Thursday forecast: Chilly temps in Chicagoland prompt Frost Advisory, then Freeze Warning overnight

Chicagoland is in for another chilly day Thursday, but sunshine does return following a totally cloudy Wednesday.

Clear morning skies, however, are leading to a cold start to Thursday in many locations, particularly inland. A Frost Advisory remains in effect until 9 a.m. for Livingston, Ford, Iroquois, Boone, DeKalb, LaSalle, Lee, Ogle, Winnebago, Grundy and Kankakee counties and until 8 a.m. for southern Cook County and Porter County in Indiana.

With more sun shining by the afternoon, Thursday’s high temperatures will reach the low 50s, a bit warmer than Wednesday. But things will get downright cold overnight, with widespread frost and temps dropping into the mid-30s, even the upper 20s in some outlying areas.

With those temps, a Freeze Warning has been issued for almost all of Chicagoland overnight, from 1 a.m. until 8 or 9 a.m. Friday. All counties under a Freeze Warning should take the necessary precautions to protect tender plants by either covering them up or bringing them inside.

Thursday: Day planner

High temps warm a few degrees above Wednesday’s levels thanks to more sunshine.   

Thursday: Afternoon area highs

Low 50s are expected Thursday afternoon areawide, still well below the 60 that’s typical for this time of year.  

Thursday wind gusts: Morning and afternoon

While not quite as blustery as the past couple days, northwest winds will still be rather brisk and add to the chill in the air.    

Friday morning: Widespread frost potential

A perfect recipe for frost: Clear skies and light winds will allow for perfect radiational cooling conditions. 

Temperatures will dip near or below freezing for many outlying areas, allowing for widespread frost to occur. Only areas close to Lake Michigan and city limits will likely escape the frost.  

Friday morning: Area satellite map

This depicts the clear skies that are expected. 

Friday morning: Wind gusts 

Much lighter winds than recent days will also help encourage frost to develop.

Friday morning: Area temperature map

Chicago forecast highs and departure from normal

A slow moderation expected over the weekend and early next, as modestly above normal temperatures return.   

Tropical Storm Melissa crawling … for now

Melissa is forecast to become a major hurricane late this weekend and early next week.  

Bathtub warm waters

Ocean surface temperatures are 29 to 30 degrees Celsius (86 degrees Fahrenheit) in the Caribbean around Jamaica, more than sufficient to generate a major hurricane.  

Atlantic Integrated Vapor Transport: Next 10 days from the ECMWF Model

This is a 10-day animation and shows a monster Hurricane Melissa spinning over the very warm western Caribbean before moving across eastern Cuba into the Atlantic. There’s still no major threat, however, to the Lower 48 at this time. 

Weather Prediction Center: Rainfall forecast

This rainfall projection indicating estimated total amounts shows upwards of 8 inches now suggested for eastern portions of Jamaica. 

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