textproduct: San Joaquin Valley

KEY MESSAGES

1. Above normal temperatures are expected in our area today, and temperatures will continue to warm through the end of the week.

2. A Moderate Heat Risk through the Central Valley is likely (50-70% chance) by Thursday with the chances increasing even further this weekend. 3. A low chance of precipitation will be in place on Sunday and Monday of next week along the Sierra Nevada crest (10-20%).

DISCUSSION

The cooler weather that was in place on Monday has quickly dissipated, with warm, or even hot temperatures by the end of this week. A strong ridge of high pressure is beginning to build over our region and will continue to build over the next couple of days. Dry and warm weather with temperatures potentially reaching 10-15 degrees above average remains likely for the end of this week into this weekend. The probability of temperatures reaching above 95 degrees will be very low today (5-20%). The probability however will increase drastically by tomorrow (65-80%) and will likely remain very high for the foreseeable future after tomorrow. The probability of a Moderate Heat Risk in the Central Valley will be around 50-70% tomorrow and on Friday, while the probability today will be close to 0%. By this weekend the probability will have increased even further, with a 70-90% chance of a Moderate Heat Risk through much of the Central Valley on Saturday and Sunday.

While there is some inconsistency with ensemble members regarding the exact strength, a shortwave trough will likely move into our region on Sunday of this coming weekend. As of now, Central Valley temperatures will still likely remain hot, with only very slight changes in the overall temperature pattern. However, this trough could provide a source for lift in mountainous terrains. The probability of precipitation on Sunday and Monday is around 10-20% along the Sierra Nevada crest. In addition to the chances for precipitation, there is a chance for gusty winds along typical wind prone regions, including Lake Isabella on Sunday and Monday of next week. Confidence in how gusty it will be remains low at this point given that this event is several days out, but the probability of wind gusts of at least 25 mph is 55-70% on Sunday, mostly along the Mojave Desert slopes and Lake Isabella.

Temperatures look to remain well above average for an extended period of time, with the Climate Prediction Center (CPC) predicting a 80-90% chance of above average temperatures in the 6-10 and 8-14 day outlooks. Near normal precipitation however is expected within this same time period.

AVIATION

VFR conditions will prevail 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.