From NOAA Forecast Discussion - button up!
(new editing format by WP is resulting in formatting issues.
I hate when wp decides to change what works for something that doesn’t)
”Unlike previous storm system this one will have plenty of moisture to work with.
Latest TPW imagery puts values of 1-1.5" or 150-200% percent of normal.
Simply put there is moisture to work with.
Atmospheric River guidance has been rather consistent
for several days now indicating IVT over 500 kg/m/s,
which would fall into the moderate category
and be one of the stronger ARs of the 2018 season.
Once the upper level TROUGH arrives Sunday afternoon it will
help to push the FRONT through the region.
Additionally, the upper level TROUGH will increase upper level support and increase overall INSTABILITY.
Model guidance shows rather decent surface and mid- level INSTABILITY Sunday afternoon through early Monday.
Decided to add a 15-20% CHC of thunderstorms with the FROPA.
It should be noted that the Storm Prediction Center
has a large portion of CA in a general mention
of thunder Sunday into Monday.
Given the landfalling AR and convective potential
there could be a brief period of moderate to heavy rainfall
leading to minor flooding/ponding on roads and urban areas.
A more showery regime will set up late Sunday night over northern areas behind the FRONT and then slowly spread S and E Monday afternoon.
Rainfall totals tonight through Monday will be greatest over the North Bay and coastal mountains 1-3" - locally 3+" North Bay Peaks and Santa Lucias.”
Repeat: Locally, over 3” in the Santa Lucias.
From Weather West, aka, Daniel Swain: “The good news: significant, perhaps even fire “season ending” rains possible across much of Northern California by late next week. The bad news: some models suggesting heavy rainfall capable of causing significant post-fire flood/debris flow concerns near #CampFire.” Looks like Big Sur is in the 2 to 3” area. So, is this significant enough to close the gates on Mud Creek and Paul’s Slide? I guess we will see 48 hours out.
From John Lindsey, SLO meterologist:
“A low pressure system will approach the coast and will deliver strong to gale-force (25 to 38 mph) southerly winds and rain Monday night into Tuesday. Showers will persist into Wednesday. Snow levels will gradually lower to 6,000 feet by Tuesday.
A wet and mild atmospheric river type weather system will move across the Central Coast Friday through Saturday for heavy rain and gusty southerly winds.”
From the ever anonymous Paul H.:
Hello All, just real quick follow up that rains begin Monday afternoon and continue through extended. Next weekend (march 25-26) there is a possibility of a moderate to strong atmospheric river. This progressive pattern developing should bring substantial rain accumulations that look highly possible by middle of week after next, thus slide/bridge/road repairs are going to have delayed time line set backs!! If wondering the teleconnections supporting this wet pattern are negative arctic oscillation, negative north atlantic oscillation, positive enso ( el nino southern oscillation), MJO phase 5 propagating east to phase 6 (this supports southern extension of Pacific jetstream off Eurasia), and positive Pacific North America Pattern. Bottomline our mother earth is alligning for moist air masses to bombard the lower latitudinal southern extent of the Northern Hemispheric jet stream.
Cheers, paul h
Time to make sure all your restocking is done. I will be doing the same.
This does not look good… do not expect any problem areas: slides, slip outs, flooding, to get fixed this week. And for whatever consolation it can provide, we are not alone. Much of Central and Northern California is getting hammered with flooding, road closures, school closures, and other forms of weather-related problems.
7:30 am – it was quiet last night, then Just before 3 am, the cats & dogs started pounding on the roof. The South Coast 24 hour rain amounts are 2.84″ at Chalk Peak, 3.15″ at Three Peaks, and 2.74″ at Mining Ridge. That’s a lot of rain for 24 hours on saturated ground. We will be seeing movement from this. The CHP website log hasn’t been updated since yesterday at 9:46 am, so will have to wait to see what CHP, CT, or locals have to say, but it can’t be good out there with this much rain.
From Meterologist John Lindsey: “Another but stronger low-pressure system will bring
increasing clouds and rain showers Sunday evening and night. As the associated a cold front approaches the Central Coast, the southerly winds will increase to moderate gale-force to fresh gale-force (32 to 46 mph) levels on Monday. This system is forecast to tap into a large plume of subtropical moisture. Consequently, 2 and 3 inches of rain may fall on Monday with higher amounts in the coastal mountains.” BTW, Rocky Butte got over 4″ in the last 24 hours. (Up in the mountains behind and north of Hearst Castle)
9:46 am – closure back in place at Ragged Point on the south end.
9:46 AM 8  27-N24 OPEN F/RAGGED PT TO LIMEKILN / CLOSURE BACK IN PLACE @ RAGGED PT [Shared]
8:30 am – Consistent with what Cal Trans put out last night – From the CHP log:
6:10 AM 5  OVERNIGHT CLOSURES **SR1 WILL REMAIN CLOSED OVERNIGHT FRM RAGGED POINT (SLO MM 72.87) TO DLOAN POINT (MONT MM 29.70) AND ALSO WILL REMAIN CLOSED IF IT IS RAINING DUE TO THE INSTABILITY OF THE ROCK/MUD SLIDES.
Rain down here 1.38″ at Anderson Peak and 1.5″ at Three Peaks. NOAA says: “Wet start to the year looks to stay in place at least through mid-month.” Rain on and off throughout the day, with another system coming in tonight through Friday, then a bit of a break on Saturday, and another system Sun-Mon.
(this post will be updated throughout the day as needed, but new post with CT update, when received.)
Current, 1/31/17, predicts for late Wednesday (tomorrow) through Friday indicate:
“By that point rainfall amounts will likely range from 2.5″ to 5″ for higher elevation spots with many urban locations in the .75″ to 1.50″ range. Thankfully local rivers and streams have greatly receded due to several dry days (and recent warmer weather), which will provide a buffer against the first round of rain.”
Then Sunday night through Monday is slated to bring:
“This will lead to a higher risk for flooding. Early numbers indicate that urban locations can expect another 1/2″ to 1.25″ with higher elevation spots generally in the 1.5″-3″ range.
Rain will change back to showers later on Monday with a third system indicated on the GFS for Tuesday (ECMWF shows dry weather).”
So far for January
And for what is coming:
And NOAA forecast discussion from this am:
Longer range models are still bringing rain chances back to Northern California by the middle of next week. The GFS starts to increase southerly winds ahead of the system by early Wednesday morning with rain beginning in the North Bay by mid morning and
spreading south into the rest of the district by the afternoon. The GFS brings a secondary punch of moisture through Wednesday night, with showers ending by late Thursday. The 00z ECMWF delays the onset of precipitation by about 12 hours, but also ends the
precip by late Friday. While excessive rainfall is not expected with this system, given that soils are still saturated from copious recent rainfall, there is the possibility of at least
minor hydro issues and slides. In addition, winds with this system may be quite strong and gusty, particularly from late Wednesday into Thursday.
And here is the satellite photo sent in by Dave Allen:
3:30 pm – 12/7/2016 Weather update
“Attached are anticipated rain totals for the upcoming rain event. There is a tropical moisture connection in this system so rain rates could be greater but for short periods of time. NWS emphasizing estimated rainfall totals are over a number of days.
Forecasters are not expecting any watches or warning at this time, but always be mindful that could happen as the storm hits landfall and develops. Plan ahead appropriately.
As always if you see anything significant happening you think we should be mindful of, please call the OES Duty Officer (DO) Line at 831-796-1920. That line is monitored 24/7. ”
(This summarizes the two attachments referenced above):
“Unsettled weather conditions likely from this evening through Saturday morning. Greatest rainfall amounts will be across the North Bay and along the Coastal Ranges of the San Francisco Bay Area and Central Coast.
· Updates are highlighted in yellow. Forecast confidence has increased with respect to the greatest storm total rainfall amounts being mostly confined to the coastal ranges.
· A wet pattern will return to our region late this afternoon and evening with rain possible off-and-on through Friday.
· Rainfall amounts are forecast to be greatest along the coastal ranges where storm total amounts in excess of 5″ will be possible.
o Please see attach graphic for potential rainfall amounts. However, please do not focus on exact values.
· Wet roadways likely to result in hazardous driving conditions, especially during morning/afternoon commuting hours Thursday and Friday.
· Reduced visibilities and ponding on roadways during periods of moderate to heavy rainfall.
· Clogged storm drains and rain gutters will likely result in localized urban flooding.
· Currently none in effect.
· For all current watch/warning/advisories, http://1.usa.gov/1boSTTW
· Moderate for rainfall amounts across the region.
· This is for the entire San Francisco and Monterey Bay Region. The highest rainfall totals are expected over the coastal ranges from Sonoma County southward through Monterey County where 3″ to 5″ will be possible through late week.
· Rainfall amounts and intensity will be much less across inland valley locations.
A change in the weather pattern will result in increased chances for precipitation across the region from tonight through early Saturday as deeper moisture advects into the California coast. Rainfall will increase in intensity and coverage tonight and continue off and on through Saturday morning with the heaviest likely to occur tonight into Thursday morning and again Thursday night into Friday. With this system, the greatest rainfall totals will likely remain confined to the coastal ranges while inland valley locations will receive lesser amounts.”
“DISCUSSION…as of 09:10 AM PST Wednesday…Cool temperatures reported across the region this morning with many near or below freezing for a few hours before sunrise. This was even with the increased mid/high level cloud cover pushing across the region. These clouds will limit overall warming today as deeper moisture begins to advect into the region from the Pacific. At this time, only a few locations across the North Bay are reporting light rainfall as the lower levels remain dry over the remainder of the region. As the day progresses, the atmospheric profile will moisten and will likely result in an increase in light rain across much of the region by late this evening. As typical with these types of systems, the coastal ranges will see rainfall begin first and will also accumulate the most while inland valley locations will receive much less. Have made a few updates to the forecast to reflect the most short-range model data in regards to timing and amount of precipitation through this evening….
Rainfall totals by Saturday evening will range from more than 4″ for some coastal hills, to generally 1 to 2.5″ for the bulk of our urban locations. Lesser amours can be expected for southern sections especially inland spots.”
Up here it was 35 degrees at dawn. Still quite chilly. Tree came down yesterday. It split close to the ground and blocked Plaskett. I was able to head off into the brush and get around it, but went down today with a friend to chain saw it open. Some nice oak for firewood, eventually.
A surprise rain this am – up to .16″ by 7 am. Was not expecting this. No reports of traffic problems on Highway One in Big Sur.