Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 221751
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1251 PM CDT TUE JUL 22 2014

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.UPDATE...
ISSUED AT 604 AM CDT TUE JUL 22 2014

A 555 AM THE MAIN CLUSTER OF STRONGER STORMS HAD MOVED NORTHWARD INTO
UPPER MICHIGAN. MORE SHOWERS AND STORMS WILL LIKELY PASS OVER
NORTHERN WISCONSIN THIS MORNING AS THE SHORT WAVE TROUGH AND
SURFACE LOW SHIFT EAST OVER THE UP...HOWEVER THE MID LEVEL CAP
EDGE APPEARS TO BE LIMITING SVR DEVELOPMENT SOUTHWARD THIS
AM...THEREFORE THE SVR WATCH HAS BEEN CANCELED. NEXT CHANCE OF
STORMS MAY BE ALONG THE COLD FRONT THIS AFTERNOON AND
EVENING...BUT ITS POSSIBLE THE CAP WILL CONTINUE TO LIMIT
CONVECTION OVER THE FORECAST AREA. A WEAK SHORT WAVE BETWEEN
500-300 MB LEVEL AND SOME H300 DIFFLUENCE MAY TRY TO BREAK THE
CAP IN THE UNSTABLE AIR MASS LATER TODAY...BUT NOT REALLY A STRONG
TRIGGER ALOFT.
&&

.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 300 AM CDT TUE JUL 22 2014

LINE OF STRONG TO SEVERE STORMS AHEAD OF SHORT WAVE TROUGH AND
SURFACE LOW TRACKING OVER MINNESOTA EARLY THIS MORNING WERE MOVING
INTO FAR NORTHWEST WISCONSIN TOWARD NORTH CENTRAL WISCONSIN.  MAIN
LINE OF STORMS MAINTAINING INTENSITY AND ALONG THE WESTERN EDGE OF
THE CAP EDGE. SOME NORTH TO SOUTH LIGHTER CONVECTION DEVELOPED
WITHIN THE CAP EDGE OR JUST EAST BUT HAS NOT INCREASED IN
INTENSITY. A SUBTLE WARM FRONT WAS LOCATED OVER NORTHERN WISCONSIN
WITH SOME INCREASE IN SURFACE TEMPS NOTED EARLY THIS MORNING. A
SEVERE WATCH WAS POSTED FOR NORTH CENTRAL WISCONSIN TO HANDLED THE
SOUTHERN PORTION OF THIS LINE WORKING ON THE CAP EDGE PERIMETER.
MAIN THREAT WILL BE WIND DAMAGE IF STORMS CAN MAINTAIN INTENSITY
NEXT FEW HOURS.

OTHERWISE THE FORECAST ISSUE CENTERS ON THE COVERAGE OF
ADDITIONAL CONVECTION TODAY INTO THIS EVENING AS THE SHORTWAVE
TROUGH AND SURFACE LOW DRAG A COLD FRONT OVER THE REGION. CAP EDGE
TO THE SOUTH MAY LIMIT CONVECTION BUT IF STORMS CAN
DEVELOP...POTENTIAL TO BE STRONG TO SEVERE AGAIN FOR THE SOUTHEAST
HALF OF THE STATE AND AREAS SOUTHEAST OF THE COLD FRONT.
CONVECTION WOULD LIKELY AFFECT PARTS OF EAST CENTRAL WISCONSIN
THROUGH THIS EVENING BEFORE DEPARTING SOUTHEAST.

COOLER DRIER AIR TO FILTER INTO THE REGION LATER TUESDAY NIGHT
INTO WEDNESDAY.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 300 AM CDT TUE JUL 22 2014

NO SIGNIFICANT CHANGES TO THE EXPECTED UPPER AIR PATTERN OVER THE
NEXT WEEK.  STILL LOOKING FOR AN UPPER LEVEL LOW TO UNDERCUT A
CENTRAL CANADA RIDGE BEFORE DROPPING INTO THE GREAT LAKES AND
FORMING A DEEP EASTERN NOAM TROUGH BY THE END OF THE PERIOD.  SPREAD
IN THE MODELS HAS INCREASED A BIT IN THE MEDIUM RANGE AS THE ECMWF
HAS SLOWED DOWN THE UPPER LOW INTO THE GREAT LAKES.  THE GFS/GEM/AND
GFS ENSEMBLE MEAN ARE IN BETTER AGREEMENT AND WILL USE A BLEND OF
THESE MODELS.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...THIS WILL BE A QUIET PERIOD
OF WEATHER AS CANADIAN HIGH PRESSURE MOVES ACROSS THE REGION.  THE
MODELS IN PREVIOUS RUNS HAVE SUGGESTED A CHANCE OF PRECIP DUE TO A
PUSH OF MID-LEVEL THETAE THURSDAY NIGHT...BUT THEY HAVE SLOWED DOWN THIS
THETAE PUSH WHILE THE LOW LEVELS REMAIN JUST AS DRY.   SO ANTICIPATE
MOSTLY CLEAR TO CLEAR CONDITIONS OVER THE PERIOD.  WILL BUMP UP
HIGHS A DEGREE OR TWO ON THURSDAY BASED ON LOW LEVEL TEMPS.  HIGHS
IN THE MID TO UPPER 70S ON THURSDAY AND LOWS IN THE 40S AND 50S.

REST OF THE FORECAST...THE WARM ADVECTION MOVES ACROSS WESTERN AND
CENTRAL WISCONSIN ON FRIDAY AND INTO EASTERN WISCONSIN FRIDAY
NIGHT.  AS A RESULT...CHANCES OF PRECIP WILL IMPROVE FROM WEST TO
EAST DURING THIS TIME.  THEN A TROUGH WILL MOVE ACROSS THE REGION ON
SATURDAY WHICH WILL KEEP SHOWERS AND ISOLATED STORMS IN THE
FORECAST.  UNSETTLED CONDITIONS WILL CONTINUE INTO EARLY NEXT WEEK
AS THE UPPER LOW FINALLY DROPS THROUGH THE REGION.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1241 PM CDT TUE JUL 22 2014

A COLD FRONT EXTENDS FOR KMNM TO KCWA AT 17Z...A LINE OF CU MARK
THE FRONT. WARM AIR MASS AHEAD OF FRONT PUTTING A CAP ON
CONVECTIVE DEVELOPMENT. MODELS AND TRENDS SUGGEST FRONT TO PASS
DRY...WITH GUSTY SOUTHWEST TO WEST WINDS BEING ISSUE. SOME CIGS
WITH CU IN 3K RANGE WITH CLEARING EXPECTED THIS EVENING AS SFC
HIGH PRESSURE BUILDS IN.

THE TAF FOR OSHKOSH WITMANN REGIONAL AIRPORT IS NOW BEING
PRODUCED BY THE NATIONAL WEATHER SERVICE IN GREEN BAY IN SUPPORT
OF THE EAA AIR VENTURE.
&&

.MARINE...
ISSUED AT 300 AM CDT TUE JUL 22 2014

STRONG AND GUSTY SW WINDS TO LEAD TO SMALL CRAFT
CONDITIONS ON TUESDAY. HIGH WAVES AND STRONG CURRENTS WILL
CONTINUE ALONG THE LAKE MI COAST.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT UNTIL 9 PM CDT THIS EVENING FOR WIZ022-
040-050.
&&

$$

UPDATE.........TDH
SHORT TERM.....TDH
LONG TERM......MPC
AVIATION.......TE
MARINE.........TDH








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