North Ops Weather-2020

[TrentTag]

NWS Eureka
Added much of Mendocino and Lake Counties

"…FIRE WEATHER WATCH IN EFFECT FOR GUSTY EAST AND NORTHEAST WINDS
AND LOW RH FROM LATE WEDNESDAY NIGHT THROUGH FRIDAY MORNING FOR
UPPER SLOPES AND RIDGES AT ELEVATIONS ABOVE 2000 FEET…

The National Weather Service in Eureka has issued a Fire Weather
Watch, which is in effect from late Wednesday night through
Friday morning.

• AFFECTED AREA…Fire weather zones 211…212…264…276…277
  and 283.

• WIND…East and Northeast wind 15 to 25 mph with locally higher
  gusts to 35 mph. Strongest winds will occur around sunrise
  Thursday and Friday.

• HUMIDITY…Daytime 10-20%. Very poor recoveries each night and
  morning 20-30%. Better recoveries in drainages and valley
  floors.

• IMPACTS…Any ongoing or new fires will likely spread rapidly.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A Fire Weather Watch means that critical fire weather conditions
are forecast to occur. Listen for later forecasts and possible
Red Flag Warnings."

[Oldcdfguy]

A warming and drying trend is expected this week as high pressure builds in across the state. Temperatures will reach the mid to upper 80s away from the coast today with light offshore winds generally below 20 mph. Temperatures will continue to rise through the middle of the week with daytime highs in the upper 80s and 90s for most areas by Thursday. On Wednesday, breezy northerly winds will develop through the Sacramento Valley during the day and will shift to the north/northeast Wednesday night and continue into Thursday or Friday across the northern interior. The strength of these winds remains somewhat uncertain, but gusts at or above 50 mph are looking possible in elevated terrain in the North Bay and Northern Sierra. Lighter winds return this weekend along with cooler conditions near the coast. Fire danger will rapidly increase mid to late this week as dead fuels quickly dry out under warmer and drier conditions and offshore winds.
pge is reporting to prepare for a potential Diablo wind event lasting from Wednesday through Thursday aside from the Northern Sierra that may experience Diablo winds through Friday morning. The current forecast shows PSPS Watch in Zones 2, 3, 4, 5, 6 and 8 for the upcoming event.
At this time, the highest probability areas for executing PSPS are the Northern Sierra Nevada foothills, the mid and higher elevations in the Sierra generally north of Yosemite (northern portion of Zone 8), the North Bay mountains near Mt. St. Helena, small pockets in the East Bay near Mt. Diablo, the Oakland Hills east of Piedmont (generally between highway 24 and Upper San Leandro Reservoir), the elevated terrain east of Milpitas around Calaveras Reservoir, as well as portions of the Santa Cruz and Big Sur mountains. This is not expected to be a widespread event in the Bay Area at this time. The weather event is expected to begin Wednesday evening and continue through Thursday morning. A second period of winds may develop Thursday evening through Friday morning in the Northern Sierra

[TrentTag]

Fire Weather Watches are being upgraded to Red Flag Warnings currently.

[Contype1]

https://www.fire.ca.gov/programs/communications/red-flag-warnings-fire-weather-watches/

[anvilhead]

Synopsis: the big trough over the upper midwest will erode the eastern side of a large subtropical ridge over CA. The latest run of the ICON & CMC bring a large swath of record snowfall to the upper midwest, as far south as Nebraska. The long wave trough over the midwest will continue, shifting slightly west which will promote offshore flow and dangerous fire weather conditions across Northern CA through much of the rest of the month.

This record breaking snowfall through the next week will promote constant surface high pressure across the upper midwest. Later this month the trough axis continues to erode the high over CA and provide upper level support and advect that cold air from the early season snowfall in that region, across the Great Basin.

For Friday a critical gradient will be present across Northern CA with SFO to WMC as high as -16.5 mb by 12z Thursday. Red Flag warnings are in place and terrain favored areas above 3,000’ could see wind gusts approach 55-60 MPH.

After this weekend please monitor fire wx conditions because no rain is anticipated and the trough over the midwest deepens further west allowing for possibly extended critical fire weather conditions, likely favoring the Sierra Nevada for the worst fire wx conditions later this month.

[Oldcdfguy]

Prepare for a Diablo wind event lasting from Wednesday through Friday morning. There is now high confidence in a Diablo wind event occurring and Federal forecast agencies are aligned this will be a high risk event. The National Weather Service has issued multiple Fire Weather Watches from Wednesday through Friday, which will likely be upgraded to Red Flag Warnings in the next 24 hours. The Federal Northern Operations Predictive Services is also forecasting high risk of significant fire potential for most of Northern CA Wednesday through Friday as well. The NOAA Storm Prediction Center (SPC) is also showing critical fire weather in Northern CA starting tomorrow.
The highest probability areas are the Northern Sierra Nevada foothills, the mid and higher elevations in the Sierra generally north of Yosemite , pockets of elevated terrain adjacent to the west side of the Sacramento Valley, the North Bay mountains near Mt. St. Helena and Morgan Valley, small pockets in the East Bay near Mt. Diablo, a pocket of the Oakland Hills east of Piedmont (generally between highway 24 and Upper San Leandro Reservoir), the elevated terrain east of Milpitas around Calaveras Reservoir, as well as portions of the Santa Cruz and Big Sur mountains. Portions of Humboldt County are also being considered generally between the communities of Bridgeville and Blocksburg. This is not expected to be a widespread event in the Bay Area at this time. The weather event is expected to consist of two periods of winds. The first period of wind starts Wednesday during the day and will strengthen after sunset and continue into Thursday morning. After a brief lull mid-day Thursday to afternoon, a second period of wind develops Thursday evening through Friday morning across Northern CA. Forecast models have trended a bit stronger for the second period of winds Thursday and Friday. Winds are expected to relax by mid-day Friday. The start of the event is more than a day away so event details may change as forecast models evolve.

[Oldcdfguy]

And May I add that the possibility of fire season running on and on is not a pleasant one. Living up in the trees in one of these fire/wind prone areas is just a different experience than it used to . Everything I read points to your conclusions. Can I be polite and still hope you/we are wrong. Living with one eye always on the horizon gets tiring

[Jimw360]

Many red flag warnings already posted
https://forecast.weather.gov/wwamap/wwatxtget.php?cwa=rev&wwa=red%20flag%20warning

[A904G]

The winds are up, but the humidity has yet to react.

[FireCapt]

Model output indicates the KWMC to KSFO pressure gradient could reach 16-17 mb during this time frame. In addition, an extremely dry air mass is projected to move in from the north and northeast beginning this afternoon. The net result will be critical fire weather conditions, beginning with the increased offshore flow this morning and then becoming significantly more extreme this evening into Thursday as relative humidities plummet and winds ramp up. Relative humidity values are projected to drop into the single digits and teens, with very poor overnight recoveries. A Red Flag Warning remains in effect for the North Bay mountains and valleys, the Diablo Range and East Bay hills and valleys, and the Santa Cruz Mountains from 5 AM PDT today to 11 AM PDT Friday. That said, some model output soundings over the North Bay indicate possible development tonight of a wind and thermal structure consistent with mountain wave amplification and resulting enhancement of downslope winds. Basic set-up does not appear as conducive to this as that associated with the October 2017 Wine Country Fires, but will nonetheless need to continue to monitor.

[norcalscan]

In the upper Sac Valley and the eastern edge of August NE Zone, saw some great recoveries last night but already by 7am some of the IRAWS are already showing 30% drops from evening peaks. IMET on August NE is expecting RH down to the teens on the incident, with northerly winds through the day and then around 1700 winds shifting out of the NE and growing more intense with gusts to 25 over night.

NorCal snooper - https://www.weather.gov/lox/fwmV3?wfo=sto&net=1,2

[anvilhead]

Impressive fire weather conditions with the peak still yet to come tomorrow into Friday.

[apocalyptic_nights]

Underwater volcano erupt??

[Twigpig]

East Bay is getting pretty good fire weather. North Bay so far is a non event.

[Oldcdfguy]

Last evening, we observed several weather stations report wind gusts in excess of 50 mph with peak gusts near 65 mph. Confidence remains high that this diablo event will continue with a second wave of gusty winds this evening into tomorrow morning, and Federal forecast agencies are aligned this second period of winds will be a high risk event. The National Weather Service has several Red Flag Warnings in effect through Friday due to a combination of gusty offshore winds and critically dry conditions. The Federal Northern Operations Predictive Services is also forecasting high risk of significant fire potential for most of Northern CA today through tomorrow as well. At this time, the highest probability areas for continuing is in portions of Humboldt (generally between the communities of Bridgeville and Blocksburg), and the Northern Sierra Nevada foothills, the mid and higher elevations in the Sierra generally north of Yosemite , The west side of the Sacramento Valley, the North Bay mountains near Mt. St. Helena and Morgan Valley, small pockets in the East Bay near Mt. Diablo, a pocket of the Oakland Hills east of Piedmont (generally between highway 24 and Upper San Leandro Reservoir), the elevated terrain east of Milpitas around Calaveras Reservoir, as well as portions of the Santa Cruz mountains. The weather event is expected to consist of two periods of winds, with the first period of winds having past overnight and expected to continue through this morning. After a brief lull mid-day today, a second period of winds develops this evening through tomorrow morning across Northern CA. Forecast models indicate this second period of winds should be generally weaker, especially for areas south of the I-80 corridor. Winds will begin to diminish tomorrow morning, and all areas will return to seasonable conditions with cooler temperatures through the weekend

[Oldcdfguy]

Wind is coming hard thru Jarbo Gap tonight. You can hear trees coming down around us in Paradise. Hundreds of thousands of burned trees out there in this mess. Wind is much harder tonight than last.

[A904G]

Wow, get your Speedo out and hit the beach in Half Moon Bay this morning!

Half Moon Bay Airport (KHAF) Severity:75

TIME	RH	WIND	TEMP	FUEL
05:15AM	14%	NE26G43mph	82
04:55AM	14%	NE21G41mph	82
03:55AM	14%	NE25G39mph	82
02:55AM	16%	NE16G28mph	82

[FireCapt]

NWS SF Friday: First and foremost the Red Flag Warnings have been extended through this evening. A very dry airmass, and well above normal temperature are present. Persistent offshore flow continues as high pressure remains anchored over the Great Basin with lower pressure along the coast. Latest offshore gradient from SFO-WMC is -15mb to -16mb, which is a moderate to lower end strong offshore event. Resulting offshore winds look to have peaked earlier in the night with gusts of 60 to 70 mph in the North Bay Mts. Since then wind speeds have dropped ever so slightly - 45-60 mph. Winds are breezy to gusty in the East Bay Hills and Santa Cruz, but not the magnitude of the North Bay. Winds are struggling to hit the valley floors, but definitely making their way into the foothills (500-1000 ft) with gusts 20-30 mph. The downsloping flow has led to some mild temperatures overnight temperatures and no humidity recovery. Winds will weaken even more by mid-late morning, but the very dry airmass will remain.

29 Red Flag weather stations now and 95 RF and flirting.

[Oldcdfguy]

Last Nights wind gusts in the Jarbo Gap/Concow were over 60 MPH with sustained winds over 30 . This kept up the rest the night . At sun up the gusts had dropped into the mid 40’s . The Red Flag Warning for high fire danger has now been extended through 6PM tonight for the valley, foothills, Northern Mountains, and a portion of the Sierra. Gusty north to northeast winds will continue to be the main driver in fire danger today, but the low humidity and well above average temperatures are also playing a big role. Sustained winds up to around 20mph are expected today, with gusts in the valley up to around 35mph. Gusts in the foothills and canyons are still over 50mph in some reporting sites this morning, and will be a big concern through at least early today. Humidity will dip to below 20 percent across most of our region, with some areas dropping into the single digits later today. High temperatures are projected to top out in the mid to high 90’s in the valley, in the 80’s to around 90’s degrees in the foothills, and in the 70’s to 80’s in most mountain areas this afternoon. The hot, dry, and windy conditions will result in high to critical fire danger today.Winds will finally diminish tonight as low pressure to our east moves further east, and high pressure in the Pacific builds into the West Coast.

[Drptrch]

Doug, Do you have the link for that one. Mine showed different listing

Thx