|Map shows the expected position of the remnants of Odile [D] at 11:00 p.m. PDT September 17.|
Yesterday there were some rare severe thunderstorms in southern California. Wind damage was reported in and around San Diego, where numerous trees and light poles were toppled and small planes were flipped over at Montgomery Field Airport. One inch hail was reported near Joshua Tree, CA in San Bernadino County.
|San Diego radar image for 3:15 p.m. PDT September 16. Storms were moving to the west.|
There are a combination of factors that will make the next few days messy, to say the least, in the Desert Southwest. CoCoRaHS observers in the region will be getting a lot of measurements in over the next several days. Although we are the tail end of the summer monsoon season, there will be heavy showers and thunderstorms because of the plentiful moisture being fed into the region. Weak flow in the upper atmosphere will provide for little steering of the showers and thunderstorms, and those that develop could remain over a relatively small area for much of the storm's lifetime. That means potentially heavy rain for a long period of time. That same weak upper flow also means that the leftovers from Odile will be slow to move out of the region.
|500 millibar map for 5:00 a.m. PDT this morning. The circulation of Odile is caught in a ridge over the Southwest.|
The NWS Weather Prediction Center is expecting as much as 4 inches of rain from southeastern Arizona through southern Arizona and into western Texas, with some locally higher amounts possible.
|Rainfall forecast through 5:00 p.m. PDT Saturday, September 20.|
Flood watches are in effect for large portions of Arizona and New Mexico.
|Flood watches (dark green) and flood advisories (light green) in effect as of 5:00 p.m. PDT|
Here is a broader picture of the rainfall expected in the southwest and across the country the next three days.
|Quantitative Precipitation forecast for the 72-hour period ending 5:00 p.m. PDT Saturday, September 20.|
The showers and thunderstorms are most numerous tonight south of the Arizona-Mexico border but are steadily feeding northward. The Tucson NWS office has a nice summary of daily and monthly rainfall records for a number of locations in southern Arizona on their web site.
|Tucson, AZ radar at 5:39 p.m. MST September 17|