344
FXUS66 KMTR 260549
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1049 PM PDT Wed Sep 25 2024

...New AVIATION, MARINE...

.UPDATE...
Issued at 858 PM PDT Wed Sep 25 2024

Forecast remains on track for temperatures tomorrow to be right
around normal for this time of year, or slightly warmer,
especially elevated locations farther inland. The beginning of
next week may bring another round of Moderate HeatRisk for
interior locations away from the marine layer influence.

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 104 PM PDT Wed Sep 25 2024

Quick check of current temps shows about 15-30 degrees cooler than
24 hours ago, depending on where you are. All thanks to a deep
marine layer and robust onshore flow in response to a passing
upper level trough in the Pacific Northwest. This pattern evolves
rather quickly back to a ridge setup with effects beginning
Thursday. High temps start to trend upwards Thursday as the marine
layer becomes compressed and cloud cover clears sooner in the day,
compared to today. Temperatures Thursday look to be about seasonal
normals. Some high clouds may end up in the picture this evening
for locations in the North Bay, making for a nice sunset if you`re
inland or above the stratus.

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 104 PM PDT Wed Sep 25 2024

Friday is expected to be the warmest day headed into the weekend
with highs ranging 5-15 degrees above normal. There`s a short
window of a weak offshore gradient that will likely set up in the
morning, eroding most of the marine layer and causing temps to
increase rapidly. By the afternoon, the gradient will reverse and
breezy onshore flow will ensue. Therefore, there is more
uncertainty than normal with the highs on Friday based on the
timing of the wind reversal. A progressive Gulf of Alaska trough
pattern remains through the weekend with another upper level
disturbance heading into the PNW Saturday and Sunday. This will
aid in flattening the ridge influence, bringing high temps back
down towards normal. However, the roller coaster ride continues
with a ridge influence building back in through early next week,
resulting in another warming trend. Ensemble guidance shows fairly
reasonable agreement in this pattern, so confidence is high that
we will see above average temperatures at least through the middle
of next week.

&&

.AVIATION...
(06Z TAFS)
Issued at 1049 PM PDT Wed Sep 25 2024

Coastal stratus and fog /IFR-MVFR/ will continue to move inland
tonight and Thursday morning. Conditions improving to MVFR-VFR
later in the morning and afternoon. Onshore winds continuing
during the period.

Vicinity of SFO...MVFR stratus ceiling developing tonight and
continuing to 18z Thursday, then VFR for the remainder of the
day and the evening. West wind 5 to 15 knots.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR-MVFR in stratus and fog tonight and
Thursday morning. Conditions lifting to MVFR-VFR by late Thursday
morning and afternoon. At least patchy IFR-MVFR due to stratus and
fog returning Thursday evening and night. Onshore winds 5 to 12
knots.

&&

.MARINE...
(Tonight through next Tuesday)
Issued at 1039 PM PDT Wed Sep 25 2024

A parade of low pressure systems to the north will support
moderate to fresh northwesterly breezes through the period. Over
the outer waters, seas will be rough and gusts will be strong.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 AM Thursday to 9 AM PDT Friday for
     Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory from 3 PM Thursday to 9 AM PDT Friday for
     Pigeon Pt to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Canepa
MARINE...Sarment

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