A Winter Storm Watch has been issued for all of southern Wisconsin and northern Illinois beginning Sunday morning and lasting through Sunday night.
*****Special Weather Statement from the Chicago NWS regarding Sunday's weather***
...WINTRY MIX OF PRECIPITATION EXPECTED FROM SUNDAY MORNING THROUGH SUNDAY NIGHT... A WINTRY MIX OF SLEET...SNOW AND FREEZING WILL DEVELOP OVER NORTH CENTRAL ILLINOIS SUNDAY MORNING AND THEN SPREAD ACROSS THE REST OF NORTHERN ILLINOIS AND NORTHWEST INDIANA...INCLUDING THE CHICAGO METRO AREA...SUNDAY AFTERNOON. SURFACE TEMPERATURES ARE EXPECTED TO INITIALLY BE IN THE UPPER 20S BUT WILL GRADUALLY WARM INTO THE LOWER 30S SUNDAY AFTERNOON AND EVENTUALLY INTO THE MIDDLE 30S SUNDAY NIGHT. SOME SLEET AND ICE ACCUMULATION WILL BE POSSIBLE BEFORE THE PRECIPITATION TRANSITIONS TO ALL LIQUID RAIN. BUT AT THIS TIME...IT IS TOO DIFFICULT TO DETERMINE SPECIFIC AMOUNTS... GIVEN THE UNCERTAINTY OF HOW FAST SURFACE TEMPERATURES WILL WARM ABOVE FREEZING. ANYONE WITH TRAVEL PLANS SUNDAY MORNING THROUGH SUNDAY NIGHT SHOULD CONTINUE TO MONITOR LATER FORECASTS FOR THIS POTENTIAL WINTRY MIX OF PRECIPITATION.
****Special Weather Statement from the Milwaukee NWS for southern Wisconsin regarding Sunday's weather*****
..WINTRY MIX OF PRECIPITATION SUNDAY AND SUNDAY NIGHT... FREEZING RAIN...SNOW...AND SLEET WILL MOVE INTO SOUTHERN WISCONSIN FROM ILLINOIS ON SUNDAY AND CONTINUE SUNDAY NIGHT. ICE ACCUMULATIONS BETWEEN 0.10 AND 0.25 INCHES IS FORECAST. 1 TO 2 INCHES OF SNOW IS EXPECTED MAINLY NORTH OF A LINE FROM MADISON AND MILWAUKEE WITH UNDER AN INCH ALONG AND SOUTH OF THAT LINE. WIDESPREAD HAZARDOUS TRAVEL IS EXPECTED...ESPECIALLY SUNDAY AFTERNOON AND NIGHT. PRECIPITATION WILL BEGIN AS SNOW AND SLEET...AND TRANSITION TO MORE FREEZING RAIN SOUTH OF MADISON AND MILWAUKEE DURING SUNDAY AFTERNOON AS TEMPERATURES REMAIN BELOW FREEZING. THE MIXED PRECIPITATION WILL BECOME LIGHTER THROUGHOUT SUNDAY NIGHT WITH WARMING TEMPERATURES. TEMPERATURES WILL RISE ABOVE FREEZING IN FAR SOUTHEAST AND FAR SOUTHERN WISCONSIN TOWARD MONDAY MORNING. TEMPERATURES WILL THEN WARM ABOVE FREEZING THROUGHOUT SOUTHERN WISCONSIN ON MONDAY. LISTEN TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA FOR THE LATER UPDATES ON THIS HAZARDOUS WEATHER SITUATION.
The weather Sunday afternoon may get a little dicey with our next approaching storm system as a mixture of sleet, freezing rain/drizzle and rain are expected to occur all within a 24 hour period.
Warm air a few thousand feet above the surface will begin to move in early Sunday morning. This will cause temperatures aloft to warm well above freezing while temperatures at the surface remain right at or slightly below freezing (32°F). Even the little bit of snow we received early Friday morning will help to the cold air lasting longer at the surface until late Sunday when enough warm air advection (push of warm air from the south) helps to overcome the cooler temperatures. With this type of set-up occurring it's possible a period of freezing rain and sleet may occur from late Sunday morning through Sunday evening until surface temperatures rise above freezing. If we do experience a period of freezing rain ice accumulations of up to a quarter of an inch will occur on surfaces such as roads, sidewalks, parking lots, trees and power lines. It's important to note that any little deviation above or below 32°F will have an impact on what happens at the surface. While a significant icing event isn't anticipated at this time roads may become dangerous for travel Sunday afternoon and evening. If you have anything you need to do over the weekend, do it Saturday. Adjustments to the forecast will be made throughout the weekend for Sunday/Sunday night so make sure you continue to check back for the latest updates!