Area Forecast Discussion
Issued by NWS Green Bay, WI

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000
FXUS63 KGRB 190203 AAA
AFDGRB

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREEN BAY WI
903 PM CDT MON AUG 18 2014

NEW INFORMATION ADDED TO UPDATE SECTION

.UPDATE...
ISSUED AT 902 PM CDT MON AUG 18 2014

HEAVY RAINS WHICH FELL OVER CENTRAL AND EAST CENTRAL WISCONSIN
MONDAY HAS SATURATED THE GROUND. OF CONCERN TONIGHT IS THE NEAR
STATIONARY BOUNDARY FROM SOUTHEAST MINNESOTA TO SHEBOYGAN AND A
FOCUS OF MORE HEAVY RAINFALL WITH APPROACHING STORMS OVER
SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN. ITS POSSIBLE THIS
NEXT CLUSTER OF HEAVY RAINS COULD STAY SOUTH OF THE FORECAST AREA
BUT THEIR IS GOOD POTENTIAL THE STORMS COULD BUILD BACK NORTH AS
THE LOW PRESSURE SYSTEM MOVES INTO WESTERN WISCONSIN. A WEST TO
EAST RIBBON OF POOLING PWATS OF 1.60 INCHES LIES OVER CENTRAL AND
EAST CENTRAL WISCONSIN FOR THE STORMS TO WORK WITH. 850/300
THICKNESS FIELDS ALSO SUGGEST A WEST TO EAST ORIENTATION.
&&

.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 351 PM CDT MON AUG 18 2014

THUNDERSTORMS CHANCES AND HEAVY RAINFALL ARE THE MAIN CONCERNS
THOUGH TUESDAY.

STORMS DEVELOPED THIS AFTERNOON NEAR A SURFACE WARM FRONT THAT WAS
ACROSS THE SOUTHWEST THIRD OF THE FORECAST AREA AS OF 19Z. WATER
VAPOR IMAGERY SHOWED SOME SHORT WAVE ENERGY MAKING ITS WAY INTO
THE STATE AS WELL...AND LOCAL MESOANALYSIS INDICATED MUCAPE VALUES
IN THE 500-2000J/KG RANGE BEHIND THE FRONT WHERE TEMPERATURES WERE
IN THE LOWER TO MIDDLE 80S AND DEW POINTS WERE IN THE MID 60S TO
LOWER 70S. 12Z SOUNDING FROM KMPX AND KGRB BOTH HAD PWATS OF AT
LEAST 1.6 INCHES AND BUFKIT SHOWED LONG SKINNY CAPE AT KGRB SO
HEAVY RAIN LOOKS LIKE A GOOD BET.

WOULD EXPECT STORMS TO CONTINUE THROUGH AT LEAST EARLY
EVENING...PRODUCING HEAVY RAINFALL AND POSSIBLY SOME HAIL AND
GUSTY WINDS. MORE STORMS WERE UPSTREAM IN WESTERN
WISCONSIN...EAST OF A COLD FRONT AND AHEAD OF AN APPROACHING UPPER
LEVEL CYCLONE SO PERIODS OF SHOWERS AND STORMS WILL CONTINUE
TONIGHT AND INTO TUESDAY UNTIL THE UPPER SYSTEM MOVES AWAY.

.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 351 PM CDT MON AUG 18 2014

CLOSED LOW WILL MOVE SLOWLY SOUTHEAST INTO NORTHERN
LOWER MICHIGAN TUESDAY NIGHT AS A COLD FRONT EXITS THE AREA. DRIER
AIR AND SUBSIDENCE BEHIND IT SHOULD CAUSE ANY REMAINING SHOWERS TO
DISSIPATE AND WE SHOULD HAVE DRY AND SEASONABLE WEATHER WEDNESDAY
AND WEDNESDAY NIGHT.

THE FRONT IS FORECAST TO RETURN NORTHWARD THURSDAY AS UPPER FLOW
BECOMES SOUTHWEST. THIS SHOULD PRODUCE AN AREA OF ELEVATED SHOWERS
AND THUNDERSTORMS AS IT APPROACHES FROM THE SOUTHWEST. THE MODELS
SUGGEST IT WILL STALL TO OUR SOUTH AND WE MAY HAVE DRY WEATHER
FRIDAY UNTIL IT MOVES NORTH AGAIN SATURDAY. IF THE FRONT GETS
NORTH OF THE FORECAST AREA SATURDAY AFTERNOON IT COULD GET UP TO
90F ACROSS THE SOUTH BUT THESE FRONTS OFTEN GET HELD UP BY COLD
OUTFLOW OR SOUTHEAST FLOW OVER COOL LAKE MICHIGAN. ALL THE MODELS
SUGGEST THAT A COLD FRONT WILL MOVE THROUGH SUNDAY WITH DRY AND
COOLER WEATHER TO FOLLOW.
&&

.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 711 PM CDT MON AUG 18 2014

THERE MAY BE SOME PERIODS OF VFR CONDITIONS WITHOUT THUNDERSTORMS
AROUND BUT THEY WILL PROBABLY NOT LAST FOR LONG. THERE WAS PLENTY
OF MOISTURE AND LOTS OF BOUNDARIES...FRONTS AND OUTFLOWS...ACROSS THE
AREA THIS EVENING. SHOWERS AND THUNDERSTORMS DEVELOPED THIS
AFTERNOON AND WERE ONGOING DURING THE EARLY EVENING. WOULD EXPECT
VFR OR MVFR CIGS IN CENTRAL AND EAST CENTRAL WISCONSIN...WITH
AREAS OF IFR OR MVFR VSBYS IN SHOWERS AND STORMS. FARTHER NORTH
CIGS WILL BE MOISTLY IN THE IFR CATEGORY...UNTIL THE FRONT
PASSES...WITH MVFR AND IFR VSBYS IN FOG AND SOME SHOWERS AND
STORMS. EXPECT MINOR IMPROVEMENT IN CONDITIONS DURING THE MORNING
ON TUESDAY BEFORE CIGS AND VSBYS LOWER DURING THE AFTERNOON.
&&

.HYDROLOGY...
ISSUED AT 351 PM CDT MON AUG 18 2014

WILL CONTINUE THE HYDROLOGIC OUTLOOK FOR THE
POSSIBILITY OF HEAVY RAINS WITH WEAK UPPER WINDS AND HIGH MOISTURE
IN THE ATMOSPHERE ALLOWING FOR SLOW MOVING STORMS AND VERY HEAVY
RAINS.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 AM CDT TUESDAY FOR WIZ035>040-045-
048>050.
&&

$$

UPDATE.........ECKBERG/TH
SHORT TERM.....MG
LONG TERM......RDM
AVIATION.......MG
HYDROLOGY......RDM







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