FXUS66 KEKA 281106
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
406 AM PDT Wed Jul 28 2021

.SYNOPSIS...Temperatures across interior portions of northwest
California will steadily warm during the week, with high
temperatures in the low 100s probable by Friday afternoon.
Conditions will then cool during the weekend into early next week.
Otherwise, showers will dissipate across the region this evening.
Additional thunderstorms may occur across the interior mountains
Thursday and Friday.

&&

.DISCUSSION...The persistent cloud band off the coast that was 
associated with yesterday's shower and tstorm activity is
gradually dissipating and moving north. Pics from space still
showing some cirrus over Del Norte county but this region should
be cloud free later this morning. High pressure centered over the
Intermountain West is then forecast to build and expand westward 
toward NWRN CA through Friday. This will result in another period
of warm to hot temperatures across the interior valleys with 
highs in the 90s to near 100 on Thursday, followed by probable low
100s Friday afternoon. The heat is then forecast to be shunted 
east away from the area this weekend into early next week due to 
the influence of an upper trough approaching the area from the 
west over the NERN PAC. Otherwise, model guidance shows monsoon 
moisture lingering near NRN CA this week. That moisture combined 
with strong surface heating Thursday and Friday afternoon, as well
as steep lapse rates aloft and subtle lobes of ascent in the 
upper-levels, will aid in mountain thunderstorm development during
the afternoon and evening hours on Thursday and Friday.

&&

.AVIATION...Lingering showers delayed the marine layer's return 
overnight, but it has gradually returned to most of the coast this 
morning along with LIFR conditions. A compressed marine layer will 
likely keep ceilings and visibilities low in the morning, but a 
still relatively weak inversion should allow the marine layer to lift 
and scatter to VFR conditions by mid afternoon. Warming interior 
conditions should allow the marine to build back in late this 
evening. Clearer conditions should return to the interior today with 
widespread VFR conditions.


&&

.MARINE...Northerly winds persist throughout the forecast area. 
Winds and seas calmed yesterday with outer water winds currently 
peaking as moderate to fresh breezes, with calmer winds near shore. 
Seas are currently moderately steep with waves no more than 5 to 6 
ft. These calmer conditions should continue through Thursday night 
when winds and short period waves will gradually increase into the 
weekend.
 
There are two minor swells impacting the area. The first is 
northwesterly 1 to 2 ft at 8 seconds and will slowly diminish 
through Thursday. The second swell is southerly 1 to 2 ft at 15 
seconds and will diminish through Friday. 


&&

FIRE WEATHER...Isolated to scattered thunderstorms will be 
possible across portions of Trinity and northeast Mendocino
Counties Thursday and Friday afternoon. Should storms produce 
lightning a very dry low level airmass will likely prevent any  
rain (or very little rain) from reaching the ground. 



.EKA WATCHES/WARNINGS/ADVISORIES...
CA...None.
NORTHWEST CALIFORNIA COASTAL WATERS...None.
&&

$$

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png