Likely, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

127
FXUS66 KMFR 042055
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
155 PM PDT Mon May 4 2026

.DISCUSSION...

Marine stratus still covers much of the coast and Umpqua Basin
this afternoon. We`re also watching some cumulus build ups along
the Cascades as the atmosphere begins to destabilize. The
Cascades and most of northern California will be areas to watch
for thunderstorms this afternoon. Convective available potential
energy(CAPE) is modest around 500-750 J/kg, which is enough to
support some stronger storms for our area. Upper level shear is
also about 20 to 30 knots out of the east. Main threats will be
some gusty winds and sporadic lightning through this afternoon and
early evening.

Thunderstorm activity will diminish tonight as the atmosphere
begins to stabilize. There could be some patchy fog along the
coast tonight and perhaps in some of the smaller river valleys.
The GFS and NAM are both showing some light QPF along the coast,
and that usually suggests some drizzle mixed with fog in the
marine layer. In any case, just something to watch out for
tonight.

The upper level low bringing all these thunderstorms will move
eastwards through the day on Tuesday into southern California as
high pressure begins to build over our region. The net effect will
be warming temperatures above normal for this time of year as
highs push into the lower 80`s here in Medford on Tuesday and mid
to 80`s through the rest of the week. Looking at Medford`s climate
data, we`ll be about 15 degrees warmer than the normal highs for
this time of year.

Towards Thursday, models are showing a short wave riding over the
top of this ridge in Washington. 850mb equivalent potential
temperature maps are showing a dry cold front approach our area
around early Thursday, yet it never really moves through according
to the GFS. With that said, our official forecast trends down
from 85 degrees to the upper 70`s on Friday, perhaps due to cloud
cover and the breaking down of the ridge. Our best chance at more
precipitation is towards Friday evening when the PoP is around
5-10% in our Oregon areas. Essentially, it`s looking pretty dry
and warm through the week.

&&

.AVIATION...18Z TAFS
MVFR ceilings will continue along the coast for the majority of
the TAF period with some clearing in the Umpqua Basin near RBG
later this afternoon. Showers and thunderstorms will start popping
up later this afternoon and evening over northern California and
the Cascades. These storms could produce some gusty outflows as
they move westwards. Fog and marine stratus will cover the coast
with some light drizzle and IFR ceilings later tonight.

&&

.MARINE...Updated 100 PM PDT Monday, May 4, 2026 An extended
period of relatively calm conditions will continue through much of
this week with west-northwest swell dominated seas likely
remaining below 10 ft through Friday. Light south winds and fog
are expected through tonight, with gradually diminishing seas.
Moderate north winds likely develop on Friday, with the return of
the thermal trough.

&&

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

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$