textproduct: San Joaquin Valley

KEY MESSAGES

1. Temperatures will remain above average through the weekend.

2. Practice cold water safety, as waterways will be running cold and fast over the next several days.

3. There is good confidence for a storm to pass through central California next Monday through Wednesday, bringing valley rain, mountain snow and strong winds to the region.

DISCUSSION

Temperatures continue to remain well above normal for the end of March, despite zonal flow. Again, the San Joaquin Valley will have above normal temperatures over the weekend as a ridge centered on West Texas and the incoming trough in the Pacific begin to bring in southwest flow, and with it, a warmup. The NBM has the probability of the San Joaquin Valley to be above 85 degrees on Saturday and Sunday at 70-80 percent. However, there is only a 15-20 percent probability to reach 90 degrees within that same time frame. With these warmer temperatures also extending into the Sierra Nevada mountains, there continues to be snowmelt runoff. Rivers that feed off of this snowmelt with continue to run cold and fast. Please exercise caution when swimming in water ways, as even the most experienced swimmers can experience temperature shock.

The pattern change continues to remain likely as the next week goes on. This pattern will bring temperatures down to normal levels as the trough begins to make its way through the area, before we drop to just a few degrees below normal towards the middle and end of the work week. The 10th percentile (best case scenario) is leaning towards temperatures being the mid to high 60s around the SJV Wednesday through Friday. The SJV is most likely to be in the low to mid 70s in that same time frame. The 90th percentile (worst case scenario) would have the area being in the upper 70s. Along with these drops in temperature, expect wind gusts to rise. Starting Monday, the very high mountains and the deserts will start to see wind gust probability begin to rise with a 25-40 percent chance of gusts reaching 40mph on Monday in the Mojave Desert and Walker Pass. There is high probability that the most windy zones (Mojave Desert 46 percent, Tioga Pass 64 percent) will have gusts exceeding 55 mph through Thursday night.

Accompanied with these lower temperatures is the chance for valley rain and mountain snow. The SJV could see 0" of rain (10th percentile, best case scenario) to .5" of rain (90th percentile, worst case scenario). The NBM 24 hour precipitation totals have remained at 40 to 50 percent chance of .1" of rain in Northern San Joaquin Valley, which is the most likely scenario. These chances steadily decrease the further south in the CWA we go. On the other hand, the Sierra Nevada is likely to get snow, as Snow Levels are projected to be 7,000 to 8,000 feet during the trough's time in California. With these snow levels, the Sierra Nevada are likely (40 to 60 percent) to see 72 hour snowfall totals of 5" or more.

AVIATION

VFR conditions will prevail across central California across the next 24 hours.

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.