Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 172223
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
223 PM PST Tue Jan 17 2017
.SYNOPSIS...Dry weather will continue through tonight. A few Pacific
storm systems will track eastward across the state from late
Wednesday through Monday and bring rain and mountain snow to the
.DISCUSSION...Our well advertised return to a very wet pattern is on
cue this afternoon as storm systems line up over the Pacific. There
are at least 3 of them out there on current satellite imagery. The
first storm is already bringing precipitation into the Pacific
Northwest. As this storm approaches, there will be an increase in
high cloudiness across the central California interior tonight.
Until those thicker, opaque clouds arrive, patchy fog could reform
in the San Joaquin Valley during the first part of tonight and
linger into the predawn hours Wednesday. Although the models are
slowing down the arrival of precip from this first storm, our break
from wet weather will come to an end by Wednesday evening as this
system moves onshore. By the time this storm exits into the Great
Basin Thursday afternoon, the heaviest precipitation will be over.
Showers will linger over mainly the higher terrain Thursday evening
and night. Storm #2 will be right on its heels and will likely bring
another round of rain and mountain snow to the district Friday into
Friday night. This second storm will be a little colder in its
wake, so precipitation could end as snow down to 3000 feet by Friday
evening. This could make for some potentially hazardous winter
travel over the Grapevine and through Tehachapi Pass.
Much of the district will get a respite, albeit brief, from wet
weather during the first half of the weekend, thanks to weak ridging
aloft. Storm #3 looks to be the wettest storm in the series and
will bring significant rain and mountain snow back into the
central California interior from Sunday afternoon through at least
midday Monday. Precip with this storm will diminish to showers by
late Monday afternoon or evening as this system departs into the
Great Basin. During this time, the arrival of colder air in its
wake will bring a renewed threat of snow into the foothills as low
as 2500 feet and over the Kern County mountain passes.
Additionally, the amount of water that each of these storm
systems bring into the central California interior, while
beneficial, could also cause flooding of some streets, highways
and urban areas along with water rises along area streams. In the
southern Sierra, the combined effects of these 3 storms will
result in a substantial increase of the snowpack with several new
feet of snow by Monday evening.
The ensembles forecast a high amplitude ridge to build along the
West coast by day 7 with a return of dry weather for the Golden
State. Other than low clouds and night and morning fog in the San
Joaquin Valley, much of the CWA will benefit from clear skies
next Tuesday and probably for much of next week as the upper level
ridge remains in control.
In the San Joaquin Valley, areas of MVFR in mist and haze with local
IFR between 06Z Wednesday and 20Z Wednesday. In the southern Sierra
Nevada, increasing areas of mountain obscuring IFR in low clouds and
precipitation after 12Z Wednesday becoming widespread IFR by 20Z
Wednesday. VFR conditions will otherwise prevail over the central CA
.AIR QUALITY ISSUES...
On Wednesday January 18 2017... Firepalce/Wood Stove Burning
Status is: No Burning Unless Registered in Fresno... Kern...
Kings... Madera... Merced and Tulare Counties.
Further information is available at Valleyair.org
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
Winter Storm Warning from 2 PM Wednesday to 2 PM PST Thursday
ABOVE 5000 FEET FOR THE CAZ096-097.