St. Patrick's Day Forecast

An approaching warm front Thursday night will bring a very light wintry mix to southern Wisconsin and northern Illinois.  Accumulations are not expected, but the wintry mix could cause roads in southern Wisconsin to become a little slick overnight.  Surface temperatures are slowly falling towards freezing and this could cause a brief period of freezing rain over southeast Wisconsin.

Once the warm front passes, temperatures will warm a few degrees into Friday morning.  This will cause any wintry weather to transition over to light rain and drizzle Friday morning.  The precipitation will end with the passage of a cold front mid-day.  Clouds may stick around through the afternoon, but most of the afternoon should remain dry.  Temperatures will warm into the middle 40's.

March chill may last to the end of the month

As Meteorologist Kristin Cwynar mentioned in the previous post, temperatures the past few days have been falling short of average.  Highs Wednesday reached the low 30's, still about 10 to 15 degrees below average but warmer than Tuesday. 

Temperatures will continue to warm through the week with highs back to, and slightly above, average by the weekend.  But the 6-10 day and 8-14 day outlook from the Climate Prediction Center suggest temperatures over the Midwest, Great Lakes and Northeast may have a higher probability of staying slightly below average.  A different end to the month of March than what happened at the end of January and February. 

While signs of a major cool down (like the one we had Tuesday and Wednesday) are not on the horizon, high temperatures may continue to remain just a few degrees below normal through the end of the month.  Normally we should be in the middle and upper 40's.

A fairly progressive jet stream will remain in place over the United States making it difficult for blocking patterns to develop, which is what brings the extreme warmth or extreme cold.  This fast moving jet stream will also increase the chance for Pacific storm systems to traverse the country, bringing an above average chance for precipitation.  

Feeling like Winter the Past Several Days

Winter made its comeback this week, with record breaking snow recorded on Monday and frigid morning temperatures. The past five days have been anywhere between 10°-20° degrees below average. The coldest was Tuesday where highs only climbed to 26º, compared to it's average of 46°. Today will be one more day with a winter-like chill, the forecast high of 29° is 17° colder then the average.

An incoming warm front will bring temperatures near 40° by Thursday, and then into the low 50's by Friday. The warmth comes with some rain, Thursday night into Friday, though right now it doesn't look like it will amount to much. 

Record daily snowfall Monday

The snow Monday wasn't much, but it was the highest amount of snow we've had since the middle of December 2016!  Officially 3.6" of snow came down from midnight to midnight Monday, breaking the previous daily snowfall record of 2.6" set back in 1972.

On average, March received just under 5 inches of snow.  So far this month we've received just over 5 inches of snow.  No snow is in the forecast this week - just a little rain before the weekend.

Snow Roundup

The snow is coming to an end across the area, but here is a look at some of the totals:
 Bull Valley 2WNW (McHenry)....................4.8
Wonder Lake 1WNW (McHenry)....................4.7
Hebron (McHenry)..............................4.5
 Harvard (McHenry).............................4.5
Mount Carroll (Carroll).................4.0
New Glarus (Green)................3.4
Lake Geneva (Walworth)................3.3
Belvidere (Boone).............................3.2
 Marengo (McHenry).............................3.2
Schapville (JoDaviess)................3.1
 Dixon 3NNW (Lee)..............................3.0
 Cary (McHenry)................................3.0
Freeport (Stephenson) .................3.0
 Ashton (Lee)..................................2.9
 Polo (Ogle)...................................2.8
 Byron 3N (Ogle)...............................2.7
 Dixon 2SW (Lee)...............................2.5
 Rockford 1NW (Winnebago)......................2.5
Janesville (Rock)................2.5
 Capron (Boone)................................2.4
 Roscoe 2ESE (Winnebago).......................2.4
Paw Paw (Lee).................................2.4
 Roscoe 2se (Winnebago)........................2.4
Genoa (De Kalb)...............................2.1
 Rockford (Winnebago)..........................2.1
Beloit (Rock)...............2.0
 Steward (Lee).................................2.0
Milledgeville (Carroll).................2.0
Woodstick (McHenry)................2.0
 Rochelle (Ogle)...............................1.7
 De Kalb (De Kalb).............................1.6
Midway Coop  Cortland (De Kalb)............................1.0
Somonauk 2NE (De Kalb)........................1.0
Rockford 3NE (Winnebago)......................0.8

Most totals were between 2-5" across the area, but just north of the Stateline in Elmwood Park which is in Racine county in Wisconsin, 8.8" fell! Snow will stay rather light through the rest of the afternoon. 

Monday Morning Snow Update

 So far across the Stateline about 2 inches has accumulated, but residents can expect an additional two inches over the next couple of hours. The highest totals have been found just west of the Stateline, with many cities in Iowa receiving 4-8 inches.

Per IDOT, US 20 west of Rockford through Freeport and to Galena is snow covered. I90 from Rockford to Chicago is rather clear, along with I90 and 39 north of Rockford. Side streets and country roads will continue to cause some problems through the morning an afternoon. Make sure to leave plenty of time to stop, and it will be hard to get going again..

Our far eastern counties could get clipped by lake effect snow that will develop this afternoon, as northeast winds off the lake will help to produce enough instability to support it.

Snow is starting to lighten west of Rockford from Freeport to Galena as the low pressure system shifts to the south and east through southern Illinois. Because of this track, heavier snow has been falling through central portions of the state as well. Snow will continue to wind down through the lunch time hour with snow totals climbing to about 4" for many with some areas receiving around 3" and as high as potentially 6". The current forecast though is around 4" for the majority of the area.

Snow will slow down Monday morning commute

A Winter Weather Advisory has been issued for all of northern Illinois and southern Wisconsin beginning Sunday evening and lasting through Monday evening.

The air mass over the Stateline is pretty dry with dew points in the low single digits.  But those dew points should quickly rise allowing the snow to reach the surface after 8pm.  The snow will begin light and then pick up in intensity during the overnight and early Monday morning.

Highest impact to travel will occur late Sunday night into Monday morning.  So please allow for extra time during the morning commute.  As the snowfall rate increases, roads will become snow covered and slick with road surface temperatures falling below freezing allowing the snow to accumulate.

Most of the accumulating snow will be done before Noon Monday, with only a few flurries expected during the remainder of the afternoon and evening.
 
Snowfall totals by Monday morning should be between 3" and 4", with another inch or two accumulating during the day Monday.  Overall 3" to 6" of snow should occur for northern Illinois and southern Wisconsin.  Winds will increase Monday, but blowing and drifting snow shouldn't be a major issue.  Road conditions will remain slick through Monday evening.