October Preview

 October tends to be a dry month; however, a decaying Tropical Storm becomes a player every so often.

There have been 7 times when there was no rain here during October since 1999. But, there have also been 6 times when an inch or more rain occurred here at the house - the maximum of 5.06 inches occurred during October 1999.

Bit More Rain

Venus over the northern Rincons at 5:30 am MST this early morning.

There were considerable CG flashes detected over eastern Pima County during 24-hours ending at 1043 UTC (0343 am) - plot above from Atmo.

Rainfall amounts for the 24-hours ending at 9:00 am this morning (above and below) were mostly over the northeastern third of the ALERT network and were generally light.

Here at the house we had thunder and 0.29" of rain. Atmo reported 0.19"; the airport had thunder and 0.06", while DM had thunder but only a Trace of rainfall.

Storm Around Lunch Hour

Heavy shower over this part of the city at about 11:00 am MST yesterday. Plot of detected CG flashes (below - from Atmo) for 24-hours ending at 0133 am this morning shows isolated storms over eastern Pima County.

Plots of ALERT observations for rainfall amounts during 24-hours ending at 8:00 am this morning (above and below) show rainfall over both the northeast and southeast portions of the array. Here at the house the storm shown at top produced 0.24" of rain after a couple of crashes of thunder. Atmo reported only 0.04" and TUS and DM had nothing. There were also gusty winds of around 30 to 35 mph. There were numerous reports of large hail up in the Phoenix metro area.

The morning 500 mb analysis (from SPC - above) shows the large, closed low lingering over the lower Colorado River Basin. Current forecast from the NWS (below) indicates only slight chances for showers at the airport today.

Showers And Storms Yesterday

Colorful, pre-sunrise view of the Rincons at 6:15 am MST this morning.

Considerable thunderstorm activity in eastern Pima County yesterday - as per plot above of detected CG flashes through 0913 UTC (0213 am - from Atmo).

Reports from ALERT network (for 24-hours ending at 8:00 am this morning - above and below) indicate widespread rains with a number of sites reporting a half inch or more. Here at the house we had rainfall both in early and late afternoon - storms around 5:00 pm had some thunder. Total rainfall here was 0.42".

Forecast from GFS model for 500 mb at 12 UTC tomorrow morning (above) shows a cyclone center near western Arizona - this feature remains nearly stationary through tomorrow.

Plumes from the the 06 UTC runs of the GEFS models (above for QPF and below for POPs at airport) indicate heavy rains today and tonight with very high POPs.

Statement above from NWS Forecast Office, with current morning forecast below.

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!