Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 232208
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
308 PM PDT MON MAY 23 2016
Cooler than normal temperatures will continue for the next few days
over the central California interior as an upper level trough
resides along the west coast. Scattered showers and a slight chance
of thunderstorms will be possible over much of Central California
Monday and Tuesday afternoon and evening. A gradual warming trend
is forecasted during the latter part of week as weak high pressure
moves in over the region.
.DISCUSSION...An upper level trough, currently extending from the
Pacific Northwest coastline south along the Central California
coastline, continues to dig slowly south. Over the past hour,
showers developed along the Sierra Nevada generally from Fresno
County northward. Additionally, radar detected a few scattered
showers along the northern portion of the San Joaquin Valley. The
HRRR as well as the high res ARW and NMM indicate that these
showers will continue through at least the early evening hours and
remain scattered in nature. Little rain and high level snow
accumulation is expected.
An upper low will form later tonight and be situated generally
from just off the San Francisco Bay east into west central Nevada.
As this upper low shifts slowly south and east, enough instability
will be generated, resulting in scattered showers and possible
thunderstorms. As of now, the high res models indicate
showers/thunderstorms developing on the west side of the San
Joaquin Valley late tomorrow morning into the afternoon. These
showers/thunderstorms are forecast to drift east through the
valley through the evening hours. The short term and medium range
models are all in good agreement with regards to the position and
movement of the upper low. In fact, the high res models paint the
entire valley with 100-200 j/kg of surface CAPE, definitely
sufficient enough for thunderstorm development for the region.
Lastly, snow levels are forecast to hover between just under 8,000
feet to around 9,000 feet, with 2 to 6 inches of snow above 8,000
feet from this afternoon through early Wednesday morning. A
dusting of snow will be possible just below 8,000 feet.
The upper low will continue to move south into southern
California on Wednesday, moving east into Arizona on Thursday with
any chance of precipitation over the valley shifting east by
Wednesday evening. A warming trend will take place over the area
Thursday into Friday as upper level high pressure nudges east from
the eastern Pacific. Chances for afternoon and evening showers and
thunderstorms remain over the Sierra Nevada through the weekend.
Please continue to monitor the forecast for the latest
Mainly VFR conditions will prevail for the next 24 hours. There is
at least a slight chance of thunderstorms for much of Central
California this afternoon and evening as well as Tuesday afternoon.
Forecast confidence low for thunderstorms impacting terminals.
.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.