668
FXUS66 KEKA 082202
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
302 PM PDT Wed May 8 2024

.SYNOPSIS...A building expansive Pacific ridge of high pressure will
continue to bring warming temperatures and strengthening N to NE
winds. This combination of elements will allow for unseasonably warm
and possibly record high temperatures closer to the coast and in
the interior valleys. A cooling trend is expected for the weekend.

&&

.DISCUSSION...High pressure is building into the Pacific
Northwest and an upper level low is slowly retrograding to the
southwest over the Central Rockies. This is creating a tight
pressure gradient across the area bringing gusty north winds to
the coastal areas and over the higher terrain. These are expected
to increase tonight over the higher terrain, especially in SE
Trinity, NE Mendocino and Lake counties. There is a 50 to 80
percent chance of greater than 40 mph wind gusts in these areas.
The wind advisories remain on track. The valleys and coastal areas
will likely decouple in most areas and winds will become light
overnight. Frost is not expected in most areas, although the
coldest spots could approach the mid 30s. Went below the NBM
guidance by several degrees for the protected valleys and coastal
areas tonight, but temperatures still remain above 36 degrees.
This offshore flow is expected to keep all the stratus away from
the coast and very few river valleys are likely to see any fog or
stratus. Thursday the low pressure over the Rockies continues to
drop south and this will gradually the pressure gradient to relax
and winds start to diminish through the day. Temperatures will
continue to warm each day through Friday as high pressure builds.
Inland temperatures will peak near 90 in the warmer valleys. As
the winds diminish they become northeast and offshore and this
should help warm temperatures along the coast. Temperatures may
peak around 70. A few locations could reach the mid or upper 70s
briefly early in the afternoon Thursday or Friday.

Saturday the ridge axis starts to move to the east and the high
pressure. This looks like it will allow stratus to move up the
coast and this will likely keep temperatures cooler. Saturday will
likely be a transition day and there may not be too much stratus,
just cooler temperatures in the coastal and near coastal areas.

Sunday and Monday a weak shortwave moving by to the north may be
enough to spark off a shower or two over eastern Trinity county.
There is a ten percent chance of thunder at this point. This
shortwave could also bring drizzle to the coast. Tuesday high
pressure starts to build back in and temperatures will warm back
into the 90s inland and low 60s at the coast. MKK

&&

.AVIATION...Overnight/early morning fog developed over the
coastal-interior river valleys, but dissipated within a few hours
after sunrise. Otherwise, benign VFR prevailed across the region.
The more concerning aviation hazard has been strong gusty NW-N
winds today along the coast, due to interaction between offshore
high pressure and thermal/inverted trofing extending offshore. An
absent marine layer was also the result of strong offshore flow:
above ground winds at night promoted low level windshear (LLWS).
Conditions are expected to stay fairly unchanged through the 24
hour Taf period. /TA

&&

.MARINE...Northerly gales continue across the waters and steep
waves have built to around 10 to 12 feet with a small swell making
them slightly larger. Winds will start to diminish tonight and
continue to diminish on Thursday. Winds will diminish more
quickly in the southern waters tonight and the gale warning may
need to be ended sooner than it currently is.

Friday and Saturday the winds continue to to diminish and will
only be around 5 to 10 kt. Saturday night into Sunday winds
increase again and may reach gale force by Monday or Tuesday. A
small NW swell of 3 to 4 feet at 11 seconds is possible over the
weekend. There may also be a southerly long period, but this will
only be around 2 to 3 feet as well. MKK

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Wind Advisory from 8 PM this evening to 9 AM PDT Thursday
     for CAZ108-111.

     Wind Advisory until 9 AM PDT Thursday for CAZ114-115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Gale Warning until 3 AM PDT Thursday for PZZ450-455-470-475.

&&

$$

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