463 
FXUS66 KEKA 082209
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
309 PM PDT Sun Sep 8 2019

.SYNOPSIS...Cooler interior temperatures will persist through the 
middle part of the upcoming work week. Scattered showers will be 
possible, over portions of primarily Del Norte and Humboldt 
counties, late today through Tuesday. Isolated thunderstorms will be 
possible across eastern Del Norte and northern Trinity counties 
Tuesday afternoon. 

&&

.DISCUSSION...Weak ridging aloft was in place across the area this 
morning which has lead to a pleasant day across Northwest
California. This ridging has already begun to break down ahead of
the next approaching system which has already begun to spread 
some clouds across the northern portion of the forecast area. 
Upper level divergence and jet streak may help to increase shower
potential this evening mainly across Del Norte and northern 
Humboldt counties however still expect activity to be scattered. 
Monday morning a shortwave will pivot across the area which should 
allow showers to expand in coverage primarily north of Cape 
Mendocino. Still expect rain amounts to be on the light side
generally remaining below a tenth of an inch. On Tuesday the main
trough will move overhead which will bring the last round of 
scattered showers to the area. As temperatures aloft cool some 
elevated instability will develop across primarily eastern Del 
Norte, northeastern Humboldt, and northern Trinity counties which
may be just enough for isolated thunderstorms to develop. As the 
low departs the area Tuesday night into Wednesday morning clearing
skies and cool temperatures aloft will lead to chilly overnight 
lows within interior valleys in the upper 30's to low 40's 
(assuming that rain is light enough to prevent valley fog from 
developing). In the wake of the low, upper level ridging will 
spread across the western U.S. leading to warming temperatures for
mid to late week. /WCI

&&

.AVIATION...Skies range from almost completely cloud-free across 
Mendocino County to nearly overcast over portions of Del Norte 
County this afternoon. Cloudiness is mostly convective in nature due 
to the upper trough which is presently digging S over the area. 
Although low-level moisture is deep, mixing should mitigate 
visibility reductions from fog. Scattered, generally light showers 
will approach the Redwood Coast late this afternoon and this 
evening. There may be some visibility reductions in rain, 
particularly at KCEC, but only a few reductions to high end MVFR are 
expected. Conditions at KUKI are expected to remain VFR. Winds will 
be generally light, although gusts to around 20 knots are expected 
this afternoon at KUKI. /SEC

&&

.MARINE...Winds will remain generally light for the next couple of 
days, with southerly flow N of Cape Mendocino and northerly flow S 
of the cape. Winds are expected to become more uniformly N across 
the area by mid-week, with wind speeds increasing near and S of Cape 
Mendocino. Advisory-level conditions are possible over the S outer 
waters by late Wednesday afternoon or evening. Mid-period NW swell 
will persist through the work week along with a smaller, longer 
period SW swell. /SEC

&&

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

$$

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