Today’s Forecast Discussion, 12/7/16

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.
UPDATED INFORMATION
· 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.
IMPACTS

*Impact (Rain):
· 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.
*Current Watches/Warnings/Advisories:
· Currently none in effect.
· For all current watch/warning/advisories, http://1.usa.gov/1boSTTW
FORECAST CONFIDENCE
· Moderate for rainfall amounts across the region.
LOCATIONS
· 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.
Weather Summary
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.