Tuesday, September 08, 2020

Smoke Aloft Reaches Southern Arizona

Thick layer of smoke aloft has moved over parts of Arizona - as per view above at about 9:45 am MST this morning. Very dreary outside this morning.

The 500 mb analysis above (at 1200 UTC from SPC) shows a strong, closed low (centered east of Salt Lake City and south of Rock Springs, Wyoming (ignore the analyzed center positions of both closed lows - bad height data at Phoenix and Chihuahua, Mexico also continue to cause problems). There is very strong, cold advection occurring southwest of the low center, which will cause it to dig further to the southwest. Models forecast it to become a closed low somewhere over southern Utah/northern Arizona.

The 500 mb skew-T analysis (above, also from SPC) indicates a very large amount of CAPE present this morning. While the potential is there, the local heating will be suppressed because of the smoke, and the BL will likely mix out only to about 800 mb, which would leave a large amount of lifting required to initiate storms - so storms are probably not going to develop. The strange layer that is well-mixed in temperature and moisture (~ 750 to 450 mb) is still present - I certainly have no explanation for the source of this adiabatic layer.

The 06 UTC plumes for QPF at airport (above) forecast showers this afternoon and evening, as does the morning NWS forecast. However, the 06 UTC WRF-GFS forecast for total precipitation through 11:00 am on Friday the 11th indicates almost no precipitation for almost all of Arizona.

No comments:

Post a Comment