Chance For Precipitation Event(s) To Begin February

First - cold low temperatures here for last seven days (including this morning). Each morning has been 32F or colder during past week, with four mornings down into mid-upper 20s F.

Snow storm moves across Great Lakes region today, prior to mid-week plunge of very cold arctic air into north-central U.S. View above shows moderate snow falling at Western Michigan University.

The 06 UTC GEFS average 500 mb height forecasts (above valid at 12 UTC this morning and below valid  00 UTC 3 February show a substantial pattern change by end of month. The intense 500 mb ridge along west coast shifts westward and southward, as a trough breaks through and under ridge. This shift brings troughing to west coast - at least for a few days.

This pattern change brings chances of precipitation to the Southwest - last significant precipitation here at house was 0.85" on January 6th. Plumes from the 06 UTC GEFS forecasts show: above chances for two rain events at TUS on the 1st and again around the 3rd; and below plumes for PW indicate gradual increase through the week and then a plunge back to dry conditions on the 3rd. Finally something to watch!