textproduct: San Joaquin Valley

KEY MESSAGES

1. Stronger easterly winds continue in the Kern Desert through Saturday afternoon.

2. The risk for fire starts remains elevated into the weekend due to lowering humidity and warmer temperatures.

3. Another chance for unsettled weather as precipitation, winds, and periodic thunderstorms return by the middle of next week.

DISCUSSION

Warm and dry conditions expected across the region this weekend as a ridge of higher pressure resides over the West Coast. Temperatures across the San Joaquin Valley expected to rise about 10 degrees above normal this weekend along with a decrease in winds across Kern County. 24 Hour change in wind gusts has seen a drop to 10-15 mph from this time Friday Morning. As the ridge axis now sits overhead, will see further upward trends in temperatures and downward trends in surface winds ahead of the next storm expected later next week.

In the short-term, while warming is expected this weekend and early next week, Probability of Exceedance (PoE) of reaching 90 degrees will remain below 30 percent (except for areas near Taft on Sunday) as the high pressure ridge will not have enough time to develop another heat-wave. Therefore, temperatures will peak into the mid to upper 80s during the period. During the same period, the Probability of Exceedance of reach 35 mph rises to a percentage in the 30-50 percent range Today and stays below 20 percent on Sunday. Therefore, confidence is high in reducing winds on Sunday and Monday before the return of winds by the middle of next week.

In the long-term, a disturbance will enter the region next week with an onset timing of between Wednesday Morning to Wednesday afternoon. Due to uncertainty in the upper level ensemble solutions, will maintain large timing spread until the storm reaches the short-term. For now, will see cooling and an uptick in winds over the favored locations of the Sierra Nevada Crest and the Tehachapi Range/Mojave Desert as the disturbance nears Central California. As for precipitation, while the atmosphere moistens will only see a 20-30 percent change of observing a tenth of an inch of precipitation.

During the latter part of the week, while ensemble uncertainty in the storms placement is high, probability of receiving a tenth of an inch (0.10) jumps to 30-50 percent across the Sierra and up to near 20 percent across the San Joaquin Valley. In addition, probability of receiving a Quarter of an inch (0.25) across the High Sierra during a 24 hour period remains around 15-25 percent. With snow levels remaining above 7,000 feet, the mentioned percentage ranges will place snow accumulation in the 2 to 4 inch category with a 10 percent chance of 5-7 inches over the Sierra Nevada Crest where orographics may enhance precipitation values near the upper range. Uncertainty in the timing of the storms passage will necessitate a mention of precipitation until early next Saturday. Furthermore, if the storm takes a later timing, will expect Thunderstorm activity for the latter part of the week as ensembles place a 15-25 percent chance of thunderstorms across Central California north of Kern County from Wednesday through Friday.

AVIATION

VFR conditions will prevail across central California for the next 24 hours. Easterly surface winds ranging from 20-35kts expected across the Tehachapi Range and Mojave Desert Slopes through 00Z Sunday.

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.