| Day | Date | High/Low | Forecast |
| Mon | 27th | 71/59 | Low clouds clearing to a sunny afternoon. Clear evening. |
| Tue | 28th | 83/64 | Sunny day. Clear evening. |
| Wed | 29th | 87/64 | Sunny day. Clear evening. |
| Thu | 30th | 82/59 | Sunny day. Some evening high clouds possible. |
| Fri | 31st | 76/57 | Mostly sunny day with scattered high clouds. Decreasing high clouds in the evening. |
Synopsis
Upper level high pressure is strengthening over the state today. Off-shore flow aloft has developed, and that should translate down to the ground in spots tonight. Widespread, significant wind (25 mph or higher wind) at low elevations are not anticipated, but it should nonetheless get breezy in Santa Ana wind prone areas at higher elevations (peak gusts up to about 45 mph for a time). The wind should diminish after tomorrow, but some brisk winds (especially east-west oriented canyons and passes) should persist through Wednesday. A return to marginal or weak, full fledged, on-shore flow is expected late Thursday into Friday. Marginal, off-shore flow is expected for this weekend (possibly into early next week).
Even without widespread, significant wind at low levels, good subsidence warming by the high pressure aloft should produce good warming. Unlike the heat spells of summer, this one should be a genuine, dry heat in most areas (this morning’s marine layer should be greatly diluted or even purged in places). For this forecast, I’ve taken a cautious approach. Some computer model forecasts show deep layered, easterly wind flow developing tomorrow into Wednesday. If true, even areas near the coast (campus included) may flirt with the 90 degree mark (even exceed it for a day). On the other hand, a persistent, weak on-shore gradient toward the low desert could prevent that much warming for areas near the coast (widespread 90 degree weather more probable farther inland).
Some cooling on Thursday and Friday should occur as high pressure aloft is forecast to weaken some (passing, weak trough aloft on Friday). High pressure should rebound in strength over the weekend, but most model solutions show surface on-shore flow occurring. That should limit the warming trend this weekend. Still, warmer than normal weather is nearly certain (would take unexpected return of a defined marine layer for better cooling in the coastal plain).
After the earlier mid-month storm, southern California hasn’t seen any relevant storm. All the longer range models keep it that way through at least early next week. A few model solutions showed a minor storm threat reaching the Southland around the 6th/7th of November, but the vast majority of model runs keep high pressure dominant for the next couple of weeks or so (at least, northern California may see some wet weather later next week). Temperatures should stay mostly at or above normal levels as a consequence.
Next issued forecast/synopsis should be on Monday, 3 November (FYI– Daylight Saving Time ends for the year on Sunday, 2 November at 2 AM…Clock time will “fall” back one hour at that time)