textproduct: San Joaquin Valley

KEY MESSAGES

1. Below average temperatures will continue through the weekend. Warming trend returns temperatures to about average by the middle of next week.

2. Rainfalls return to the forecast this weekend in the Mojave Desert and Sierra Nevadas of Kern and Tulare County.

DISCUSSION

Today was a nice start to the Labor Day weekend. While the official temperatures for observation sites wont be published until midnight, most observation sites continued to have temperatures in the mid 80s. Temperatures will continue to be below normal as troughing is still the dominant feature. The current Probability of Exceedance (PoE) of 90 degrees on Saturday is 20-37% from Delano southward, including Bakersfield. For the counties north of Kern, the PoE of 85 degrees is 80-90%. So, most counties will see high temperatures ranging between 85-90 degrees on Saturday. Now that seems like perfect Labor Day Weekend weather. Sunday is a similar story for most of the Valley, if not a few degrees cooler. There is a 10% chance of Delano and Bakersfield seeing temperatures exceed 90 degrees on Sunday. Even the Mojave Desert will be cooler than normal, as the National Blend of Models (NBM) currently has Ridgecrest at a 30% chance of temperatures greater than 90 degrees. This is because the trough mentioned above has moved more on shore and providing two things. Its providing northwesterly flow, keeping the temperatures below normal. Its also providing a surge of moisture. Unfortunately (or fortunately, if you dont want rain on the proverbial parade), the rain is going to remain mostly in the Mojave Desert. Edwards has the greatest chance of rain, with a 45% chance of 0.10 or more on Sunday. Tejon Pass has a 25% chance of the same amount of rain in the same time frame. That might not seem like a large chance, but that is enough rain to make roads wet and slick over this holiday weekend in that busy corridor. The Climate Prediction Centers 6-10 day outlook has all of California in at least a 50-60% chance of above normal precipitation and the Sierra Nevada at a 60-70% chance of precipitation. This is thanks to Tropical Storm Marie sending a surge of moisture up into another trough off to the west. Even into the 8-14 day outlook, there is a 33-40% chance for above normal precipitation.

AVIATION

VFR conditions expected for the next 24 hours.

AIR QUALITY ISSUES

None.

CERTAINTY

The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is medium.

Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback.

HNX WATCHES/WARNINGS/ADVISORIES

None.