NWS Forecast for O'Hare International Airport Chicago, IL Last Update: 9:57 pm CDT Oct 14, 2024
Hazardous Weather Outlook
Monday Night: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 2am. Low around 42. North northwest wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday: Showers and thunderstorms before 10am, then showers likely and possibly a thunderstorm between 10am and 1pm, then a chance of showers after 1pm. High near 51. North wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night: A 10 percent chance of showers before 7pm. Mostly clear, with a low around 36. North northwest wind 10 to 15 mph.
Wednesday: Areas of frost before 8am. Otherwise, sunny, with a high near 57. Northwest wind 5 to 10 mph.
Wednesday Night: Areas of frost after 5am. Otherwise, mostly clear, with a low around 36. West wind around 5 mph becoming calm.
Thursday: Areas of frost before 8am. Otherwise, sunny, with a high near 64.
Thursday Night: Clear, with a low around 44.
Friday: Sunny, with a high near 68.
Friday Night: Clear, with a low around 46.
Saturday: Sunny, with a high near 71.
Saturday Night: Mostly clear, with a low around 50.
Sunday: Sunny, with a high near 73.
Sunday Night: Mostly clear, with a low around 51.
Monday: Sunny, with a high near 73.
Monday Night: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 2am. Low around 42. North northwest wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday: Showers and thunderstorms before 10am, then showers likely and possibly a thunderstorm between 10am and 1pm, then a chance of showers after 1pm. High near 51. North wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night: A 10 percent chance of showers before 7pm. Mostly clear, with a low around 36. North northwest wind 10 to 15 mph.
Wednesday: Areas of frost before 8am. Otherwise, sunny, with a high near 57. Northwest wind 5 to 10 mph.
Wednesday Night: Areas of frost after 5am. Otherwise, mostly clear, with a low around 36. West wind around 5 mph becoming calm.
Thursday: Areas of frost before 8am. Otherwise, sunny, with a high near 64.
Thursday Night: Clear, with a low around 44.
Friday: Sunny, with a high near 68.
Friday Night: Clear, with a low around 46.
Saturday: Sunny, with a high near 71.
Saturday Night: Mostly clear, with a low around 50.
Sunday: Sunny, with a high near 73.
Sunday Night: Mostly clear, with a low around 51.
Monday: Sunny, with a high near 73.
Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
311 PM CDT Mon Oct 14 2024
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
311 PM CDT Mon Oct 14 2024 /411 PM EDT Mon Oct 14 2024/
This Hazardous Weather Outlook is for portions of north central
Illinois...northeast Illinois and northwest Indiana.
.DAY ONE...Tonight.
Weather hazards expected...
Limited Thunderstorm Risk near the lake.
DISCUSSION...
Lake effect showers with isolated embedded thunderstorms are
possible near Lake Michigan.
.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.
Tuesday...
Limited Thunderstorm Risk near the lake.
Wednesday and Thursday Mornings...
Significant Frost Risk.
.SPOTTER INFORMATION STATEMENT...
Spotter activation will not be necessary through tonight.
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
323 AM CDT Tue Oct 15 2024
Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 323 AM CDT Tue Oct 15 2024
.KEY MESSAGES...
- Lake effect showers are expected downwind of Lake Michigan through tonight, including the potential for embedded storms and waterspouts.
- Frost and freeze conditions are expected early Wednesday and Thursday mornings, especially away from Chicago and Lake Michigan.
- A warming trend is expected through early next week with dry conditions forecast.
&&
.DISCUSSION... Issued at 323 AM CDT Tue Oct 15 2024
Through Wednesday:
Attention in the near term remains the ongoing lake effect showers with isolated embedded thunderstorms which have at times been capable of producing small hail and waterspouts. Current activity extends along the entire western periphery of Lake Michigan and inland into northwest Indiana. This band is now expanding in coverage further inland across northeast Illinois in response to an approaching inverted shortwave trough pivoting across the region through this morning. A more focused lake effect band is then expected to set back up by late morning as lake effect parameters maximize. This will initially be oriented into northeast Illinois and then gradually shift east into northwest Indiana during the afternoon where it will remain through the evening before gradually diminishing overnight. Similar to yesterday, with such low freezing levels in place, expect any of the deeper lake effect showers/storms (saturated well into the -10 to -20C layer) to be capable of small hail/graupel.
Winds will pick back up out of the north after daybreak with gusts to 25-30 mph expected through this afternoon. With temperatures forecast to struggle to even reach the lower 50s today, daytime wind chills will largely remain in the low 40s.
As lake effect showers/clouds shift mainly across northwest Indiana this evening, easing winds and mostly clear skies over northern Illinois will set the stage for the coldest night of the season. The current Freeze Watch was upgraded to a Warning with this update and while there is some uncertainty as to whether winds can ease enough for more widespread frost development, opted to issue a Frost Advisory for the rest of our Illinois counties, with the exception of central and southern Cook County where the urban heat island and lake influence should further help keep frost at bay. After a chilly start, Wednesday looks quiet weather-wise with highs in the mid 50s.
Petr
Wednesday Night through Monday:
Clouds are expected to clear out area wide overnight into Thursday morning. Winds will be light and temperatures will once again drop. Most of the forecast area is expected to bottom out into sub freezing values, with only the city of Chicago remaining in the upper 30s/low 40s. There remains a consistent signal which could prompt another Freeze Warning being needed for areas not receiving a freeze on Wednesday morning.
As upper-level ridging builds eastward into the western Great Lakes during the end of the week, a notable warming trend is expected. Afternoon high temperatures will climb back into the 60s for the end of the work week. Temperatures will continue to warm into the 70s over the weekend and linger into early next week. A drier air mass and higher pressure should keep the conditions dry through the end of the weekend.
There is the chance for a weak cold front to pass to the north Sunday morning. And while it will be something to monitor, it is expected to remain north of Illinois with dry conditions currently forecast. For early next week, ensemble models are suggesting a short wave trough could approach the Great Lakes from the Southern Plains. However, these models are also showing the trough weakening as it approaches. The blend added some low end PoPs (slight chance, less than 20 percent) which is within reason but confidence is low at this time on impacts and timing.
DK
&&
.AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 1238 AM CDT Tue Oct 15 2024
Key Aviation Impacts for the current TAF period:
- Showers over the lake will push westward for rain and periods of MVFR conditions at terminals overnight.
- Prevailing winds will be out of the north to northwest, but chances in morning hours having a period of northeasterly winds at Chicago terminals with the showery activity
- Gusty northwesterly winds will continue late morning through the afternoon (into Tuesday evening at KGYY)
A band of lake effect showers has developed out over the lake. While there has been some lightning generated over the lake which could impact approaches, the lack of instability over land keeps TS mention out of the TAFs. However, the lake effect boundary is expected to push its way inland overnight providing showers at most terminals. There is lower confidence that KRFD receives showers, but maintained the PROB30. Stronger pulses may develop within the showers which kept the mentioned for periods of MVFR vis and cig reductions in the TAFs.
There is fairly high confidence in the rain showers overnight, but lower confidence in the accompanying wind directions. Most of the time should have winds out of the north to just west of north (340-350). However, models have consistently been suggesting a window for northeasterly winds to move inland to ORD/MDW during the westward push of showers in the morning.
Winds will start to return to north-northwest as early as late morning. The axis of lake effect showers will once again drift east of the Chicago area terminals, with prevailing showers over KGYY through the end of the TAF. Terminals will gradually have improving weather conditions and VFR skies. However, there is expected to be another stronger jet aloft which will translate in gusty northwesterly winds through the afternoon. As skies clear over Illinois Tuesday evening, winds will gradually diminish, the exception being over northwest Indiana as the lake effect band of clouds will remain through the end of the TAF period with gustier winds.
DK
&&
.MARINE... Issued at 323 AM CDT Tue Oct 15 2024
Key Messages:
- Lake effect showers continue through tonight with the potential for embedded storms and waterspouts.
- Occasional gale force gusts to 35 kt possible today.
Conditions remain favorable for continued lake effects showers with embedded thunderstorms through tonight. Conditions will also be conducive for small hail and waterspouts.
Another period of higher wind gusts to 30 kt and building waves is expected today though confidence in an extended period of gales remains low.
Petr
&&
.LOT WATCHES/WARNINGS/ADVISORIES... IL...Freeze Warning from 1 AM to 9 AM CDT Wednesday for ILZ003- ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-ILZ012-ILZ019-ILZ020- ILZ021-ILZ032.
Frost Advisory from 1 AM to 9 AM CDT Wednesday for ILZ006- ILZ013-ILZ023-ILZ033-ILZ039-ILZ103-ILZ106-ILZ107-ILZ108.
IN...None. LM...Small Craft Advisory until 4 PM CDT Wednesday for the IL nearshore waters.
Small Craft Advisory until 7 PM CDT Wednesday for the IN nearshore waters.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Freeze Warning from 1 AM to 9 AM CDT Wednesday for ILZ003-
ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-ILZ012-ILZ019-ILZ020-
ILZ021-ILZ032.
Frost Advisory from 1 AM to 9 AM CDT Wednesday for ILZ006-
ILZ013-ILZ023-ILZ033-ILZ039-ILZ103-ILZ106-ILZ107-ILZ108.
IN...None.
LM...Small Craft Advisory until 4 PM CDT Wednesday for the IL
nearshore waters.
Small Craft Advisory until 7 PM CDT Wednesday for the IN
nearshore waters.
&&
$$