Wednesday, September 30, 2020

Fair And Dry


Perfectly clear skies this morning, a bit after sunrise, as September bows out. Will have monthly and summer summaries for our very dry season of 2020.

Forecast below (from 06 UTC GFS) is for total precipitation through 00 UTC on Saturday, October 10th. Model forecasts no rainfall this period for about 3/4 of the mainland. So, more of the same for us. 

Tuesday, September 29, 2020

Windy Morning

Windy morning here in Tucson area as easterly winds have spilled over from New Mexico during the night. Some dust in air (above as bird flies by).

Observations from airport show gusts during night of 25 to 30+ mph - about the same here at the house.

Forecast below (from 06 UTC run of WRF-GFS at Atmo) indicates that winds peak around, or before 10:00 am MST, and then fall off rapidly after that.

Sunday, September 27, 2020

Drought Continues


Mostly fair skies this morning, but with varying amounts of high cirrus coming by.

Models forecast continuing dry conditions well into early October. Above graphic shows the GEFS plumes for QPF at the airport through next Sunday.

Serious drought conditions continue across much of the western US, including southeastern Arizona. Below is part of drought monitor map from last Tuesday. I snipped the eastern and islands portion of the map to show that the northeast, Alaska, and the Hawaiian Islands are suffering from dry conditions also.

Forecast below is from the 00 UTC WRF-GFS and is for total precipitation through 5:00 pm MST on Tuesday, October 4th. Our lack of measurable rain here during September, continues into October.

Tuesday, September 22, 2020

September 22nd

Bit of pre-sunrise color this morning, which is the first day of astronomical fall. View from campus at bottom shows some virga east of the Catalinas. Two ALERT sites on the mountain reported rainfall yesterday. 


The morning TWC sounding (above) exhibits a shallow layer of CAPE around 500 mb, which will probably support more showers on the Catalinas today. The GFS forecast of total rainfall through 00 UTC on October 1st (below) continues to leave most of Arizona high and dry.

Sunday, September 20, 2020

Rain In September?

Actually some clouds drifting overhead this morning - first time in quite a few days. Down at bottom the two images show sunrise from Mt. Wilson with LA lights but no fires in sight; and the light pillars at LAX a bit before midnight Friday night.

Extremely quiet over the Southwest and Mexico yesterday, with no detected CG flashes (above plot for 12-hours ending at 10:00 pm last night - from Atmo and Vaisala). Morning sounding from TWC (below) is dry and stable, with light wind speeds below 300 mb.

The long-range, GFS forecast, from 00 UTC last evening, for precipitation (second below) is valid for period ending at 12 UTC on October 1st. Very dismal, dry outlook from the GFS model.

Friday, September 18, 2020

Smoke Continues Here


The layer(s) of smoke aloft have gotten a bit thicker today, as a large, 500 mb anticyclone dominates the western U.S.  Photos above and below are from just after sunrise this morning. The image at bottom (from Jack Hales webcam wall) is from Mt. Wilson observatory early this morning - view is looking south as the Bobcat fire burns close by.

A look at CG flashes across the US (above from Atmo and Vaisala) for the 12 hours ending at 10:00 pm MST last evening. All-in-all very quiet across the US wrt thunderstorms.

The coming week appears to remain very quiet across the Southwest. Forecast above from the 00 UTC WRF-GFS shows total precipitation forecast (on the 5.4 km grid) for the next seven days ending at 5:00 pm next Friday. The GEFS plumes below show that the sprinkles forecast for southeast Arizona occur at the end of the period. Our dry period here continues into second half of September.

Wednesday, September 16, 2020

Smoke Outlook For Today

Smoke continues across large portions of the U.S. and southern Canada today. Above is view of Catalinas - there is a bit more smoke here than there was yesterday. At bottom is view of Denver smoke at mid-afternoon yesterday.

Below is an experimental smoke forecast (I think from NCAR RAP) valid this afternoon at 3:00 pm MST. We are just on the eastern edge of the California smoke plume.

Plot below shows the large number of active wildfires currently burning in the western U.S. - many of the fires from near Fresno to near Portland have burned well over 100,000 acres.