Addition 10:05pm 8-15-23 by Dave Hovde, Meteorologist:
I just want to explain the intensity graphic in my social post below. It indicates that the system is either potentially a tropical storm or just a little weaker on arrival to SoCal/Central Coast area (after being a much stronger storm before it gets here). Important to note that a storm *does not* need to be a hurricane to do a lot of potential damage. The amount of water and wind with thunderstorm and surge potential create a hybrid of weather conditions that California doesn't see often.
Rainfall will hug the potential track so models are putting a lot in SoCal for now but you can't breath easy on the Central Coast yet there is too much uncertainty. Even a glancing blow could deliver inch plus rain, and a more direct or lingering track could deliver more.
Addition 9:44pm 8-15-23 by Dave Hovde, Meteorologist:
The new model runs are agreeing with the prior runs putting a strong storm if not still a tropical storm either in or near SoCal on Monday. This is still a yet-to-be-named system but it would likely be "Hilary". Inches of rain, winds, and serious surge and swell would result if these tracks verify. Stay tuned.
Addition 7:20pm 8-15-23 by Dave Hovde, Meteorologist:
The afternoon GFS model run showed some very rare potential for California: a very close brush with a tropical system. It is quite common for tropical leftovers to have an influence on California weather but rare for a named storm to visit California (there have only been 2 since 1900). The afternoon GFS model not only keeps a potentially named tropical system (likely "Hilary") near the coast but brings the system while still maintaining strength into SoCal and possibly the Central Coast. Now, this is just a one-off model run, and it is far too early to do tropical tracks for a system that has yet to even form or be named. That said, for days now models have suggested a storm and put it at least nearby which brings rain, t-storm potential and large swells possibly into play. Should the track become a concern it would introduce some rare potential to an area that typically doesn't get tropical landfills due to cold water temps.
——-from the prior story———
There's another day for the Central Coast where we're watching the radar for activity in the eastern interior valleys. This is the same area that saw a few isolated thunderstorms Monday. This afternoon there were few cells by California Valley. This activity is driven by monsoonal moisture combined with daytime heating. Any isolated thunderstorm should stay in the deep interior and dissipate as temperatures cool later this afternoon and into early this evening.
At the coast, it's a much different story with beaches on the cool side due to marine clouds but a steep temperature gradient as you go inland. Interior valleys are 100 plus today with some coastal valleys stretching into the 80s.
Wednesday also looks quite hot in the interior with some valleys potentially being close to 105 degrees for a daytime high. Coastal valleys will range from the 70s to lower 80s and beaches in the 60s and 70s with early marine cloud cover possible. Temperatures look to cool slightly on Thursday but more significantly on Friday and Saturday as a trough of low pressure off the West Coast will deepen the marine influence.
Temperatures begin to warm again Sunday through Tuesday. Something to watch next week is the possible inclusion of some tropical rainfall from a yet-to-be-named system in the lower latitudes.
This potential tropical system would be named Hillary and could introduce some moisture to Southern California and the Central Coast. We would not be in the direct path of the system but related moisture could stream to the north of it. This is something to watch as we get into the weekend and early next week.
