***Watch WISN 12 News for the latest on the rain and snow!***
Thank you for stopping by the Weather Watch 12 blog! A large and powerful early Spring storm system will impact the area over the next 2 days. This ‘signature’ storm in the pattern will once again produce record setting weather over the Midwest. From heavy rain, to heavy snow, and severe weather – we can expect many weather headlines to surface in the coming days.
Now that the rain has reached southern Wisconsin, the question is how much can we expect, and when will it change to snow? For a current look at our interactive radar just click below.
Let’s start by looking at the surface map from 11am Tuesday morning. At this time Milwaukee was just reporting cloudy skies with a cold east breeze and a temperature of 36 degrees. Madison was reporting light rain indicated by the two ‘..’ next to the symbol labeled MSN. Fond du Lac was reporting light snow at this time, indicated by the two ‘**’ symbols.
The warm air was sitting well to the southwest of Wisconsin, with temperatures in the 70s over parts of Kansas and Missouri. The mild readings will not make it into our region with this storm system.
So that means a cold rain, a wintry mix, or snow in southeast Wisconsin from this storm. For Tuesday expect temperatures to remain in the 30s to near 40 degrees, warmest near the WI/IL border. It will just be tough to see temperatures warm with winds blowing in refrigerated air from Lake Michigan.
The heaviest rains will likely occur late Tuesday afternoon through the early morning hours of Wednesday. The 12Z GFS(Global Forecast System) model below shows 0.50″ to 0.75″ of rain possible between 7pm and 1am across southeast Wisconsin. Thunderstorms are also likely during this time, and some could produce small hail. If we were going to see any flooding issues surface during the rain, it may be during this time window.
Temperatures at the surface and aloft should keep the moisture as rain in Milwaukee during this time, but the ‘Zero’ line indicated by the blue line near Sheboygan would be likely anything from a mix to snow! The blue line is the 850 mb(1500 meters above the ground) freezing line.
Below is the 12Z GFS forecast map valid at 1 a.m.Wednesday.
The rain/snow line will drift south on Wednesday, and snow is likely in many areas.
Precipitation totals from Tuesday through early Thursday could be very impressive. Some locations may push 2.00″ of moisture! A majority of this would be rain in southeast Wisconsin. Below is the RPM precipitation forecast. Remember, this is just one forecast from one model that we look at.
Now how much of this would be snow? Below is the RPM snowfall forecast. This puts a wide swath of 12″ of snow in northern Wisconsin. This would be heavy, wet snow.
Below are the watches, warnings, and advisories that were in place as of Tuesday. Fond du Lac and Sheboygan counties were included in the Winter Weather Advisory.
Through midday Tuesday most of the models we use for forecasting had surface temperatures about 1-3 degrees too warm. If the colder trend holds for the entire storm, then the accumulating snow bands would be shifted a bit farther south. I do think West Bend, Waukesha, and Milwaukee will see some snow stick from this storm. Just a slight shift of 20-50 miles in the rain/snow line will make a huge difference in the forecast.
If you follow the blog you know we call this part of the weather pattern the ‘signature’ storm. It occurred on October 26-27, December 11-12, and February 1-2. It is now back and will likely set more weather records. This storm was forecast back on February 3 and again in more detail on February 27 here in the blog.
From February 27 blog entry!
The ‘signature’ storm should return around March 22-24 and I am expecting a classic Spring storm with a severe weather outbreak in the warm sector, and a major winter storm in the cold sector.
Each time through the cycle over a half inch of liquid precipitation has been measured. This is one of the wettest storms in this year’s pattern.
The big question is what will southeast Wisconsin see? I would lean to a rain to snow, with gusty winds with this storm. Behind the storm a push of cold air will settle in to the region.
The first discussion of exact dates for this part of the pattern, and its return, was discussed back on February 3 in the blog!
I would expect this storm to return again, likely somewhere around March 22-25. Let the anticipation begin!
For the latest on the rain and snow watch WISN 12 News, and make sure to post your thoughts and questions to the comments section of the blog.
Have a great day!