Scientific Forecaster Discussion
fxus66 khnx 231300
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
449 am PDT Sat Jun 23 2018
Synopsis...dry weather will continue for the next several
days. High temperatures will be well above normal through
at least Tuesday or Wednesday. A trend to cooler weather
is likely later next week.
Discussion...Summer is getting off to a hot start throughout
much of the central California interior. If you have a low tolerance
for hot weather, you're going to be miserable for at least the next
few days. High temperatures will be above the century mark in the
San Joaquin Valley, lower foothills and the Kern County desert each
and every day through Tuesday. Sunday will be the hottest day of this
four day heat wave. Thermometer readings could top the 105 degree mark
in some locations of the San Joaquin Valley and lower foothills and
peak as high as 112 degrees in the Kern County desert. Without a
doubt, this will be our longest spell of triple digit heat so far this
The heat can be blamed on a strong upper level ridge of high pressure.
It's currently centered over the eastern Pacific and it will build over
the Golden state this weekend and remain firmly in control through Tuesday.
This high pressure ridge has completely squashed the marine layer along
the central California coast since yesterday. So in spite of an onshore
flow this weekend, valley residents can Forget about any cooling comforts
coming this far inland. Ditto through Tuesday, although by then this high
pressure ridge will have shifted eastward and be centered over Arizona and
And now for the good news. A cooling trend is in the offing for the second
half of next week. The models forecast an upper level trough to move into the
Pacific northwest by late Wednesday with a gradual settling southward of
this trough into the Great Basin in the 5 to 7 day period. The GFS is more
aggressively deepening this trough over the western Continental U.S. Compared to the
ecm and actually develops a closed low over the Great Basin by next Saturday.
Either way, this pattern change will mean we'll see the re-establishment of
a deeper marine layer along the central California coast and a strengthening
onshore flow later in the week. It could begin as early as Wednesday as
marine air pushes through the Sacramento Delta and trickles into the northern
San Joaquin Valley. Otherwise, high temperatures on Wednesday will still be
above the century mark over much of the San Joaquin Valley, lower foothills
and the Kern County desert. Temperatures will finally drop back to seasonable
levels or slightly lower in the 5 to 7 day period thanks to a prevailing
Until then, if you can't travel to the coast or the mountains to seek cooling
relief from the heat, it's best to stay indoors in an air conditioned building.
If you have to be outdoors, avoid doing so during the hottest time of the day,
lather on the sunscreen and wear light, loose fitting clothing. More importantly,
stay hydrated! A swimming pool or a Water Park are great places to cool off but
area rivers aren't. Their waters are cold and they carry swift undercurrents.
VFR conditions will prevail across the central California interior during
the next 24 hours.
Air quality issues...
on Saturday June 23 2018... unhealthy for sensitive groups in
Fresno... Kern... Kings and Tulare counties 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.
heat advisory until 8 PM PDT Sunday evening caz089>092.