Risk of severe storms Tuesday night
On this first full day of autumn, temperatures were well above normal. An approaching cold front will bring a round of thunderstorms later tonight.
There is a risk of severe thunderstorms tonight, mainly northwest of Madison. Thunderstorms will develop by this evening will form ahead of a cold front from west-central Wisconsin through southeastern Minnesota into northern Iowa. Atmospheric instability and wind shear will cause some of these thunderstorms to become severe, with hail, high winds, and a few tornadoes possible with the strongest thunderstorms.
These thunderstorms will move quickly because of a strong jet stream well above the ground, arriving around Madison around midnight. With fewer hours of daylight, the thunderstorms should weaken as the air cools after dark. By the time the storms reach the Madison area, they are likely to be below severe limits, with gusty winds, small hail, and brief heavy rainfall possible. The fast movement of the thunderstorms should limit the amount of rainfall away from the area where the thunderstorms first develop.
Dry weather is expected for Wednesday and Thursday. Another weather system will bring showers and isolated thunderstorms from late Thursday night through Friday. Cooler temperatures should limit the strength of any thunderstorms, so severe weather and heavy rainfall is not expected, although rainfall amounts of around one-half inch are expected, with localized areas that receive thunderstorms may get up to an inch of rainfall. This should limit the threat for flooding.
The weather pattern is expected to become unsettled for the first half of next week. A strong southwest to northeast jet stream will be flowing through the middle of the country dividing cool, fall-like weather over the western part of the country from very mild and humid air over the central and eastern United States. This weather pattern may bring several storms systems that will affect the Midwest and Wisconsin from Sunday through Thursday. Periods of showers and thunderstorms are likely over the first half of next week, with threats for severe weather and heavy rainfall. It is impossible to pinpoint exact areas and timing of the threat, but long-range computer model forecasts are in agreement that much of the central Midwest may have the potential for significant amounts of rainfall for the first half of next week.
The rain should end and more fall-like weather should arrive by the end of next week. Several days of dry weather may continue into the following weekend.
Stay tuned to News 3 Now newscasts, Channel3000.com on the internet, and the Channel 3000 First Alert Weather and Traffic App for further weather updates.
COPYRIGHT 2020 BY CHANNEL 3000. ALL RIGHTS RESERVED. THIS MATERIAL MAY NOT BE PUBLISHED, BROADCAST, REWRITTEN OR REDISTRIBUTED.