Marine Weather and Tide Forecast for Nora, IL

SHORT TERM /THROUGH FRIDAY NIGHT/
Issued at 244 PM CDT Thu Apr 30 2026

Tonight...The latest water vapor(WV) loop showing the story nicely with a large upper low acrs the northern GRT LKS, with embedded vort max's swirling under the northwest flow from the northern plains to the OH RVR Valley. One max is right overhead producing the local showers, and one noted upstream acrs the eastern Dakotas. Enough heating with cloud breaks developed in the south to allow for a few thunderstorms to move acrs mainly the southern third of the DVN CWA through early this evening. Some lightning strikes and gusty winds to 40 MPH the main concerns with any maintaining cell. This wave to move off and loss of heating after sunset should bring a temporary lull in precip and even some cloud clearing during the mid to late evening period, before the following upstream vort max rolls toward midnight and into the early morning hours bringing more clouds and some spotty light showers/sprinkles into the northwestern CWA toward dawn. Cool airmass in place making for the advertised frost concerns for tonight, but with the chance for more clouds coming in late tonight during the best frost formation time, it looks marginal with lows more in the mid to upper 30s and will not hoist any frost headlines. That said, if between wave-clearing holds on longer there will be some lower 30s and better chance for more of a widespread frost. The location more prone to this potential will be acrs NW IL.

Friday...While there may be a few spotty sprinkles or light showers with the next vort max arrival during the morning, expect more coverage and development during the Friday afternoon heating period.
Will keep them all showers for now, but signs of enough low to mid level lapse rates and MUCAPEs to help the cause for a few lightning flashes again. Mixing depth and fcst vertical thermal profiles support widespread highs in the mid to upper 50s, with a few areas approaching 60 if they get more sun time. Friday night will be another frost concern night, and with the same cloud and clearing trend uncertainty again. Will advertise the 75th percentile mid 30s for much of the area, but there may be a better shot at late night clearing behind a upper wave exit for lower 30s and a more widespread frost at least in the northern CWA

LONG TERM /SATURDAY THROUGH WEDNESDAY/
Issued at 244 PM CDT Thu Apr 30 2026

Saturday and Sunday...With some upper ridge bulge and between vort timing, Saturday looks mainly dry with more sunshine to help high temps make it more in the upper 50s to lower 60s. Then the next upper wave with related sfc front slated to slip through the area for more shower chances by Sunday. Also a more robust pre-frontal southwesterly draw to help temps warm into the upper 60s to 70s on Sunday despite the clouds and precip chances.

Monday through Wednesday...The latest ensembles suggest a pattern reload of the sunday scenario, but a stronger cool front and pre- frontal warming to make for the warmest day of the fcst period. This may also be a window for more substantial shower and thunderstorm development Monday afternoon and evening, depending on moisture return into the FROPA process. The blocked pattern looks to re- amplify if current upper jet progs/ensembles are correct, with near meridional flow allowing for a Canadian cold dump down the upper MS RVR Valley by mid next week. Thus it's back to well below normal temps in the longer term.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
Issued at 1245 PM CDT Thu Apr 30 2026

Vort max rolling in producing areas of light showers out of mainly VFR CIGs , or briefly reduced to MVFR levels. This will continue through early evening before the showers move out and CIGs decrease or scatter out. A chance for an isolated thunderstorm mainly south of I-80 and the BRL VCNTY during the afternoon. The showers are producing higher wind gusts up to 25 KTs mainly from the west, otherwise winds will continue to veer to the west- northwest through the afternoon around a passing frontal system. The sfc winds will then trend light and variable later tonight into Friday morning.

DVN WATCHES/WARNINGS/ADVISORIES
IA...None.
IL...None.
MO...None.