008
FXUS63 KGRB 211919
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
219 PM CDT TUE JUL 21 2026
KEY MESSAGES
- SCATTERED LIGHT SHOWERS ENDING BY LATE AFTERNOON AND BREEZY
WINDS SUBSIDING TOWARD SUNSET. SMALL CRAFT ADVISORIES ARE IN
EFFECT THROUGH EARLY WEDNESDAY MORNING.
- COMFORTABLE AND QUIET CONDITIONS THROUGH FRIDAY, FOLLOWED BY
INCREASING HEAT, HUMIDITY, AND THUNDERSTORM CHANCES (30 TO 50
PERCENT) OVER THE WEEKEND.
DISCUSSION
ISSUED AT 218 PM CDT TUE JUL 21 2026
A SUBTLE WEST TO EAST SFC TROUGH IS MOVING SWD ACROSS THE AREA
WITH A WIND SHIFT FROM NWLY TO MORE NLY EXPECTED. SCATTERED
LIGHT SHOWERS ARE AHEAD OF AND ALONG THE TROUGH WITH DRIER AIR
AND ISOLATED SHOWERS BEHIND THE TROUGH. THE COLD ADVECTION
WILL CONTINUE TNT AS THE 992 MB LOW JUST SOUTH OF JAMES BAY
LIFTS NEWD INTO NORTH CENTRAL QUEBEC THROUGH TOMORROW. CLOUD
COVER WILL GRADUALLY CLEAR THROUGH THE EVENING WITH THE LOSS OF
HEATING AND THE ARRIVAL OF DRIER AIR. LOW TEMPS IN THE 40S ARE
FORECAST FOR NE WI WITH LOWER TO MIDDLE 50S OVER THE FOX VALLEY.
ON WEDNESDAY, A SHORTWAVE TROUGH WILL MOVE ACROSS THE NRN GREAT
LAKES TO SRN ONTARIO, WHILE HIGH PRESSURE WILL TRACK FROM THE
NRN GREAT PLAINS TO SW WI AND NE IA. LINGERING COOL AIR ALOFT
WILL LEAD TO BROKEN CLOUD COVER FOR A TIME ON WED, WITH HIGH
TEMPS MAINLY IN THE LOWER TO MIDDLE 70S.
A RELATIVELY DRY AIRMASS AND GRADUALLY WARMING TEMPERATURES BACK
TO NEAR NORMAL ARE ANTICIPATED FOR THU-FRI AS HIGH PRESSURE
TRACKS FROM NRN IL TO THE LOWER GREAT LAKES.
SHOWER AND THUNDERSTORM CHANCES RETURN TO THE FORECAST FOR THE
WEEKEND AND EARLY NEXT WEEK. NWLY FLOW ALOFT WILL CONTINUE WITH
EMBEDDED SHORTWAVE TROUGHS. THERE MAY BE A COUPLE LOW PRESSURE
AREAS THAT TRACK ACROSS SRN CANADA OR THE NRN USA AND AFFECT NE
WI AND EAST CENTRAL WI. HIGH TEMPERATURES IN THE 80S ARE
FORECAST WITH INCREASING RELATIVE HUMIDITY.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1232 PM CDT TUE JUL 21 2026
CEILINGS HAVE TRENDED UP THROUGH THE MORNING WITH SCATTERED TO
BROKEN VFR CUMULUS PERSISTING THROUGH THE AFTERNOON. SKIES WILL
GRADUALLY CLEAR THROUGH THE LATE AFTERNOON/EVENING. SCATTERED
SHOWERS WILL CONTINUE THIS AFTERNOON WITH THE THUNDER RISK QUITE
LOW (LESS THAN 15%). GUSTY NORTH TO NORTHWEST WINDS WILL
GRADUALLY SUBSIDE THIS MORNING, REMAINING NORTHERLY INTO
WEDNESDAY.
KOSH
SCATTERED SHOWERS MAY IMPACT KOSH THROUGH AROUND 21Z THIS
AFTERNOON, ALTHOUGH ANY SHOWER WILL BE BRIEF. SHORT-LIVED MVFR
CONDITIONS COULD NOT BE RULED OUT WITH A MORE INTENSE SHOWER,
BUT THE THUNDER POTENTIAL IS VERY LOW. SKIES WILL CLEAR THROUGH
LATE AFTERNOON/EVENING.
THERE IS A LOW CHANCE FOR A FEW GUSTS OVER 30 KTS THIS AFTERNOON
WITH STRONGER DIURNAL MIXING/COLD ADVECTION, BUT THE GUSTINESS
WILL WANE THROUGH THE EVENING.
MARINE
ISSUED AT 218 PM CDT TUE JUL 21 2026
BREEZY NLY WINDS WILL CONTINUE FOR MUCH OF THE NIGHT WITH THE
SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 AM CDT WED. LIGHT TO
MODEST NNWLY WINDS ARE EXPECTED ON WED WITH LAKE BREEZE
DEVELOPMENT POSSIBLE BY MID TO LATE AFTERNOON. LIGHT WLY WINDS
THU AM ARE EXPECTED TO BECOME MODEST SLY WINDS FOR THU
AFTERNOON.
GRB WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM CDT WEDNESDAY FOR LMZ521-522-
541>543.
DISCUSSION...MG
AVIATION...JM
MARINE...MG
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page