Seasonably hot today, gradual cooling later this week

July 17, 2019 – Dry weather with seasonably hot temperatures continue, gradually cooling by late this week. Breezy winds through the Delta and over the Sierra crest at times.

Discussion

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Not much change in the overall pattern as a weak trough lingers along the West Coast into the weekend. Therefore, dry conditions and seasonably hot temperatures will continue. Temperatures in the Delta Breeze influenced areas will vary slightly day-to-day depending on the depth of the marine layer and strength of onshore flow.

Extended Discussion (Sunday through Wednesday)

Current extended forecast remains dry as NorCal remains under the western portion of a strong high pressure ridge over the western U.S. Should see fairly stable conditions under upper southwest flow between this high pressure ridge and troughing over the eastern Pacific.

Operational GFS has been hinting at bringing monsoon moisture up the Sierra in more southerly flow for some possible Sierra thunderstorms early next week. GEFS ensemble members not really backing up this idea at this time so have kept Sierra afternoon thunderstorms out of the forecast.

With NorCal being under the western fringe of the western U.S. ridge, the CWA will not see the full effects of subsidence warming and as a result, daytime temperatures through the extended will stay near or just slightly above normal with no heat wave expected.

Winds should remain fairly light except for occasionally breezy through the delta and over the Sierra crest.