Marine Weather and Tide Forecast for Valley Wells, CA

UPDATE
Corrected timing of Extreme Heat Warning.



KEY MESSAGES
1. Extreme Heat Warning continues for the Mojave Desert and Indian Wells Valley through Monday evening. Major HeatRisk expected with afternoon highs 108 to 112 each day.

2. High pressure over the region will maintain temperatures near season averages for the remainder of Central California before hotter conditions appear late next week.

3. Mainly dry conditions prevail until next week.



DISCUSSION
Good Saturday morning from a relatively peaceful San Joaquin Valley. Current satellite imagery shows a decent cirrus deck crossing over the valley north of Kern County, likely supported by a combination of upper level southerly flow and a happy little trough off the coast of the Oregon and Washington. Peak 500mb height approaching 600 decameters is currently centered over the Four Corners, covering much of the southwest US. Latest deterministic GFS and ECMWF modeling shows this strong high pressure anomaly staying near stationary over the area. For us here in California, both models are showing the strongest portion of this anomaly moves out of the area by Monday, thus giving credence to maintaining the Extreme Heat Warning for the Kern County desert until Monday night (9PM PDT).

In spite a temporary reprieve from extreme heat set for next work week, the aforementioned deterministic models show the strongest core of high pressure moving directly over California by next weekend. Consequently, both the Climate Prediction Center (CPC) and Weather Prediction Center (WPC) currently indicate moderate to high confidence for Extreme Heat across the Mojave Desert and San Joaquin Valley to start August. Latest National Blend of Models (NBM) guidance pins moderate confidence (50-60% probability) for triple digit heat in the San Joaquin Valley by Wednesday becoming more confident (70-80% probability) by Friday.

While still a ways away, the latest 10 day forecast indicates this next heat push will bring mid 100s to the San Joaquin and low to mid 110s to the Mojave Desert. Combined with overnight lows in the 70s for the former and 80s in the latter area, this appears on track for our next Heat Advisory product. Should a more aggressive scenario track, a region-wide Extreme Heat product extending up to the Sierra Nevada foothills cannot be ruled out.

On the other hand, favorable surface to upper level flow and some lingering mid to upper level moisture will keep thunderstorm probabilities pinned at about 10-15% today along the Sierra Crest. By Sunday, probability falls to 5% and lower, until a subtle moisture injection from monsoon air channeled by the remnants of Tropical Storm Genevieve bump probabilities slightly to 5-10% later in the work week. For the rest of us, however, precipitation is not expected in the foreseeable future.



AVIATION
10-15% probability of afternoon thunderstorms along the Sierra Nevada Crest from 20Z Saturday through 03Z Sunday. Otherwise, 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
Extreme Heat Warning until 9 PM PDT Monday for CAZ337-339.