The cold, closed low I have been talking about for almost a week now is on schedule for Southern California and then into the Southwest later tonight and tomorrow. The low this afternoon was just off the coast of San Luis Obispo by mid-afternoon Thursday and will go south of Pt. Conception tonight, turn east tomorrow and move across the LA Basin tomorrow afternoon then to near the Colorado River by Friday morning. There will be two distinct maximum areas of rainfall with this storm. The first will be over Southern California especially from the mountains on west and in the Upper Deserts and the second in Arizona north into Nevada and Utah. Thunderstorms will be locally heavy, and there is the potential for locally severe weather in the form of strong, gusty winds, heavy downpours and hail. There is even the slight chance of a waterspout in the coastal waters of Southern California and a funnel cloud or weak tornado over land.
Precipitation will end tomorrow night in Southern California except near the Colorado River where a shower or thundershower could linger in spots late tomorrow night and to start on Friday. Precipitation in Arizona, southern Nevada and Utah continue on Friday with the heaviest activity in the morning hours.
This one storm is the only one the area will see for some time to come. Longer-range computer models show a big ridge building in California and the Southwest over the weekend and next week and temperatures rise back to above-normal levels.
This is some serious and dangerous heat. Outdoor activity is just not at all recommended during the daytime.
A strong ridge of high pressure in the West brings the highest heat of the season so far to a large area.
Combine the cold with the wind and some precipitation and there is a real danger of hypothermia.
Any shower and thunderstorm can contain heavy downpours, heavy enough to cause temporary, low-lying ponding.
According to all long-range models, the warmest area in North America compared to average will be over the Northwest.
No matter where you are, the sunshine gets more intense and causes quicker burning