Wednesday’s unseasonably mild 57 degrees

  • The 4th-warmest high for a January 11 since records began in 1871
  • The 57 degree high is more typical of early April—25 degrees above normal!

Widespread 50s across much of the area Wednesday afternoon except far north near the Wisconsin border. NORMAL JANUARY 11 HIGH: 32 DEGREES!

Following a brief late week “cooldown” in Chicago, readings surge to unseasonable levels again early next week!

Full-day temperature departures from normal:

Recap – California Precipitation Dec. 26 – Jan. 11

Total precipitation for the series of atmospheric rivers that have affected California since December 26, a period of 16 days.

In this time California averaged 8.61 inches of precipitation and the San Francisco-Oakland metropolitan statistical area averaged 13.34 inches. Greatest amounts in excess of 30-inches (light areas on map) have occurred along the coast and then in higher elevations due to orographic uplift.

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Thursday Outlook

Broad area of rain/drizzle changing-over to wet snow occurs late day Thursday/overnight in Chicago area:

  • Strong to severe storms south and east of low pressure track ahead of approaching cold front.
  • Broad area of rain/drizzle changing-over to wet snow from west to east north of the low pressure track (occurs late day Thursday/overnight here in Chicago area).
  •  As low center moves east, cold air/light snow curls south behind the departing low pressure as winds shift from east to north and strengthen. 

Saturday Set-up

Atmospheric River continues in full force across northern Pacific Ocean into West Coast (primarily California) of U.S.

 SW#1 (short wave aloft #1) Over Appalachians, drifting east – pulling cool air away from Chicago – driving it south into Florida.

 SW#2 Moving inland off eastern Pacific into California.

 SW#3 Caught in 190 mph Jet stream – looks to impact California Sunday-Monday

 SW#4 (Not shown) – farther west upstream in Atmospheric River – will likely impact California/West Coast next Tuesday-Wednesday