textproduct: San Joaquin Valley

KEY MESSAGES

1. Heat Advisory now in effect for the majority of the area until 11 PM Tuesday.

2. Widespread Moderate Heat Risk, including triple-digit heat, in the lower elevations through Wednesday.

3. Hot and dry conditions will create elevated fire risk in eastern Kern and Tulare Counties for the next few days.

4, Chance for thunderstorms in the Sierra Nevada the next few days, which may include dry lightning.

5. Practice safety around lakes, rivers, and streams, as water is still running cold.

DISCUSSION

Heat Advisory in effect for the majority of the area until 11 PM Tuesday.

The heat continues, with the majority of the Valley sitting at a 50-80% chance to exceed 100 degrees in the southern half of the Valley on Monday and a 15-30% chance in the northern half. The ridge looks to remain quite stable as the week begins, with high temperatures expected to remain in the upper 90s and low 100s across the Valley through Wednesday before a cooldown begins Thursday. It is imperative to ensure access to proper cooling, stay hydrated, limit outdoor activity, and wear light and breathable clothing if you must be outdoors. Take extra precaution for vulnerable people and for animals and check in on those in need.

The good news is that clusters continue to be in unusually strong agreement that the ridge will break down to some degree later next week, thanks to a minor trough that will form off the coast. This should help us return to more reasonable temperatures near climatological normals, with temperature spreads being abnormally narrow for a long-term forecast, indicating good confidence in this eventuality. That being said, the prolonged period of hot and dry conditions will create continued elevated fire conditions, particularly in eastern Kern and Tulare Counties, though all areas should exercise caution, as we have seen many fires across the entire area recently, several of which have prompted evacuations. This fire risk will be augmented by thunderstorm risk in the Sierra Nevada every day, which includes a risk of dry lightning. We saw a lot of lightning in the Sierra Nevada today, and the stationary nature of these storms also led to some flooding concerns. While the worst of the rain thankfully avoided burn scars today, those in the area should be on alert the next few days, as any prolonged rain could pose a flooding threat, particularly over burn scars.

As people attempt to cool down from these hot temperatures, please remember that waterways are still running cold. Even the most experienced swimmers can lose dexterity in 10-15 minutes in water that is 50 to 60 degrees.

AVIATION

VFR conditions expected in the San Joaquin Valley for the next 24 hours. Gusty winds at and near KBFL with sustained winds near 11 kts and gusts to 19 kts until 06Z. Any thunderstorms that form over the Sierra Crest tomorrow afternoon may include strong winds, rain, small hail, lightning, and turbulence.

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 high.

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

Heat Advisory until 11 PM PDT Tuesday for CAZ300>321-332.