Thursday, July 24, 2014

Showers Mostly West Yesterday/Huge MCS Southern GoC This Morning

Models and forecasts were too optimistic for Tucson metro yesterday, as most storms were out to the west. The 00 UTC sounding from campus had just a tiny sliver of CAPE and there were isolated storms here and there in southeastern Arizona. Graphic above shows CG flash locations through midnight last night. Radar below is from 5:30 pm MST. The small storm to west of "T" in Tucson developed nearly over the house and produced 0.09" of rain here during brief but heavy shower.

Across the ALERT network no sites measured rainfall through 5 pm yesterday afternoon. After 5 pm 16 sites had light rains, mostly over the southwest portion of network - see above. Areal coverage after 00 UTC was less than 20% - the 0.59" amount above was highest amount recorded in the network.

The morning sounding from TUS is plotted above, showing a truly pathetic situation here this morning. The PW is back to around 30 mm and there is little to no CAPE likely during the afternoon. The 250 mb analysis for 12 UTC shown below indicates that the upper-level anticyclone is nearly overhead. So a lucky bit of rain yesterday for the house and now we'll continue to await the return of some mT air.

Finally, there were several MCS events during the night from the central to lower GoC. The large MCS (IR image below is from 6:15 am MST) currently over the southern end of GoC has been moving steadily north-northwestward during the early morning hours. The MCS activity may push better low-level moisture into the lower Colorado River Basin.

No comments:

Post a Comment