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Wildfire Smoke and Severe Thunderstorms in the East; Monsoon Thunderstorms in the Southwest

Wildfire smoke continues to impact air quality from the Great Lakes region into New England and the Mid-Atlantic today with widespread Air Quality Alerts in effect. Severe thunderstorms are expected across portions of the Ohio Valley and Lower Great Lakes into the Mid-Atlantic and Northeast, this afternoon into the evening. Monsoonal thunderstorms may bring areas of flooding to the Southwest. Read More >

 

Freezing Drizzle Explained

There is a very small margin of error in determining primarily light snow vs. light freezing drizzle for forecasters.  However, the difference in impacts between these two precipitation types is often significant, with freezing drizzle prone to quickly cause slick surfaces, even with only trace amounts.

 


 



Model Analysis
An 8 am model analysis sounding near Romeoville, IL, indicating a saturated layer that was within temperatures close to both flurries/snow grains and supercooled liquid for freezing drizzle. 
 

Radar Loop
Radar loop and observations during from 9 pm January 23 through 12 pm January 24.  A gradual expansion in light echoes occurs during the overnight/early morning of the 24th.  There are some embedded heavier echoes that are likely light freezing rain showers.  As an indication of that, NWS Chicago recorded 0.05" of liquid during the morning of January 24.

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