Bit Of An Upturn Today

The water vapor image above essentially shows moisture in the upper-half of the troposphere. It illustrates the extent of the very large, middle level anticyclone that is centered over the Texas/Oklahoma Panhandles. Loops show the circulation extending from coast-to-coast. Most of the thunderstorm activity is located in the western half of the anticyclone. But at 06 UTC there were also strong storms in the Tennessee River Basin; MCSs in Colorado, Kansas and Nebraska; and also western Mexico. Strong storms occurred over the lower Colorado River Basin and southern California yesterday afternoon. Much of the central US will be very hot again today, with 100+ readings centered on Oklahoma and north Texas.

Note that an area of storms moved into Cochise County from Mexico late yesterday afternoon and moved north-northwestward to the east of Tucson. These storms were associated with a weakening, upper-level cyclone/inverted trough. Tucson experienced an outflow from these storms around 11 pm to midnight last with east to southeast gusts of around 30 to 35 mph (57 mph at Atmo's roof anemometer). An area of light, anvil rains crossed portions of the metro area around the same time. Over the ALERT network 33% of the sites had rain. Amounts were very light and generally less than 1/10" - here at house there was 0.02" in the gauge this morning.

The Tucson morning sounding (below) has PW of about 1.33" and minimal CAPE as per SPC analyses. The upper-level winds are chaotic this morning - due to the 500 mb inverted trough to the west and the decaying upper-level feature which is nearly overhead. The outflow left behind a fairly deep layer of cooling near the surface that is affecting the CAPE calculations.

The early WRF-GFS forecast indicates a deep boundary layer by mid-afternoon, with some recovery of CAPE. The area of suppressed activity is forecast by the model to shift westward some today. So, the model forecasts a bit of an upturn for afternoon storms over eastern Pima County. Above image is model forecast of composite radar echoes at 2 pm this afternoon. Most storm activity is in Cochise County and far off, over the high country to the north-northeast. Model forecast of total rain through midnight tonight is shown below, with most activity from  Tucson eastward and north-northeastward. Enough things were happening during the middle of the night, that it would be a good idea, again today, to follow the morning forecast runs of the WRF model at the Atmo web page -

                                         http://www.atmo.arizona.edu/?section=weather&id=wrf