820
FXUS63 KMKX 201610
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1110 AM CDT SUN APR 20 2025
KEY MESSAGES
- INCREASED RAIN CHANCES (+90%) FOR THIS AFTERNOON INTO MONDAY
MORNING WITH MULTIPLE WAVES OF SHOWERS AND FEW THUNDERSTORMS,
ESPECIALLY THIS EVENING.
- THE HEAVIEST RAINFALL (>60% CHANCE OF EXCEEDING 0.5 INCH)
WILL BE WEST OF I-39 CORRIDOR.
- WARM UP TUESDAY THROUGH THE END OF THE WEEK WITH WELL ABOVE
NORMAL HIGHS AND ADDITIONAL RAIN CHANCES FOR THE SECOND HALF
OF THE WEEK.
UPDATE
ISSUED 1110 AM CDT SUN APR 20 2025
RAIN HAS BEGUN TO MOVE INTO WISCONSIN THIS MORNING. THIS RAIN IS
BEING DRIVEN BY MID LEVEL WARM AIR ADVECTION AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. RAIN WILL CONTINUE TO ADVECT
NORTHWARD THROUGHOUT THE MORNING SPREADING TO SOUTH CENTRAL AND
EAST CENTRAL WISCONSIN BY EARLY THIS AFTERNOON AT THE LATEST.
INCREASED POPS ACROSS SOUTHWESTERN WISCONSIN AS THE RAIN HAS
MOVED IN A BIT EARLIER THAN PREVIOUS EXPECTED. SHOWERS ARE
EXPECTED TO CONTINUE ACROSS SOUTHERN WISCONSIN THROUGH THE
AFTERNOON. SOUTHEASTERN WISCONSIN SHOULD STILL GET A LULL
BETWEEN THIS WAA WAVE AND RAIN ASSOCIATED WITH THE COLD
FRONT/APPROACHING LOW. THE FORECAST IS STILL ON TRACK THROUGH
THIS EVENING.
PATTERSON
SHORT TERM
ISSUED 333 AM CDT SUN APR 20 2025
TODAY THROUGH MONDAY:
A FEW LOW CLOUDS ARE SNEAKING IN FROM LAKE MICHIGAN INTO EAST-
CENTRAL WI WHILE HIGH CLOUDS TRY TO WORKING THEIR WAY IN FROM
THE SOUTHWEST. EXPECTING CLOUD COVER TO INCREASE THROUGH THE
MORNING AS THE HIGH PRESSURE PUSHES EASTWARD WHILE AN UPPER-
LEVEL SHORTWAVE TROUGH LIFTS ACROSS THE PLAINS AND BECOMES
INVERTED AS IT LIFTS INTO THE MIDWEST THIS EVENING/TONIGHT.
AHEAD OF THE TROUGH LOOKING AT 850MB WAA TO LIFT ACROSS SOUTHERN
WI THIS AFTERNOON BRINGING THE FIRST WAVE OF SHOWERS TO THE
AREA. THEN EXPECTING TO SEE PERIODS OF SHOWERS THROUGH THE
EVENING WITH MORE OF A LULL IN SOUTHEASTERN WI AS THE ASSOCIATED
SURFACE LOW LIFTS ACROSS EASTERN IA INTO SOUTH WI. ADDITIONAL
WAVE OF SHOWERS PROGGED AROUND THE LOW AS WELL AHEAD OF IT AND
ITS COLD FRONT LATE THIS EVENING AND OVERNIGHT. THE SURFACE LOW
THEN IS PROGGED TO LIFT ACROSS CENTRAL WI INTO THE NORTHERN HALF
OF LAKE MICHIGAN MONDAY MORNING BRINGING ADDITIONAL WAVE OF
SHOWERS ON THE BACKSIDE. MAINLY LOOKING AT THIS SCATTERED SHOWER
ACTIVITY ACROSS THE NORTHERN HALF OF THE CWA FOR MONDAY MORNING
BEFORE DRIER AIR PUSHES INTO THE REGION FOR MONDAY AFTERNOON.
WILL SEE GUSTY WINDS WITH GUSTS UP TO AROUND 30-35 MPH ACCOMPANY
THE LOW PRESSURE SYSTEM AS IT WORKS ITS WAY ACROSS THE AREA AS
WELL.
OVERALL MOST OF SOUTHERN WI WILL SEE RAINFALL FROM THIS EVENT,
BUT AREAS ALONG AND WEST OF I-39 CORRIDOR HAVE THE HIGHER
POTENTIAL TO SEE HIGHER RAINFALL TOTALS. 00Z HREF LPMM SHOWS
24HR QPF ENDING MONDAY GREATER THAN HALF AN INCH FOR AREAS WEST
OF LINE FROM RIPON TO JANESVILLE WITH AREAS AROUND THE LOWER
WISCONSIN RIVER VALLEY APPROACHING AND EVEN EXCEEDING AN INCH.
NBM ALONG WITH THE EPS, GEPS, AND GEFS MEMBERS SHOW SIMILAR
TREND IN QPF AMOUNTS. MEANWHILE AREAS FURTHER EAST OF I-39 LOOK
TO SEE LESSER AMOUNT AS THERE CONTINUE TO REMAIN LOWER
CONFIDENCE IN 24HR QPF EXCEEDING HALF AN INCH. BASED ON THE 00Z
HREF LPMM, GENERALLY LOOKING AT RAINFALL TOTALS BETWEEN 0.25-0.5
INCH. HOWEVER GIVEN SOME MUCAPE (200-400 J/KG) SNEAKING
NORTHWARD INTO SOUTHERN WI WITH THE EVENING ROUND OF SHOWERS,
COULD SEE LOCALIZED POCKETS OF HIGHER RAINFALL (>0.5 INCH) WITH
ANY TALLER/PERSISTING THUNDERSTORMS AHEAD/ALONG THE COLD FRONT.
AS FOR TEMPS, TODAY LOOKS TO START MILD, BUT INCREASING CLOUD
COVER AND EASTERLY FLOW OFF OF LAKE MICHIGAN WILL LIMIT THINGS.
INLAND AREA LOOK TO TOP OFF IN THE MID 50S, WHILE AREAS WILL BE
COOLER BY THE LAKE AND MAY NOT EVEN GET OUT OF THE 40S. MONDAY
LOOKS TO SEE SIMILAR TEMPS IF NOT A FEW DEGREES COOLER IN THE
50S AS CLOUD COVER LINGERS AND CAA ON THE BACKSIDE OF THE LOW.
WAGNER
LONG TERM
ISSUED 333 AM CDT SUN APR 20 2025
MONDAY NIGHT THROUGH SATURDAY:
THE SURFACE AND UPPER LOW WILL CONTINUE TO LINGER OVER THE
GREAT LAKES REGION MONDAY NIGHT WITH A PERIOD OF SURFACE HIGH
PRESSURE AND UPPER LEVEL RIDGING. THIS PERIOD WILL BE BRIEF
HOWEVER AS A SHORTWAVE SLIDES THROUGH TUESDAY ASSOCIATED WITH A
WEAK LOW PRESSURE SYSTEM. THE CURRENT TRACK OF THIS SYSTEM TAKES
IT THROUGH NORTHERN MINNESOTA WITH CHANCES REMAINING FAIRLY LOW
(30-40%) THROUGH THE DAY TUESDAY. HOWEVER, INTO TUESDAY
EVENING/NIGHT CHANCES WILL INCREASE (50-65%) AS THE REGION GETS
AN ADDITIONAL INFLUX OF MOISTURE IN THE MID -LEVELS WITH SOME
WAA/LLJ INFLUENCE, PARTICULARLY AT 850MB. SOME THUNDERSTORMS
COULD BE EXPECTED, PARTICULARLY INTO THE EVENING HOURS.
INTO WEDNESDAY EXPECT LARGELY ZONAL FLOW ALOFT AT LEAST
INITIALLY WITH WEAK HIGH PRESSURE OVER THE REGION. EXPECT DRY
CONDITIONS THROUGH THE DAY WEDNESDAY BUT INTO WEDNESDAY
EVENING/OVERNIGHT THROUGH FRIDAY BECOME A LOT MORE UNCERTAIN
THOUGH LIKELY FEATURING AT LEAST SOME PRECIPITATION. MODELS ARE
ALL OVER THE PLACE WITH THIS NEXT SYSTEM BUT THE GENERAL PATTERN
ALOFT SHOWS A FEW SHORTWAVES PUSHING THROUGH THE REGION; ONE
COMING FROM THE SOUTHERN PLAINS WITH THE OTHER ORIGINATING FROM
THE ROCKIES. THESE WILL CONVERGE IN SOMEWAY OR ANOTHER LATER IN
THE WEEK MAKING FOR AN ACTIVE PERIOD OF WEATHER THOUGH LIKELY
FEATURING SOME DRIER INTERMITTENT PERIODS FROM WEDNESDAY NIGHT
THROUGH FRIDAY. STORMS SEEM LIKELY GIVEN THE SETUP BUT SOME
MODELS FAIL TO BRING INSTABILITY UP TO THE REGION BUT IT DEPENDS
ON THE DEVELOPMENT OF THE SYSTEM(S).
INTO AND THROUGH THE WEEKEND MODELS SEEM TO BE MORE SOLD ON
LARGE SCALE RIDGING AND HIGH PRESSURE OVERHEAD WITH A RETURN TO
QUIET CONDITIONS ACROSS THE REGION. THIS IS NOT EXPECTED TO BE A
PROLONGED PERIOD OF RIDGING, HOWEVER.
KUROSKI
AVIATION
ISSUED 1110 AM CDT SUN APR 20 2025
VFR CONDITIONS ARE EXPECTED TO CONTINUE ACROSS SOUTHERN
WISCONSIN THROUGH THIS AFTERNOON. RAIN IS MOVING IN FROM THE
SOUTHWEST THIS MORNING AND WILL OVERSPREAD THE ENTIRE AREA OVER
THE NEXT COUPLE HOURS. AS A LOW PRESSURE SYSTEM ADVANCES FROM
MO, LOWER MVFR TO IFR CEILINGS WILL MOVE FROM THE SOUTHWEST.
THESE LOWER CEILINGS ARE EXPECTED TO OVERSPREAD SOUTHERN
WISOCNSIN THIS EVENING INTO TONIGHT. MORE SPECIFICALLY,AREAS
WEST OF I-39 (MSN AND JVL) WILL SEE MORE PERSISTENT RAINFALL
AND LOWER FLIGHT CONDITIONS WHILE AREAS FURTHER EAST ARE LIKELY
TO SEE MORE OFF AND ON TYPE OF SHOWERS THIS AFTERNOON AND
TONIGHT. CAN NOT RULE OUT A FEW THUNDERSTORMS THIS EVENING AND
TONIGHT.
BREEZY EASTERLY WINDS THIS MORNING ARE EXPECTED TO CONTINUE INTO
TONIGHT BEFORE BECOMING SOUTHERLY. SOUTHERLY WINDS OVERNIGHT
WILL BECOME WESTERLY BEHIND THE EXITING LOW PRESSURE SYSTEM
MONDAY. WESTERLY WINDS ARE EXPECTED THROUGH MONDAY NIGHT.
PATTERSON
MARINE
ISSUED 333 AM CDT SUN APR 20 2025
THE HIGH PRESSURE WILL SHIFT EASTWARD TODAY AS LOW PRESSURE
LIFTS INTO THE AREA FROM THE SOUTHERN PLAINS. EXPECT INCREASING
EAST TO NORTHEASTERLY WINDS TO DEVELOP THROUGH THE DAY AS LAKE
MICHIGAN SITS IN BETWEEN THE DEPARTING HIGH AND AN APPROACHING
LOW. THE LOW PRESSURE WILL LIFT ACROSS THE NORTHERN HALF OF THE
LAKE ON MONDAY WITH GUSTY SOUTHERLY WINDS THEN TURNING WESTERLY
ACROSS THE LAKE AS IT DEPARTS. GUSTS TO AROUND 30 KNOTS AND
BUILDING WAVES ARE EXPECTED ACROSS THE NEARSHORE AS WELL AS THE
OPEN WATERS. THUS SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THIS
EVENING THROUGH MONDAY. ALSO CANNOT RULE OUT A FEW BRIEF GALE
FORCE GUSTS, ESPECIALLY OVER THE WESTERN AND CENTRAL PORTIONS OF
LAKE MICHIGAN THROUGH MONDAY. LIGHTER WINDS ARE EXPECTED
TUESDAY INTO THE MIDDLE OF THE WEEK AS HIGH PRESSURE BUILDS IN
BEHIND THE EARLY WEEK SYSTEM.
WAGNER
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...SMALL CRAFT ADVISORY...LMZ643-LMZ644-LMZ645-LMZ646...7 PM
SUNDAY TO 7 PM MONDAY.
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