Scientific Forecaster Discussion
fxus66 khnx 230117 aaa
Area forecast discussion...updated
National Weather Service San Joaquin Valley - Hanford California
617 PM PDT Sat Jul 22 2017
updated air quality issues section.
temperatures will rise back to above normal levels this weekend
as high pressure strengthens over the region. Dry conditions will
prevail this weekend except for the possibility of an isolated
thunderstorms over the southern Sierra Nevada. A moist southerly
flow will bring a chances of thunderstorms to the mountains and
Kern deserts on Monday and Tuesday.
quiet day as sunny and warm conditions continue across the west.
In addition, winds remain light under the ridge pattern that
continues to build as temperatures go through a warming trend.
Based on the trend of warming by 2-4 degrees, will have no problem
with valley temperatures reaching to passing the century mark
today. Yet, with the combination of smoke from wildfires, heat and
light winds, an air quality alert remains in effect for most of
central California interior. These unhealthy air conditions are
expected to persist through the dissipation of smoke from area
The heat will continue to make a comeback during this weekend as 100
degree temperatures become widespread. Yet, some change in the
current weather pattern is progged starting early next week. Model
upper-air analysis and water-vapor satellite imagery continues to
indicate a possible weak disturbance approaching California from
the west. Current satellite imagery now has the disturbance
located about 500 miles west of the Monterey Bay area California
coast and moving slowly west-northwest. Models have this
disturbance approaching the northern California by
Sunday...allowing for a more southerly flow pattern to set-up over
the district. Therefore, will expect dry conditions until early
next week as models prog a surge of subtropical moisture pushing
up by the end of the weekend. Will introduce more cloud cover on
Sunday along with a slight chance of precipitation over the Sierra
crest ahead of the main area of deep moisture. Models prog a
deepening of moisture over the West Coast on Monday for even
better chances of precipitation. However, models only showing a
weak southeasterly flow pattern developing early next week.
Therefore, will confine the precipitation to the mountains and
deserts from Monday through Wednesday.
Model analysis later next week shows the upper level disturbance
pushing through California and shifting into the Great Basin. With
a return of the onshore flow pattern later next week, will allow
the precipitation to diminish. Therefore, best chances of
precipitation will exist from Monday through Wednesday for the
mountains and deserts. While precipitation could linger over the
mountains on Thursday, but by that time period the potential will
have diminished to very low levels. Models do show high
uncertainty in the later periods, but do have a signal toward a
trof over California later on Wednesday. Therefore, will keep the
forecast on track toward a drier period later next week.
areas of MVFR and local IFR visibilities in smoke from area
wildfires. Otherwise, VFR conditions will prevail across the
central California interior during the next 24 hours.
Air quality issues...
please see sfoaqahnx for air quality alert.
On Sunday July 23, 2017...unhealthy for sensitive groups in Kern
County and Sequoia National Park and Forest.
Further information is available at valleryair.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.