Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 191323
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
523 AM PST Thu Jan 19 2017
A series of Pacific storm systems will continue to move inland
across the state through Monday, bringing periods of rain and
mountain snow along with gusty winds to the region.
Upper trough is currently draped over the west coast with areas of
showers across the district. The bulk of the activity overnight
has been in Kern County and up along the southern Sierra Nevada.
Precip rates have been from one to two tenths of an inch per hour
but activity has been progressive which has limited accumulations.
The trough axis will shift through this morning with showers off
and on through the day, especially over the mountains. Snow levels
are running from around 4500 feet in the Sierra to near 5000 feet
in the Tehachapi mountains, and a Winter Storm Warning remains in
effect for these areas through 2 PM this afternoon. Also, increased
instability will provide a slight chance for thunderstorms today.
There has been some lightning offshore overnight and an isolated
thunderstorm has developed over the Sacramento Valley in the last
There will only be a brief lull in activity tonight as the next
upstream trough will quickly dive down from the northeast Pacific.
Widespread precip is expected on Friday with showery conditions
continuing through Friday night, especially over the mountains
again. Rain amounts in the San Joaquin Valley look to be similar
to this past storm, with one to three quarters of an inch. Snow
levels will be around 4-5K feet during the bulk of the precip on
Friday with one to two feet of snow possible over the high Sierra.
Snow levels then lower to near 3000 feet late Friday night, down
to the pass levels in Kern County. Thunderstorms will possible
again on Friday in the post frontal environment. Southerly winds
may also become quite gusty again Friday morning as a deep surface
low is progged to develop off the Pac NW coast.
Another brief lull is likely on Saturday then the third system is
expected to move in by early Sunday morning. This system looks to
be the most significant as it will be broader and slower to move
through as additional energy drops down the backside of the trough
on Monday. Early QPF suggest up to an inch of rain in the SJV with
correspondingly higher rain/snow amounts in the mountains/foothills.
Similar snow levels are forecast with this one with the bulk of
QPF during 4-5K snow levels on Saturday, then lowering to around
3000 feet on Monday in a more showery regime. Should also see more
gusty southerly winds on Sunday.
A slight chance of light showers remains on Tuesday as the trough
slowly exits to the east. Upper ridging is then progged to build
in from the Pacific Wednesday with dry conditions through the end
of next week.
Expect areas of MVFR ceilings and visibilities in scattered showers
for the next 24 hrs. A few thunderstorms may develop between 18z
Thursday and 03z Friday. Local IFR conditions in heavier showers or
thunderstorms as well as local mountain obscurations in clouds and
precipitation. VFR conditions will otherwise prevail over the
Central CA Interior for the next 24 hours.
.AIR QUALITY ISSUES...
The level of certainty for days 1 and 2 is medium.
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 until 2 PM PST this afternoon above 4500 feet
for the CAZ096-097.
Winter Storm Warning until 2 PM PST this afternoon above 5000 feet
for the CAZ095.