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Area Forecast Discussion (AFD)

Issued by San Joaquin Valley, CA (HNX)

                            
000
FXUS66 KHNX 182115
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
215 PM PDT Tue Jun 18 2019


.SYNOPSIS...A few isolated showers and thunderstorms remain 
possible over the Sierra Nevada through this evening. Temperatures
will be around 10 degrees above normal today and Wednesday. A 
cooling trend will occur later in the week with temperatures 
falling to near normal by Friday.

&&

.DISCUSSION...Visible satellite imagery shows sunny skies across 
the central California interior with the exception of scattered
cumulus buildups over the Sierra Nevada and Tehachapi Mountains.
These clouds are fewer than yesterday and no showers have formed
yet. Much quieter weather compared to this time yesterday when 
several showers and a strong thunderstorm had already developed. 
The upper trough is shifting east towards Arizona as an eastern
Pacific ridge is nosing in over northern California. Instability
and moisture are on the decrease but we could still see isolated
showers or even a thunderstorm or two later this afternoon and
early evening as high resolution models are suggesting. The most
likely areas looks to be in the Tulare and Kern County mountains.
A northeast steering flow would push any showers/storms towards
the southwest, possibly into the foothills east of Bakersfield.
Temperatures are running slightly higher than this time yesterday
due to the approaching ridge. Temperatures are forecast to top 
out around 10 degrees above climatological normals for mid June.
This means highs right around the century mark for much of the
San Joaquin Valley, lower Sierra foothills, & Kern County Desert.

The ridge will build farther inland and south on Wednesday with 
the E-W oriented axis passing over central California. Triple
digit heat will again occur across the lower elevations, with a
few areas nudging up a degree or two from today. While there may 
still be some afternoon cumulus buildups along the Sierra crest, 
the ridge should squash any potential for showers or t-storms.
But this heat will be short-lived as medium range models show a
large upper low dropping down from western Canada to over the
Pacific Northwest and northern Rockies on Thursday. A long wave 
trough over the western CONUS will shunt the ridge back offshore.
Temperatures will lower several degrees both Thursday and Friday
with highs by Friday at to slightly below normal. Wind will be
on the increase Thursday with breezy to windy conditions by the
afternoon. Gusty conditions will continue through Friday night.

The upper ridge makes a subtle return inland over the weekend,
resulting in a few degrees of warming. But models show another
closed upper low dropping down from the Queen Charlotte Islands
to off the PacNW coast early next week. The models diverge a bit 
from there but the general idea is for the low to linger along
the PacNW coast through at least midweek. The associated trough 
will extend down over California with a cooler onshore flow at
the surface. Temperatures will trend lower early next week with 
highs by Tuesday forecast to be a little below normal again.

&&

.AVIATION...
VFR conditions will prevail at MCE, MER, FAT, VIS, and BFL through
at least the next 24 hours. 

&&

.AIR QUALITY ISSUES...
On Tuesday June 18 2019...Unhealthy for sensitive groups in 
Fresno...Kern and Tulare Counties. Further information is 
available at Valleyair.org

&&

.CERTAINTY...
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.html for additional information 
and/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

public...DCH
aviation....BS

weather.gov/hanford