UPDATED POST: SUNDAY, FEBRUARY 16, 2014, 4:01 p.m.
A winter storm starting out with freezing rain, sleet, and snow and then changing over to all moderate to heavy snow is still in the forecast early Monday morning into Monday afternoon.
Here are the updated snow forecast totals for Monday. The biggest change has been to shift some heavy snow into our southern hometowns.
You can see the original contours and the details below.
ORIGINAL POST: SUNDAY, FEBRUARY 16, 2014, 8:29 a.m.
Enjoy the sun and cloud mix Sunday with highs in the 20s because our next winter storm is threatening us with a wintry mix of snow, sleet, and freezing rain Monday.
Here’s the reason we always tell you to keep up on the latest forecast with storms.
Our big warm-up is still coming Tuesday through Thursday. However, instead of a wintry mix changing over to all rain Monday, it’s now likely to change over to all snow and accumulate!
A “Winter Weather Advisory is in effect from 3 a.m.- 3 p.m. Monday for much of eastern Iowa and northern Illinois (6 a.m.-6 p.m. for Knox and Stark counties in Illinois).
A combination of sleet, freezing rain, and snow will begin across the area after midnight and intensify Monday morning.
The best chance of seeing freezing rain will be south of the Quad Cities. From around the metro area northward, mostly sleet and snow is expected. By mid-morning, all of the wintry mix will change over to all snow and start piling up.
Here is the situation based on the American GFS models.
This first map shows light moisture over the area at 6 a.m. Monday and that blue line across the Quad Cities shows the freezing line. Thus, it’s very likely we’ll be seeing a combination of freezing rain and snow (south), icy mix of sleet, freezing rain, and snow in the Quad Cities, and snow and sleet (north).
The map below is at noon. By that time, the cold air has arrived and all of the precipitation should be in the form of snow. And, notice that the green is darker indication heavier snow.
By 6 p.m., the winter storm pulls away and the snow should end as light snow or flurries.
Here is the likelihood of seeing 4″ of snow or more from the NOAA’s Weather Prediction Center. The greens show a 20-40% chance and the blues indicate a 40%+ chance.
I’m showing you that graphic because it lines up with my forecast. Here’s how much snow I’m predicting for Monday.
THIS IS A DEVELOPING SITUATION SUBJECT TO BIG CHANGES. A 2°-3° SHIFT IN TEMPERATURES COULD MAKE A BIG DIFFERENCE IN US GETTING A COLD RAIN, AN ICE STORM, OR A HEAVY SNOW!
Thank you to the National Weather Service in the Quad Cities for the base map with the “Winter Weather Advisory” colored in for Monday.
After this system, it warms up this week into the 30s and 40s Tuesday through Saturday.
As a matter of fact, another storm moves in late week and it should be all rain. This is the precipitation forecast map for Wednesday morning through Friday morning.
It could be a decent rain maker (0.5″ or more is possible). That would not be good on top of melting away the 5″ of snow on the ground now in the Quad Cities and the new snow coming in Monday.
This does raise some flooding concerns, but let’s deal with one system at a time and that would be the ice and snow coming in Monday.
I’ll give you another update later today and I’ll have the very latest beginning at 5 a.m. Monday on “CBS4 News This Morning” in the Quad Cities.