Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 212256
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
256 PM PST Tue Feb 21 2017
A significant storm impacting California will keep showers across
the area today, then tapering off by Wednesday. After a brief
drier and cooler period Thursday and Friday, another system will
return wet weather to the region during the weekend.
Unsettled weather continues across Central California with
convective storms being observed this afternoon. While the
strongest storms have been confined to areas north of Merced
County, the atmosphere is primed for storms to develop from near
Fresno County northward. Will maintain a wording of afternoon
thunderstorms through sunset this evening before the atmosphere
becomes stable. In the meanwhile, showers continue to develop
across Central California with hourly precipitation rates of less
then a tenth of an inch. These values are half to a third of the
values seen over the President`s Day weekend. Currently, winter
storm warnings and flood watches and statements are in effect for
today`s unsettled conditions. Both Oakland and Vandenberg upper
air observations are now showing under an inch of precip-water
(which are near 150 percent of normal for this date) but still
running high. Therefore, support exist for the continuation of
moderate precipitation across Central California through this
The main concern for this week is the current hydrologic
conditions of the region. The current storm continues to causes
problems for area rivers and other water control facilities that
are running at or near capacity. Therefore, confidence is high
that the even the latest precipitation accumulation will cause
problems. River statements and flood products will continue to
focus on the rivers and many creeks that are reaching levels that
may threaten life and property across Central California.
Models continue to show higher confidence levels that cyclonic
flow will remain over the West through most of the week.
Therefore, unsettled conditions will linger beyond the short term
as precipitation may exist over the West Coast (off and on)
through most of the next seven days. One thing to note is that
models currently show no major atmospheric river type event
occurring in the next seven days. Yet, models do show a good plume
of moisture that may allow for a good precipitation potential
between Saturday night into Sunday. Therefore, will the mention of
higher than climo probability of precipitation for next weekend
as ingredients starting to come into phase for yet another storm.
Beyond Monday, models show weak ridging and yet another upper low
off the British Columbia coast that may affect the district later
next week. While the focus will be through the beginning of next
week and the off and on precipitation, the winter weather
pattern is not over as more precipitation is received over the
region through the start of March.
.AVIATION...MVFR conditions can be expected along the west slopes
of the Sierra through 00z Thursday with local IFR and mountain
obscurations in heavier precipitation over the higher elevations
through 12z Wednesday. VFR conditions will prevail elsewhere
across the central California interior during the next 24 hours.
.AIR QUALITY ISSUES...
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.
Flood Watch until 10 PM PST this evening CAZ093-094-096-097.
Winter Storm Warning until 10 PM PST this evening ABOVE 7000
FEET FOR THE CAZ096-097.