High Wind Watch 4, NWS San Francisco Bay Area, CA

536 
WWUS76 KMTR 251234
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
534 AM PDT Fri Oct 25 2019

CAZ505>507-510-511-260000-
/O.CON.KMTR.HW.A.0004.191027T0300Z-191028T1800Z/
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-North Bay Mountains-
East Bay Interior Valleys-East Bay Hills and the Diablo Range-
Including the cities of Tamalpais-Homestead, Sausalito, 
Santa Rosa, South Santa Rosa, Napa, San Rafael, Petaluma, Novato,
Rohnert Park, Angwin, Lagunitas-Forest Knolls, Woodacre, Concord,
Antioch, Livermore, Walnut Creek, Pleasanton, Pittsburg, 
San Ramon, and Blackhawk
534 AM PDT Fri Oct 25 2019

...HIGH WIND WATCH REMAINS IN EFFECT FROM SATURDAY EVENING
THROUGH MONDAY MORNING...

* WHAT...Northeast winds 15 to 30 mph with frequent gusts of 45 
  to 55 mph. Locally stronger gusts up to 65 to 75 mph in the 
  region's highest peaks such as Mt Saint Helena and Mt Diablo.

* WHERE...Coastal North Bay Including Point Reyes National 
  Seashore, North Bay Interior Valleys, North Bay Mountains, 
  East Bay Interior Valleys and East Bay Hills and the Diablo 
  Range.

* WHEN...From Saturday evening through Monday morning.

* IMPACTS...Damaging winds could blow down trees and power 
  lines. Widespread power outages are possible. Travel could be 
  difficult, especially for high profile vehicles.

* ADDITIONAL DETAILS...The strongest winds are likely from late 
  Saturday evening into Sunday morning before diminishing 
  slightly Sunday afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this
situation. Fasten loose objects or shelter objects in a safe
location prior to the onset of winds.

&&

$$

CAZ509-512-260000-
/O.CON.KMTR.HW.A.0004.191027T1000Z-191028T1800Z/
San Francisco Peninsula Coast-Santa Cruz Mountains-
Including the cities of Pacifica, Scotts Valley, Boulder Creek, 
and Day Valley
534 AM PDT Fri Oct 25 2019

...HIGH WIND WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH MONDAY MORNING...

* WHAT...Northeast winds 15 to 30 mph with gusts up to 45 mph.

* WHERE...San Francisco Peninsula Coast and Santa Cruz Mountains.

* WHEN...From late Saturday night through Monday morning.

* IMPACTS...Damaging winds could blow down trees and power 
  lines. Widespread power outages are possible. Travel could be 
  difficult, especially for high profile vehicles.

* ADDITIONAL DETAILS...The strongest winds are likely from late 
  Saturday night into Sunday morning before diminishing slightly 
  Sunday afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this
situation. Fasten loose objects or shelter objects in a safe
location prior to the onset of winds.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/mtr

944 
WWUS76 KMTR 251421
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
721 AM PDT Fri Oct 25 2019

CAZ509-260200-
/O.NEW.KMTR.HT.Y.0012.191025T1700Z-191026T0200Z/
/O.CON.KMTR.HW.A.0004.191027T1000Z-191028T1800Z/
San Francisco Peninsula Coast-
Including the city of Pacifica
721 AM PDT Fri Oct 25 2019

...HEAT ADVISORY IN EFFECT UNTIL 7 PM PDT THIS EVENING...
...HIGH WIND WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH MONDAY MORNING...

* WHAT...For the Heat Advisory, upper 80s to low 90s possible, 17
  to 22 degrees above normal. Coastal areas may be equally as warm
  or warmer than inland areas. For the High Wind Watch, northeast
  winds 15 to 30 mph with gusts up to 45 mph possible.

* WHERE...San Francisco Peninsula Coast.

* WHEN...For the Heat Advisory, from 10 AM PDT this morning to 7 
  PM PDT this evening. For the High Wind Watch, from late Saturday
  night through Monday morning.

* IMPACTS... The heat may cause an increased risk of heat related
  illnesses. Heat related illnesses such as heat exhaustion and
  heat stroke will be possible. People most vulnerable include
  those who are spending considerable time outdoors...those who do
  not have air conditioning...young children...the elderly... and
  those with chronic ailments. Damaging winds could blow down 
  trees and power lines. Widespread power outages are possible. 
  Travel could be difficult, especially for high profile vehicles.
  Hot temperatures and high humidity may cause heat illnesses to 
  occur.

* ADDITIONAL DETAILS...The strongest winds are likely from late 
  Saturday evening into Sunday morning before diminishing 
  slightly Sunday afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this
situation. Fasten loose objects or shelter objects in a safe
location prior to the onset of winds.

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ006-508-513-528>530-260200-
/O.NEW.KMTR.HT.Y.0012.191025T1700Z-191026T0200Z/
San Francisco-San Francisco Bay Shoreline-
Santa Clara Valley Including San Jose-
Northern Salinas Valley/Hollister Valley and Carmel Valley-
Northern Monterey Bay-Southern Monterey Bay and Big Sur Coast-
Including the cities of San Francisco, Oakland, Fremont, Hayward,
Daly City, Berkeley, San Jose, Salinas, Santa Cruz, Watsonville, 
Live Oak, Seaside, Monterey, and Marina
721 AM PDT Fri Oct 25 2019

...HEAT ADVISORY IN EFFECT UNTIL 7 PM PDT THIS EVENING...

* WHAT...Temperatures will range from the upper 80s to mid 90s
  which is 17 to 22 degrees above normal. Coastal areas may be
  equally as warm or warmer than inland areas. 

* WHERE...San Francisco Bay shoreline, Santa Clara valley,
  Northern Salinas valley, Monterey Bay shoreline, Big Sur 
  coastline.
  

* WHEN...from 10AM PDT this morning through 7 PM PDT this 
  evening.

* IMPACTS...The heat may cause an increased risk of heat related
  illnesses. Heat related illnesses such as heat exhaustion and
  heat stroke will be possible. People most vulnerable include
  those who are spending considerable time outdoors...those who do
  not have air conditioning...young children...the elderly... and
  those with chronic ailments. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ505>507-510-511-260200-
/O.CON.KMTR.HW.A.0004.191027T0300Z-191028T1800Z/
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-North Bay Mountains-
East Bay Interior Valleys-East Bay Hills and the Diablo Range-
Including the cities of Tamalpais-Homestead, Sausalito, 
Santa Rosa, South Santa Rosa, Napa, San Rafael, Petaluma, Novato,
Rohnert Park, Angwin, Lagunitas-Forest Knolls, Woodacre, Concord,
Antioch, Livermore, Walnut Creek, Pleasanton, Pittsburg, 
San Ramon, and Blackhawk
721 AM PDT Fri Oct 25 2019

...HIGH WIND WATCH REMAINS IN EFFECT FROM SATURDAY EVENING
THROUGH MONDAY MORNING...

* WHAT...Northeast winds 15 to 30 mph with frequent gusts of 45 
  to 55 mph. Locally stronger gusts up to 65 to 75 mph in the 
  region's highest peaks such as Mt Saint Helena and Mt Diablo.

* WHERE...Coastal North Bay Including Point Reyes National 
  Seashore, North Bay Mountains, North Bay Interior Valleys, 
  East Bay Interior Valleys and East Bay Hills and the Diablo 
  Range.

* WHEN...From Saturday evening through Monday morning.

* IMPACTS...Damaging winds could blow down trees and power 
  lines. Widespread power outages are possible. Travel could be 
  difficult, especially for high profile vehicles.

* ADDITIONAL DETAILS...The strongest winds are likely from late 
  Saturday evening into Sunday morning before diminishing 
  slightly Sunday afternoon.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this
situation. Fasten loose objects or shelter objects in a safe
location prior to the onset of winds.

&&

$$

CAZ512-260200-
/O.CON.KMTR.HW.A.0004.191027T1000Z-191028T1800Z/
Santa Cruz Mountains-
Including the cities of Scotts Valley, Boulder Creek, 
and Day Valley
721 AM PDT Fri Oct 25 2019

...HIGH WIND WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH MONDAY MORNING...

* WHAT...Northeast winds 15 to 30 mph with gusts up to 45 mph.

* WHERE...Santa Cruz Mountains.

* WHEN...From late Saturday night through Monday morning.

* IMPACTS...Damaging winds could blow down trees and power 
  lines. Widespread power outages are possible. Travel could be 
  difficult, especially for high profile vehicles.

* ADDITIONAL DETAILS...The strongest winds are likely from late 
  Saturday night into Sunday morning before diminishing slightly 
  Sunday afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this
situation. Fasten loose objects or shelter objects in a safe
location prior to the onset of winds.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/mtr

123 
WWUS76 KMTR 251812
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
1112 AM PDT Fri Oct 25 2019

CAZ507-260200-
/O.UPG.KMTR.HW.A.0004.191027T0300Z-191028T1800Z/
/O.NEW.KMTR.HW.W.0004.191027T0300Z-191028T1800Z/
North Bay Mountains-
Including the cities of Angwin, Lagunitas-Forest Knolls, 
and Woodacre
1112 AM PDT Fri Oct 25 2019

...HIGH WIND WARNING IN EFFECT FROM 8 PM SATURDAY TO 11 AM PDT
MONDAY...

* WHAT... Extremely strong north to northeast winds are 
  forecast Saturday night through Sunday morning.  

  Sat Night... Sustained 30-55mph Gusts 60-80mph...
  Sun Day...   Sustained 20-35mph Gusts 40-60mph...
  Sun Night... Sustained 15-25mph Gusts 25-40mph...
  Mon Day...   Sustained 5-15mph Gusts 15-25mph...

* WHERE...North Bay Mountains.

* WHEN...From 8 PM Saturday to 11 AM PDT Monday.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Widespread power outages are expected. Travel will be 
  difficult, especially for high profile vehicles. Rapid fire 
  growth potential.

* ADDITIONAL DETAILS... Winds gradually decrease from Sunday 
  through early Monday but will remain locally gusty 
  throughout Sunday night. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around
trees and branches. If possible, remain in the lower levels of
your home during the windstorm, and avoid windows. Use caution if
you must drive.

&&

$$

CAZ509-260200-
/O.UPG.KMTR.HW.A.0004.191027T1000Z-191028T1800Z/
/O.NEW.KMTR.WI.Y.0014.191027T1000Z-191028T1800Z/
/O.CON.KMTR.HT.Y.0012.000000T0000Z-191026T0200Z/
San Francisco Peninsula Coast-
Including the city of Pacifica
1112 AM PDT Fri Oct 25 2019

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM PDT THIS EVENING...
...WIND ADVISORY IN EFFECT FROM 3 AM SUNDAY TO 11 AM PDT MONDAY...

* WHAT...For the Heat Advisory, upper 80s to low 90s possible, 17
  to 22 degrees above normal. Coastal areas may be equally as warm
  or warmer than inland areas. For the wind advisory, northeast
  winds 15 to 35 mph with gusts up to 55 mph possible.

* WHERE...San Francisco Peninsula Coast.

* WHEN...For the Heat Advisory, until 7 PM PDT this evening.  For 
  the Wind Advisory, from 3 AM Sunday to 11 AM PDT Monday.

* IMPACTS... HEAT. The heat may cause an increased risk of heat related
  illnesses. Heat related illnesses such as heat exhaustion and
  heat stroke will be possible. People most vulnerable include
  those who are spending considerable time outdoors...those who do
  not have air conditioning...young children...the elderly... and
  those with chronic ailments. WINDS. Damaging winds could blow down 
  trees and power lines. Widespread power outages are possible. 
  Travel could be difficult, especially for high profile vehicles.
  Rapid fire growth potential.

* ADDITIONAL DETAILS...The strongest winds are likely from late 
  Saturday evening into Sunday morning before diminishing 
  slightly Sunday afternoon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

CAZ505-506-510-511-260200-
/O.UPG.KMTR.HW.A.0004.191027T0300Z-191028T1800Z/
/O.NEW.KMTR.WI.Y.0014.191027T0300Z-191028T1800Z/
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-
Including the cities of Tamalpais-Homestead, Sausalito, 
Santa Rosa, South Santa Rosa, Napa, San Rafael, Petaluma, Novato,
Rohnert Park, Concord, Antioch, Livermore, Walnut Creek, 
Pleasanton, Pittsburg, San Ramon, and Blackhawk
1112 AM PDT Fri Oct 25 2019

...WIND ADVISORY IN EFFECT FROM 8 PM SATURDAY TO 11 AM PDT
MONDAY...

* WHAT...Strong and dangerous north to northeast winds are forecast 
  Saturday night into Sunday morning.  Winds are expected to reach 
  the lower elevations particularly by Sunday morning and through 
  the day Sunday. Offshore winds weaken but remain locally gusty 
  Sunday night into Monday.

  Mountains/Hills...  Sat Night... Sustained 30-50mph Gusts 55-75mph...
                      Sun Day...   Sustained 20-35mph Gusts 40-60mph...
                      Sun Night... Sustained 15-25mph Gusts 25-40mph...
                      Mon Day...   Sustained 5-15mph  Gusts 15-25mph...
 
  Valleys/Coast...    Sat Night... Sustained 5-15mph  Gusts 15-35mph...
                      Sun Day...   Sustained 15-25mph Gusts 30-50mph...
                      Sun Night... Sustained 5-10mph  Gusts 10-20mph...
                      Mon Day...   Light Winds...

* WHERE...Coastal North Bay Including Point Reyes National 
  Seashore, North Bay Interior Valleys, East Bay Interior 
  Valleys and East Bay Hills and the Diablo Range.

* WHEN...From 8 PM Saturday to 11 AM PDT Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result. Rapid fire growth potential.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

CAZ512-260200-
/O.UPG.KMTR.HW.A.0004.191027T1000Z-191028T1800Z/
/O.NEW.KMTR.WI.Y.0014.191027T1000Z-191028T1800Z/
Santa Cruz Mountains-
Including the cities of Scotts Valley, Boulder Creek, 
and Day Valley
1112 AM PDT Fri Oct 25 2019

...WIND ADVISORY IN EFFECT FROM 3 AM SUNDAY TO 11 AM PDT MONDAY...

* WHAT...Strong north to northeast winds will develop through
  Saturday night into Sunday, peaking early Sunday morning. 
  Sustained wind speeds of 15 to 30 mph with gusts 35 to 55 mph
  are possible.  Winds gradually weaken from Sunday morning through 
  Monday morning, but will remain locally gusty into early Monday.

* WHERE...Santa Cruz Mountains.

* WHEN...From 3 AM Sunday to 11 AM PDT Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result. Rapid fire growth potential.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

CAZ006-508-513-528>530-260200-
/O.CON.KMTR.HT.Y.0012.000000T0000Z-191026T0200Z/
San Francisco-San Francisco Bay Shoreline-
Santa Clara Valley Including San Jose-
Northern Salinas Valley/Hollister Valley and Carmel Valley-
Northern Monterey Bay-Southern Monterey Bay and Big Sur Coast-
Including the cities of San Francisco, Oakland, Fremont, Hayward,
Daly City, Berkeley, San Jose, Salinas, Santa Cruz, Watsonville, 
Live Oak, Seaside, Monterey, and Marina
1112 AM PDT Fri Oct 25 2019

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM PDT THIS EVENING...

* WHAT...Temperatures will range from the upper 80s to mid 90s
  which is 17 to 22 degrees above normal. Coastal areas may be
  equally as warm or warmer than inland areas. 

* WHERE...Portions of western California.

* WHEN...Until 7 PM PDT this evening.

* IMPACTS...The heat may cause an increased risk of heat related
  illnesses. Heat related illnesses such as heat exhaustion and
  heat stroke will be possible. People most vulnerable include
  those who are spending considerable time outdoors...those who do
  not have air conditioning...young children...the elderly... and
  those with chronic ailments. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/mtr

Area Forecast Discussion
National Weather Service San Francisco Bay Area
620 PM PDT Thu Oct 24 2019

.SYNOPSIS...Critical fire weather conditions will persist through
Thursday afternoon with gusty offshore winds and low relative
humidity. Additionally, high pressure over the region will also
lead to above normal temperatures. Temperatures will cool over the
weekend and into next week. Another and likely stronger offshore
flow event is in the forecast late this weekend. The offshore flow
will bring renewed fire weather concerns and possible wind damage
concerns as well.

&&

.DISCUSSION...as of 03:45 PM PDT Thursday... Active weather day
across California as a 592dm high pressure ridge anchored just off
of the Northern California coast is being counterbalanced by a
564dm low pressure trough over eastern NM/Texlahoma panhandles.
Consequently, the SFO-WMC gradient (used as a proxy for offshore
flow strength) peaked at 16.7mb at 8am this morning but has since
eased to 13.4mb this afternoon. This steep offshore gradient led
to strong, gusty offshore winds, particularly across the North Bay
hills and ridges. Winds peaked around midnight near the
#KincadeFire with sustained winds 53mph and gusts to 76mph out of
the North East (11% RH). Extreme fire weather conditions prompted
by these winds and poor overnight humidities allowed for the
explosive fire growth on the Kincade fire which started late last
evening and expanded at around 1000 acres/hour into this morning.
Outside of the Kincade, a few smaller fires also popped up but
were rapidly campaigned by fire personnel (Muir fire in Marin,
Spring near Santa Rosa, a vegetation fire near Berkeley). Winds
began to taper off from early to mid morning regionwise though a
few stubborn spots remained breezy to occasionally gusty into the
early afternoon. As of 3pm, most winds have fallen into the light
category. As such, the current red flag warning is set to expire
on time at 4pm.

Fire weather aside, the high pressure system also has brought
oppressively warm temperatures along the California coast today.
Heat advisories are in effect along the coast from Sonoma all the
way to San Diego until 7pm today as the warmest air mass lingers
just offshore and over the coast. In addition, the high pressure
system has suppressed nearly all onshore cooling influences,
replacing them with warming and drying offshore flow.
Consequently, the usual suspects when it comes to heat -- extreme
inland areas -- were relatively mild in comparison to the usually
much cooler coastal areas. For example, Monterey topped out at
96F degrees, breaking the old record not only for the day, but
also for the month of October. Other notable coastal locations:
Dillon Beach 94F, Bodegahead 91F, Point Reyes 91F, Half Moon Bay
91F, Watsonville 97F, and slightly further away from the coast,
Corralitos tops the list at 98F. These afternoon high temperatures
not only are on pace to shatter records but are also roughly 16 to
25 degrees above seasonal normals for this time of the year.
Internal confidence statistics place these temperatures along the
coast at roughly 5 standard deviations above the norm (3.5+ is generally
record territory).

A cooling trend is expected through the next several days as this
high pressure system slides southward along the Pacific coast,
eventually dropping off of Baja through this weekend. Tomorrow's
temperatures will be well above average once again (14 to 18
degrees above normal, generally), however, still a few to locally
several degrees cooler than today. Further cooling is expected
this weekend, with a return of near to only slightly above normal
temperatures on Sunday. The cooling trend continues into early
next week with nearly normal temperatures regionwide on Monday.

Now that today's offshore wind event is winding down, all
operational focus has shifted towards this weekend's offshore
wind event. Confidence is high that the strongest offshore wind
event yet this season will take aim at a broad swath of Northern
California late Saturday into Sunday. Internal confidence
statistics indicate offshore winds on the order of 4.3-5.2
standard deviations above the norm (3.5+ usually is record
territory) will occur late Saturday into Sunday. This aligns with
forecast model data which shows the development of 60-70kt low to
mid level offshore flow during the same time frame. 70kt roughly
translates to 80mph, which is currently the top of end of forecast
gust range overnight Saturday into Sunday across the highest
peaks. In addition, these winds are anticipated to cover a broader
area across most of the San Francisco Bay area and Santa Cruz
mountains, with a higher likelihood of seeing these winds make it
to the lower elevations. Winds are forecast to taper down in
intensity with elevation, however, downsloping/mixing down of
winds could bring rather gusty conditions to areas downwind of the
hills/peaks particularly into Sunday. This downslope/mixdown phenomena
was particularly evident today, with gusty winds along the lower
slopes of the East Bay hills, downwind of the Marin headlands, and
particularly near Half Moon Bay, which was gusting to 50mph
around 7am this morning. As a result, may see some wind damage
impacts from this weekends offshore winds across a broader area,
such as downed trees, localized power outages, debris in
roadways, difficulty driving high profile vehicles, etc.

Despite near normal temperatures... the combination of critically
low humidity, dry fuels, and very strong offshore winds will
bring extreme fire weather across the region once again this
weekend. As soon as the heat advisory/current red flag warning
expire today, expect to see a high wind watch and fire weather
watch for this weekend's system to be issued. For what its worth,
do not see any significant precipitation on the horizon in the
mid to long range models.

&&

.AVIATION...as of 6:20 PM PDT Thursday...Local influxes of cooler
marine air at the immediate coast otherwise offshore winds easing
into Friday with onshore winds then returning by afternoon mainly
near the coastline and bays. With the ongoing wildfire in Sonoma
county, smoke will likely spread to the south reducing visibilities
to MVFR tomorrow morning for the terminals based on recent HRRR
model near surface smoke forecasts. Smoke will reduce slant range
visibilities to moderate to poor mainly on Friday.

Vicinity of KSFO...VFR. Light wind tonight, increasing to near 10
knots from the west Friday afternoon and evening. MVFR visibilities
and poor slant range visibilities in wildfire smoke on Friday.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...VFR. Light/variable winds becoming light
E-SE tonight with late night and morning drainage winds increasing
over the Salinas Valley.

&&

.FIRE WEATHER...as of 4:55 AM PDT Thursday...Red Flag Warnings
remain in effect through this afternoon.

A fire broke out shortly after 9 PM last evening in Sonoma County
and was named Kincade Fire in the northeast corner of Sonoma
County. Wind speeds were gusting 60-70 mph during this timeframe
with RH values in the lower teens. The combination of strong NE
winds, low RH, and dry fuels led to a very rapid rate of spread.
Latest intel as of 4 AM says the fire grew roughly 10,000 acres.
Since then the winds have diminished, but definitely don't want to
downplay it as gusts are still in the 40-50 mph. Latest short term hi-
res models drop the winds through day, but the very dry airmass
and above normal temperatures remain. Definitely not out of the
woods yet despite weakening winds.

Weaker winds over the next 24-48 hours, but not a lot of relief as
relative humidity values remain low and temperatures remain mild
to hot.

On to the next event slated for Saturday night through Sunday
evening...to alleviate any confusion will let first round of Red
Flags expire before issuing any new fire watches.

Now for the details...a very strong offshore flow gradient is
forecast to develop and peak early Sunday. The GFS and ECMWF put
this on par, strength wise, with the 2017 offshore flow event that
led to the devastating North Bay Fires. It will be interesting to
see what the 12Z WRF shows, but even the courser models of the
GFS/ECMWF show 50kt wind flags over the North Bay, 30-40kt over
the East Bay early Sunday. The weekend event has better upper
level support than today's event, hence the stronger winds. Now
for some finer details, specifically focused on the North Bay.
Taking a look at a cross section over the North Bay Mountains
shows some signs of a downsloping wind event on the lee side of
the mountains. Hi-res WRF shows a nice theta-ridge on the lee
slopes with a horizontal wind max of 56 kts mid slope. A forecast
point sounding also shows potential for mountain wave development
as a nice inversion is forecast just above some of the peaks with
strong winds above the inversion. This thermal profile combined
with flow perpendicular to the ridge could result in a mountain
wave surfacing down slope or a hydraulic jump. Keep in mind this
is just a model and one tool in the weather tool box, but the
Sunday setup could be the real deal.

&&

.MARINE...as of 4:53 PM PDT Thursday...Light offshore winds
continue throughout the day before switching to northwesterly
Friday morning. Winds will increase, particularly for the Northern
outer waters, Friday afternoon, strengthening  into Saturday
morning. The moderate northwest swell with light southerly swells
will persist through the forecast period, but the middle of next
week is expected a long period northwest swell is expected.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tngt...Heat Advisory...

&&

PUBLIC FORECAST: DRP
AVIATION: Canepa
MARINE: DK
FIRE WEATHER: MM

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