584
FXUS63 KIWX 230707
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
307 AM EDT SUN AUG 23 2026
KEY MESSAGES
- HAZARDOUS SWIMMING CONDITIONS ARE EXPECTED ON LAKE MI BEACHES
ALONG BERRIEN CO, MI AND LA PORTE COUNTY, IN TODAY. DANGEROUS
WAVES AND CURRENTS ARE EXPECTED. MONITOR THE BEACH FORECAST
FOR UPDATES.
- CHANCES (20-30%) FOR RAIN SHOWERS TODAY, WITH PARTLY CLOUDY
SKIES AND GUSTY NORTHWEST WINDS. HIGHS IN THE LOW-MID 70S.
- DRY TONIGHT INTO WEDNESDAY MORNING. CHANCES FOR SHOWERS AND
THUNDERSTORMS (30-60%) RETURN WEDNESDAY AFTERNOON AND PERSIST
INTO THURSDAY. HIGHS IN THE 70S, LOW 80S.
DISCUSSION
ISSUED AT 306 AM EDT SUN AUG 23 2026
THE 500MB LOW HOVERING OVER NORTHERN ONTARIO WILL DEEPEN AND SHIFT
SOUTHWARD INTO THE LAKE HURON/SOUTHERN ONTARIO/QUEBEC AREA BY LATE
TONIGHT, THEN LIFT SLOWLY NORTHEASTWARD THROUGH WEDNESDAY ALONG WITH
THE CORRESPONDING SURFACE LOW. OUR AREA LINGERS UNDER CYCLONIC FLOW
ALOFT/AT THE SURFACE THROUGH LATER TONIGHT WHEN SURFACE HIGH
PRESSURE BUILDS IN BENEATH AN EXPANDING RIDGE TO OUR WEST. THE UPPER
LEVEL RIDGE BUILDS IN MORE BROADLY ON TUESDAY. A SHORTWAVE
PINWHEELING AROUND THE CLOSED LOW MOVES THROUGH THIS AFTERNOON/EVE
ALONG WITH A SURFACE TROUGH, WHICH WILL RE-INVIGORATE THE STRONGER
NORTHWEST WIND GUSTS AND WAVE ACTIVITY ON LAKE MI (THUS BEACH
HAZARDS STATEMENT/SMALL CRAFT REMAIN IN PLACE UNTIL THIS EVENING
DESPITE THE LULL OVERNIGHT/EARLY AM). IT WILL ALSO BRING US THE
POTENTIAL FOR RAIN SHOWERS WHERE DEEPER MOISTURE REMAINS AND WE GET
SOME AFTERNOON INSTABILITY (PERHAPS A LITTLE ENHANCEMENT FROM COOLER
AIR OVER LAKE MI). HAVE CHANCES AROUND 20-30 PERCENT. WITH COOLER
850MB TEMPS (7-10C) HIGH TEMPS THIS AFTERNOON WILL PRIMARILY BE IN
THE LOW TO MID 70S, WARMEST EAST OF I 69. LOWS TONIGHT WILL BE IN
THE LOW TO MID 50S.
DRY CONDITIONS PERSIST FROM TONIGHT INTO WEDNESDAY MORNING AS A
DAMPENING UPPER LEVEL RIDGE MOVES IN OVER THE GREAT LAKES. HIGHS
WILL BE IN THE 70S, LOW 80S. LOWS WILL BE IN THE 50S.
ANOTHER UPPER LEVEL TROUGH MOVES THROUGH THE GREAT LAKES WEDNESDAY
AFTERNOON INTO THURSDAY NIGHT, BRINGING A SURFACE LOW THROUGH
NORTHERN ONTARIO INTO HUDSON/JAMES BAY. A COLD FRONT WILL MOVE WEST
TO EAST ACROSS OUR CWA WED AFTERNOON INTO THU, BRINGING US CHANCES
(30-60%) FOR SHOWERS AND THUNDERSTORMS. BEYOND THAT PERIOD, THE
UPPER LOW LINGERS OVER HUDSON BAY INTO SATURDAY, EVENTUALLY MOVING
NORTHEAST THROUGH THE WEEKEND. FLOW OVER OUR AREA BECOMES MORE ZONAL
IN THIS TIME, WITH POTENTIAL PRECIPITATION CHANCES WITH EACH
SHORTWAVE RIPPLING THROUGH. CONFIDENCE WASN'T HIGH ENOUGH TO HAVE
ANY POPS FOR FRIDAY/SATURDAY, BUT ON SUNDAY WE SEE A STRONGER WAVE
MOVE IN SO HAVE 20-30 PERCENT CHANCES ADDED IN. TEMPERATURES REMAIN
IN THE MID-UPPER 70S, LOW 80S THROUGH THE PERIOD.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 151 AM EDT SUN AUG 23 2026
PREDOMINANTLY VFR CONDITIONS AT THE TERMINALS THIS PERIOD, WITH
MVFR CEILINGS/VIS POSSIBLE DURING SHOWER ACTIVITY THIS MORNING
(KSBN) AND POSSIBLY THIS AFTERNOON (KFWA). SOME OF GUIDANCE
HINTING AT SOME BR DEVELOPMENT AT KFWA EARLY BUT LEFT OUT FOR
NOW GIVEN WINDS ARE SLIGHTLY STRONGER THAN MODELS DEPICT.
STRONGER W-NW WINDS RETURN THIS AFTERNOON, WITH GUSTS UP TO
AROUND 20-25 KNOTS POSSIBLE. CONFIDENCE IN SHOWER ACTIVITY
IMPACT EITHER TERMINAL IS FAIRLY IS LOW-A LOT OF THE GUIDANCE IS
PRETTY WIDELY SCATTERED IN TERMS OF AREAL COVERAGE. HOWEVER,
FELT CONFIDENT TO AT LEAST PUT A MENTION FOR KSBN GIVEN UPSTREAM
SHOWERS OVER LAKE MI WITH INCOMING TROUGH. ADDED A PROB30 TO
KFWA FOR LATER THIS AFTERNOON.
IWX WATCHES/WARNINGS/ADVISORIES
IN...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR INZ103.
OH...NONE.
MI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MIZ177-277.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ043-
046.
DISCUSSION...MCD
AVIATION...MCD
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