Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 242152

National Weather Service Eureka CA
252 PM PDT Sun May 24 2020

.SYNOPSIS...Dry weather and increasing interior temperatures are
expected through Thursday as high pressure continues to build over
Northwest California. High temperatures across much of the
interior will climb into the 90s. Onshore breezes will keep
coastal areas seasonable cool, along with periodic episodes of
overnight and early morning marine stratus.


.DISCUSSION...Low clouds in the Eel River Valley and around
Humboldt Bay dissipated by mid-morning today and give way to
another mostly sunny day across NW California. Inland temperatures
have continued to rise, with readings approaching 90 degrees in
the warmer spots across the interior. Areas of stratus will be
possible again tonight along portions of the coastal plain and
inland valleys. However, the marine layer has been shrinking over
the last 24 hours, and that trend should continue with warming
temperatures aloft.

Similar conditions are expected across the forecast area on Monday
as high pressure continues to build. Interior temperatures will
continue to be on the increase by several degrees, with highs in
the lower 90s in the warmer interior locations. Highs will climb
into the mid to upper 90s in the some inland areas starting on
Tuesday. These hot temperatures are expected to persist through
Thursday. Some of the warmer spots may reach over 100 during the
three-day period. Have gone ahead and hoisted a heat advisory for
Tuesday through Thursday for S Lake County and portions of
Mendocino County. This advisory may need to be expanded N across
portions of CAZ111, but it is a bit early at this time. Coastal
areas will continue to be seasonably cool during this time frame
thanks to onshore breezes and morning bouts of marine stratus.

Some relief is expected starting on Friday as guidance continues
to show a low pressure system moving in from the SW as the ridge
shifts to the E. Confidence continues to grow with this scenario,
though there are slight timing differences in the models. That
being said, slightly lower temperatures and increasing
precipitation chances are expected to return to the area on
Friday. Some thunder will be possible across portions of the
interior Friday afternoon and early evening as instability
associated with the low spreads across the area. /SEC


.AVIATION...VFR conditions prevail again this afternoon as high
pressure continues to support sunny skies across NW CA. Will likely
see some patches of stratus redevelop overnight along the Redwood
Coast, especially around Humboldt Bay and the Eel River Valley. This
could support a few hours of IFR/MVFR flight categories around
sunrise at KACV and to a lesser extent KCEC. Otherwise, expecting
VFR to continue through the TAF period along with the typical
diurnally driven breezy conditions along the coast each afternoon.


.MARINE...Little change in forecast thinking for the next few
days as a strengthening thermal trough over interior CA helps to
maintain a tight coastal pressure gradient and persistent northerly
wind regime for much of the coming week. Wind-driven short period
seas will thus remain as the dominant wave group for the foreseeable
future, with an arriving mid period NW swell giving a boost to
combined seas early in the week. Small Craft Advisory conditions
will persist through at least Tuesday and likely beyond, with
conditions primarily driven by sea states over the northern
nearshore waters while the strongest winds remain farther offshore
and downwind of Cape Mendocino. /CB


CA...Heat Advisory from noon Tuesday to 6 PM Thursday
      for CAZ110-113-115.

     Small Craft Advisory until 9 AM Tuesday for PZZ450-455-470-475.


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