Marine Weather and Tide Forecast for Olmsted, IL

DISCUSSION
Issued at 115 AM CDT Thu May 22 2025

Elevated instability may touch off a shower/storm early this morning, and cool temps aloft means small hail will be possible with any tstorm. However, most convection will stay just south and west of the FA.

Surface high pressure under the broader long wave trof will keep us mostly dry and seasonally cool ending this work week, with temperatures remaining in the 60s-70s and dew points mostly in the 40s.

Heading into the weekend, the high slides east, as does the heart of the long wave trof and we go a little teleconnected ridging aloft. As energy from the Plains starts to spill into/overtop the weak ridge, it flattens and we get into a little better convective environment as dew points recover into the 50s. Pops increase with the surging elements from the primary Plains storm system moving overtop the FA. This will bring off/on chance of showers/storms esp over the back half of the weekend into early next week, with the main impact being a broad swath forecast of 1-3" average storm total rainfall. It's possible there will be locally higher totals, esp across SEMO.
These totals will gradually heighten the risk of flooding with time over the weekend into early next week. They may also contain some risk of stronger to potentially severe storms, but for now, the main impact hazard looks like heavy rain/flooding.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
Issued at 115 AM CDT Thu May 22 2025

Mainly mid to high level bases are forecast but may include CIGS at times. It looks like pcpn stays just south of the terminals this package, closest to KCGI/KPAH.

PAH WATCHES/WARNINGS/ADVISORIES
IL...None.
MO...None.
IN...None.
KY...None.