textproduct: San Joaquin Valley

KEY MESSAGES

1.Warming trend Wednesday into the weekend with high confidence of at least Moderate Heat Risk in the Valley Sunday through Tuesday.

DISCUSSION

The cutoff low that brought cooler temperatures on Monday and Tuesday is moving off to the east. A ridge of high pressure slides in overnight into Wednesday morning and will strengthen into the weekend. The ridge will bring a strong warming trend. However, the heating trend brings high confidence of a Moderate Heat Risk for Sunday through Tuesday including Fresno's 75th percentile high temperatures being around 105 degrees on Monday and Tuesday.

This ridge of high pressure also keeps winds to be light and diurnal especially for the foothills. However, the mean minimum Relative Humidity values drop to the low teens in the Valley and in the high teens to low 20s for the Foothills and Sierra Nevada by Tuesday. The CPC has the area under a 80 to 90 percent chance of above average temperatures in the 6-10 day outlook. The 8-14 day outlook suggests a pattern change with a 33 to 40 percent chance of above average precipitation, however, that would be anything above a trace in the Valley for mid-May. The 8-14 day outlook also has a 50 to 60 percent chance of above average temperatures.

AVIATION

VFR conditions will prevail for the next 24 hours over Central California.

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.