Earth Day 2024

 

Light Sprinkles

Added comment - I forgot to make note of the wind gusts yesterday and will add here:

Numerous sites reported gusts of 45 to 50 mph yesterday. I found 5 sites with gusts over 50 mph in southeastern Arizona. Tucson reported gusts to 53 mph as did Empire ranch; Ft. Huachuca had 52 mph; Pioneer Airfield reported 60 mph, and Guthrie reported 67 mph. I estimate that we had gusts here at house in the 50 to 55 mph range. It was a cold, nasty wind.

Golden skies over the Catalinas at 6:00 am this Saturday morning.

There were light showers and sprinkles scattered around the metro area after midnight last night. The plots (above and below - from ALERT and MesoWest) show that showers mostly avoided the metro area and amounts were all 0.04" or less. It does not appear to have rained any here at the house.

Windy Tomorrow

Sunrise this morning at about 6:10 am MST.

Forecast of 500 mb level from 06 UTCGFS (above) valid at 00 UTC on 6 April. Below is forecast for 250 mb from the same model run - note the very strong upper-level jet over southeastern Arizona with maximum speeds over 150 kt.

Forecast above (from 12 UTC WRF-RR run at Atmo) is for total precipitation through 2:00 am on Saturday the sixth - just a bit of light precipitation over parts of Pima County. Forecast below is for wind speeds from the same model run valid at 2:00 pm tomorrow afternoon, showing quite strong winds at the airport.

Morning statement and forecast for the airport from the NWS forecast Office (above and below) emphasizing the strong wind conditions tomorrow. Note that it has been wet lately, making blowing dust a long-shot for the airport.

Brief Summary - March

 

View of the Rincons before sunrise on March 14, 2024.

Total rainfall here at the house during March was 1.55 inches. This was the wettest March since I started my precipitation observations, besting the previous high of 1.27 inches in 2020.

There was measurable rainfall on 6 days, with the highest amount being 0.65 inches on March 31st. I did not hear thunder during the month, but there were a couple of days that the CG flashes indicate I probably missed hearing it.

More Re Rain Event

View toward Redington Pass at 5:15 am MST this early morning.

ALERT network data for 24-hours ending at 7:oo am this morning (above and below) again show almost 100 percent coverage, but with amounts smaller than those yesterday. Here at house we had an additional 0.25" for a total event amount of 0.35".

Plumes shown here are from the GEFS 06 UTC runs. QPF at airport (above) forecasts indicate chances for light showers on the 6th and the 9th. Temperatures  (below) rise dramatically through the 4rth, and then cool down for rest of week. Plumes for winds (second below) indicate a very windy day on Friday. Basically an unsettled week, but with no really significant storms.

Widespread Precipitation Event

Morning showers on the Catalinas at 7:30 am April 1st - no fooling.

Data from the ALERT network for 24 hours ending at 7:30 am (above and below) shows 100 coverage of amounts greater than 0.04". Here at house we had 0.75" in the gauge this morning - most of this fell before midnight, with about a tenth of an inch after midnight. Atmo reported 0.52", DM had 0.42":, and the airport reported 0.29". Heaviest amounts in the ALERT network were on the north side of the Catalinas - even the high elevation sites started out as rain.

The TWC/TUS sounding this morning (above) shows moist conditions up to 400 mb, a sliver of CAPE, and very strong southwest winds aloft, reaching 180 kts. The trough is still out to our west, keeping some chance for additional showers as it moves across Arizona today.

Plumes for the GEFS 06 UTC runs shown here - QPF above, temperature below, and winds second below. The QPF plumes show rain at the airport continuing well into the night tonight. Temperature recovers, before another cool spell at end of the week. The winds are forecast to be very strong on Friday the 5th.

Forecast from the 12 UTC WRF-RR model (below) shows precipitation forecast through noon tomorrow. Amounts exceed a tenth of an inch over most of eastern Pima County. This is proving to be quite a nice event to end March and begin April.

Morning Showers

Showers on the Catalinas already this Easter morning(view above from 7:50 am MST). Light sprinkles here at house.

The 12 UTC GEFS plumes for QPF at the airport (above) don't get things really started here until around noon.

The 12 UTC runs of the WRF-RR at Atmo show a similar scenario - above is total precipitation through noon and below shows total precipitation through midnight tonight.

Showers Likely On Easter

Some pre-sunrise color at about 6:05 am MST this morning - looking toward the Rincons.

The 500 mb forecast from 06 UTC GFS run showing strong trough from eastern Idaho south to central Baja. Precipitation forecast (from 06 UTC WRF-GFS - below) indicates significant precipitation event for most of Arizona through 5:00 am on Tuesday, April 2nd. The GEFS plumes from 06 UTC (second below) indicate averages for airport around 0.75".

Morning graphic from NWS TUS Forecast Office (below) summarizes situation through April 1st. The NWS forecast POPs are 70 to 80 percent at the airport from Sunday, through Sunday night and Monday.

Showers Last Evening

Storm in foothills at 4:50 pm MST yesterday afternoon. This one skipped by to our east, but there were heavy showers later, around 7:00 to 7:30 pm at the house. View at bottom is looking toward Redington Pass at 5:25 am this morning.

There were only isolated CG flashes in eastern Pima County yesterday. Above plot shows flashes detected through 0833 UTC this early morning (from Atmo and Vaisala). Graphic below shows 24-hour rainfall amounts ending at 15 UTC this morning (from Univ. of Utah). Here at house we had 0.12".

GEFS plumes from 06 UTC runs (above) are for precipitation at the airport. Plumes indicate an active, showery period on the 31st of March and 1st of April. The 500 mb forecast (below, from the 06 UTC run of the GFS) indicates a deep, positively-tilted trough over the Southwest at 00 UTC on April second - next Tuesday.

Showers Here Again

View toward the Rincons at 6:15 am MST shows a bit of color.

Light rains fell over much of the lower elevation Alert sites during the past 24-hours ending at 7:30 am this morning (above and below). Here at the house there were showers late in the afternoon and a couple of times during the night. Gauge showed 0.11" this morning.

Plot of detected CG flashes (above for 24-hours ending at 0803 UTC this morning) shows that most thunderstorm activity avoided the metro area.

The 06 UTC QPF plumes (below) suggest that a more significant event may develop for the first day or two of April.

Finally, there was a strange disconnect regarding the forecast on the NWS TUS website. Above graphic (issued 4:08 am) indicates fairly high POPs for today. However, the point forecast for the airport (below - issued at 5:47 am) indicates only slight chances for showers today.

Update Midday Sunday

Snowy morning up in Summerhaven - view above is from 9:50 am MST.

ALERT plots (above and below) show rain amounts across the network for 24-hour period ending at 6:00 am this morning. Note that rain event occurred mostly from 3 to 5 am, early this morning. Here the house we had 0.25", as did Atmo; the airport reported 0.30" and DM had 0.36". Plot of detected CG flashes (second below - from Atmo and Vaisala) is for 24-hours ending at 1703 UTC this morning. There were thunderstorms in Pima County but they mostly avoided the metro area. Note that the airport did record a wind gust to 45 mph at 3:53 am.

Plot of 250 mb observations (above) shows that there is a very strong jet across northern Mexico and also that the trough axis is still to the west of Arizona. The current NWS morning forecast for the airport (below) continues with 60 POPs for tonight, as the trough axis passes by.