UPDATE
Issued at 800 PM PDT Thu Sep 19 2024

The KMUX radar still remains active picking up lingering showers over Southern Monterey/San Benito counties this evening. Most of the activity occurred during the pre-dawn hours into early this morning as far as thunderstorms go. Since then, there's been a gradual decline since then. Latest analysis from NUCAPS and KVBG soundings show some instability aloft with some inhibition near the lingering shower activity. However, further analysis from radar/MRMS data reveals not a lot of vertical depth or ice through any convective column leading to no lightning production.
All that being said, a few showers to the east of San Benito may produce a strike or two this evening, but not much more than that.
The storm motion with these convective showers has been slow leading to wetting rains across some parts of Monterey county.
Lockwood has recorded 0.28" and a station near Greenfield measured 0.42". Not bad for September.

On the flip side...while the instability inland is aloft a much more stable regime persists at the coast with a marine layer near 1500 feet. This marine layer will deepen slightly and move inland overnight night.

No update needed this evening, but we'll be monitoring the nearby precip/convection.

MM

SHORT TERM
(This evening through Friday)
Issued at 130 PM PDT Thu Sep 19 2024

The upper level low that brought rain showers and thunderstorms to the interior Central Coast this morning remains south of the Monterey Bay region. As it moves onshore, there will be a chance of additional convection this afternoon over the aforementioned region as the air mass aloft is marginally unstable. The warmest conditions this afternoon will be across the North Bay and East Bay with interior areas warming into the low 80's with 60's and 70's as you move closer to the coast.

The marine layer is projected to deepen tonight bringing low clouds locally inland to the coastal adjacent valleys. The upper level trough will push further inland Friday, yet its effects will still linger with temperatures remaining below seasonal averages. Tomorrow expecting more widespread 80's across the interior with the potential for a few spots to reach 90 degrees such as Lake Berryessa. Elsewhere, 60's and 70's near the coast and San Francisco Bay Shoreline.

LONG TERM
(Friday night through next Wednesday)
Issued at 130 PM PDT Thu Sep 19 2024

Warming will continue into Saturday and moreso on Sunday as a ridge of high pressure builds over the eastern Pacific. HeatRisk increase by Monday and Tuesday with moderate risk across the interior. During this time, evening clouds will spread into the coastal adjacent valleys through early morning and then retreat back to the coast by the afternoon.

AVIATION
(06Z TAFS)
Issued at 1045 PM PDT Thu Sep 19 2024

Coastal stratus and fog /LIFR-IFR/ moving inland on onshore winds tonight and Friday morning, MVFR-VFR farthest inland. Stratus and fog mixing out back to near the coast and bays by late Friday morning and afternoon.

Vicinity of SFO...Satellite shows stratus moving inland, at SFO tempo IFR 06z-10z then IFR prevailing to 16z, MVFR to 1730z Friday. West to southwest wind 5 to 15 knots.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR-IFR due to stratus and fog tonight and Friday morning, conditions improving to MVFR-VFR by late Friday morning and afternoon. Onshore winds mainly 5 to 15 knots.

MARINE
(Tonight through next Wednesday)
Issued at 1037 PM PDT Thu Sep 19 2024

Northwesterly breezes will be gentle to moderate, with fresh gusts over the outer waters through Monday. Seas will be moderate, continuing to build and remain rough in the outer waters through Monday. Winds decrease and seas abate Tuesday through the end of the forecast period.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory until 9 AM PDT Saturday for Pt Arena to Pt Reyes 10-60 NM.