Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 242116
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
216 PM PDT Fri Mar 24 2017
.SYNOPSIS...A Pacific weather system will move through the region
tonight and Saturday bringing rain and mountain snow. A second
much weaker disturbance will clip the region on Sunday before
high pressure builds in for next week.
.DISCUSSION...Radar shows first area of light precipitation
affecting Fresno, Madera, and Mariposa counties. Snow is
accumulating at Sentiel Dome at around 8300 feet and this is
backed up by the ESRL FMSW S-band Snow Level Radar at New
Exchequer Dam. Meanwhile upstream a band of heavy rain is moving
out of the Bay Area and it should move into Merced County during
the next hour or so. Satellite imagery shows the main frontal band
extending from the Bay area southwest to around 30N/130W with a
baroclinic leaf forming along the frontal band.
The latest High Resolution Rapid Refresh model pushes the above
mentioned heavier Bay Area rain band into Fresno by around 5 pm
into Bako by 10 pm and California City after midnight. Meanwhile
steady rain and snow is projected to continue in the Sierra
through the evening and overnight. Models are in good agreement in
quickly pushing the upper level trough through the area band by
Saturday afternoon the trough axis will be nearing the Colorado
River. This will end most precipitation threat by mid day, with
lingering showers in the Sierra and upslope areas of Kern County
where near the Grapevine, some light precipitation is progged to
continue well into Saturday evening.
The next weather system will quickly move in from the Pacific on
Sunday however models are farther north and much weaker with the
feature. The latest 12z models bring two impulses across Central
California, one Sunday afternoon and a second on Sunday Night. It
appears that any precipitation will be light withe the Sierra
having the greatest accumulation. Ridging then is progged to build
Tuesday through Thursday with a warming and dry period.
Rain will impact the terminals this evening until 18z Saturday, with
possible MVFR visibility and ceilings. Expect IFR over the Sierra
Nevada due to mountain obscurations tonight into Saturday afternoon.
In addition, moderate southeasterly winds will continue into the
.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.
Winter Weather Advisory until 11 AM PDT Saturday ABOVE 7000 FEET
FOR THE CAZ096.