Light Showers In Parts of Tucson Last Evening

Light showers moved across the Tucson area late yesterday afternoon and evening. Above image shows light showers on the Catalinas and north part of town at 5 pm yesterday. The very tail end of the weekend event left 30 of the 93 ALERT gauges in eastern Pima County with light precipitation, measured at 6 am for the past 24 hours (remember that the highest elevation stations may have had snow that was not recorded). Here at the house we had 0.04" between 5 and 7 pm. Six ALERT stations had 0.10" or more and highest amount was 0.31" up on the north slopes of the Catalinas. So, we now have a tiny bit of rainfall for February. Low temperature this morning at the house was 31F.

The NAM 500 mb analysis at 12 UTC this morning (top chart) shows a trailing cutoff low off the Oregon coast. This feature is forecast by the model to drop rapidly southward over the Pacific and then to turn inland and weaken across Arizona and northern Mexico on Wednesday afternoon and night (60 hour forecast shown in bottom panel). At this time the models forecast some middle-level moisture and clouds to come across Arizona with this short wave, but only precipitation forecast is for northeastern portions of the state.