TL;DR

The NOAA Storm Prediction Center (SPC) has issued a Marginal Risk for severe thunderstorms across the middle Florida Peninsula today and parts of the Upper Midwest and middle Missouri Valley tonight. Florida's main threat is waterspouts and brief tornadoes near a surface front, while Iowa and Missouri face isolated elevated supercells with hail potential overnight.

What's Driving Today's Weather?

Two distinct weather systems are shaping Thursday's severe weather potential across widely separated regions of the country.

In Florida, a semi-persistent front draped across the middle Peninsula continues to serve as a focus for afternoon and evening thunderstorms. The front has been reinforced by convection over recent days, and conditions today favor slightly better organization than Wednesday. Surface dewpoints in the 73–75°F range are feeding a very moist environment, while winds aloft have trended upward overnight—a subtle but meaningful change that could support brief rotating storms.

Meanwhile, across the Upper Midwest, warm advection and isentropic ascent will increase tonight ahead of a northeastward-advancing warm front. Elevated thunderstorms should develop late this evening into the overnight hours as moisture and instability build in the cloud-bearing layer above the surface. Effective wind shear values of 40+ knots will support supercell potential, with hail the primary concern.

Where is the Marginal Risk Today?

The SPC's Day 1 Convective Outlook places a Marginal Risk across two areas:

  • Middle Florida Peninsula — from the eastern Gulf coast inland, roughly from Tampa Bay south through the Lake Okeechobee region
  • Upper Midwest and middle Missouri Valley — including parts of Iowa and northern Missouri

The Marginal Risk is the lowest category on SPC's five-tier scale, indicating isolated severe storms are possible but not expected to be widespread.

Florida: Waterspouts and Brief Tornadoes Possible

The Setup

Florida's threat window opens this afternoon and continues into the evening. The key feature is a surface front lying across the middle part of the Peninsula, with storms expected to fire along and just inland from the front.

Radar wind profiler data from Tampa Bay (KTBW) sampled weak lower-tropospheric winds early Thursday but showed moderate directional turning and a speed increase above 10,000 feet. SPC notes that this yields around 25–30 knots of effective shear—enough to support organized storms in a high-moisture environment.

Observed soundings from Tampa Bay also reveal a mid-level cooling trend and an increase in winds aloft between 00Z and 12Z Thursday. If this trend continues into the afternoon, as some guidance suggests, a few sustained storms with weak or transient rotation could develop.

What to Expect

The primary hazards in Florida today are:

  • Waterspouts near the Gulf coast and along the front
  • Brief tornadoes inland, especially near the front
  • Lightning and locally heavy rain

SPC describes this as "not a high-confidence scenario," but notes that "a few subtleties may imply a bit more near-shore supercell and waterspout/brief tornado potential as compared to yesterday." Cloud cover appears less extensive early Thursday within the warm sector, which could modestly boost storm intensity.

Boaters and beachgoers along the Gulf coast should monitor radar closely this afternoon. Waterspouts can develop quickly and occasionally move onshore as brief tornadoes.

Iowa and Missouri: Elevated Hail Risk Tonight

The Setup

The Upper Midwest threat is a nocturnal event. Isolated to widely scattered elevated thunderstorms should develop late Thursday evening as warm advection increases ahead of a warm front pushing northeast across the region.

Elevated storms form above the surface in a layer of warm, moist air—often while cooler, stable air remains at ground level. These storms can still produce severe weather, particularly large hail that falls through the stable layer to the surface.

SPC forecasts 750–1,250 J/kg of MUCAPE (a measure of atmospheric instability) may develop in the elevated layer, supported by sufficient mid-level moisture. With effective shear increasing to 40+ knots, conditions favor a few elevated supercells.

What to Expect

The primary hazard across Iowa and northern Missouri tonight is large hail. A few instances of hail reaching severe criteria (1 inch diameter or larger) are possible, mainly between late evening and the overnight hours.

Timing is less certain with elevated convection, but the window appears to open around 9 pm CDT and continue past midnight. Residents in the risk area should check radar before bed—elevated storms can be deceptively strong and may wake you with hail on the roof.

What About Tomorrow?

SPC's Day 2 outlook, valid Friday, upgrades the risk to Slight across parts of Alabama, Georgia, and Florida as a front pushes into the Southeast. The Day 3 outlook maintains a Slight Risk across similar areas Saturday.

The pattern suggests the Southeast will remain active into the weekend, while the Upper Midwest threat is confined to tonight.

Recent Severe Weather

The last 24 hours have been quiet across the Lower 48. SPC logged just 1 hail report and 5 wind reports, all from Michigan and New York on Wednesday evening. No tornadoes were reported.

The hail report came from Wilson, New York, where 1-inch hail fell around 9:30 pm EDT. Wind reports included tree damage and a damaged mobile home in northern Michigan.

Stay Weather Aware

Marginal Risk days don't generate headlines, but they're a reminder that severe weather doesn't take October off. If you're in the Florida Peninsula today or across Iowa and Missouri tonight, keep an eye on radar and have a way to receive warnings.

Third-party weather apps are silenced by Do Not Disturb, though Wireless Emergency Alerts for tornado warnings still break through on most phones. If you're concerned about sleeping through a nighttime warning—especially relevant for tonight's Iowa and Missouri threat—consider a solution that can ring through Do Not Disturb intentionally, such as VORTEX Pro.

VORTEX is a free web app at vortexintel.app that monitors severe weather nationwide. Pro ($4.99/month) places phone calls to your phone when a tornado or flash flood warning is issued for a location you care about — calls can ring through Do Not Disturb once you enable Emergency Bypass for the number, unlike most third-party app notifications.