Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 010902
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
402 AM CDT FRI AUG 1 2014

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 401 AM CDT FRI AUG 1 2014

PCPN TRENDS...FOG TRENDS...THE THREAT OF STRONG TO SEVERE TSTMS
THIS AFTERNOON AND EVENING...AND TEMPERATURES...ARE THE MAIN FCST
CONCERNS.

ISOLD SHRA/TSRA CONTINUED THROUGH THE OVERNIGHT HOURS IN CENTRAL
WI. THIS CONVECTION WAS OCCURRING ALONG A WEAK BOUNDARY...WHERE A
NARROW BAND OF INSTABILITY/MOISTURE WAS SITUATED. EXPECT A GRADUAL
WEAKENING TREND TO CONTINUE TOWARD DAYBREAK. AREAS OF FOG...LOCALLY
DENSE...WERE ALSO REPORTED ACROSS THE REGION...ESPECIALLY OVER NC
WI. AT THIS TIME...IT DOESN`T APPEAR THAT THE DENSE FOG WILL BE
WIDESPREAD ENOUGH TO ISSUE AN ADVISORY...SO WILL PROBABLY HANDLE
WITH AN SPS AND THE HWO. WV IMAGERY SHOWED A S/W TROF DROPPING
SOUTH THROUGH WESTERN ONTARIO. THIS FEATURE WILL LIKELY HAVE AN
IMPACT ON OUR WEATHER THIS AFTERNOON AND EARLY EVG.

DAYTIME HEATING AND THE S/W TROF APPROACHING FROM ONTARIO WILL
COMBINE TO TRIGGER SCT/NMRS TSTMS THIS AFTERNOON AND EARLY EVG.
INSTABILITY WILL INCREASE ACROSS THE CWA TODAY...WITH CAPE RANGING
FROM 500-1000 J/KG OVER THE FAR NORTH TO 2000+ J/KG IN PARTS OF
C/EC WI. SHEAR WILL BE MARGINAL...BUT IS EXPECTED TO INCREASE TO
15 TO 25 KTS LATER IN THE DAY...WHICH SHOULD BE SUFFICIENT TO
SUPPORT SCT STRONG TO SEVERE MULTICELL STORMS. WET BULB ZERO
HEIGHTS OF 9500-10000 FT ARE FAVORABLE FOR LARGE HAIL...AND WINDEX
VALUES OF 50-60 KTS SHOW SOME POTENTIAL FOR DAMAGING WINDS. THERE
HAVE BEEN A FEW REPORTS OF SVR WX AROUND THE WESTERN GREAT LAKES
REGION FOR THE PAST THREE DAYS...BUT WITH INCREASED INSTABILITY
EXPECTED TODAY...WE COULD SEE A BIT MORE ACTIVITY. SCT TSTMS WILL
LINGER INTO THE EVG HOURS...THEN TAPER OFF AS THE S/W TROF SHIFTS
EAST AND INSTABILITY WANES. CLEARING SKIES...LIGHT WINDS AND
MOISTURE FROM THE AFTERNOON/EVENING RAINS...SHOULD LEAD TO ANOTHER
ROUND OF FOG LATE TONIGHT.

EXPECT LESS CONVECTION ON SATURDAY...AS WEAK UPPER LEVEL RIDGING
OCCURS. HAVE KEPT SOME SMALL POPS OVER OUR WESTERN AND SOUTHERN
COUNTIES DURING THE AFTERNOON...WHERE SOME MARGINAL INSTABILITY
IS EXPECTED TO DEVELOP.

USED A BLEND OF THE TOP-PERFORMING GUIDANCE SETS FOR MAX/MIN
TEMPS. EXPECT HIGHS TO BE IN THE UPPER 70S AND LOWER 80S AT
MOST LOCATIONS...WITH LOW TEMPS IN THE UPPER 40S TO MIDDLE 50S.

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 401 AM CDT FRI AUG 1 2014

FROM SATURDAY NIGHT THROUGH EARLY NEXT WEEK...THE FORECAST AREA
WILL REMAIN IN THE NORTHWEST FLOW ALOFT. A FRONTAL SYSTEM IS
PROGGED TO DROP SOUTHEASTWARD OVER THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT THROUGH SUNDAY BEFORE STALLING OVER THE SOUTHWEST
HALF OF WISCONSIN. THIS FRONTAL SYSTEM WILL BE AIDED WITH A SHORT
WAVE TROUGH ON SUNDAY

AFTER MONDAY...THE FRONT IS PROGGED TO BE NEARLY STATIONARY AS
THE FLOW BECOMES MORE ZONAL. MEANWHILE HIGH PRESSURE WILL BUILD
INTO THE NORTHERN GREAT LAKES REGION. AS A RESULT POPS FOR MUCH OF
NEXT WEEK WILL LIKELY BE TAPERED FROM LITTLE OR NO PRECIP OVER FAR
NORTH CENTRAL AND NORTHEAST WISCONSIN TO HIGHER POPS SOUTHWARD. THE
FORECAST AREA WILL BE CAUGHT BETWEEN THESE SYSTEMS. THE H850
BOUNDARY ALSO INTENSIFIES MY MID WEEK NEXT WEEK WITH A SURFACE OR
H850 LOW PRESSURE REGION MOVING ALONG THIS BOUNDARY...WHICH COULD
SET UP AN AREA OF HEAVY RAIN. PWATS CLIMB TO 1.50 TO 1.75 INCHES
BY TUESDAY OVER THE SOUTHWEST HALF OR TWO THIRDS OF THE STATE. FOR
PROG COMPARISON...THE 00Z GFS INDICATES THE BOUNDARY IS MAINLY
SOUTH OF THE AREA ALONG WITH THE HEAVY RAIN. THE 12Z ECMWF WAS A
BIT FURTHER NORTH WITH MORE RAIN INTO CENTRAL WISCONSIN BUT THE
LATER 00Z RUN HAS ALSO TRENDED SOUTHWARD.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1014 PM CDT THU JUL 31 2014

FOG AGAIN TO BE ISSUE OVERNIGHT WITH LIGHT WINDS AND CLEARING.
HAVE TRENDED TOWARDS LAST NIGHTS VSBY FOR TAFS...DROPPING VSBYS A
BIT IN SOUTHERN FOX VALLEY AS MAIN AREA OF PCPN TODAY MOVED
THROUGH THERE. ANOTHER DAY OF DAYTIME SHOWERS AND STORMS EXPECTED
FRI AS UPPER LOW CONTINUES TO SPIN TO OUR NORTHEAST.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....KIECKBUSCH
LONG TERM......TDH
AVIATION.......TE





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