Big snow totals and colder air 1/5-1/11

Tomer’s Take: A major Western pattern shift delivers colder air and big snow totals 1/5-1/11. It’s comprised of vanguard snow 1/5 then two storm systems. #1 occurs 1/6-1/8 followed by #2 on 1/9-1/11. Before all that happens, a storm system hits the Sierra late 1/2-1/3 then takes a southern track through AZ/UT/CO/NM 1/3-1/4.

In the Northeast, the 1/7 stormtrack continues to wobble. If it wobbles back to the north then snow totals increase VT/NH/ME. Another large storm system is possible 1/9-1/10.

My afternoon forecast video update:

Current Setup

Water vapor satellite shows two large storm systems in the north Pacific. The first storm system hits the Sierra late 1/2-1/3 then takes a southern track 1/3-1/4 through AZ/UT/CO/NM. The 2nd powerful storm system is the pattern changer.

Orange/red = drier air aloft.

Forecast Jet Stream

Valid 1/5. First key snow window is 1/5-1/8. The northern branch buckles south with a pattern changing area of low pressure. Vanguard snow races through the Intermountain West.

Valid 1/8. First trough moves east of the Rockies. This marks the end of key window #1. Key window #2 arrives 1/9-1/11.

Valid 1/10. Northern branch buckles south with 2nd large trough. Snow and cold.

Forecast Radar & Satellite

Forecast Totals

CA Snow: Late 1/2-1/3. Rain/snow line starts at 7000′ then drops to 5000′.

UT/AZ Snow 1/3-1/4.

CO/NM Snow: 1/4-1/5.

Forecast includes two storm systems. Key snow windows: 1/5-1/8, 1/9-1/11.

1/7 stormtrack continues wobble. If it wobbles north then snow totals increase VT/NH/ME.

Another large storm system possible 1/9-1/10.