620
FXUS63 KMKX 210849
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
349 AM CDT MON APR 21 2025
KEY MESSAGES
- SOME LINGERING SHOWERS THIS MORNING, BUT OTHERWISE TODAY WILL
BE GUSTY THROUGH THE AFTERNOON WITH GUSTS UP TO AROUND 25-35
MPH POSSIBLE.
- THUNDERSTORM CHANCES RETURN TUESDAY MORNING/AFTERNOON WITH A
POTENTIAL FOR AN ISOLATED STRONG TO SEVERE THUNDERSTORM OR TWO
CAPABLE OF PRODUCING HAIL. MAY BE AN ADDITIONAL WINDOW FOR
THUNDERSTORMS TUESDAY EVENING IN SOUTHWEST WI, BUT MORE
UNCERTAINTY WITH THIS ROUND.
- TEMPS WILL WARM UP THROUGH THE END OF THE WEEK WITH WELL
ABOVE NORMAL HIGHS AND THERE WILL BE ADDITIONAL RAIN AND
THUNDERSTORM CHANCES FOR THE SECOND HALF OF THE WEEK.
SHORT TERM
ISSUED 339 AM CDT MON APR 21 2025
TODAY THROUGH TUESDAY NIGHT:
THE SURFACE LOW AND ACCOMPANYING MID-LEVEL SHORTWAVE TROUGH
CONTINUE TO LIFT ACROSS CENTRAL WI AND INTO NORTHERN PORTIONS
OF LAKE MICHIGAN THROUGH THE MORNING. THE BULK OF THE SHOWER
ACTIVITY HAS ALREADY PUSHED THROUGH OVERNIGHT AND A DRY SLOT IS
LIMITING ADDITIONAL WIDESPREAD COVERAGE FROM DEVELOPING.
HOWEVER, SPORADIC/SCATTERED LIGHT SHOWER CHANCES WILL LINGER
THROUGH DAYBREAK BEFORE DIMINISHING BY MID MORNING HOURS AS A
COLD FRONT PUSHES THROUGH THE AREA. LOOKING AT DRIER CONDITIONS
BEHIND THE COLD FRONT FOR THE REST OF DAY, BUT GIVEN THE LOW
DEEPENING TO SUB 1000MB, THE PRESSURE GRADIENT WILL REMAIN
TIGHT ACROSS SOUTHERN WI. THUS RESULTING IN STRONGER WESTERLY
GUSTS OF 20-30 MPH THROUGH THE AFTERNOON WITH THE STRONGEST
GUSTS POSSIBLY EVEN APPROACHING 35-40 MPH FOR EAST-CENTRAL
PORTIONS OF WI.
OTHERWISE, WINDS WILL DIMINISH THROUGH THE EVENING AS HIGH
PRESSURE AND UPPER-LEVEL RIDGE QUICKLY TRAVERSES JUST SOUTH OF
THE AREA. SHOULD SEE LIGHT WINDS AND COOL CONDITIONS OVERNIGHT
WITH LOWS DIPPING INTO THE MID TO UPPER 30S.
THEN A MID-LEVEL SHORTWAVE TROUGH FROM THE NORTHERN PLAINS IS
PROGGED TO FOLLOW RIGHT BEHIND THE RIDGE AND PUSH INTO THE
UPPER MIDWEST LATER TONIGHT/EARLY TUESDAY MORNING. THIS SYSTEM
WILL THE FOCUS FOR OUR NEXT ROUND OR TWO OF SHOWERS/STORMS. THE
ASSOCIATED SURFACE LOW PAIRED WITH THE UPPER-LEVEL WAVE IS
EXPECTED TO BREAK AWAY AND MEANDER UP THE ND/MN BORDER THROUGH
TUESDAY. AHEAD OF IT A WING OF LOW-LEVEL WAA WILL LIFT UP THE
UPPER MISSISSIPPI RIVER VALLEY TUESDAY MORNING. THE LOW-LEVEL
DYNAMICS PAIRED WITH A SWATH OF MUCAPE 500-750 J/KG, STEEP MID-
LEVEL LAPSE RATES (7.5-8.0C/KM), NOSE OF 850MB LLJ, AND
INCREASED DEEP LAYER SHEAR LOOKS TO SUPPORT ELEVATED CONVECTION.
WITH THE MORNING ROUND OF ELEVATED STORMS, COULD SEE A FEW
STRONGER AND EVEN AN ISOLATED SEVERE STORM OR TWO CAPABLE OF
PRODUCING LARGE HAIL DEVELOP ACROSS SOUTHERN WI DAYBREAK THROUGH
THE EARLY AFTERNOON.
THERE MAY BE ADDITIONAL ROUND OF SHOWERS AND CONVECTION TO
DEVELOP LATER IN THE AFTERNOON AND EARLY EVENING IF THE SURFACE
WARM FRONT AND NOSE OF THE HIGHER SURFACE MOISTURE LIFTS NORTH
OF THE WI/IL BORDER. THERE IS A BIT MORE UNCERTAINTY WITH THIS
ROUND AS THE ENVIRONMENT MAY NOT HAVE ENOUGH TIME TO RECOVER
AFTER THE MORNING ROUND OF STORMS ALONG WITH EASTERLY FLOW OFF
OF THE LAKE PREVENTING IT FROM LIFTING. HOWEVER THERE ARE HINTS
THAT IT MAY HAVE ENOUGH MOMENTUM TO LIFT NORTH INTO OUR CWA
ESPECIALLY FOR SOUTH-CENTRAL AND SOUTHWESTERN PORTIONS. IF THE
WARM FRONT IS ABLE TO MAKE IT NORTH OF THE CHEDDAR CURTAIN, THEN
COULD SEE MORE SURFACE BASED CONVECTION DEVELOP, WHICH MAY BE
CAPABLE OF PRODUCING HAIL AND GUSTY WINDS. AGAIN, UNCERTAINTY
REMAINS GREATER AS IT LOOKS TO BE NARROW WINDOW THAT FAVORS
CONVECTION DEVELOPMENT INTO THE EVENING HOURS.
WAGNER
LONG TERM
ISSUED 339 AM CDT MON APR 21 2025
WEDNESDAY THROUGH SUNDAY:
WEDNESDAY MORNING IS EXPECTED TO REMAIN DRY AT THIS TIME AS
ANOTHER SURFACE WARM FRONT SHARPENS JUST SOUTH OF THE BORDER
THROUGH THE DAYTIME HOURS. BY WEDNESDAY EVENING, THUNDERSTORM
ACTIVITY IS EXPECTED TO BLOSSOM AND EVENTUALLY MOVE INTO
SOUTHWESTERN WI WEDNESDAY NIGHT INTO THURSDAY FOLLOWING WARM
ADVECTION OF THE LLJ NORTHWARD. BY THURSDAY MORNING, MOST OF THE
SHOWER ACTIVITY WITH THE FRONT SHOULD BE NORTH OF OUR CWA, AND
WE STAND TO REMAIN DRY MOST OF THE DAY GIVEN MOST OF THE BETTER
FORCING FOR ASCENT WILL BE EITHER NORTH OR WEST OF US. THURSDAY
NIGHT, HOWEVER, A SLOW MOVING FRONTAL BOUNDARY IS EXPECTED TO
MOVE TOWARD WESTERN WI BRINGING CHANCES FOR OVERNIGHT SHOWERS
AND STORMS INTO FRIDAY MORNING. MODELS DEPICT THE BOUNDARY
LINGERING ENOUGH ON FRIDAY TO ALLOW SOME DESTABILIZATION AND
SOME MORE SHOWER AND STORM FORMATION FRIDAY AFTERNOON OVER
SOUTHEAST WISCONSIN BEFORE THE FRONT CLEARS THE STATE.
BEYOND, HIGH PRESSURE LOOKS TO TAKE HOLD FOLLOWING THE FRONTAL
PASSAGE WITH SEASONABLE TEMPERATURES IN THE UPPER 50S TO LOW 60S
REMAINING OVER THE REGION.
CMILLER
AVIATION
ISSUED 339 AM CDT MON APR 21 2025
WIDESPREAD MVFR AND POCKETS OF IFR CEILINGS SIT OVER SOUTHERN
WI THIS MORNING ASSOCIATED WITH THE SURFACE LOW. EXPECTING THE
LOW TO LIFT NORTHEAST THROUGH THE DAY, BUT LOWER CEILING ARE
PROGGED TO LINGER THROUGH THE REMAINDER OF THE MORNING AND INTO
THE AFTERNOON BEFORE CLEARING BY THIS EVENING. ADDITIONALLY WILL
SEE BREEZY SOUTHERLY WINDS TURN WESTERLY AND INCREASE THROUGH
THE MORNING AS WELL. LOOKING AT GUSTS OF 25-30KT THIS AFTERNOON.
CONDITIONS IMPROVE AND WINDS EASE BY THE EVENING AS HIGH
PRESSURE QUICKLY PUSHES THROUGH THE AREA OVERNIGHT. THEN ANOTHER
SYSTEM TREKS INTO THE AREA FROM THE NORTHERN PLAINS AND WILL
BRING ANOTHER PERIOD OF LOWER FLIGHT CONDITIONS ALONG WITH
INCREASED SHOWER AND THUNDERSTORMS CHANCES TUESDAY MORNING.
WAGNER
MARINE
ISSUED 339 AM CDT MON APR 21 2025
LOW PRESSURE WILL CONTINUE NORTH-NORTHEAST AND TRACK ACROSS
NORTHERN LAKE MICHIGAN THROUGH TODAY AND MOVING TO NORTH OF
LAKE HURON TONIGHT. BREEZY SOUTHEASTERLY WINDS WILL QUICKLY
BECOME SOUTHERLY, THEN SOUTHWESTERLY AFTER DAYBREAK, WITH
PATCHY GALE FORCE GUSTS OVER MOST OF THE OPEN WATERS THROUGH
TODAY. A GALE WARNING REMAINS IN EFFECT FROM 7AM TO 7PM CDT FOR
AREAS SOUTH OF THE CENTER OF THE LOW PRESSURE.
WINDS THEN BECOME WESTERLY LATE THIS AFTERNOON AND EVENING AND
WILL GRADUALLY EASE OVERNIGHT INTO TUESDAY MORNING. LIGHT
NORTHWESTERLY WILL BEGIN TO TURN THROUGH TUESDAY AFTERNOON AS
THE SURFACE HIGH PRESSURE PASSES PUSHES EAST OF THE LAKE. WINDS
THEN INCREASE AND BECOME SOUTHEASTERLY TUESDAY
AFTERNOON/EVENING AHEAD OF A WARM FRONT LIFTS AND STALLS ACROSS
THE SOUTHERN THIRD OF LAKE MICHIGAN TUESDAY EVENING. LIGHTER
WINDS ARE EXPECTED FOR THE MIDDLE OF THE WEEK AS HIGH PRESSURE
BUILDS IN FROM THE WEST.
CMILLER/WAGNER
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...SMALL CRAFT ADVISORY...LMZ643-LMZ644-LMZ645-LMZ646 UNTIL 7 AM
MONDAY.
GALE WARNING...LMZ080-LMZ567-LMZ643-LMZ644-LMZ645-LMZ646-
LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878...7 AM MONDAY TO 7 PM MONDAY.
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