July 28, 2019 – Well above normal temperatures today with a heat advisory in effect for the Central Valley and surrounding foothills. Cooling to near or slightly below normal Monday through the week.
High pressure aloft remains over the state bringing fair skies and warm temperatures this morning. Most valley early morning temperatures have dropped into the 70s this morning but some thermal belt areas remain in the 80s. Overall airmass today should be similar to Saturday and the delta breeze remains weak so expecting another hot day today so heat advisory for the valley and foothills will remain in place.
Conditions start to change late this afternoon and evening as a weak upper trough starts to dig in along the coast. Models indicate a significant increase in the delta breeze this evening with gusts up to near 30 knots expected by late this evening.
Delta breeze continues to strengthen during the day on Monday while overall airmass cools by several degrees. As a result, daytime highs Monday are forecast to drop to right around normal for this time of year. Southwest flow aloft ahead of the weak trough along the coast will keep stable conditions over NorCal so no mountain thunderstorms are expected.
Only minor changes are expected through the remainder of the short term period Tuesday and Wednesday as the upper trough remains over the eastern Pacific. Daytime highs Tuesday and Wednesday should remain near normal under mainly fair skies.
Extended Discussion (Thursday through Sunday)
Little change to the forecast this morning as ensemble guidance is in fairly good agreement troughing off the West Coast will be balanced by the Four Corners High. This pattern means near normal weather conditions for the later part of this upcoming workweek. Onshore flow will also allow for a Delta Breeze.
The ridge is expected to slowly strengthen into next weekend and could bring a little warm up to our area by next weekend. We could be talking about some triple digits in the North Sacramento Valley again for next weekend.