Area Forecast Discussion
Issued by NWS Chicago, IL
Issued by NWS Chicago, IL
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464 FXUS63 KLOT 292325 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 625 PM CDT Wed May 29 2024 .KEY MESSAGES... - Dry and pleasant weather is expected today through Friday as temperatures gradually warm. - Periodic chances of showers and storms will return over the weekend into early next week. && .DISCUSSION... Issued at 205 PM CDT Wed May 29 2024 An upper level ridge will continue to build through Friday. As it builds, better height rises and subsidence aloft will help provide quieter weather through the short term. With onshore flow expected each day (northeast today, becoming east tomorrow, southeast Friday), plus diurnal heating, light cumulus may develop each afternoon, but otherwise the sun should have no issues shining through. Temperatures will steadily climb from the 60s and low 70s today to the mid to upper 70s on Friday, though cooler conditions can be expected along the lake shore. A short wave trough moves eastward out of the Plains late Friday and into Saturday morning bringing rainy conditions back to northern Illinois and northwestern Indiana. The GEFS model has a comparatively stronger low at the surface that moves northeastward over Illinois through Saturday, where the Euro Ensemble has a weaker, less organized low moving toward northwestern Indiana. Mid level lapse rates are not particularly impressive and there will be a question to just how much instability sufficient for thunderstorms can advect northward. And while most models have the better chances for thunder more confined to the track of the low, which may deviate in the next 48 hours, chances appear better near Chicago. With fairly weak shear through the column, the primary expectation remains for general thunderstorms, but if models start trending more toward the GFS solution with a more northern track, perhaps a severe risk can be re-evaluated. Lastly, models continue to trend the timing slightly later and later where it may not arrive in northwest Indiana until Saturday afternoon with lingering showers trailing behind it. Temperatures on Saturday will likely be kept in the middle 70s, while low 80s are forecasted for Sunday. Both days look to be noticeably cooler near the lakeshore, especially on the IL side. Most of Sunday should be dry, but some models are spitting out isolated pockets of rain during the day. Temperatures should continue to warm into next week when we expect a return to the 80s for several days. There has been a strong and consistent signal for a cold front to pass through the region sometime between Monday and Monday night with a favorable thermodynamic environment to support thunderstorms building out ahead of it. The GEFS, CIPS, and CSU severe prob guidance are all highlighting Monday for a potential for severe weather in the region. A lot of that will be dictated by the time of day that the front decides to move through. A generally unsettled pattern will keep intermittent rain chances in the forecast through midweek with another cold frontal passage and thunder potential perhaps on the scope around Wednesday. DK/Doom && .AVIATION /00Z TAFS THROUGH 06Z THURSDAY/... Issued at 625 PM CDT Wed May 29 2024 No forecast concerns this period. Northeast winds 10-15kts with some higher gusts will diminish quickly with sunset this evening and turn more to the north/northwest this evening and then shift back to the northeast Thursday morning. cms && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Beach Hazards Statement until 10 PM CDT this evening for ILZ103-ILZ104. IN...Beach Hazards Statement until 10 PM CDT this evening for INZ001-INZ002. LM...Small Craft Advisory until 10 PM CDT this evening for Wilmette Harbor IL to Michigan City IN. && $$ Visit us at weather.gov/chicago