Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 281136 AAA
Area Forecast Discussion...UPDATED
National Weather Service San Joaquin Valley - Hanford CA
436 AM PDT FRI OCT 28 2016
...UPDATED TO ADD MENTION OF THUNDERSTORMS OVER THE KERN COUNTY
DESERTS FOR THIS MORNING...
.SYNOPSIS...A strong Pacific weather system will move through the
region today bringing widespread rain and high elevation snow.
This system will move east of the area on Saturday before another
storm system arrives on Sunday.
.DISCUSSION...Thunderstorms have been observed in the Kern County
Deserts so have added mention for this morning.
.PREV DISCUSSION... /issued 350 AM PDT FRI OCT 28 2016/
DISCUSSION...A low pressure center currently situated near
34N/125W from IR imagery is spreading a moisture surge with high
PW into central CA this morning resulting in widespread
precipitation across our area. Short range models are indicating
increasing divergence aloft, increasing PVA and increasing
boundary layer moisture convergence through this morning which
will result in increased rainfall rates across our area. Mesowest
indicating several locations in the Southern Sierra Nevada north
of Kings Canyon have already picked up between half and inch and
an inch of rainfall while a few locations in the west side of the
San Joaquin Valley have picked up close to a half inch of rain.
Radar composites are indicating widespread rain spreading inland
across central CA with embedded t-storms noticed over the Southern
Sierra Nevada and adjacent foothills. One quarter to one half
inch hourly rainfall rates have been indicated by radar with a
line pushing through the western San Joaquin Valley as the area is
in the LFQ of an 80kt 250mb jet max. Although the precipitation
bands are moving through rapidly, localized flooding will be
possible in orographically favored areas. Mesowest indicating snow
levels have been above 10000 feet as a warm airmass prevails over
the area and most of the moisture impacting our area being of
The short range models are indicating the rain bands will
continue pushing eastward this morning with the main cold front
pushing through our area later this morning. Post frontal
showers will be possible throughout our area this afternoon and
evening with thunderstorms possible in much of our area through
this afternoon. The low is progged to move into the Great Basin
tonight with another low approaching the Norcal coast on Saturday.
Some spotty showers will be possible mainly north of Fresno County
on Saturday. Another period of widespread precipitation is
anticipated from late Saturday Night through Sunday evening as
this colder system pushes across norcal. Our area will be in the
LFQ of a 120kt 250mb jet max on Sunday with strong UVM taking
place across our area. Later shifts may need to consider adding
mention of thunderstorms on Sunday. With this system being colder,
snow levels will be lower on Sunday with snow levels lowering to
around 7500 feet in Yosemite Park by Sunday afternoon which will
result in adverse impact to travel over the Tioga Pass.
Medium range models indicating shortwave ridging on Monday before
another low pressure system pushes across Norcal on Tuesday.
Bother the GFS and ECWMF have been trending further north with
this system so have cut back on precipitation chances and cloud
cover for Tuesday. The models are showing better consistency with
a ridge building over the southwestern Conus during the middle of
next week which would result in a period of drier conditions for
our area from Wednesday onward. temperatures will lower to
slightly below seasonal normals for the beginning of November on
Tuesday, but rise to slightly above normal by the end of next week
as heights and diurnal thicknesses rise.
SCT rain showers through 12z Saturday and isolated thunderstorms
through 00z Saturday. BKN/OVC 060-090 ceilings through 15Z today
becoming SCT. IFR in precipitation with mountain obscurations along
the Sierra in precipitation.
.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.