Yreka, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

875
FXUS66 KMFR 231136
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
436 AM PDT Fri May 23 2025

...New Aviation Section...


.AVIATION (12Z TAFs)...

Low clouds will burn off later today with generally mostly clear
skies expected by this afternoon. Typical afternoon breezes will
diminish after sunset. Low clouds could develop overnight, but
currently not expecting any categorical changes. Overall,
expecting a mostly VFR TAF cycle after this morning clouds burn
off.

-Guerrero

&&

.PREV DISCUSSION... /Issued 314 AM PDT Fri May 23 2025/

DISCUSSION (Today through Thursday)...

Overview:

Relatively quiet conditions are expected through the end of week,
but we will see precipitation chances increase on Sunday as an upper
level system impacts the region. This will lead to showers and
perhaps a couple thunderstorms Sunday and Monday. This is of course
over the holiday weekend, so anyone with outdoor plans should have a
plan in place for lightning. Not expecting severe weather at this
time, but a couple storms could be strong with lightning and gusty
winds as the main threats. Thereafter, warm conditions expected
through mid-week with Wednesday potentially having highs around 90
for westside areas. For Medford, this would be the first 90 degree
day this year.

Further Details:

In the upper levels, we will be under mostly zonal flow through
today with a transition to ridging on Saturday. This ridge will be
in place until Sunday at which point an upper trough and associated
front will begin impacting the region. This open wave will have most
of the dynamics north of our area, but the base of the trough will
slide over the forecast area through Monday. The best chance for
thunderstorms will be on Sunday as MUCAPE values are the highest
albeit only a few hundred J/kg to upwards near 500 J/kg. Much less
instability expected on Monday, but cannot rule out a thunderstorm
on this day. Both of these days could produce lightning and gusty
winds with any storms that form. Since its Memorial Day weekend,
expecting a lot of outdoor activities, and anyone with outdoor plans
should have a plan in place for thunderstorm activity. Bulk shear
values are not overly impressive, so not expecting storms to
maintain long enough for hail production. However, DCAPE values are
progged to be around 1000-1300 J/kg which seems reasonable given the
inverted-v sounding profiles. These values could easily produce wind
speeds around 45 to 55 mph with any downburst through evaporative
cooling processes. This threat will be highest Sunday for eastside
areas where DCAPE will be highest between the two days of
thunderstorms. Lastly, not expecting a lot of rainfall with these
showers, but a few areas could pick upwards near a 0.10" of
rainfall.

On Tuesday, another ridge will build in over the forecast area. Then
another trough comes through the PacNW beginning on Wednesday.
Before the next front comes through, Wednesday will be the warmest
day of the current 7 day forecast. However, not expecting record
temperatures. For perspective, Medford`s record high temperature for
May 28th is 99 degrees and we are forecasting 91 for a high. Another
round of precipitation expected late Wednesday into Thursday. At
this time, instability values are low to nonexistent, so not
expecting thunderstorms through middle of next week, but given the
time of year this could change over the coming days.

-Guerrero

AVIATION...VFR conditions continue across northern California
and southern Oregon will persist through the TAF period except for
areas of MVFR ceilings which will develop along the coast north
of Cape Blanco, including at North Bend (KOTH), late this evening
into early Friday morning. Local MVFR is also possible in the
Umpqua Valley late tonight and early Friday morning.

MARINE...Updated 300 AM Friday, May 23, 2025...Northerly winds
increase this morning south of Cape Blanco, building steep seas
south of Port Orford through the afternoon and evening hours. Wind
driven steep seas are forecast south of Port Orford and within 50
nm of shore this afternoon and evening.

Below advisory winds and seas return on Saturday. On Sunday,
westerly swell increases through the day, peaking Sunday night
into Monday morning. Scattered marine showers are also possible on
Sunday and Monday morning , but these should be unimpactful.
Stable conditions return on Monday afternoon and could continue
through the middle of next week.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...None.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 11 AM this morning
     to 5 AM PDT Saturday for PZZ356-376.

&&

$$