Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

453
FXUS66 KHNX 242314
AFDHNX

Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
314 PM PST Sat Feb 24 2018

.SYNOPSIS...
Dry weather and a minor warming trend will be in store through
the rest of the weekend, followed by a cold front arriving Monday
and bringing more precipitation and increased. Another storm
system is forecast to impact our area Wednesday night and continue
through Saturday night.

&&

.DISCUSSION...
NW flow today across the region today as EPAC ridge is locked in
place. Upper level short wave moving through this evening will
usher in more cold air for the overnight hours. Freeze warning for
the SJV has been issued. It is a marginal event tonight, but
wanted to err on the side of caution. Temps will be around 30 in
most rural locations, with some areas getting into the upper 20s.
Heat island areas, such as the major cities, will not see
freezing conditions overnight.

We will see a few more clouds tomorrow as moisture increases in
the mid and high levels. Models are still advertising a cold
front to push through here on Monday in association with a
decaying low pressure center in the Gulf of AK. This system is
expected to be a cold system and once again bring snow levels down
to around 3000 feet on Monday. This system is forecast to be much
drier than the last system that brought 4 to 8 inches across
elevations that normally dont see that kind of snow. We are not
expecting this system to be as moisture laden as the last one and
would only expect to see up to an inch around 3000 and higher. The
track of the developing upper low is farther to the west (coastla
hugger) and is not as dynamic as the last event. We will continue
to monitor if a winter weather advisory needs to be hoisted, but
at this time, the system appears to be significantly weaker and
warmer than the last one.

The front pushes out Tuesday as a surface high builds in across
the Great Basin. Cold air returns to the San Joaquin Valley with
the potential of another freeze event on Tuesday morning and
especially on Wednesday morning. We will continue to monitor the
situation for a potential freeze event returning early next week
to the SJV.

Guidance is trying to come together as a complex low pressure
system will push a strong and more moisture laden cold front
through the region. Models still are differing on timing and
amount of moisture at this time. However the trend has been wetter
over the past couple of runs of the GEFS. We are currently
thinking that the front will start to bring precipitation into the
central CA interior by late Wednesday night into Thursday morning
and then the front will push through by Friday morning. The
parent low center will be sitting off the NW pac area and will
provide moisture across the region with instability showers post
frontal across the region on Friday as a series of weak mid level
weather disturbances move across the area into Friday night.
Confidence is low at the moment for possible convection on Friday
as MUCapes go above 100j/kg mainly Merced county northward. Lapse
rates from 700mb- 500mb are around 5 C/km. Cold core will swing
across the region north of Fresno county on Friday with -20 to
-26 celsius temps at 500mb. Depending on timing of the upper
 trough, we could see some isolated convection. Did not put it in
 the forecast because confidence is very low this far out, however
 we will keep an eye on it. The region remains unsettled into
 Saturday with some continued showers possible into Saturday
 night.

&&

.AVIATION...
Areas of MVFR and local IFR due to mountain obscurations over the
southern Sierra Nevada thru 06Z Sun. In addition, gusts of 35 to 40
kts are possible thru 09Z Sun over the Tehachapi Mountains and Kern
County desert areas. Otherwise VFR conditions are expected across
the remainder of the Central CA interior during the next 24 hours.

&&

.AIR QUALITY ISSUES...
None.

&&

.CERTAINTY...

The level of certainty for days 1 and 2 is medium.
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.

&&

.HNX Watches/Warnings/Advisories...
Wind Advisory until 10 PM PST this evening CAZ095-098-099.

Freeze Warning from 3 AM to 8 AM PST Sunday CAZ089>092.

&&

$$

public...JDB
avn/fw...BSO
synopsis...JDB

weather.gov/hanford



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.