Scientific Forecaster Discussion
fxus66 khnx 292305
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
405 PM PDT Mon may 29 2017
high pressure will give way to a series of weak low pressure
systems moving through the region during the next couple of days.
This will bring cooler temperatures through midweek, with
increased chances for mountain thunderstorms on Wednesday. A
gradual warming trend will then return into next weekend as high
pressure rebuilds over the area.
temperatures across central California are warming above climo again
this afternoon, ahead of an upper level low pressure system currently
tracking into the northern part of the state. Isolated showers end
and thunderstorms have developed over the Sierra, mainly to our
north, but a few showers are starting to pop near Yosemite. Short
range, high res convective models suggest just isolated additional
activity along the crest for the remainder of this afternoon.
Models are in good agreement on the evolving synoptic pattern
during the next few days. The low pressure trough is progged to
push inland across the state tonight and Tuesday, with a
reinforcing shot of energy dropping in on Wednesday. This will
begin a cooling trend through midweek, though temperatures
Tuesday are expected to be only a degree or so lower than today
except up toward Merced County where some cooler marine air may
spill in. By Wednesday, afternoon highs will be a few degrees
below climo as the developing trough moves through. High res
models bring more significant cloud cover over our area with
better chances for mountain showers on Wednesday, but limited
instability suggests thunderstorms are not likely.
Model agreement continues through the end of the week as heights
and thicknesses increase behind the exiting trough. This will
bring dry conditions with warming temperatures, back to around 4-8
degrees above normal by Saturday. By the start of next week,
model solutions begin to diverge a bit, but generally indicate a
troughy pattern over the western US. This would halt the warming
trend for our area and could allow for some isolated convection
over the Sierra Sunday and Monday afternoons.
areas of MVFR and local IFR possible over the southern Sierra Nevada
due to mountain obscurations from showers and isolated thunderstorms
thru 04z Tue and after 20z Tue. Otherwise, VFR conditions are
expected across the central California interior during the next 24 hours.
Air quality issues...
on Tuesday may 30 2017... unhealthy for sensitive groups in Kern
County and Sequoia National Park and Forest.
Further information is available at valleyair.Org
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.