Another day with widespread, morning cloudiness over Arizona, northwestern Mexico, and now New Mexico. It has gotten about as wet as the atmosphere can get - Yuma has PW of 2.25" this morning and TUS is near 2.00". The time series for the past five days is shown below for GPS values, with RAOB values shown as the green dots. The PW has doubled during this period. The last two evening soundings were way too dry wrt to GPS, making it hard to assess the specific reasons for the lack of storms across the metro area.
This morning's Tucson sounding plot is shown above, with SPC diagnostics. Even with warm middle-level temperatures, the sounding is very unstable as afternoon CAPE is estimated to be over 2000 J/Kg. The wind field is quite strange, with westerly flow through much of the troposphere. A weak, short-wave trough has moved into the anticyclone from the GoC region and is across central Arizona this morning. Steering flow for storms that develop today will be weak - increasing threat for heavy rain and wet downbursts. The latest NAM forecast moves another, slightly stronger, vorticity maximum into southern Arizona by midnight tonight (NAM 500 mb forecast below).
Both the early WRF-GFS and the latest NAM forecast significant coverage of storms and rain today (WRF-GFS composite radar echoes at 2 pm MST below) across most of southern Arizona. Hopefully, the third time is a charm.
No comments:
Post a Comment