Saturday, August 02, 2008

Storm Outlook for Today

Visually spectacular storms yesterday evening - if anyone has photos for pasting on the blog, let me know.

Hot boundary layer temps and pocket of cooler 500 mb air, plus slight increase in moisture allowed storms, particularly at higher elevations, to overcome the strong inversion near 400 mb. Rain reported at 23 of the 91 Alert gauges in eastern Pima County - again mostly in mountains and foothills - the 1.50" at Agua Calienta Park seems an outlier, but there was spectacular lightning off that way. One wind damage report out at Pinal Airpark. Afternoon cells did not seem to have much in the way of precip shafts but then things obviously changed before dark.

Here at house - lightning, thunder and brief spit of rain shortly after 9 pm.

Situation today is very difficult with a number of competing plus and minuses.

Negatives first:

Very dry air to east in NM

Morning soundings continue with marginal IPW and boundary layer moisture.

Best difluence ahead of approaching upper-level, inverted trough appears to remain south of border.

Upper-level winds weak as we remain near the center of upper anticyclone.

Cool pocket at 500 mb has moved on to our west and northwest.


Nice push of subtropical moisture occurring into lower Colorado Basin, with some signature in PHX am sounding and Yuma VAD showing the influx to be about 4,000 ft deep. GPS IPW shows nice increases at the stations around the northern GoC.

Outflows from MCS over Mexico last night have pushed Td up across all of southern AZ and helped the GoC surge along.

Tropical low spinning off Baja in good location to keep low-level moisture flow going for a couple of days.

Very nice steering winds for storms that will tend to leave anvils to rear of strong cells.

Approaching inverted trough that extends down to 700 mb.

Summary - Looks good for strong storms with likely tropical squall line organization and somesevere storms and heavier rains, but today or tomorrow? I think things will come together today better than one might expect and that afternoon and evening should have strong storms - tomorrow will of course be highly affected by what does or does not happen during the next 12 hours. Chance of rain here at house probably at least 50% this evening.

No comments:

Post a Comment