Area Forecast Discussion
Issued by NWS Eureka, CA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

FXUS66 KEKA 102134

National Weather Service Eureka CA
234 PM PDT Mon May 10 2021

.SYNOPSIS...Temperatures across the interior will warm through
mid-week while coastal areas remain seasonable. No appreciable
rain is expected during the next seven days, though a slight
chance of thunderstorms will exist over Trinity County Friday


.DISCUSSION...An upper ridge was positioned over the NERN PAC this
afternoon, while a shortwave trough was moving southeast across
the Great Basin. Northwesterly flow aloft occurring between those
two features was favoring dry conditions over NWRN CA. In
addition, abundant sunshine was aiding in highs in the upper 50s
along the coast, while inland, the warmest valleys were in the
upper 80s.

A tight northerly pressure gradient at the surface is forecast to
progressively weaken during the next 24 hours, which will lead to
a cessation in strong gusty winds. Otherwise, low to mid 90s are
forecast to occur on Tuesday for locations such as Ukiah and
Weaverville. Thereafter, slight cooling will occur aloft during
Wednesday and Thursday, which will aid in modestly lower high
temperatures across the interior...though values will still be in
the 80s inland from the marine layer. Model guidance then shows a
shortwave trough moving southeast across NRN CA on Friday.
Temperatures at 500 mb will be around -20C near the center of the
trough, which will aid in a steep lapse rate environment due to
favorable timing of cooling aloft with peak surface heating.
Destabilization combined with synoptic and orographic ascent will
yield a slight chance of thunderstorms mainly in Trinity County
late Friday afternoon into early evening.



.AVIATION...Coastal stratus stretching from Cape Mendocino to
Trinidad resulted in IFR conditions at ACV this morning. The
marine clouds extended deep throughout the EEl River valleys. Haze
developed by mid-morning at CEC. The remainder of the region
continued under VFR conditions. A moderate pressure gradient at
the coast allowed CEC to keep gusty northern winds
overnight...with possible >25kt weak directional windshear
surface-020 feet briefly in middle morning. Robust
afternoon/evening winds will persist today...especially along the
North Coast. Also, surface winds will increase by late afternoon
over inland areas. Overnight and Tuesday morning, model data
indicating skepticism for low clouds at the coast. However, will
not rule out pockets of marine stratus and fog around Humboldt Bay
to Trinidad...including ACV airport. /TA


.MARINE...Gale force northerlies will continue across the outer
waters through Tuesday. Furthermore, seas will be steep and
hazardous near shore. Winds are forecast to weaken Wednesday and
Thursday, followed by additional northerly gales Friday and



.FIRE WEATHER...Gusty ridgetop winds will be collocated with low
RH values through this evening. However, fuels remain marginally
receptive to fire spread. Otherwise, hot and dry conditions will
persist through Thursday.



     until 5 AM PDT Tuesday for PZZ450.

     Gale Warning until 2 AM PDT Wednesday for PZZ470.

     Small Craft Advisory until 5 AM PDT Tuesday for PZZ455.

     Gale Warning until noon PDT Tuesday for PZZ475.



Visit us at

Follow us on Facebook and Twitter at:

For forecast zone information
see the forecast zone map online: is the U.S. government's official web portal to all federal, state and local government web resources and services.