FXUS66 KHNX 271012
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
312 AM PDT FRI MAY 27 2016
Dry weather will prevail over the district today except for isolated
afternoon and early evening thunderstorms along the Sierra Crest.
There is a better chance of afternoon and evening thunderstorms over
the mountains Saturday and Sunday as a weak upper level disturbance
tracks through the central California interior. A dry and more
stable air mass will settle into California Memorial Day and remain
over the region for much of next week as an area of High pressure
builds over the state. A day to day warming trend will occur through
Memorial day with temperatures remaining well above normal through
the end of next week.
.DISCUSSION...Since last Friday, residents of the central
California interior have been comforted by cooler than normal
temperatures. As of today, that spell has ended. The temperature
pendulum will swing in the other direction during the next several
days as a strong high pressure ridge over the eastern pacific
gradually builds into the Golden State. Until this ridge becomes
firmly anchored over California early next week, a northwesterly
flow aloft will reside over the state. The air mass over the
central California interior has been dry and fairly stable lately
and will remain so today with little more than a few pop up
thunderstorms this afternoon near the Sierra Crest.
A weak upper level disturbance embedded in the northwest flow
aloft will destabilize the atmosphere over the mountains Saturday
and Sunday. This means there will is a much better chance of
afternoon and evening thunderstorms over the Sierra both days.
Isolated late day thunderstorms could also pop up over the Kern
County mountains on Saturday and Sunday, too. Hikers, campers and
back packers should be wary of this if they are spending time in
the Sierra this holiday weekend. This does include Memorial Day,
although by then we expect thunderstorm activity to lessen and be
scaled back to just the Sierra crest as the atmosphere becomes
slightly more stable again.
As mentioned earlier, a day to day warming trend will take place
over the next several days. Max temperatures will end up well
above normal by Memorial Day. Thermometer readings could even
reach the century mark in the hottest locations of the San
Joaquin Valley by then with a repeat occurrence Tuesday.
The models forecast the upper level ridge of high pressure to
dominate the pattern over California for much of next week. That
means dry weather and above normal afternoon temperatures will
likely continue through next Friday. Although we are still
carrying slight chance pops along the Sierra Crest through the
middle of next week, thunderstorms will not be the highlight of
the week`s weather. This Memorial Day weekend will open the door
to Summerlike weather and that door will remain open for many
days thereafter. No doubt by then many residents of the central
California interior will be reminiscing about the good old cooler
than normal days we`ve just experienced. In fact, it may be quite
a long while before we see see temperatures that cool again.
On a final note, the National Weather Service San Joaquin Valley
office wishes everyone safe travels this holiday weekend. With the
advent of much warmer weather, please remember that area lakes
and rivers are fed by melting snow over the high Sierra and are
dangerously cold this time of year. It only takes fifteen minutes
in 45 degree water to cause the onset of hypothermia.
Areas of MVFR and local IFR in showers and isolated thunderstorms in
the southern Sierra Nevada from 19Z today through 04Z Saturday.
Otherwise, VFR conditions will prevail in the central CA interior
for 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 high.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.