Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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FXUS66 KMTR 250530
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
1030 PM PDT Wed Apr 24 2019

.SYNOPSIS...A gradual cooling trend will continue through the
second half of the week and into the weekend ultimately bringing
temperatures back closer to seasonal norms.

&&

.DISCUSSION...as of 09:18 PM PDT Wednesday...Recorded breaking
heat across interior portions of the Bay Area this afternoon.
These are all preliminary records: Moffett Field was 86 deg and
previous was 84, Kentfield (87) and Salinas (84) both tied their
records. A slight onshore breeze kept coastal areas in check and a
tad cooler. Today was an early preview of summer...inland heat
and cooler at the coast.

The ridge of high pressure that brought heat to the Bay Area will
gradually weaken over the next 24 hours. More importantly, low
level onshore flow will increase bringing with it the marine
layer. A quick look at the satellite fog product already shows low
stratus creeping up the coast near Morro Bay. Latest short term
models continue to the northward creep of the low resulting in
coastal low clouds tomorrow morning. Current forecast has this
already mention and no need to update forecast for tonight.

Given the returning marine layer temperatures near the immediate
coast/Bay Shoreline will see a decent cooldown tomorrow of 5-10
degs(15 in a few spots). Interior locations will cooldown as
well, but closer to 5 degrees cooler. Highs will end up being 60s
to near 70 at the coast and 80s to near 90 inland. Despite
cooling temperatures will still be above normal for late April -
5 to 10 degs above normal.

Looking farther down the road cooling will continue into the
weekend. The longwave pattern gets rather interesting late in the
weekend as a cut off low spins toward SoCal on Sunday and inland
on Monday. Models can struggle with the evolution of cut off
lows, but the lastest runs are not half bad with timing and
location. Precip chances are another story. Confidence remains low
for any precip and pop/rain chances may need to be cut back on
Sunday for the Central Coast.

&&

.AVIATION...as of 10:30 PM PDT Wednesday...Evening observations
and satellite are showing haze along the coast developing into low
clouds as the temperature drops toward the dewpoint. The upper
ridge over the area will let a small short wave pass through it
tonight. This in turn will allow for some deepening moisture along
with a weak onshore push. As such, the 06Z tafs maintain some low
cloud decks into several terminals, but not all. Timing and
coverage has been adjusted toward current model guidance. Once
this short wave clears, the low clouds should dissipate quickly
and VFR is expected to dominate once again. This is expected to
occur before sunrise for most locations. A more robust onshore
push will occur as the ridge exits the region Thursday night into
Friday.

Vicinity of KSFO...VFR through the night. Some low clouds will
loop around the east bay, but are not expected to reach SFO.

SFO Bridge Approach...Same as KSFO.

Monterey Bay Terminals...Look for low level clouds to develop this
evening across SNS and MRY. Clouds will dissipate around sunrise
Thursday. Therefore, VFR this evening -> IFR tonight -> VFR by
sunrise.

&&

.MARINE...as of 10:25 PM PDT Wednesday...High pressure off of the
Pacific Northwest coast will continue to dominate the weather
pattern through late week resulting moderate to gusty winds over
the northern waters. Elsewhere, winds will be weaker but may
become occasionally gusty during the afternoon and evening hours
near the coast.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm until 3 AM
             SCA...Pt Arena to Pigeon Pt 10-60 nm until 3 AM

&&

$$

PUBLIC FORECAST: MM/Sims
AVIATION: BFG
MARINE: BFG

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