Helm, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

114
FXUS66 KMFR 040546
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1046 PM PDT Sun May 3 2026

...Updated the Aviation and Marine Sections......

.AVIATION...04/06Z TAFs...
Along the coast, persistent LIFR/IFR conditions in stratus and fog
will continue through much of Monday morning. Marine stratus is
expected to lift to IFR for the late morning and afternoon hours on
Monday before fog and lower ceilings fill back in Monday evening.
Besides the coast, stratus is expected to filter into the Umpqua
Valley overnight, with MVFR likely at Roseburg from around 10Z to
20Z Monday morning.

Elsewhere, VFR conditions will prevail with mid and high level
clouds. Isolated shower/thunderstorm activity is expected on Monday
afternoon and evening, with activity near the Cascades and across
northern California. An east to northeast storm motion is forecast
with gusty and erratic winds in the vicinity of thunderstorms.

&&

.MARINE...Updated 800 PM PDT Sunday, May 3, 2026...An extended
period of relatively calm conditions has begun, with west-northwest
swell dominated seas likely remaining below 10 ft through Friday.
Light south winds and fog are expected through Monday night, with
gradually diminishing seas. Moderate north winds likely develop on
Friday, with the return of the thermal trough. Stronger north winds
are possible Saturday into next week.

&&

.PREV DISCUSSION... /Issued 845 PM PDT Sun May 3 2026/

DISCUSSION...Showers and thunderstorms moved through more areas
west of the Cascades this evening, and there were storms that
developed half inch hail and brought heavier rain. Some 12-hour
totals as of 8:45 PM reached 0.40"-0.50" in western Jackson County
and eastern Josephine County. The shower activity continues this
evening, but the thunderstorm threat has decreased. Tomorrow is
still on track to see showers and a slight chance of thunderstorms
in Northern California and along/east of the Cascades.


PREV DISCUSSION... /Issued 159 PM PDT Sun May 3 2026/

DISCUSSION...Radar returns are showing activity developing over
southeast Klamath County early this afternoon, following westward
flow wrapping around a cutoff low. Activity looks to increase later
into the afternoon, especially over Siskiyou County. Northwest flow
aloft is expected to move activity over Jackson and Josephine
counties. Curry and Douglas counties may see some activity as well.
Overall rainfall amounts are fairly negligible, but periods of
moderate to heavy rainfall are possible under any thunderstorm. This
may be more likely in the Illinois Valley, which has estimates of
0.25 to 0.75 inches of rainfall through tonight. Thunderstorms may
also bring erratic gusty winds as well as lightning. Rain showers
may continue into tonight but should dissipate by early Monday
morning.

Another round of thunderstorm activity is expected on Monday
afternoon and evening. With the cutoff low farther to the east, most
activity is expected over Siskiyou and Modoc counties. Southern Lake
and Klamath counties may also see some activity. Modeled CAPE values
are somewhat moderate, in the 400-600 J/Kg range. This is enough to
support additional thunderstorms but doesn`t imply severe activity.
Rain showers are expected as well, with amounts in the 0.2 to 0.5
inch range possible along the Lake/Modoc southern border.

An upper ridge settles into place through the day Tuesday and looks
to remain in control of conditions through the rest of the forecast
period and beyond. The Oregon coast is forecast to be about 5
degrees above seasonal norms, with highs in the mid 60s. Inland areas
are forecast to be 10 to 15 degrees above normal. Areas east of the
Cascades as well as the Umpqua Valley have forecast highs in the
high 70s to low 80s, while other west side valleys could reach the
mid 80s. A passing front could flatten the ridge somewhat, bringing
a bit of relief into Friday and Saturday before temperatures rebound
on Sunday. NBM probabilistic data keeps Medford out of the 90s for
this week, but has 40-60% chances for next Sunday and into the start
of the following week. -TAD

&&

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

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$