2009

Yesterday was an extremely hot day in the Central Valley, with a number of locations exceeding 110 degrees. Many daily records were set, and more record-breaking heat is possible there today. Yesterday was also hot elsewhere in the state, but fewer records were broken elsewhere. Temperatures are expected to creep down back to seasonal normals this week.

As usual, the models are failing to capture the current pre-monsoonal moisture surge accurately. Lightning has been detected just south of the U.S. / Mexico border in CA and over the ocean west of Baja. These storms and the associated moisture are moving north to northwest and are likely to affect the San Diego area soon and possibly the Los Angeles are by nightfall. Though thunderstorm activity does not look extremely likely, I do think there is a substantial chance of lightning outside of the mountains over the next couple of days. A weak upper low is forecast to develop in about 24 hours, which may help funnel some of this moisture north through the state, certainly setting off t-storms in the Sierras and possibly elsewhere. We’ll just have to wait and see how this develops…

El Nino continues to develop rapidly in the Eastern Pacific. Also of note is the large positive anomaly in SSTs present off the west coast of North America. This is probably related to the developing El Nino, and could certainly have an impact on our weather through the summer and going into the fall. Again: more as this develops.