Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 201246

National Weather Service Eureka CA
446 AM PST Sun Jan 20 2019

.SYNOPSIS...Showers and isolated thunderstorms will spread across
the region today. This will be followed by shower dissipation on
Monday, and then mild dry conditions during mid to late next


.DISCUSSION...An upper-level shortwave trough is in the process of
moving eastward across the NERN PAC this morning. A surface cold
front has subsequently moved onshore, and is shunting heavy
stratiform precipitation out of NWRN CA. However, colder midlevel
temperatures are entering the region behind the front. As that
takes place, lapse rates will steepen and modest SBCAPE values
will materialize by afternoon. This will aid in shower and
isolated thunderstorm development within the cyclonic shear side
of a 125+ kt upper-level jet. Inspection of model forecast
soundings indicates showers and storms will be capable of
producing small hail and gusty erratic winds.

The back-side of the previously mentioned trough will move east
across the CWA during Monday morning, with showers quickly
dissipating in response to warming midlevel temperatures and
increasing large-scale subsidence. After Monday, an upper ridge
over the NERN PAC will become the predominant synoptic-scale
feature during mid to late next week. Model guidance shows several
minor upper impulses moving through the ridge on Tuesday and
Wednesday. However, as those features move toward NWRN CA, they
will be embedded within an increasingly unfavorable environment
for the maintenance of frontal precipitation...thus the forecast
appears to be dry at this time. Otherwise, mild afternoon
temperatures appear likely Wednesday into next weekend.



.AVIATION...Another rainy morning across NW CA as a cold front
sweeps across the region. MVFR conditions are occurring earl this
morning along the coast where a persistent rain bad slowly moves
east. This is expected to continue through the morning hours
before the airmass begins to de-stablize and becomes more showery
in nature. Although the consistent rainfall may diminish coastal
thunderstorms look probable later this afternoon thus lightning,
heavy showers or hail is possible. Toward the end of the taf cycle
conditions should begin to improve as high pressure begins to
build over the area.


.MARINE...A vigorous fast moving front brought chaotic wind
directions and gusty speeds to the northern inner waters earlier
this morning. The front has since moved inland which will allow
winds across all waters today to become mainly west or southwest
and range from 10 to 20 kts. However one more round of
thunderstorms is possible later this afternoon so have issued a
general marine statement (mwseka) to reflect the potential of
lightning, hail and gusty erratic winds. The possibility of
waterspout formation exists as well in or around the stronger
thunderstorm cells. The elevated westerly swell will continue to
hamper the southern outer waters.


.COASTAL FLOODING...High astronomical high tides (king tides)
will continue through early next week. Tidal anomalies will likely
aid in minor coastal flooding during the daily late morning and
early afternoon high tides, with the highest astronomical tides
expected on Monday.


CA...Coastal Flood Advisory from 9 AM this morning to noon PST today
     for CAZ103.

     9 AM PST this morning for PZZ450-455- 470.

     Small Craft Advisory until 3 AM PST Tuesday for PZZ475.



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