At 8:30 PM CDT, radar indicated that accumulating snow was generally east of I-55, and was shifting off to the east. The snow should end across the immediate metro area by 11 PM. Accumulations have generally been in the 1/2 to 1 inch range, with as much as 1.6 inches reported at Marengo.
Later tonight, a total lunar eclipse will occur. Current RPM model forecasts show that skies should clear across most of the Chicago area around midnight. This is supported by latest satellite imagery, which shows skies clearing along the Mississippi river. The clearing line is shifting eastward and should pass Chicago in time for viewing the eclipse. The exception may be over northwest Indiana, where lake effect clouds may persist much of the night.
At 6 PM CDT, snow had overspread just about the entire Chicago metro area. Temps were just above freezing, with slushy accumulations on grassy areas, cars, and rooftops. Roadways, including secondary routes were still reported to be wet.
With sunset, temps are forecast to dip just below freezing and snow may accumulate 1 to 2 inches in some areas, again, mainly on grass and elevated surfaces.
Radar continues to show light snow spreading across northeast Illinois, with bands of moderate to heavy snow embedded within this precipitation area. Temperatures remain just above freezing, and most reporting stations have visibilities of 1 to 2 miles, suggesting that snow is generally melting on contact.
Heavier snow is being reported at Quincy and Macomb in west central Illinois, with visibilities reduced to 1/2 mile. Temperatures are forecast to slowly fall this evening. Areas receiving heavier snowfall may begin to develop slushy accumulations on grassy areas.
As of 3:30 PM CDT, IDOT reported all roads in the area to be wet, but free of snow and ice. This is expected to remain the case on major routes through this evening.
Radar and surface reports indicate that snow has spread across north central, and portions of northeast Illinois. At 3:00 PM CDT the snow was along and west of a line from Mundelein, to Arlington Heights, to Elgin, to Peru. The snow is expected to continue spreading across the metro area heading into this evening.
Where the snow is falling, temperatures are running in the mid 30s so most of what is falling will melt on contact. Also, visibilities are generally around 2 miles.
Heavier snow, with temperatures hovering near freezing and visibilities near 1 mile are reported across northwest Illinois. Some slushy accumulations may begin later this afternoon, mainly on grassy areas. Roadways heading into the evening rush are expected to remain wet.
By Meteorologist Paul Merzlock
Climatologically, the month of April produces the area’s largest tornado events. Thursday marked the 40th anniversary of one of the nation’s most devastating tornado outbreaks. On April 3, 1974, at 1:10 p.m., a weak tornado touched down 10 miles north of Morris. It was the beginning of an 18-hour rampage that produced 148 tornadoes across 13 states. Thirty of those were particularly violent, EF4- and EF5-intensity twisters. By the morning of April 4, a total of 330 people had lost their lives, with over 6,000 injured. Damage totaled $4.5 billion in current U.S. dollars, and 10 states were declared federal disaster areas. From this tragic event, a silver lining emerged. Funding and research that followed produced the modern Doppler radar system now used by the National Weather Service.
Springtime weather across the Midwest can be notoriously fickle. The latest storm system to pass across the area was a good example. Temperatures in the low 40s, combined with wind gusts over 40 mph made for a less-than-pleasant April 4th. Highest winds were reported SW of the city, with Minooka registering a 55 mph gust. Though not the best baseball weather, conditions could have been much worse. The storm produced heavy snow across the upper Midwest, with 18” accumulations reported over northeast Minnesota and northern Wisconsin. To the south, flooding rains, damaging hail and tornadoes occurred from Missouri to Texas, and eastward through the Tennessee valley. Tranquil weather is forecast this weekend, with sunshine, light winds and seasonable temps expected.
High temperatures Sunday afternoon soared into the 60s and 70s from the central plains, eastward across the Mississippi valley. Similar warmth is expected Monday, even as a strong cold front settles into the upper Midwest. This scenario will establish a large temperature contrast, setting the stage for storm development. Deepening low pressure west of Chicago is then forecast to produce gusty south winds that will bring the city its warmest day in over 4 months. Unlike Sunday, which started with daybreak temps in the mid 20s, readings Monday morning will be much milder, making 60-degree temps likely in the afternoon. The flow of mild air will be short-lived. By Tuesday night, cold northeast winds are expected to develop, and continue the remainder of the work week.
Chicagoans have endured a cold and snowy winter, and a transition to spring that has been anything but balmy. Aside from 2014, only nine other years since 1928, have failed to record a 60-degree reading at Midway airport by March 29th. The average date for the first occurrence of a 60-degree temp is March 2nd. On Sunday, temps are expected to approach 60 degrees. Increasing south to southwest winds will deliver mild air to the region. Highs on Saturday reached 60 degrees or higher as far north as the Dakotas. It will be even warmer Monday, as temps reach the mid and upper 60s, just in time for the White Sox home opener. Chilly, unsettled weather is to return as April arrives. The Cubs home opener on Friday looks chilly, with brief showers possible, and highs in the low 40s.
A winter storm watch has been issued for areas south and east of Chicago for Tuesday night into Wednesday morning.
From the National Weather Service:
DEEPENING LOW PRESSURE WILL TRACK SOUTHEAST OF THE AREA TUESDAY
AND WEDNESDAY. WARM AIR INITIALLY WILL ALLOW FOR PRECIPITATION TO
FALL AS RAIN ACROSS THE AREA BUT IT IS EXPECTED TO TRANSITION TO
MODERATE TO BRIEFLY HEAVY SNOW LATE TUESDAY EVENING AND WEDNESDAY
MORNING. SNOW AMOUNTS AND LOCATION OF HIGHEST AMOUNTS IS STILL NOT
CLEAR BUT THERE IS THE POTENTIAL FOR SIGNIFICANT SNOW ALONG WITH
BLOWING SNOW ACROSS THE WATCH AREA.
The winter storm watch includes the following counties…
INCLUDING THE CITIES OF…KANKAKEE…PONTIAC…WATSEKA…PAXTON…
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A WINTER STORM
WATCH…WHICH IS IN EFFECT FROM 10 PM CDT TUESDAY EVENING UNTIL 1PM CDT WEDNESDAY
TIMING…RAIN WILL CHANGE TO SNOW FROM LATE TUESDAY EVENING INTO
THE OVERNIGHT HOURS FROM NORTH TO SOUTH.
MAIN IMPACT…MODERATE TO AT TIMES HEAVY SNOW IS POSSIBLE WITH
HIGH ACCUMULATION RATES. TOTAL AMOUNTS OF 6 OR MORE INCHES OF
SNOW IS POSSIBLE.
OTHER IMPACTS…NORTHERLY WINDS WILL INCREASE TO 20 TO 35 MPH
WITH GUSTS OF 35 MPH TUESDAY NIGHT THROUGH WEDNESDAY MORNING
LEADING TO BLOWING AND DRIFTING SNOW. TRAVEL MAY BECOME
TREACHEROUS DUE TO SNOW COVERED ROADS AND SIGNIFICANTLY REDUCED
VISIBILITY LATE TUESDAY EVENING THROUGH WEDNESDAY MORNING.