Area Forecast Discussion

Logo_NWS.jpg

National Weather Service - San Joaquin Valley / Hanford, CA
Issued: Tuesday, May 14 2024 - 12:29 PM PDT

KEY MESSAGES... 1. High temperatures will remain well above seasonal values through Saturday.

2. A slight cooling trend is expected to take place beginning this weekend.

3. A few strong thunderstorms are possible in the Sierra Nevada each afternoon through Wednesday and again next weekend.

DISCUSSION... We currently have a rex block over the Pacific coast with a strong ridge and a trough to the west of the California-Mexico border. This setup has been helping with the high temperatures being above the seasonal highs in the high 80s to 90s. However, latest model ensembles are showing that the rex block will dissipate Wednesday into Thursday as the trough off the coast slides east but the main ridge remains but will weaken. The ridge will continue to weaken into the weekend because of a strong trough sliding through the Pacific Northwest. However, this trough is not expected to bring rain to our area but will temperatures will trend down to begin next week.

Afternoon thunderstorms are possible in the Sierra Nevada this afternoon and tomorrow afternoon thanks to small popcorn patches of high CAPE values around 2000 J/kg over the Sierra. However, down in the Valley, the heat is the issue as we are looking at a 40 to 70 percent chance of high temperatures of at least 90 degrees today for most Valley locations with lower values around 20 to 30 percent closer to the foothills. The probabilities increase to a widespread 45 to 80 percent chance of at least 90 degrees tomorrow before a widespread 75 to 90 percent chance of hitting at least 90 degrees on Thursday. The probabilities of highs of at least 90 drop to 55 to 80 percent on Friday and 40 to 70 percent on Saturday. This drop continues on Sunday to a 15 to 40 percent probability of a high of at least 90 degrees for the Valley.

Here are probabilities for certain San Joaquin Valley cities reaching 90 degrees as a high temperature on Thursday, May 16, 2024:

Fresno: 91% Bakersfield: 86% Lemoore: 91% Merced: 76% Reedley: 76% Delano: 86% Hanford: 86% Madera: 76% Porterville: 81% Visalia: 91%

Here are probabilities for certain San Joaquin Valley cities reaching 95 degrees as a high temperature on Thursday, May 16, 2024:

Fresno: 61% Bakersfield: 51% Lemoore: 51% Merced: 31% Reedley: 16% Delano: 51% Hanford: 46% Madera: 36% Porterville: 31% Visalia: 51%

AVIATION... Other than some areas of MVFR in thunderstorms over the Sierra Nevada through 03Z, 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... None.