413
FXUS63 KLOT 230602
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
ISSUED BY NATIONAL WEATHER SERVICE LINCOLN IL
102 AM CDT WED APR 23 2025
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS CONTINUE TO BE IN THE FORECAST
TONIGHT, WITH A MARGINAL RISK FOR SEVERE STORMS LATE THIS
AFTERNOON/THIS EVENING.
- WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED INLAND THROUGH
WEEK'S END, THEN TURNING MORE SEASONABLE FOR THE WEEKEND.
- CHANCES FOR SEVERE STORMS RETURN EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 309 PM CDT TUE APR 22 2025
THROUGH WEDNESDAY:
ZONAL FLOW ALOFT EXISTS ACROSS THE AREA TODAY, WITH UPPER LEVEL
LOWS ACROSS NORTHERN MN AND QUEBEC CURRENTLY. AT THE SURFACE, A
WARM FRONT IS LIFTING NORTHEAST ACROSS NORTHERN IL THIS
AFTERNOON...USHERING IN WARMER AND MORE HUMID AIR INTO THE
AREA. EXPECT SHOWERS AND THUNDERSTORMS TO MOVE IN/REDEVELOP
ACROSS THE FORECAST AREA BY LATE AFTERNOON. BELIEVE THE GREATEST
THREAT FOR STORMS IN THE CHICAGO METRO TO BE FROM 6 PM TO 8 PM
THIS EVENING. INSTABILITY (CAPE OF NEAR 1000 J/KG) AND SHEAR
(0-6 KM BULK SHEAR NEAR 30 KTS) WILL PROVIDE THE RISK FOR SOME
SEVERE STORMS THROUGH THIS EVENING. THE SPC CURRENTLY HAS MUCH
OF LOT AREA IN A MARGINAL RISK FOR TONIGHT (EXCEPT THE SE).
SHOWERS AND ISOLATED STORMS WILL BE POSSIBLE OFF AND ON THROUGH
THE NIGHT ACROSS NORTHERN IL, WITH THE BEST CHANCE FOR A SECOND
ROUND FROM 3 AM TO 7 AM.
FOR WEDNESDAY, SHOWERS AND STORMS WILL LINGER IN THE VICINITY OF
A BOUNDARY NEAR THE IL/WI BORDER. EXPECT ACTIVITY TO BE MOSTLY
IN WI, AND GENERALLY, SEVERE STORMS ARE NOT EXPECTED TOMORROW.
HOWEVER, SOME MODELS HAVE CAPES NEAR 1000 J/KG AND DEEP SHEAR AT
25-30 KTS, SO IT'S NOT OUT OF THE QUESTION. CURRENTLY, NORTHERN
IL IS NOT OUTLOOKED FOR SEVERE WEATHER BY THE SPC. HIGHS
TOMORROW SHOULD BE IN THE MID TO UPPER 70S INLAND.
KNUTSVIG
WEDNESDAY NIGHT THROUGH TUESDAY:
WARM TEMPS WILL CONTINUE THROUGH THE WEEK WITH THE NEXT
WEATHER-MAKER COMING ON FRIDAY. SHOWERS AND ISOLATED STORMS ARE
GENERALLY EXPECTED, WITH SEVERE STORMS NOT EXPECTED CURRENTLY.
AFTER A RETURN TO COOLER TEMPERATURES OVER THE WEEKEND, EXPECT A
CHANCE FOR SEVERE STORMS POSSIBLY AS EARLY AS MONDAY.
KNUTSVIG
AVIATION /06Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 1226 AM CDT WED APR 23 2025
KEY AVIATION MESSAGES:
- SCATTERED SHOWERS REMAIN A POSSIBILITY (40% CHANCE) THROUGH
ABOUT 15Z/10AM THIS MORNING.
- GENERALLY LIGHT SURFACE WINDS (5-12 KTS) WILL OSCILLATE
BETWEEN SOUTHWEST AND EAST THROUGH THIS EVENING.
WATCHING AN AREA OF SHOWERS AND THUNDERSTORMS ACROSS EASTERN
IOWA EARLY THIS MORNING, COINCIDING WITH A WEAK SURFACE FRONT.
THIS ACTIVITY WILL ATTEMPT TO MOVE EASTWARD INTO NORTH CENTRAL
AND NORTHEAST ILLINOIS TOWARD SUNRISE. WHILE SCATTERED SHOWERS
REMAIN PLAUSIBLE, AND HAVE THEREFORE BEEN MAINTAINED FOR THE
REGIONAL TERMINALS, SOME QUESTION AS TO WHETHER THUNDER CHANCES
MAY PERSIST. FOR NOW, CONFIDENCE AND COVERAGE REMAIN LOW ENOUGH
TO NOT MENTION THUNDER IN THIS ROUND OF TAFS; THINKING THAT THE
CURRENT STORMS WILL OUTPACE THE MEAGER INSTABILITY. WE WILL
CONTINUE TO MONITOR TRENDS AND ADJUST ACCORDINGLY.
OTHERWISE, THE OTHER CHALLENGE TODAY WILL BE SURFACE WINDS.
WHILE BLENDED FORECAST GUIDANCE SUGGESTS A SOUTHWESTERLY WIND
THROUGH MUCH OF THE DAY, WE WILL NEED TO KEEP WATCH OF HOW THE
IMPENDING SHOWERS THIS MORNING MIGHT DISRUPT THE AMBIENT FLOW BY
AFTERNOON. COULD WELL BE DEALING WITH THE DREADED VARIABLE WIND.
NWS CHICAGO
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
VISIT US AT WEATHER.GOV/CHICAGO
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