999
FXUS63 KGRB 221758
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1258 PM CDT TUE APR 22 2025
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
KEY MESSAGES
- PERIODIC CHANCES FOR RAIN EXPECTED THROUGH THE WORK WEEK, WITH
DRY CONDITIONS RETURNING FOR THE WEEKEND. THUNDERSTORMS
POSSIBLE WEDNESDAY AFTERNOON AND EVENING.
- GUSTY NORTHEAST WINDS POSSIBLE THURSDAY NIGHT INTO FRIDAY NIGHT,
ESPECIALLY IN THE FOX VALLEY AND LAKESHORE AREAS.
- WARMING TEMPERATURES INTO MID-WEEK, DROPPING BACK TO NORMAL ON
FRIDAY, THEN MODERATING AGAIN OVER THE WEEKEND.
DISCUSSION
ISSUED AT 503 AM CDT TUE APR 22 2025
PRECIPITATION CHANCES: A BAND OF FRONTOGENETIC FORCING AND WAA
WILL BRING AN AREA OF SHOWERS THROUGH THE FORECAST AREA THIS
MORNING AND EARLY AFTERNOON. THE SHOWERS WILL LIKELY WEAKEN AS
THEY SHIFT INTO FAR NE WI, DUE TO THE PRESENCE OF A DRY CANADIAN
HIGH PRESSURE SYSTEM. WILL CARRY THE HIGHEST POPS OVER THE
WESTERN PART OF THE FORECAST AREA. ALTHOUGH THUNDERSTORMS ARE
ONGOING ON THE WESTERN PERIPHERY OF THE PRECIPITATION IN EASTERN
MN, MODELS SHOW THE BEST INSTABILITY STAYING TO OUR SOUTHWEST/
SOUTH, SO HAVE LEFT ANY MENTION OF STORMS OUT OF THE FORECAST.
THE WEAKENING SHOWERS WILL LIFT INTO UPPER MI BY MID-AFTERNOON,
FOLLOWED BY DRY WEATHER FOR THE REST OF THE AFTERNOON AND TONIGHT.
A COLD FRONT WILL APPROACH THE REGION ON WEDNESDAY, AND EDGE INTO
NC WI LATER IN THE AFTERNOON. AHEAD OF THE FRONT, MOISTURE WILL
INCREASE, WITH PWATS RISING TO AROUND AN INCH IN EASTERN WI DURING
THE AFTERNOON. IN ADDITION, MODEST INSTABILITY (CAPE OF 300-800
J/KG AND MID-LEVEL LAPSE RATES AROUND 7 C/KM) WILL BUILD AHEAD OF
THE FRONT, RESULTING IN A DIURNAL INCREASE IN SHOWERS AND
SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. DEEP
LAYER SHEAR IS STRONG (45-60 KNOTS), SO ISOLATED STRONG STORMS
COULD FORM IF ENOUGH HEATING OCCURS. THE SHOWERS AND STORMS WILL
DECREASE IN COVERAGE AS THE FRONT SHIFTS EAST LATER IN THE
EVENING, BUT A FEW SHOWERS MAY RETURN TO THE SOUTHERN PART OF
FORECAST AREA LATE.
ON THURSDAY AND THURSDAY EVENING, SCATTERED SHOWERS MAY PERSIST
ACROSS CENTRAL AND EAST CENTRAL WI, WHERE BETTER MOISTURE WILL
RESIDE, BUT OVERALL FORCING LOOKS TO BE WEAK. FARTHER NORTH, HAVE
REDUCED MODEL BLENDED POPS, AS HIGH PRESSURE OVER ONTARIO WILL
CONTINUE TO FEED DRY AIR INTO THE REGION. GENERAL MODEL CONSENSUS
IS FOR SHOWERS TO INCREASE LATE THURSDAY NIGHT INTO FRIDAY MORNING
AS A SHORT-WAVE TOUGH MOVES THROUGH AND LOW PRESSURE TRACKS SOUTH
OF THE REGION. SHOULD SEE A DIMINISHING TREND IN THE PRECIPITATION
FRIDAY AFTERNOON AND EVENING, FOLLOWED BY DRY CONDITIONS OVER THE
WEEKEND AS HIGH PRESSURE BUILDS INTO THE THE WESTERN GREAT LAKES.
A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO LIFT NORTHWEST OF THE
REGION EARLY NEXT WEEK, AND DRAG A COLD FRONT THROUGH WI TUESDAY
AND TUESDAY NIGHT. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL
INCREASE AS THE FRONT APPROACHES.
GUSTY WINDS THURSDAY NIGHT INTO FRIDAY NIGHT: WINDS WILL BE
LIGHT TO MODERATE THROUGH THURSDAY MORNING. THE PRESSURE GRADIENT
WILL INCREASE BETWEEN HIGH PRESSURE OVER HUDSON BAY AND LOW
PRESSURE TRACKING THROUGH IL LATE IN THE WORK WEEK. THIS IS A
GOOD SETUP FOR GUSTY NE WINDS TO FUNNEL DOWN THE BAY OF GREEN BAY.
GUSTS TO 25 TO 35 MPH WILL BE POSSIBLE IN THE FOX VALLEY AND
LAKESHORE AREAS, ESPECIALLY FRIDAY INTO FRIDAY EVENING.
TEMPERATURES: A WARMING TREND IS EXPECTED INTO MID-WEEK, WITH
HIGHS REACHING INTO THE 60S AND LOWER 70S ON WEDNESDAY. A MODEST
DROP IN TEMPERATURES IS EXPECTED AFTER THE COLD FRONT MOVES
THROUGH WEDNESDAY NIGHT, AND IN ASSOCIATION WITH INCREASING
CLOUDS AND PRECIPITATION. THIS SHOULD CAUSE TEMPERATURES TO
SETTLE BACK TO AROUND NORMAL BY FRIDAY. PARTLY CLOUDY SKIES WILL
HELP BOOST READINGS ABOVE NORMAL OVER THE WEEKEND, WITH MUCH
ABOVE NORMAL TEMPERATURES POSSIBLE EARLY NEXT WEEK.
AVIATION
FOR 18Z TAF ISSUANCE
ISSUED AT 1258 PM CDT TUE APR 22 2025
A BAND OF RAIN SHOWERS CONTINUES TO MOVE OFF TO THE NORTHEAST
EARLY THIS AFTERNOON. KEPT A MENTION OF LIGHT SHOWERS IN
CENTRAL/NORTH-CENTRAL WI TAF SITES, AND GRB FOR ANOTHER 30 TO 60
MINUTES UNTIL THE RAIN FULLY CLEARS OUT.
A MIX OF VFR/MVFR CIGS WILL FOLLOW BEHIND THE RAIN, ALONG WITH A
BRIEF PERIOD OF SE WIND GUSTS TO ~15 KTS.
PARTIAL CLEARING AND LIGHT WINDS ARE EXPECTED OVERNIGHT. THIS WILL
ALLOW FOR SOME FOG FORMATION. GUIDANCE IS MIXED ON HOW DENSE/LOW
VSBY WILL BE LATE TONIGHT. A COUPLE HOURS OF IFR VSBYS ARE
POSSIBLE, WITH FOG QUICKLY DISSIPATING AFTER SUNRISE.
VFR CONDITIONS RETURN FOR WEDNESDAY MORNING, THROUGH THE 18Z TAF
PERIOD. SCATTERED RAIN SHOWERS AND THUNDERSTORMS ARE FORECAST
WEDNESDAY AFTERNOON AND OVERNIGHT.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....KIECKBUSCH
AVIATION.......KLJ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page