Monday, April 24, 2023

Continued Dry

Clear and dry skies over the Catalinas at about 8:00 am MST tis morning. Our warm to hot and very dry period continues - relative humidity fell into single digits at the airport yesterday afternoon. High temperatures forecast by NWS Tucson Forecast Office range mid 80s into low 90s F for coming seven days.
Plumes for QPF (above from 06 UTC runs of the GEFS) are flat-lined into early May. Wind plumes from GEFS (below) indicate chances for gusty winds today and tomorrow, making wild fire danger quite high.

The GFS forecast for total precipitation (out through 06 UTC on May 9th - below) keeps southern 2/3rds of Arizona dry. It's now the time of year where we have to wonder if there will be any local rainfall until late June or July.

Monday, April 17, 2023

Warm Week Ahead

View looking toward the Rincons at about 6:00 am MST this morning captures a thin, crescent moon.
The 06 UTC GEFS plumes are flat-lined at 0.00 for QPF. Plumes for temperature (above) indicate a warm week with highs in the mid-to upper 80s. Plumes for wind (below) indicate strongest winds today through Wednesday.

 Forecast (below) from the GFS is for precipitation totals through 06 UTC on May 1st, indicating continued dry conditions for most of southern Arizona. No rainfall here at the house since March 22nd.

Thursday, April 13, 2023

Red Flag Alert Today

Morning view of Catalinass at 8:30 am - there have been some virga around this morning.
Wind continues to be the main weather worry - the airport recorded gusts as high as 33 mph yesterday. The forecast plume speeds above (from the 06 UTC GEFS runs) indicate that today will be the windiest of coming seven days. The NWS graphic this morning (below) discusses the dangerous fire weather situation, as very dry conditions prevail over the Southwest.

Tuesday, April 11, 2023

Continued Dry

Cloudless skies over the Catalinas at 8:20 am MST this morning. Yesterday's high at the airport of 97 F was the record high for the date.

Plumes from 00 UTC runs of the GEFS - above temperature and below wind. Temperatures remain fairly hot, but with several cooler days toward the weekend. Plumes for wind indicate strong speeds for Wednesday and especially Thursday. Current NWS TUS forecast calls for gusts as high 43mph on Thursday afternoon.

Current morning graphic from the Forecast Office (above) indicates chances for another record high today at the airport, as well as slight chances for high-based thunderstorms over Cochise County this afternoon.

The morning runs of WRF model at Atmo forecast isolated light showers over Cochise County but keep the lightning activity along the Continental Divide in northern Mexico. Long-range forecast for total precipitation (below, through 06 UTC on April 27th) keeps almost all of Arizona precipitation-free.

Wednesday, April 05, 2023

March Overview Plus Dust

March summary for Tucson (above, from John Glueck) is currently available at the NWS Forecast Office webpage, and also at:

Here at the house we had three rainfall events that totaled 0.75". That's about the March average here since 2000. There was  a bit snow mixed in with the rain on the 1st.

Winds yesterday brought dusty skies, especially during the morning. Image above shows view of the Catalinas at 8:42 am MST. View below is looking east along I-10 from San Simon at about the same time.

Monday, April 03, 2023

Windy Today Cooler Tomorrow

Perfectly clear skies over the Catalinas this morning, as we start the first, full week of April.

During the next 36-hours a strong trough at 500 mb will be swinging across Arizona. The GFS 500 mb forecast (above) is valid at 12 UTC tomorrow morning. This feature will bring windy conditions today, followed by much cooler temperatures tomorrow.

Forecast plumes here are from the 06 UTC runs of the GEFS. Precipitation (above) is flat-lined at zero. The temperature trend (below) shows a significant drop for tomorrow, but with gradual warming for rest of the week. Winds are very strong for today and then mostly quite light for rest of week.

The 12 UTC WRF-RR forecast for winds at 2:30 pm this afternoon (above) indicates strong speeds for southeast Arizona and high winds for northern locations. The current morning forecast from the Tucson NWS office (below - for the airport) includes a wildfire Red Flag Warning, as well as an advisory for wind gusts that could reach over 40 mph. 

Saturday, April 01, 2023

Severe Storm Outbreak Yesterday

Visible satellite image (above - from from 2206 UTC on March 31st) shows large cyclone over the northern Plains that was moving eastward, producing widespread thunderstorms over a large area to its east and south. Storm reports (for 24-hours ending at 1324 UTC - 6:24 am MST) this morning from SPC - number of reports shown were 747 with 65 reports of tornadoes. The tornadoes produced widespread destruction and a number of fatalities. 

Shown above is a large tornado near Wynne, Arkansas (which is a bit northwest of Memphis). The hook echo that produced this tornado is shown in the base radar scan (below) from Memphis at 2322 UTC. Second below shows CG flashes detected during the 12 hours ending at 0401 UTC (9:01 pm MST).

This outbreak was somewhat similar to the Tri-State event of March 18, 1925, as well as the "Jumbo Outbreak" of April 3 and 4, 1974. However, both of those events produced many hundreds more casualties than did yesterday's storms.