY THIS
AFTERNOON AND THEY WILL CONTINUE UNTIL EARLY EVENING. MOSTLY VFR
EXPECTED. HOWEVER MVFR CIGS MAY DEVELOP OVER THE SOUTHERN TAF
SITES THIS AFTERNOON.

MVFR/IFR FOG/CIGS MAY DEVELOP OVERNIGHT AS SKIES CLEAR. ABUNDANT
LOW LEVEL MOISTURE REMAINS FROM RECENT RAINS.


&&

.MARINE...
ISSUED AT 329 AM EDT MON JUN 29 2015

OVERALL LIMITED MARINE CONCERNS WITH A FAIRLY WEAK WIND REGIME IN
PLACE THE NEXT COUPLE OF DAYS. WAVES SHOULD GENERALLY BE 2 FEET OR
LESS THROUGH WEDNESDAY. TUESDAY NIGHT IT DOES APPEAR NORTH WINDS
KICK UP TOWARDS 15 KNOTS...BUT NOT EXPECTING MUCH MORE THAN SOME 2-3
FOOTERS AT THE PEAK.


&&

.HYDROLOGY...
ISSUED AT 220 PM EDT MON JUN 29 2015

SEVERAL RIVER FLOOD ADVISORIES REMAIN AT SOME POINTS IN THE GRAND
AND KALAMAZOO RIVER BASINS. RIVER LEVELS AT MOST LOCATIONS ARE
FALLING. SHOWERS AND THUNDERSTORMS TODAY AND TUESDAY MAY PRODUCE
LOCALLY HEAVY RAINFALL... BUT BASIN AVERAGE RAINFALL AMOUNTS WILL
BE RATHER LOW AND SHOULD NOT IMPACT THE LARGER RIVERS. NO
WIDESPREAD HEAVY RAIN EVENTS ARE EXPECTED THIS WEEK.

&&

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

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...LAURENS
AVIATION...04
HYDROLOGY...CAS
MARINE...DUKE



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