Saturday, August 26, 2006

Drying out slowly

The TUS sounding this morning shows west-northwest winds in the 600 to 400 mb layer and precipitable water values down to 33.5 mm. The PHX sounding is drier with stronger winds.
Interestingly, the TUS sounding still has a fair amount of potential CAPE, so storms continue likely over mountains to the east.

I have just checked the 12Z soundings for TUS for the last four mornings. The winds in the 600 to 400 mb layer have been west-southwest to west-northwest each of these days and precipitable water has ranged from 42.9 to this morning's 33.5 mm. One could ask:

Did the monsoon end four days ago?

What kind of storms have been occurring with baroclinic westerly winds and lingering high moisture and CAPE?

I would call these "hybrid" or "mixed flow regime" storms since they are occurring in a meteorologically mixed environment. There is a preprint article about hybrid storms at:

http://www.wrh.noaa.gov/twc/monsoon/bobpres.php

2 comments:

  1. Anonymous9:47 AM

    Bob,

    There was an article in BAMS last year about how poorly the models do once profilers and soundings are removed. Without the Mexican soundings, the models are having a terrible time forecasting downstream. I remember a Canadian model ruin last week that had Ernesto near Houston this week. I am going to have my students plot up all of the NHC forecasts on this storm this week; timing and track errors are going to be huge past 72 hours. NHC is going to have a big problem with this storm since Ernesto will run into a blocking surface high as it gets north of the jacksonville area...a loop back into D.C. area is possible as a CAT 2. I believe that instead of investing monies to move the Tucson upper air site to the U/A that it should be invested into the Mexican upper air program.

    Pat Holbrook

    ReplyDelete
  2. Anonymous9:47 AM

    Bob,

    There was an article in BAMS last year about how poorly the models do once profilers and soundings are removed. Without the Mexican soundings, the models are having a terrible time forecasting downstream. I remember a Canadian model ruin last week that had Ernesto near Houston this week. I am going to have my students plot up all of the NHC forecasts on this storm this week; timing and track errors are going to be huge past 72 hours. NHC is going to have a big problem with this storm since Ernesto will run into a blocking surface high as it gets north of the jacksonville area...a loop back into D.C. area is possible as a CAT 2. I believe that instead of investing monies to move the Tucson upper air site to the U/A that it should be invested into the Mexican upper air program.

    Pat Holbrook

    ReplyDelete