North Richmond, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

132
FXUS66 KMTR 051758
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1058 AM PDT Mon May 5 2025

...New AVIATION...

.SYNOPSIS...
Issued at 100 AM PDT Mon May 5 2025

Gusty north winds across the interior North and East Bay mountains
with a Wind Advisory in effect through 2 PM. Winds diminish later
this afternoon into the evening, with generally dry and warm
conditions through Saturday.

&&

.UPDATE...
Issued at 932 AM PDT Mon May 5 2025

Strong northerly winds are being observed across the East Bay Hills
and North Bay Interior Mountains. RH values have plummeted across
those areas as strong offshore winds brought warmer and drier
conditions. Near critical fire weather conditions are expected
across the North Bay Interior Mountains through this evening.
Residents are advised to listen to local guidance and to take
caution if using an outdoor stove or campfire. Winds at Mt. St.
Helena (elevation of 4340 ft) has been consistently gusting above 70
mph since 11 PM last night with gusts peaking at 87 mph. Offshore
winds will ease by this evening before transitioning back to onshore
flow Tuesday.

&&

.SHORT TERM...
(Today and tonight)
Issued at 100 AM PDT Mon May 5 2025

Short Term Key Messages:
- Wind Advisory in effect for North Bay interior mountains and East
Bay Hills until 2 PM
- Wind gusts reach 35-45 mph in the North Bay interior mountains and
East Bay Hills during the Wind Advisory
- Winds begin to diminish in the afternoon

Gusty north winds are developing across the interior mountains of
the North and East Bays, the result of an interaction between a
cutoff low slowly moving east over southern Arizona and a developing
upper level ridge off the coast of the Pacific Northwest. This
interaction is creating a strong pressure gradient that is helping
to drive the gusty north winds across the northern half of the
state. As of 11 PM Sunday night, the pressure gradient between SFO
and ACV (Arcata Airport, around 12 miles north of Eureka) was a
relatively strong 8.2 millibars. In addition, a narrow jet streak is
coming into the North and East Bays with winds of 50-55 mph at the
700 mb (around 10,000 feet above sea level).

So far tonight, the mountain gusts have been pretty intense with a
PGE station on Mount St Helena reporting gusts up to 78 miles per
hour and rising as of the latest update. A Wind Advisory is in
effect for the North Bay interior mountains and the East Bay Hills
through 2 PM today, with sustained winds around 20-30 mph across the
warned area and gusts of up to 55 mph. The current thinking is that
the northerly component of the winds will limit mixing down into the
valley regions, but the operations team will keep an eye on the
observations and extend the Wind Advisory if necessary.

There are some fire weather concerns with the northerly winds across
the interior North and East Bays. Relative humidities across the
region have dropped to 15-25 percent, and the dry offshore winds
will not help matters by inhibiting overnight humidity recoveries.
Several stations across the North Bay interior have even met Red
Flag criteria for several hours of time. The main limiting factor is
that most fuels have remained moist after the past winter season,
but North and East Bay residents should still follow local advice on
outdoor burning and take caution around open flames, including
campfires and outdoor stoves, as any fires that do start could still
spread quite rapidly via the gusty winds.

As the cutoff low continues to trek eastwards through the Desert
Southwest, and the upper level ridge broadens as it approaches the
western United States, the pressure gradient will relax through the
day, allowing the gusts to diminish, especially in the afternoon and
evening. While gusty winds may linger in the higher elevations, the
gusts will fall below Wind Advisory criteria across the afternoon
and evening. The relaxing pressure gradient should also contribute
to diminishing the jet streak as it continues to move southward. As
a result, there is high confidence that the rest of the Bay Area and
Central Coast will be spared the strong wind gusts.

High temperatures today range from the lower to middle 80s in the
inland valleys, to the upper 70s to the lower 80s along the San
Francisco Bay and Santa Cruz County, and the 60s along the Pacific
coast.

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 100 AM PDT Mon May 5 2025

Long Term Key Messages
- Winds continue to ease through Tuesday
- Ridging pattern continues through the week
- Generally dry and warm through Saturday
- Possible trough early next week

Winds will continue to ease on Tuesday and return to a generally
onshore breeze through the rest of the week. A positively tilted
upper level ridge will result in generally dry and warm conditions
across the region, with inland highs ranging in the 70s to the lower
80s into Thursday, close to or slightly above seasonal averages,
while marine layer stratus keeps the coastal areas cool in the upper
50s to the middle 60s, around 5 to 10 degrees below seasonal
averages.

Friday and Saturday could see a spike in the temperatures with a
strengthening ridge over the Intermountain West, with inland highs
reaching the lower to middle 80s (perhaps into the 90s in the
southern reaches of Monterey and San Benito County). Moderate
HeatRisk is possible in the southern Salinas Valley, meaning that
there is a risk for heat-related illnesses in most people sensitive
to heat, including children, the elderly, people with certain
medical conditions, and people without access to effective cooling.
Minor HeatRisk, where some risk exists for people extremely
sensitive to heat, is expected throughout most of the region.

Ensemble model cluster analysis reveals the potential for an upper
level trough to arrive later this weekend into the early part of
next week, with considerable variation in how fast the trough will
travel and how strong the trough will be when it arrives. Thus, any
discussion of potential impacts to sensible weather is somewhat
premature. There will be greater confidence in the evolution of the
upper level trough throughout the week, so stay tuned to the
forecast as the details emerge.

&&

.AVIATION...
(18Z TAFS)
Issued at 1040 AM PDT Mon May 5 2025

Clear skies with strong, shifting winds are expected through the
TAF period. LLWS remains a threat, but as the surface winds have
increased, the vertical wind speed gradient has lessened. Strong
surface winds are the primary hazard, particularly due to cross
wind component created by the less common N-NE direction. These
winds are bringing dry air, and there is high confidence that
skies will remain clear through the day. Overnight, a southerly
surge will likely bring some stratus to the Central Coast.

Vicinity of SFO...VFR conditions are expected to continue
throughout the TAF period, with high confidence of clear skies
through the evening. Strong northerly winds will gradually shift
to a more standard NW direction through the afternoon while the
strength diminishes overnight. There is about a 25% chance for
marine layer ceilings to reach SFO Tuesday morning, with a much
higher chance Wednesday morning as the marine layer reorganizes.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Winds are weaker at MRY and SNS, and
will still be shifting from onshore during the afternoon to
offshore overnight. A southerly surge of stratus will likely
bring IFR ceilings to both MRY and SNS early Tuesday morning.

&&

.MARINE...
(Today through Saturday)
Issued at 932 AM PDT Mon May 5 2025

After a rough weekend, the pressure gradient will relax this week.
Strong to near gale force winds will steadily diminish through
the day while very rough seas gradually subside to moderate
through mid-week.

&&

.BEACHES...
Issued at 535 PM PDT Sun May 4 2025

A Beach Hazards Statement remains in effect through Monday
morning for the Monterey County coastline, where breaking waves of
15 to 20 feet are expected with the highest waves reaching 28
feet in favored locations. Elevated surf is also expected along
west and northwest facing beaches towards the north, but with a
slightly shorter period in this region, confidence in hazardous
conditions is somewhat lower. Additionally, gusty winds will cause
blowing and shifting sand, as well as increase sea spray, which
can complicate water rescues due to reduced visibilities.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 2 PM PDT this afternoon for CAZ504-515.

PZ...Small Craft Advisory until 3 PM PDT this afternoon for SF Bay N
     of Bay Bridge.

     Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
     to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena
     to Pt Reyes 0-10 nm.

     Gale Warning until 9 PM PDT this evening for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Flynn
MARINE...Flynn

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