Marine Weather and Tide Forecast for Urbana, IL

DISCUSSION
Issued at 133 PM CDT Tue Apr 14 2026

***** BOOM OR BUST CONVECTIVE SCENARIO THIS AFTERNOON *****

At 1pm, a warm airmass was in place across central and southeast Illinois with temperatures in the upper 70s to low 80s. Gulf moisture continues to surge into the region on 15-20 (gusting to 30)
mph southwest breezes, with dewpoints currently in the mid 60s.
Consequently, the airmass is becoming increasingly unstable with RAP mesoanalysis indicating 1500-3000 J/kg SBCAPE. A capping inversion should prevent convective initiation unless and until a trigger lifts parcels to the LFC, which at this point remains unclear.
Recent iterations of the HRRR and several members of the 12z REFS suggest that cap will break, resulting in explosive convective development and scattered severe weather across the CWA by mid afternoon. However, about 60-70% of CAMs keep the cap in place throughout the evening - maintaining warm and breezy conditions.
The 18z raob confirms this notion, depicting a 3 degC capping inversion around 800mb which would take a lot of forcing to overcome. Given the parameter space for severe weather is forecast to become volatile over the next few hours, with SBCAPEs climbing to 2500-4000 J/kg, 700-500 lapse rates reaching 8-8.5C/km, and 45-55 kt effective bulk wind shear, any storms that form would pose a risk for severe weather, especially large hail where storm relative inflow (from the SSW/SW) is unimpeded in right- moving supercells (favored by clockwise curved hodographs). In addition, a few of the more bullish models show localized pockets of 3+ inches of rain falling in a few hours with training storms, which could result in some hydrological issues; accordingly, WPC has expanded the level 2 of 5 (slight)
risk for excessive rainfall southward into much of our CWA
We'll be keeping a close eye on mesoscale trends this afternoon to assess the potential and issue any necessary warnings.

***** MORE NUMEROUS SHOWERS AND STORMS TOMORROW *****

We'll likely (50-70% chance) have a few more storms overnight tonight as a weakening MCS lifts up into our area from northeast Missouri. We may end up needing some short-fused wind headline if the HRRR and RRFS are correct in their depiction of a meso-high feature impacting our west/southwest counties between 11pm and 4am, though confidence in this scenario is also low.

The upper level low will slowly approach our area tomorrow, with continued warm advection ahead of it bringing waves of thunderstorms through the Prairie State. It appears instability will be a bit weaker tomorrow due to widespread clouds and scattered storms limiting surface heating, though the risk for severe weather will increase during the late evening or early overnight period (8pm-2am)
west of I-55 where a few CAMs bring a weakening line of storms capable of locally severe winds.

***** DRY THURSDAY(?), STORMS RETURN FRIDAY NIGHT *****

A weak cold front will settle across the district on Thursday, bringing a moment's repose from the active pattern. However, the front will lift back north Thursday night into Friday, when instability will build ahead of a more potent kinematic system. As with today, we'll be in the warm sector on Friday, so a volatile thermodynamic environment would support severe weather if a trigger ruptures the capping inversion. Otherwise, more numerous showers and storms will pass through the area along the cold front sometime late Friday night or Saturday morning. While this is not a diurnally favorable period for severe weather, the strong forcing with the cold front and 45-55 kt deep layer shear could result in at least scattered severe winds if a mature line of storms enters our area from the west Friday night...or develops along the cold front in eastern Illinois on Saturday.

***** COOLER WEATHER RETURNS SATURDAY *****

A cold front will cross the area sometime on Saturday, with stiff west winds ushering in a more seasonably cool airmass for the second half of the weekend. NBM indicates a 30-50% chance low temperatures by Saturday night fall to 36 deg or cooler north of I-70, though winds should remain elevated to prevent frost formation. The better opportunity will be Sunday night, when NBM chances are 30-60% area- wide for sub 37 degF lows and winds should be calm with surface high pressure parked across the CWA Protective action may be needed to prevent frost from damaging tender vegetation.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
Issued at 1241 PM CDT Tue Apr 14 2026

Isolated (20-30% coverage) thunderstorms are forecast to develop this afternoon, potentially impacting any of the airfields from roughly 19z to 02z. These could be severe and produce high winds and large hail, though confidence in a direct impact at any given location was too low to add a mention of GR or 50+kt gusts in the TAFs.

Tonight into Wednesday morning, periods of isolated, though less intense, showers and storms are forecast. There is a 20% chance that a period of gusty winds impacts PIA, SPI, and BMI between 05z and 09z as a decaying storm complex approaches from the southwest, though again confidence was too low to add this to the TAFs.

Outside of storms, winds will predominantly blow from the SSW around 12-15 kt with gusts up to 25 kt throughout the period.
MVFR ceilings at the northern terminals early this afternoon should lift and/or break up by 20z.

CLIMATE
Issued at 307 AM CDT Tue Apr 14 2026

RECORD HIGHS FOR 4/14:

PEORIA: 86 (2024)
SPRINGFIELD: 89 (2006)
LINCOLN: 87 (2006)
NORMAL: 84 (2006)
URBANA: 84 (2010)
DECATUR: 88 (1941)

FORECAST HIGHS FOR 4/14/2026:

PEORIA: 84 SPRINGFIELD: 87 LINCOLN: 86 NORMAL: 84 URBANA: 84 DECATUR: 85

ILX WATCHES/WARNINGS/ADVISORIES
None.