480
FXUS63 KGRB 101704
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1204 PM CDT MON AUG 10 2026
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
UPDATE
ISSUED AT 519 AM CDT MON AUG 10 2026
MID CLOUDS CLEARING OUT EARLY THIS MORNING HAS ALLOWED FOG TO
INCREASE IN COVERAGE NORTH AND WEST OF WAUSAU, EXTENDING TO THE
U.P. BORDER. AS TEMPS HAVE FALLEN BELOW CROSSOVER TEMPS (LOWEST
DEWPOINT DURING THE PEAK OF HEATING ON SUNDAY), AREAS OF DENSE FOG
HAVE FORMED WITH MANY OBS REPORTING VISIBILITY LESS THAN ONE-HALF
MILE. WEBCAMS SHOW SOME DENSE FOG AS WELL, SUGGESTING THIS IS NOT
JUST TYPICAL SHALLOW GROUND FOG. HAVE ISSUED A DENSE FOG ADVISORY
FOR PORTIONS OF CENTRAL AND NORTH-CENTRAL WI UNTIL 10 AM. SOME
FOG EXPECTED AWAY FROM THESE AREAS, BUT SHOULD STAY MORE PATCHY.
KEY MESSAGES
- WARMER TODAY, WITH HIGHS IN THE LOWER TO MIDDLE 80S. HIGHS IN
THE 80S THROUGH WEDNESDAY, THEN SLIGHTLY COOLER LATE THIS WEEK.
- DRY TODAY, THEN POTENTIAL FOR ADDITIONAL ROUNDS OF SHOWERS AND
STORMS LATE TONIGHT THROUGH MIDDLE OF THE WEEK. AT THIS TIME,
RISK OF SEVERE STORMS IS LOW.
DISCUSSION
ISSUED AT 1250 AM CDT MON AUG 10 2026
TODAY INTO THIS EVENING...SCATTERED CLOUDS AND SOME FOG (LOCALLY
DENSE) EARLY WILL GIVE WAY TO MOSTLY SUNNY SKIES IN THE AFTERNOON
AS WE WILL BE NORTH OF FRONT THAT IS MOVING THROUGH EARLY THIS
MORNING. A COUPLE CAMS HINT THAT IF SOME ELEVATED SHOWERS FORM IN
EASTERN SD THIS MORNING, THEY COULD DRIFT OVER OUR SOUTHERN AREAS
THIS AFTERNOON. SOMETHING TO WATCH, BUT MOST GUIDANCE KEEPS US
DRY, SO WILL RIDE WITH THAT IDEA. DRY WEATHER AND MORE SUN THAN
SUNDAY WILL BOOST TEMPS INTO THE LOWER TO MIDDLE 80S, THOUGH EAST
COMPONENT WINDS WILL KEEP LAKE MICHIGAN SHORE/DOOR COUNTY COOLER.
DRY WEATHER HOLDS FOR ANY EVENING ACTIVITIES, THOUGH PATCHY FOG
MAY OCCUR NEAR LAKE MICHIGAN. TEMPERATURES WILL BE IN THE LOW TO
MID 70S.
SHOWER AND STORM CHANCES (15-30%) RETURN LATE TONIGHT THROUGH
WEDNESDAY...SHOWERS AND STORMS DEVELOPING THIS EVENING OVER
DAKOTAS FORECAST TO PRODUCE SHORTWAVE/UPPER JET THAT SHIFTS EAST
TOWARD WI LATE TONIGHT. GRADIENT OF INSTABILITY FROM MN TO
SOUTHERN WI, AS IS THE STRONGER CONVERGENCE WITH LLJ. EVEN SO,
WITH THE WAVE AND ELEVATED INSTABILITY FARTHER NORTH, CANNOT RULE
OUT SOME SHOWERS AND STORMS ON TUESDAY MORNING, WITH PERHAPS
SLIGHT BOOST IN COVERAGE FARTHER NORTH DURING PEAK HEATING OF
AFTERNOON AS MLCAPES INCREASE OVER 1000J/KG. EFFECTIVE SHEAR OVER
40 KTS WOULD SUPPORT STRONGER STORM IF CONVECTION DEVELOPS. SPC
DOES KEEP THE MARGINAL RISK FOR SEVERE FARTHER SOUTH NEAR THE MORE
PERSISTENT FRONTAL BOUNDARY/HIGHEST INSTABILITY.
RAIN CHANCES (30-60%) THEN CONTINUE TUESDAY NIGHT INTO WEDNESDAY
AS ADDITIONAL AS ANOTHER SHORTWAVE MOVES THROUGH THE REGION AND
THE FRONT REMAINS CLOSE ENOUGH TO OUR AREA. SIMILAR TO EXPECTATIONS
FOR LATE TONIGHT AND TUESDAY, APPEARS BETTER SIGNAL FOR SEVERE
REMAINS SOUTH. HOWEVER, LATE TUESDAY NIGHT THROUGH WEDNESDAY,
THERE IS STRONGER FORCING FARTHER NORTH AND SUFFICIENT INSTABILITY.
SEEMS LIKE THIS TIME FRAME MAY HOLD THE GREATEST CHANCES FOR SOME
STRONGER STORMS OVER OUR AREA, ESPECIALLY IF THINGS SLOW A BIT AND
THESE FACTORS CATCH UP TO AT LEAST THE BEGINNING OF PEAK HEATING
ON WED. FWIW, ML PROGS SHOW A WEAK "BUMP" IN SEVERE PROBS TO 5-15%
FOR WED AFTER A RELATIVE MINIMUM IN SEVERE POTENTIAL MON-TUE.
DRY AND COOLER LATE THIS WEEK, THEN CHANCES FOR RAIN (30-40%) RETURN
FOR THE WEEKEND...HIGH PRESSURE BUILDS IN ACROSS THE AREA WEDNESDAY
NIGHT THROUGH FRIDAY, PUSHING THE FRONT AND LINGERING INSTABILITY
SOUTH AND GENERALLY KEEPING THE AREA DRY THROUGH THE REST OF THE
WEEK. HIGHS WILL SETTLE INTO THE 70S REGIONWIDE. LOW TEMPERATURES
IN THE 40S NORTH SEEM A CERTAINTY THURSDAY NIGHT WITH HIGH OVERHEAD.
LOW END FROM NBM (5TH PERCENTILE) EVEN POINTS TO POTENTIAL FOR
UPPER 30S IN TYPICAL COOL SPOTS NEAR THE U.P. BORDER (E.G. KLNL).
THE HIGH EVENTUALLY SHIFTS EAST, ALLOWING FOR THE CHANCE FOR SHOWERS
AND THUNDERSTORMS TO RETURN TO THE AREA FRIDAY NIGHT INTO NEXT WEEKEND.
ON THE EARLY SIDE, BUT DOES SEEM THAT SUNDAY WOULD BE THE DRIER OF THE
TWO DAYS.
AVIATION
FOR 18Z TAF ISSUANCE
ISSUED AT 1203 PM CDT MON AUG 10 2026
FAIR WEATHER CUMULUS CLOUDS WILL CONTINUE TO DEVELOP THIS
AFTERNOON WITH DAYTIME HEATING. CURRENTLY BASES RANGE FROM
015-025 ACROSS CENTRAL AND EAST-CENTRAL WISCONSIN WITH HIGHER DEW
POINTS, TO 4-5K FT ACROSS NORTH-CENTRAL WISCONSIN GIVEN THE LOWER
DEW POINTS. BASES SHOULD SLOWLY RISE TO 3-4K FT ACROSS CENTRAL AND
EAST-CENTRAL WISCONSIN THIS AFTERNOON AS TEMPERATURES RISE. THESE
CLOUDS SHOULD THEN DISSIPATE SHORTLY AFTER SUNSET WITH THE LOSS
OF DAYTIME HEATING. SOME PATCHY FOG COULD DEVELOP OVERNIGHT ACROSS
EAST- CENTRAL WISCONSIN, REDUCING VSBYS TO MVFR AT TIMES AT
GRB/ATW/MTW. HIGHER UP IN THE ATMOSPHERE A PLUME OF SMOKE WILL
CONTINUE TO STREAM IN ABOVE THE LOWER CLOUDS. WINDS WILL BE LIGHT
THROUGH THE TAF PERIOD.
CHANCES FOR SHOWERS AND SOME STORMS OCCUR ON TUESDAY MORNING ALONG
A FRONTAL BOUNDARY. HOWEVER, THE BEST CHANCE FOR STORMS APPEARS TO
BE FURTHER SOUTH CLOSER TO THE ACTUAL BOUNDARY. THEREFORE, WILL
NOT INCLUDE PRECIPITATION AT THE TAF SITES AS CHANCES ARE TOO LOW
WITH THIS FORECAST ISSUANCE. OCCASIONAL MVFR CONDITIONS MAY OCCUR
WITH THE SHOWERS.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE.........JLA
DISCUSSION.....JLA
AVIATION.......KURIMSKI
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