Light Showers Yesterday

View of showers over western Catalinas and this part of town at 4:15 pm CST yesterday afternoon.

ALERT rainfall reports for 24-hours ending at 9:00 am this morning. We had frequent thunder and 0.04" here at the house around 3 to 5 pm yesterday afternoon. The airport and Atmo had no rainfall , while DM reported a Trace.

The 06 UTC GEFS plumes for QPF indicate a dry week ahead (above).

The current NWS forecast for the airport (below) highlights fire weather conditions tomorrow and Sunday.

As for the monsoon storm season: an old, empirical definition used to require three consecutive days with an average daily dewpoint of 60 F or higher. Current Td tracker (below) shows that we have yet to have one such day. Current GFS forecasts indicate that the Four-Corners anticyclone does not set up until after July 4th. So, things are off to a slow start this year.

Summer Solstice

Yesterday was the summer solstice and the longest day of the year in the northern hemisphere. Photos of the solstice at Stonehenge above and below.

Quick Update

 

Photo of double rainbow by neighbor John Ferner, taken Wednesday afternoon

My previous post reported some poles down west of airport. However, the morning paper today reported there were many poles down that afternoon and evening across southern parts of Tucson. Only a single report made it into the SPC data base.

Heavy Storms

Heavy rain on Catalinas about 5:15 pm MST yesterday afternoon. View of orange rain at bottom was around 7 pm when sun broke-thru to illuminate the rain.

Plot of detected CG flashes (from Atmo for 24 hours ending at 0733 UTC, above), shows heavy activity across eastern Pima County. There were several loud crashes of thunder here at house. There was also a report of power poles down a bit west of the airport,

Rain amounts across the ALERT Network for 24-hours ending at 9:00 am this morning (above and below) show widespread reports with a couple of sites exceeding an inch. Here at the house we had 0.38"; DM had 0.33"; while Atmo and airport reported 0.65".

Local Outlook

Sunrise east of the Catalinas this morning.

The local NWS outlook here is for a chance of severe thunderstorms with damaging winds (above). However, SPC outlook for today keeps severe storm risks far to northeast of our area. The current NWS forecast for the airport is second below.

Update And Monsoon "Start"

View looking toward the Rincons at around 4:30 am MST this morning.

There is an article in the the morning paper that states the 2026 monsoon has arrived, right on time. However, this is based on the NWS definition of a "Monsoon Season" running from June 15th to September 30th. This definition ignores the actual meteorological conditions that might be prevailing.

Yesterday's 0.19" of rainfall presents an example of the problems of the seasonal definition.

The rainfall was associated with a weak shortwave that sneaked in from the Pacific - consider the 500 mb charts from the 06 UTC GFS forecasts.

The 500 mb chart for this morning (above) shows the weak disturbance over Arizona. The 7-day forecast (below) shows the typical monsoon high at 500 mb situated across central Baja, with a weak trough still across Arizona. The fourteen day forecast (bottom) indicates a large trough dominating the western US at 500 mb. There is no indication in the forecasts of the typical Four-Corners anticyclone that defines the summer monsoon circulation at 500 mb. So, if the forecasts are accurate, the start of the summer monsoon, from my perspective, remains several weeks away.

Stormy

Skies clearing at 11:00 am MST. Current rainfall reports across eastern portions of the ALERT Network (below) indicate amounts up to just over an inch. Here at house there is currently just 0.19" in the gauge.

Several periods of showers and some thunder beginning yesterday evening and continuing this morning. At 6:45 am (view above) there was only 0.06" in the gauge but more rain has fallen since. Will update things later today. Plot of detected CG flashes (below - from Atmo) shows considerable activity over eastern Pima County through 1443 UTC.