360
FXUS63 KIWX 311119
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
719 AM EDT FRI JUL 31 2026
KEY MESSAGES
- CHANCES (50-90 PERCENT) FOR SHOWERS AND STORMS THIS EVENING
INTO THE WEEKEND. HEAVY RAIN, GUSTY WINDS, AND LIGHTNING ARE
EXPECTED WITHIN ANY STORMS. LOCALIZED FLOODING IS POSSIBLE.
THERE IS A MARGINAL RISK FOR STRONGER STORMS SATURDAY
AFTERNOON FOR PORTIONS OF IN, GENERALLY ALONG/SOUTH OF
IN-218/IN-18. DAMAGING WINDS TO 60 MPH ARE THE PRIMARY THREAT.
- THERE IS A MODERATE SWIM RISK FOR LAKE MICHIGAN BEACHES ALONG
THE SOUTHERN BERRIEN COUNTY, MI AND LA PORTE COUNTY, IN
SHORELINE. BREAKING WAVES AND CURRENTS ARE EXPECTED.
- THERE IS A HIGH SWIM RISK FOR BEACHES ALONG BOTH LA PORTE
COUNTY, IN AND ALL OF BERRIEN COUNTY, MI SHORELINES ON SUNDAY.
LIFE-THREATENING WAVES AND CURRENTS ARE EXPECTED. THOSE
PLANNING TO VISIT THE BEACH SHOULD STAY OUT OF THE WATER.
DISCUSSION
ISSUED AT 527 AM EDT FRI JUL 31 2026
ONE LAST DRY DAY BEFORE CHANCES FOR SHOWERS AND STORMS MOVE INTO THE
AREA FOR THE WEEKEND (50-90 PERCENT CHANCES), AND PERSIST ON AND OFF
THROUGH NEXT WEEK (20-40 PERCENT). EXPECT INCREASING CLOUDS TODAY
WITH A LOW CHANCE FAR WEST OF A FEW SHOWERS TOWARDS THE EVENING
HOURS. EXPECT RAIN CHANCES TO INCREASE AND SPREAD EASTWARD THROUGH
THE NIGHT, WITH THE BEST POTENTIAL WEST OF I 69. MORE WIDESPREAD
RAIN SHOWERS AND SCATTERED STORMS PERSIST SATURDAY (70-90 PERCENT
CHANCE). ADDITIONALLY, SPC ISSUED A MARGINAL RISK FOR ISOLATED
STRONG/SEVERE STORMS SATURDAY AFTERNOON, MAINLY INCLUDING A SMALL
PORTION OF OUR INDIANA COUNTIES ALONG/SOUTH OF IN-218/IN-18 (WELLS,
GRANT, BLACKFORD, JAY, AND ADAMS COUNTIES). THE PRIMARY THREAT WITH
ANY STRONGER STORMS WOULD BE DAMAGING WINDS UP TO 60 MPH. OTHERWISE,
THE MAIN HAZARDS WITH STORMS WILL BE GUSTY WINDS, LIGHTNING, AND
HEAVY RAIN. LOCALIZED FLOODING COULD OCCUR IN AREAS THAT SEE HIGHER
RATES, DEPENDING ON HOW FAST THE SYSTEM MOVES/MOISTURE CONVERGENCE
FOCUSES. THE MARGINAL RISK IS ASSOCIATED WITH A MORE NARROW
AXIS OF SFC INSTABILITY (300-800 J/KG SFC CAPE) THAT REACHES
INTO THE AFOREMENTIONED AREA, WITH DECENT MOISTURE TRANSPORT
(TD'S IN UPPER 60S, LOW 70S) AND 0-6 KM BULK SHEAR RANGING FROM
30-50 KNOTS (PER MOST GUIDANCE, THE NAM12 HAS 50-60KTS BUT
CLOSER TO NE IN/NW OH...AS IT IS FURTHER NORTH THAN THE OTHER
GUIDANCE). DON'T EXPECT ANY WIDESPREAD SEVERE WEATHER GIVEN
PALTRY MID LEVEL LAPSE RATES AT THIS POINT.
TEMPERATURES WILL BE IN THE 80S TODAY, THEN FALL INTO THE 70S, LOW
80S FOR SATURDAY INTO MONDAY. TEMPERATURES RISE INTO THE LOW-MID 80S
ONCE AGAIN TUESDAY INTO FRIDAY.
OUR UPPER LEVEL RIDGE AND SUBSEQUENT SURFACE HIGH WILL DRIFT
EASTWARD TODAY, WITH A BROAD UPPER LEVEL TROUGH/CLOSED LOW DROPPING
INTO THE IA/IL/IN/KY AREA TODAY INTO SUNDAY, WHERE IT MEANDERS
SLOWLY EAST (OR SLIGHTLY NORTHEAST) FROM THERE. THERE IS STILL A
BIT OF A DIFFERENCE IN THE PLACEMENT OF THE UPPER TROUGH/VORT
MAX AMONGST GUIDANCE. BECAUSE OF THIS, THE SURFACE LOW IS PLACED
DIFFERENTLY, WITH DISCREPANCIES REALLY SHOWING UP BY 00Z SUN.
SOME OF THE GUIDANCE TAKES THE SURFACE LOW FURTHER SOUTH
(CENTERED NEAR INDY/KY) WHEREAS THE NAM SHIFTS THE LOW MORE
NORTHEAST INTO LAKE ERIE/SOUTHERN ONTARIO. WITH THE BLOCKING
PATTERN ESTABLISHING ITSELF THROUGH MONDAY AS MENTIONED IN THE
PREVIOUS DISCUSSION, THE TROUGH MAY LINGER LONGER-ESPECIALLY
THROUGH SUNDAY, BUT COULD BE AS LATE AS MON/TUE. INCREASED POPS
SUBSTANTIALLY SUNDAY TO ACCOUNT FOR THIS SLOWER MOVEMENT, WITH
THE BEST POTENTIAL IN THE MORNING ALONG/SOUTH OF US 24 (55-85
PERCENT). ELSEWHERE, CHANCES RANGE FROM 20-50 PERCENT SUNDAY.
THERE IS A MODERATE SWIM RISK FOR LAKE MICHIGAN BEACHES ALONG BOTH
LA PORTE COUNTY, IN AND SOUTHERN BERRIEN COUNTY, MI ON
SATURDAY, WITH EASTERLY WINDS STRENGTHENING AND SHIFTING TO THE
NORTHEAST AT 15 TO 25 KNOTS LATER IN THE DAY. WAVES WILL BUILD
UP TO AROUND 3 FEET BY LATE AFTERNOON, GREATEST NEAR NEW
BUFFALO, MI TO MICHIGAN CITY, IN.
THERE IS A HIGH SWIM RISK FOR ALL BEACHES IN BERRIEN AND LA PORTE
COUNTIES ON SUNDAY. NORTHEAST WINDS WILL BE AROUND 15 TO 25 KNOTS
WITH GUSTS UP TO 30 KNOTS, SHIFTING TO THE NORTH SUNDAY AFTERNOON.
WAVES CONTINUE TO BUILD FROM 3 TO 5 FEET SATURDAY EVENING TO
AROUND 4 TO 7 FEET BY SUNDAY AFTERNOON-WITH THE HIGHEST WAVES
FROM WARREN DUNES TO MICHIGAN CITY, IN. EXPECT A STRONG
SOUTHWARD FLOWING LONGSHORE CURRENT AND STRONG STRUCTURAL
CURRENTS, ESPECIALLY ON THE NORTH SIDES OF PIERS AND BREAKWALLS.
RIP CURRENTS ARE EXPECTED. THOSE PLANNING TO VISIT THE BEACHES
SHOULD STAY OUT OF THE WATER.
ISSUED A SMALL CRAFT ADVISORY FROM 18Z SATURDAY INTO 9Z MONDAY FOR
BOTH MARINE ZONES. FOR NOW, HELD OFF ON ISSUING A BEACH HAZARDS
STATEMENT-PREFER TO WAIT UNTIL THE NEXT WAVE MODEL RUN THIS
AFTERNOON TO NARROW DOWN TIMING/INCREASE CONFIDENCE GIVEN IT'S STILL
BEYOND 24 HOURS.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 716 AM EDT FRI JUL 31 2026
PREDOMINANTLY VFR CONDITIONS AT THE TERMINALS THIS PERIOD, WITH
CALM/VARIABLE WINDS STRENGTHENING OUT OF THE SOUTH, THEN
SHIFTING SOUTHEAST. MVFR CONDITIONS ARE MORE LIKELY AT KSBN
ONCE RAIN MOVES IN (AND POSSIBLY A THUNDERSTORM) AFTER 00Z;
THEN AT KFWA AFTER 6Z. GUIDANCE HAS CEILINGS AROUND 700-1500 FT
AT KSBN, ESPECIALLY AFTER 6Z WITH HEAVIER SHOWERS AND
POTENTIALLY STORMS, SO IFR CONDITIONS ARE POSSIBLE. FOR NOW
HANDLED WITH PROB30 GROUPS AT BOTH SITES.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 5 AM EDT MONDAY FOR
LMZ043-046.
DISCUSSION...MCD
AVIATION...MCD
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