Moisture-Starved Short Wave Tomorrow and Wednesday

A short-wave trough will be coming by tomorrow tomorrow and Wednesday. Currently models forecast this feature to be somewhat starved for moisture and precipitation is forecast to stay off to the north the Tucson area. I thought that I would highlight a few forecasts  from the 00Z WRF runs that Mike Leuthold is now running at Atmo.

The graphics below show forecasts made by the 00 UTC WRF-NAM forecast cycle and are on the 5.4 km grid. This domain now extends well out onto the Plains. All the graphics (except for the one at bottom) are valid at 5:00 am MST on Wednesday, January 21st. Shown below are: 250 mb winds, indicating a moderate jet streak overhead; 500 mb winds and temperatures, with the short wave located north-to-south out along the western border of Arizona; 700 mb winds and RH; low-level winds and Precipitable Water (PW); and at bottom, total precipitation forecast through 5:00 am on Thursday, January 22nd. At this time the only "weather" forecast by the WRF variants with this system for southern Arizona are gusty southwest winds on Wednesday afternoon.

The accumulated precipitation forecast at bottom indicates very heavy rains at low latitudes southwest of Baja. There is at least some possibility that subtropical moisture will be pulled northward next week by the cyclone that is spinning out there - something to keep an eye on as we head toward the end of January.