Stormy Outlook

Perfectly clear skies this morning, with view toward the Rincons at 6:00 am MST. The plot of detected CG flashes (below from Atmo - through 0803 UTC this early morning) shows that storms yesterday mostly avoided Pima County. There were 2 sites in the Catalinas that reported 0.04" and 0.08" of rain yesterday.

The GEFS 06 UTC plumes for QPF at the airport (above) indicate considerable rainfall into Saturday morning. The POPs for the airport from same runs (below) show very high probabilities tonight and tomorrow morning.

Current forecast from the NWS for the airport (above) shows high POPs tonight and Friday, along with a Flash Flood watch through Saturday. Strong and gusty winds are also mentioned by the NWS - quite a change from the sunny morning that we're having now. The 12 UTC WRF-RR forecast from Atmo (below for period through 6:00 am Saturday morning) shows heavy precipitation over eastern Pima County, as well as to our north, east, and south. Big changes on tap, assuming these various forecasts pan out!

Widespread Showers

Pre-sunrise view of Rincons about 6:20 am MST this morning.

Note - today is the first day of astronomical Fall.

Plot of detected CG flashes (above, from Atmo) for 24-hours ending at 0833 UTC (0133 am) shows a classic Tucson donut hole. However, there were widespread, mostly light, showers across the entire ALERT network (below and second below). Light shower here a bit after dark left 0.13" in the gauge. The airport had 0.05"; DM recorded 0.04"; and Atmo had 0.11".

Current morning forecast from the NWS for the airport - above - indicates only slight chances for precipitation today. The 06 UTC WRF-GFS forecast  from Atmo (below) - valid through midnight Tuesday night - keeps almost all of Pima County dry.

Suppressed Yesterday

Crescent moon and Venus over Rincons at 5:30 am MST this morning.

Thunderstorms mostly avoided eastern Pima County yesterday - plot of detected CG flashes for 24-hours ending 0733 UTC this morning (above from Atmo).

Only ten sites across ALERT network recorded rainfall yesterday - data for 24-hours ending at 7:00 am this morning (above).

GFS 06 UTC forecast of 500 mb chart valid at 18 UTC today (above). WRF-GFS forecast of rainfall through 6:00 pm 24 Sep (below from Atmo).

More Rain

View before storms yesterday evening.

CG flashes for 24-hours ending at 0833 UTC (0130 am) this morning - note cluster of activity in eastern Pima County.

ALERT data for 24-hors ending at 8:00 am this morning (above and below). The MesoWest observations (fom Univ. of Utah) for same period are shown at bottom. Here at house we had 0.62" - the two day total of 1.68" is the largest here since July 23/24 2021 when there was 1.89". First rain events of September were much needed.

Current forecast from the NWS office in Tucson (below).

Heavy Storm Here

Heavy storm over this part of town about 5:00 pm MST yesterday afternoon.

Plot of detected CG flashes through 0803 UTC (0103 am) above shows a bit of a donut hole over eastern Pima County. But ALERT plots (below) show numerous sites with rainfall through 7:00 am this morning. Here at house we had 1.06" - the most in a single day in a very long time. Rain was accompanied by 40 to 50 mph wind gusts.

The WRF-GFS forecast from 0600 UTC (below - from Atmo) indicates much reduced activity eastern Pima County through 6:00 am tomorrow morning.

Chances For Showers

Some color looking toward the Rincons at 6:00 am MST this morning. 

There were some storms scattered around eastern Pima County yesterday - above shows detected CG flashes through 0733 UTC (0033 am) today. We had rumbles of thunder here but no rain. The ALERT plot for 24-hours ending at 7:00 am (below) shows a few sites had rain over the Catalinas and off to the south.

The GFS forecast 500 mb chart valid at 18 UTC today (above) shows a large anticyclone, with its main center over northeast Mexico near the Rio Grande.

The current morning forecast for the airport (above) indicates 40 to 30 percent chances for precipitation through Friday night. The morning forecasts from the WRF runs at Atmo are interesting. The 06 UTC WRF-GFS forecast through 6:00 am tomorrow morning (below) shows heavy precipitation across all of eastern Pima County. However, the 12 UTC run of the WRF-HRRR through 6:00 am tomorrow (second below) forecasts a classic Tucson donut hole. So, take your pick!

Thunder Here Yesterday

View of storms on the Catalinas at 10:50 am MST yesterday, September 12th. We heard thunder here at the house a bit before the time of this image,

Detected CG flashes yesterday were mostly east of the metro area - plot above from Atmo for 24-hours ending at 1033 UTC (0330 am this morning).

Rainfall for ALERT sites for 24-hours ending at 8:00 am this morning (above) show that some sites had rain across northeast corner of the array. The airport reported 0.06" about the time of the image at top of post.

Plumes for 06 UTC run of the GEFS (below) show chances for light showers for the coming week. The indicated early morning rain did not happen here or at the airport. Still no September rain here at the house.

August Summary

 

Sunrise showers looking toward the Catalinas on August 26th at 6:00 am MST,

During August we had measurable rain on 5 days, but the amount only totaled 0.29" - the driest August since I started my records in 1999. There were four days on which I noted thunderstorms. On the 31st very strong winds over Cochise County pushed  dust and 35 to 40 mph gusts westward across the Tucson area.

The total rainfall for the summer (Jun, Jul, and Aug) amounted to 2.69", which was the fifth driest summer in my records. 

Rain To The South Yesterday

View of the Rincons about 5:15 am this morning - note the one lonely cloud atop the mountain.

Detected CG flashes for 24-hours ending at 1103 UTC this morning (from Atmo - above) show that the metro area was mostly storm free. The ALERT plot for same 24-hours (below) shows sites with rainfall were scattered across the south half of the network. No rain this part of town.

The 06 UTC GEFS plumes for QPF (above) show that chances for rain at the airport occur around the end of the week. The POPs (below) indicate a maximum of only 40 percent on Friday.

Another Dry Day Here

Sunrise north of the Rincons at about 6:15 am this morning.

There were some CG flashes detected around the edges of eastern Pima County during the 24-hours ending at 0833 UTC (0133 am) this morning (above plot from Atmo). I did not hear any thunder. Rainfall was scattered around the northern 2/3rds of the ALERT network, as per the plot below for 24-hours ending at 8:00 am this morning, but nothing here..

The 06 UTC GEFS plumes for QPF at the airport are very aggressive for today (above). The GEFS POPs (below) are 100 percent  during the day today, but then are very low for rest of coming seven days.

The forecast from the 12 UTC run of the WRF-HRRR at Atmo (above) keeps precipitation through midnight tonight on the mountains and also south of the airport. The current morning forecast for the airport from the NWS is shown below.