Summer Outlook

View toward the Rincons at 5:30 am this morning - a bit after sunrise.

This spring (Mar, Apr, and May) was relatively dry here with only a total of 0.66" of rain. Since 1999 this was the 11th driest spring. The wettest spring here was 2004 with 2.71", while the driest was in 2018 with only 0.03" for the three months.

The current NWS Climate Prediction Center (CPC) outlook for this summer is below - they expect the warmth over the West to continue, along with a slight chance for above normal rainfall. Of course, one big storm day here can determine the character of the entire summer - so we will watch to see how things evolve.

Eastern Pacific Tropical Storm

The eastern Pacific is fairly active as we head into June - above. Tropical Storm Amanda is the first of this season.

Her center is just to the east of the stroger storm cluster in the 1350 UTC IR image above. The storm is far southwest of Baja and poses no threat to land. The forecast from NHS early this morning is shown below. It keeps Amanda at TS levels as she drifts generally westward.

Storms Yesterday

View of heavy storm over the Catalinas and foothills at 5:45 pm MST yesterday afternoon.

Plot of CG flashes detected during 24-hours ending at 7:30 am this morning. Note the abundant activity across eastern Pima County.

Rain from the ALERT network (above) for 24-hours ending at 7:00 am this morning, and for same period from CoCoRaHS at Atmos Science page CSU, Ft. Collins CO, across low-elevations of the metro area (below). Here at house we had two brief showers between 3:00 pm and 6:00 pm yesterday afternoon. There was thunder and wind to around 30 to 35 mph with the second shower. Total rainfall was only 0.07" here.

Very Isolated Showers

 Update - only four ALERT sites had rainfall yesterday of 0.04" or more (one of these had 0.08"). Sites were in the Catalinas, plus one at far southwest corner of network.  In sum, a very quiet day across the metro area.

Widespread Rains

Showers on Catalinas and foothills at 6 pm MST yesterday afternoon.

There were widespread rain reports across the ALERT Network yesterday (above and below) for 24-hours ending at 7 am this morning. A couple of the null reports look a bit suspect. Here at the house we had 0.31"; the airport had 0.23"; DM AFB reported 0.32"; and Atmo had 0.16". This was first significant rain here since March 10th.

The 09 UTC SREF plumes for QPF at TUS (above - from SPC webpage) show several  members indicating very light amounts after 12 UTC at the airport, but with a few showing over a quarter on an inch. The current morning forecast from the NWS for the airport (below) indicates slight chances for showers and thunder today. We shall see.

A Dry April

It looked promising late yesterday afternoon - view of the Catalinas above from 5:45 pm MST.

However, measurable rain stayed to east and south of the metro area. ALERT observations (above) are for 24-hours ending at 9:00 am this morning. There was no rain at the house during all of April, making this one of 8 Aprils with no rain here since 1999.

The plumes from the 06 UTC runs of the GEFS (below) indicate slight chances for light showers around the 5th of May. 

Chance For Showers Mid-Week

Clear skies over the Rincons pre-sunrise this morning (note - sunrise was at 5:42 am MST).

The 06 UTC GEFS plumes for temperature (above) indicate a distinct cooling at mid-week, as April draws to a close.

Plumes for QPF at the airport (above) indicate chances for measurable rain on the 30th and 1st of April and May. There's a large range in both the timing and amounts among the various ensemble members.

The GFS forecast from the 06 UTC run (below, for 500 mb) indicates a distinct shortwave from Wyoming south-southwestward across the Four Corners, Tucson, and central Baja at 00 UTC on May 1st.

The GEFS POPs for the airport (bottom) reach above 50 percent on the 30th. So far, April has been rain-free here at the house, so Thursday and Friday will be interesting.