Jump to content
Search In
  • More options...
Find results that contain...
Find results in...
US Wild Weather

Extreme active pattern across the entire US continues, what does it mean for your region? Join the conversion


Feb. 4-5 West Coast 'Snow' Storm/ low snow to 1,000ft or less!

Staff Recommended Posts

The past 3-4 days have brought wild weather to the Bay Area and the rest of California...feet of new snow in the Sierras and thunder, lightning and hailstorms...several days saw high winds and torrential downpours...especially in mountains and the valleys near the coast...now possible snow!?


this satellite view shows the low just off the OR/CAL border swirling towards the Bay Area...temperatures are dropping...SeaPac airport in Seattle reported 1.7" of snow today according to NWS Seattle tweet...many mountaintops in the Bay Area could see 1 to 2 inches overnight...


FXUS66 KMTR 050114

Area Forecast Discussion
National Weather Service San Francisco Bay Area
514 PM PST Mon Feb 4 2019

.SYNOPSIS...Rain showers, and higher elevation snow showers, will
continue to impact the region today with the potential for
isolated thunderstorms this afternoon. A very cold air mass will
lower snow levels to around 1,500 feet or potentially lower
tonight into Tuesday morning with snow accumulations over the
peaks and passes. Dry weather and cold overnight temperatures are
likely midweek with unsettled weather returning late in the week.


.DISCUSSION...as of 02:00 PM PST Monday...Current situation -
Widespread showers, high elevation snow showers, continue to
sweep across the Bay Area this afternoon. Precip amounts over the
last six hours have generally been a few tenths up to about an
inch. Profilers, webcams and observations indicate snow levels
continue to drop since this morning. Snow levels are currently
sitting about 2500 feet. Webcams even show some minor
accumulations over the highest peaks in the N and E Bay. It should
be noted that Crescent City did report snow earlier today. The
airmass remains unstable and the threat for thunderstorms
continues, but have not observed any strikes in the Bay Area.
There is lightning in the Central Valley however. Spotters have
reported small hail earlier today with the stronger cells.

For the rest of today into Tuesday:
Showers, possible thunderstorms and high elevation snow will
continue through early this evening. The biggest impacts will be
locally heavy rain adding to a wet/saturated soil and full to
nearly full creek/stream. Therefore, rock/mud slides will be
possible along with localized flooding. In particular will be
monitoring the Big Sur River and Carmel River closely for any
additional rise.

By this evening all focus turns to a cold upper low dropping
southward along the NorCal coast and ultimately over the Bay Area
early Tuesday. Snow levels will drop another 1000 feet by early
tonight and less than 1000 feet by Tuesday morning for some
locations. Models are in decent agreement with bringing
impressive 1000-500mb thicknesses to the Bay Area Tuesday morning.
12Z Tuesday - North Bay is near 520 DAM, SF Bay is 524 DAM, Big
Sur 530 DAM thickness. 850 MB temps are projected to be -6C to -3C.
Those thickness values and 850 MB temps will translate to some
rather low snow levels. In fact, probably the lowest snow levels
since 2011. Here is a breakdown of the lowest snow levels - North
Bay 400-1000 feet. SF to East Bay and Santa Cruz Mountains
1000-1500 feet. Big Sur Mts to Southern Gabilan Range 1500-2000
feet. The big question is, will there be any flakes down to sea
level? And the answer is - one of the best set ups we can hope
for. Model soundings, thickness charts and mos guidance does bring
snow or snow/rain mix to sea level (North Bay Valleys most likely
shot). As always, timing the coldest air and precip is tricky.
The NAM for instance tapers precip off rather quickly on Tuesday
from N to S as the cold core moves in from the north.

All of that being said NWS Monterey has issued a Winter Weather
Advisory for locations above a 1000 feet except Big Sur Mts/S
Gabilan is above 1500 feet. The Winter Weather Advisory will be
valid from 4 PM Monday through Tuesday morning for most areas and
southern area through Tuesday afternoon. Accumulations will
generally be 2-4 inches locally 4-8 inches Monterey Bay northward
above 1000 feet. Santa Lucias will likely see the highest with 4-8
inches and locally 10-15 inches above 4000 feet. Needless to say
the morning commute will be potentially hazardous with snow
impacting higher elevation roads and passes. One final note -
given the recent rains and wet ground as cold air fills in from
the north black ice could also impact the morning commute.

Precip is still on track to taper off from N to S on Tuesday
afternoon. Lingering showers/snow showers will be possible over
southern areas.

It goes without saying, but colder overnight temperatures will
impact the region beginning tonight into Tuesday morning and again
Wednesday morning. Models are still on track indicating some of
the coldest temperatures so far this winter will be possible with
inland valley locations dropping into the upper 20s with upper
30s near the coast. These temperatures will be of great concern to
those without access to heat or shelter. In addition, sensitive
vegetation and outdoor animals will be as risk during this period
of cold temperatures.

A brief break in the weather Wednesday into Thursday, but
temperatures will remain seasonably cool/cold. The medium range
models are showing a return of rain late in the week and next
weekend.  Stay tuned.

...the OPC map shows the next two 'fronts' coming straight down from the NW, where snow has already fallen at very low altitudes and some record cold has arrived...Mt. Hamilton (4,265ft) east of San Jose, and Loma Prieta (3,790ft.) in the Santa Cruz Mountains should see snow...










...a local 'forecaster' says that some inland valleys may get mixed precipitation, light flurries, or  even snow to nearly sea-level, possible 'thunder-snow' can come from thunderstorms 'embedded' in the 'cold portion of this system...clearing possible late Tuesday into Wednesday...

...the 'horizon' and GOA look to send more storms by this weekend...

Edited by idecline

Share this post

Link to post
Share on other sites

It briefly rained heavily down my way about two hours ago when it was only 43 degrees.

Share this post

Link to post
Share on other sites

...very cold overnight...it was raining in San Jose at 38 F late that night ...significant snows were seen all over the Bay Area!



After making a spectacular return to the Bay Area on Monday, snow continued to fall on peaks across the region during the early hours of Tuesday, leaving the terrain coated in a blanket of shimmering white.

Locations that received a dusting of snow or more since Monday included the Bay Area's highest peaks — Mount Diablo, Mount Tamalpais, Mount Hamilton and others — along with spots in the Santa Cruz Mountains and the rolling hills above Livermore, Fremont, Palo Alto, Morgan Hill and Calistoga, among many other cities.

Among the locations where snowfall amounts were reported, Mt. Hamilton led the way, receiving 8 inches, according to the National Weather Service. On the other side of the Santa Clara Valley, Mt. Umunhum picked up 3 inches of snow.

Spots in the Santa Cruz Mountains collected 2 inches, with the summit along Highway 17 recording 1 inch, the weather service reported. Even Twin Peaks in San Francisco welcomed a light winter dusting, picking up a trace of snow.


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.