Helm, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

712
FXUS66 KMFR 250527
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1027 PM PDT Sun May 24 2026

...Aviation Discussion Updated...

.DISCUSSION...

Key Points:

* Thunderstorm chances (10-20%) exist near central and southern
  Siskiyou County near Gazelle and Mount Shasta, this afternoon.
* The next trough arrives Monday afternoon, bringing a chance of
  rain.
* Monday will have strong westerly winds and 10-20% RH east of the
  Cascades.

There are cumulus clouds in Lake and Siskiyou counties. A 10-20% of
showers in southern and central Siskiyou County near Gazelle and
Mount Shasta exists this afternoon. Once again, these showers will
bring less than 0.10" of rainfall for the aforementioned areas.
Temperatures are on track to warm to the 60s/low 70s at the coast,
80s in the west side, and 70s/low 80s for east of the Cascades. If
you`re enjoying the ~10-15 degree above normal temperatures, enjoy
it today because a cooldown will begin tomorrow.

Rain chances will return to more of Southern Oregon and Northern
California Monday. The mean timing shows an arrival at the coast
near 9-10 AM, with the median time for west side valleys not until 5-
7 PM. Forecast models are hinting at a line ahead of the cold front
could develop, and this would bring rain chances between 10-12 PM
for Siskiyou County and areas east of the Cascades. However,
rainfall will focus on Curry and Coos counties, and more of Douglas
County and along the Cascades. Between late Monday morning and
Wednesday morning, near 0.25"-0.50" is forecast for the coast and
portions of the Cascades near and north of Crater Lake. Between
0.05"-0.20" is forecast in west side valleys, with the Umpqua Basin
forecast to see the higher end. Forecast CAPEs are not highlighting
our area Monday, but values increase Tuesday afternoon, especially
east of the Cascades and in Modoc County.

Gusty winds will begin later Monday morning and will continue
through the late evening. Forecast 700 mb winds are near the 45-50
mph mark, resulting in 20-30 mph surface sustained winds in the
afternoon during peak mixing. Probabilities for wind gusts to reach
45 mph Monday for portions of Lake and Modoc counties are nearing 40-
60% Monday afternoon. However, portions of southern Lake County into
the Warner Mountains through Modoc County have a 60-80% probability
for gusts of 45 mph. There is a possibility for a Wind Advisory for
portions of Lake and Modoc counties including Summer Lake, Fort
Rock, and Valley Falls. In the Rogue and Shasta valleys, winds are
forecast to peak at 20-25 mph with gusts in the 30-35 mph range. As
stated above the rain will move inland in the afternoon Monday, but
the winds will impact outdoor Memorial Day activities.

Getting back to the temperatures, they will return to near normal by
Monday before another drop brings them to 10-15 degrees below normal
Tuesday (50s/low 60s). Showers remain Tuesday, and this will focus
on locations west of the Cascades, especially in Douglas and Coos
counties. The low will stall in the area, leaving us with cloudier
skies and below normal temps through at least Wednesday. For now,
the the low will move south Thursday, and this will rebound
temperatures to normal or warmer. -Hermansen

&&

.AVIATION...25/06Z TAFS...LIFR/IFR will be widespread along the
coast through Monday morning. Coastal ceilings will lift to MVFR,
southerly winds will increase, and rain will develop as a cold front
moves in late Monday morning. These conditions will then persist
through Monday afternoon and night.

Elsewhere, expect continued VFR into Monday afternoon. Gusty west to
southwest winds will affect all areas Monday afternoon, with strong
winds (gusts 30 to 45 kt) east of the Cascades. As rain spreads into
the area Monday afternoon and evening, expect mountain obscurations
and local MVFR ceilings.


&&

.MARINE...Updated 230 PM PDT Sunday, May 24, 2026...Winds and seas
briefly diminish this afternoon and evening. Wave heights will be
relatively low at around 5 to 6 feet at 13 seconds. A cold front
will move through the waters on the morning of Memorial Day bringing
rain and increasing seas. Seas will become steep again by Monday
afternoon, with the strongest south winds expected to occur north of
Cape Blanco. Steep, northwest swell builds in behind the front
Monday afternoon and night, reaching a peak on Tuesday morning.
These west-northwest swell dominated seas are expected to peak at
around 13 to 17 ft at 14 seconds. Diminishing seas are expected to
remain steep later Tuesday into Wednesday morning.

After brief, slight improvement, high pressure offshore and
lingering low pressure inland are likely to bring increasing north
winds on Wednesday afternoon with the strongest winds likely to
occur south of Gold Beach. The gusty north winds and a long period
west-northwest swell are likely to bring a return of steep seas
Wednesday night into Thursday while a long period west-northwest
swell builds.

&&

.FIRE WEATHER...Updated 100 PM PDT Sunday, May 24, 2026...Most
areas in Southern Oregon and Northern California will remain dry
through the weekend, with the exception of a few showers/isolated
thunderstorms in central Siskiyou County. Recent min RHs in the
Rogue Valley, Northern California and east of the Cascades are in
the 15-25% range. There is an elevated threat for fire weather
conditions in the coming days.

Monday will bring the highest threat with stronger winds ahead of a
cold front. Sustained southwest/west winds east of the Cascades and
in the Shasta Valley will be in the 20-25 kt range. As it stands,
there is still a 40-60% probability to see gusts reach 45 mph and
this increases to 60-80% near Summer Lake, Lakeview and south near
the Warner Mountains. There is more agreement that the cold front
will arrive at the coast Monday afternoon, leaving an opportunity
for peak heating and gusty winds to combine east. The latest reports
on fuel conditions from fire agencies bring enough of a concern to
issue a Red Flag Warning. This includes southeastern Modoc County
and most of Lake County, and this cuts into eastern Klamath County
as well. This will be in effect starting at 1 PM Monday, and will be
in effect through 8 PM for southern Oregon locations and 11 PM for
portions of Modoc County. Precautionary actions should continue,
especially during this higher threat Monday. -Hermansen



&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 1 PM to 11 PM PDT Monday for ORZ625.

CA...Red Flag Warning from 1 PM to 11 PM PDT Monday for CAZ285.

PACIFIC COASTAL WATERS...Small Craft Advisory from 11 AM Monday to 8
     AM PDT Wednesday for PZZ356-376.

     Small Craft Advisory from 5 AM Monday to 8 AM PDT Wednesday for
     PZZ350-370.

&&

$$