Tuesday, August 22, 2006

Brief review of yesterday and last night's weather

There was much more storm activity yesterday over south central and southeast Arizona than there was on Sunday. The "favorables" dominated yesterday apparently and intense storms had developed by noontime. For Arizona there were quite a few severe reports during the afternoon. See the reports at:

http://www.spc.noaa.gov/climo/reports/yesterday.html

There were also a couple of measured severe gusts within the PRISMS mesonet in the Phoenix metro area that are not on the report map. A brief story and photo of damage in the Tucson area yesterday is at:

http://www.azstarnet.com/metro/143128.php

Here at the house there was much thunder from nearby cells early in the afternoon, but once again only wind and sprinkles and a trace of rain. However, the evening sounding was much moistened with considerable instability in all layers below 650 mb - nighttime/early morning storms developed and it was raining here at sunrise with 0.18" in the gauge.

The morning sounding at Tucson exhibits a very nice "onion" sounding with a deep, ice saturated layer producing anvil rainfall above the onion bulb. Sounding is at:

http://www.rap.ucar.edu/weather/upper/tus.gif

Today appears to favor a heavy rain threat in southeast Arizona, as the inverted trough at 700 mb that brought a favorable wind profile for severe storms yesterday has moved on to the west. The western lobe of the 500 mb subtropical high is over southeastern Utah this morning, and the weak trough separating this anticyclone from the larger anticyclone over the Southern Plains appears to be between here and Phoenix. Thus, winds aloft are very light and variable up to about 300 mb and storms should be very slow moving in this part of Arizona today.

Tropical Storm Eleana is predicted to become a hurricane shortly and the NAM and NHC forecast the storm to move northwestward and to come north of 20N. Thus, this storm may come close enough to the south end of Gulf oc California to trigger yet another push of deep tropical moisture into Arizona Friday or over the weekend.

No comments:

Post a Comment