textproduct: San Joaquin Valley

DISCUSSION

Cooling begins in earnest as a developing, strengthening storm Monday, west of Vancouver island, imbues an unsettled weather pattern later this week. Although timing of the rainfall has become clearer, late Wednesday afternoon through Thursday, the ensemble members with the most extreme amounts of precipitation have calmed. Nonetheless, local effects due to topography and wind direction/strength will have a lot to do with where the axis of heavy/training rainfall sets up. This is a detail typically not resolved well by the coarser ensemble suite. Another important detail is the remanant tropical moisture from Trudy.

Thus, the Weather Prediction Center has continued the Marginal Risk for Flash Flooding within 25 miles of a point (5% Probability) across much of Kern County and southeastern Tulare county, starting Wednesday at 5a until Thursday at 5a. The Borel Burn Scar and the very flood prone areas of eastern Kern, especially along Highways 58 and 14 should monitor the forecast. Probabilities for a half inch of rain during this period are far more bullish than a typical 4 day forecast, sitting at 50-60%. There is also a 10% probability of thunderstorms for the regions mentioned above.

Probabilities have risen to 70-80 percent chance of at least a tenth of an inch in the San Joaquin Valley. A 40-50% probability remains (for at least 4 inches) from Yosemite to Sequoia NP.

This amount of snow on Tioga Road/Pass in Yosemite NP will cause hazardous travel for those crossing the Sierra Nevada.

Another chance for precipitation occurs late next weekend into early next week. Confidence is high regarding the cooler temperatures to persist for much of next week and the following weekend. In addition, the CPC (Climate Prediction Center) mentions below average temperatures (near 40 percent chance) and above average precipitation (40-60 percent) for the 6-10 day and 8-14 day periods.

AVIATION

VFR conditions and light winds will prevail for the next 24 hours. There will periods of calm winds overnight. KBFL will see winds veering to the east from 03-06z Monday.

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.