An “Atmospheric River Storm” will hit Chicago later this week

CURRENT US SNOW COVER 42.4% IS HIGHEST AS OF MARCH 13 SINCE AT LEAST 2003

Recent US snow cover on March 13

LOWER MARCH 2023 SUNNY

Percentage of possible sunlight

March 10-13 – Four days without sun – longest stretch without sun in March since 1989

• Snowfall once again blanketed the region today – the 5th day in a row that the city has officially recorded snow measurements. O’Hare got 0.2 inches and Midway got 0.3 inches, though local reports saw up to an inch of snow in places.
• Monday is OFFICIALLY SUNLESS for the 4th day in a row. Frank Wachowski reports that the last time March had four days without sun was in 1989.
• And there’s further evidence that the same parade of storms that has battered California is affecting the weather in the Midwest – this month’s lack of sun and increased rainfall here. March produced only 30% of the possible sun. Common March produces 48%. So, at least for today, Chicago has had less than 2/3 of its normal March sunshine.
• And in 2023, 7.58 inches of water-equivalent precipitation exceeds the 4.89 inches that is normal for today. In fact, it is 155% (more than one and a half times the norm).
• Fortunately, the clouds will clear tonight and the sun will return on Tuesday. It will not immediately affect the taps, the temperature of which is on average more than 11 degrees below normal — not only today (Monday), but also on Tuesday.
• But the storm now bearing down on California — the 11th atmospheric river storm to hit the state since Dec. 22 — is expected to skip the Rockies and head that way later this week. A southerly wind will move into the Chicago area on Wednesday, with midweek temperatures 14 degrees higher Wednesday than Tuesday, and in the upper 50s.
• Temperatures climb into the 50s Thursday into early Friday morning as rain from the storm moves into the region. There’s a chance we’ll see isolated thunderstorms Thursday night into Thursday.
• MUCH COLDER air is moving into the region on Friday due to the classic high winds with dropping temperatures. Highs starting in the 50s will drop into the 20s or 30s overnight, with gusts in excess of 40 mph possible and near 50 mph Friday as temperatures cool.
• The region will cool off on the back of the storm this coming weekend, which may even bring some showers/sleet.

UNSEASONALLY COLD OPEN WEEK ACROSS THE NATION

Monday’s high temperature and how much below normal?

WEATHER SITUATION IN CALIFORNIA GOING FROM WORSE TO WORSE

Snowpack has already surpassed all-time records across much of the state, reports Dr. Daniel Swain, UCLA Climate Research

• Another ‘Pineapple Express’ and ‘Atmospheric River’ Sedimentary Siege Coming – Potentially STRONGER Than Last
• Dr. Swain – in a tweet on Sunday afternoon – noted: “As of this weekend, the southern Sierra appears to have the largest snowpack on record (as measured by snow and water equivalent).”
• A mammoth ‘atmospheric river’: a deep stream of moisture originating west of Hawaii that spans more than 3,000 miles of the Pacific Ocean and is headed ominously for California
• As a result of an already serious flood, an evacuation order was issued
• This same storm system will affect the Midwest, including Chicago, later this week

https://wgntv.com/weather/weather-blog/atmospheric-river-storm-to-impact-chicago-later-this-week/