Saturday, April 22, 2017

Earth Day 2017 - Sad And Challenging

After decades of improvement, we have to revise Pogo's famous statement from 1971 - We have new enemies and they are Trump and his billionaire cronies he's brought into our swamp.

Friday, April 21, 2017

Hot Weekend In The Deserts

Forecast models indicate a hot weekend for the Sonoran and Mojave Deserts, as a 500 mb short-wave ridge passes by. The forecast above is from the 06 UTC WRF-NAM forecast run at Atmo and is for 2-m temperatures at 03:00 pm MST on Sunday afternoon.

In the longer-term, a strong 500 mb short wave is forecast into the Southwest by the last weekend of the month. Above forecast is from the operational ECMWF forecast from 00 UTC last evening.

The NWS GEFS plumes indicate a windy week (above and below from 06 UTC forecast runs), as per the 10-m winds shown above. Some members forecast quite strong speeds for next Thursday and Friday. Several of the members also forecast a bit of precipitation for the airport (below). At this point we can probably bank more on the winds than on the rain chances.

Thursday, April 20, 2017

Nice Morning Here In Tucson

Was quite nice at sunrise today as we head into another warm and dry day. Issues for rest of month are mainly two - will it rain before May begins?; and will it break 100 F? Looks like the high temperatures this weekend will flirt with 100 F, but outlook for rain continues dim. Since the 19th of February, it has only rained here at house on two days, with a grand total of 0.08". Photos below from my morning walk today.

Vermilion Flycatcher.

Cooper's Hawk with crescent moon above and Palo Verde tree with yellow snow below.

Saturday, April 15, 2017

Tornadoes Around Dimmitt, Texas

A couple of supercells did develop late yesterday near Dimmitt, Texas. They produced a number of tornadoes that danced around wind energy turbines, as per images by S. Speransky above and below.

The Amarillo 00 UTC sounding (above) continues to indicate the nasty weak wind layer, but with stronger flow above and a SRH rich environment up to 4 km. Lubbock radar about 02 UTC at bottom shows two supercells north-northwest of the radar. Chasers in the right spot had quite a show.

Friday, April 14, 2017

Mid-April Weather Doldrums

The weather doldrums seem to have spread from southern Arizona across much of the CONUS for mid-April. Above map (which is blurry in all versions for unknown reasons) shows severe thunderstorm reports to SPC yesterday - April 13th. There were only two. Weak tornadoes were reported near Bend, Oregon, and Wichita Falls, Texas, and that was it.

The large-scale pattern is dominated by a split flow regime that leaves the Plains under a weak trough in southern branch, below a bent-back ridge that extends from Minnesota northwestward toward Alaska. The pattern has resulted in strange vertical wind profiles that are not supportive of organized thunderstorm systems.

The sounding from Dodge City, Kansas, this morning provides a nice example. There is considerable CAPE above 700 mb, but a strong low-level jet gives way to wind speeds of 15 to 20 kts from 500 to 300 mb. This produces the bizarre hodograph shown below - strongly veering jet below 2 km, topped by weirdness resembling an accordion. Not exactly a classic Plains supercell hodograph.

Locally, not much in sight except for some windy afternoons - rain seems far away in the model forecasts.

Tuesday, April 11, 2017

The Latest Test for the White House? Pulling Off Its Easter Egg Roll

Guess my April Fools' Day post wasn't too far off. Below from NY Times article this am.

Sunday, April 09, 2017

Short-Lived Lenticulars With Irridesence

We were at Santa Rita Abbey yesterday and I observed small, lenticular clouds forming and then dissipating, turbulently, in very rapid sequence. I had never seen anything like this and any insights much appreciated. First photo in sequence below was at 01:03 pm MST and last was at 01:19 pm (the complete sequence has about 20 photos in it). There were about 8 to 10 separate clouds involved in the sequence.