textproduct: San Joaquin Valley

KEY MESSAGES

1. The warming temperatures will continue through late this week, becoming triple digits in some parts of the Valley tomorrow.

2. Hot and dry conditions this week will create increased fire risk across the region.

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

DISCUSSION

Satellite imagery is showing the marine layer deep into the coastal regions with surface observed temperature analysis showing a wedge of cooler air a bit lower then 24 hour ago. While breezy conditions still have the potential of reaching pass level, will expect lower wind speeds this afternoon. Probability of Exceedance of reaching 30 MPH is down to 15-25 percent with gusts this morning down by 4-6 mph. Winds did manage to reach 25 mph on two occasions Monday afternoon, yet, winds will have more difficulty reaching those speeds today. Therefore, will not issue a Lake Wind Advisory this afternoon and wait for the next big wind event toward the end of this week.

Ensemble upper-air analysis is showing signs of having a zonal flow component in the developing ridge pattern. Satellite imagery is also showing this scenario as clouds drift eastward this morning. Therefore, local winds will still be an issue and the possible heat wave may be limited. In addition, ensemble moisture analysis does show a northward surge from the subtropics (monsoonal) that will reach Central California in limited amounts due to the prevailing westerlies still over the area.

Warming trend is in store for Central California as the upper level pattern still show heights-rises from a high pressure area south of the Four Corners. While fighting a weak disturbance, Probability of Exceedance (PoE) of reaching 100 degrees ranges from 60 percent over the San Joaquin Valley portion of Kern County Today to lower percentages of 30-50 percent for areas north of Kern and Kings Counties. Peak heating and PoE will occur on Wednesday as widespread triple digits will be seen ahead of another trough expected on Friday. Heat lingers on Thursday before a significant drop in temperatures occurs on Friday and into the weekend. Therefore, while a heat wave will hit Central California this mid-week, the strength of the heat wave will be on the lower-end as the Valley struggles to receive PoE of reaching 103 degrees above 15 percent. Therefore, 97 to 102 degrees (5 to 8 degrees above seasonal normal) will be more common during this event. Longer range analysis has the Climate Prediction Center placing Central California in the leaning above normal category (40-50% chance) for temperatures in both the 6 to 10 and 8 to 14 day outlooks.

Precipitation-wise, will see slight chances for convection over the Sierra Crest and portions of the Tehachapi Mountains closer to the late-week period as an area of high pressures remains steady over an area south of the Four Corners. While the flow aloft will remains mostly westerly, the flow will have a slight southerly component. While limited, some moisture surge does makes its way toward Central California. Thunder will return closer to Friday across the Sierra Nevada Crest and will trend toward an increase in the Probability of Thunder to almost 15 percent by Friday afternoon (Best Chances). Climate Prediction Center shows a slight northward surge of precipitation chances in the 6 to 10 Day period toward leaning above (33-40% chance) normal. This is a good indicator of Monsoonal type moisture starting its northward surge this summer.

AVIATION

VFR conditions expected across the area 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.