Klamath River, California Weather Forecast Discussion

783
FXUS66 KMFR 251051
AFDMFR
Area Forecast Discussion
National Weather Service Medford OR
351 AM PDT Thu Sep 25 2025
.DISCUSSION...An upper trough will swing by to the north of the
area today and a dry surface cold front will push through. This
will mostly go unnoticed except for some gustier N-NW breezes that
will develop this afternoon/evening for inland areas. Along the
coast, a shallow marine layer this morning will cause some fog/low
clouds, but these should erode with sunny skies developing. High
pressure will then re-establish over the area tonight into the
weekend, which will bring more sunny, dry and warm weather. It
appears Saturday will be the warmest day across inland sections.
We are forecasting a high of 91F here in Medford. The flow will
become more southwesterly aloft Sunday as an upper trough
develops in the Gulf of Alaska. This trough will send a cold front
toward the PacNW Sunday night, which is forecast to move onshore
Monday. Gusty S-SW winds could precede the front Sunday in the
Shasta Valley and over the East Side. Guidance is showing a high
probability of rain across the CWA (generally 60-80% chance),
though slightly lower east of the Cascades. Most models are
showing that first front pushing east of the area Monday night,
and then another surge of precipitation with a second front/upper
trough Tue/Tue night, though there are some timing/strength
details that still need to be ironed out. Overall, though, it
looks like we`ll be transitioning to a breezy to windy, cooler,
wetter pattern Mon-Wed of next week with some beneficial
rainfall, which should, at the very least, lessen the impacts of
late-season fires burning in the region. -Spilde
&&
.AVIATION...25/12Z TAFs...Along the coast and just offshore, LIFR
conditions are expected to impact portions of the Coquille Basin,
including at North Bend, and also areas south of Port Orford this
morning under a shallow marine later. Offshore flow will re-
establish south of Cape Blanco today, so conditions there improve to
VFR as the winds erode the marine layer. Gusty north winds will
develop again this afternoon at North Bend (~25 kt).
VFR conditions will continue through the TAF period for inland
locations. Expect more widespread breezy to gusty north to northwest
winds to develop this afternoon as a dry front passes through the
region. -Spilde
&&
.MARINE...Updated 230 AM PDT Thursday, September 25, 2025...A
thermal trough will maintain gusty north winds through Friday,
resulting in steep to very steep and hazardous seas, steepest south
of Cape Blanco. North winds could briefly approach gales south of
Port Orford each afternoon and evening (today and Friday). Winds
ease on Saturday, then turn southerly on Sunday ahead of the first
appreciable storm system of the season. Meanwhile, seas will
transition to swell dominated as northwest swell increases late
Saturday and persists into early next week. Active weather is likely
through the first half of next week. -Spilde
&&
.FIRE WEATHER...Updated 300 AM PDT Thursday, September 25, 2025...
Dry weather will continue through this weekend with afternoon
temperatures trending downward for the interior. We`ll have improved
recoveries this morning with less wind for southwest Oregon and
western Fire zone 280.
An upper trough will swing through the area today with a dry cold
front moving through the area. In the wake of the front, the
pressure gradient will tighten up with gusty breezes setting up
along and east of the Cascades this afternoon, lasting into early
this evening. At the same time, relative humidity will be low, but
not as low as recent days. While winds will be gusty with fairly low
afternoon RH, we`re not expecting criteria for a Red Flag Warning.
As such, we`ll continue with a headline at the top of the Fire
Weather Planning Forecast.
In the wake of today`s dry front, there`s good agreement another
thermal trough will set up along the south Oregon coast. Similar to
the one earlier this week, models are showing gusty northeast winds
(15-20 kt) at 925 mb along the southwest Oregon coast, and similar
speeds at 850 mb in portions of Fire zone 280 tonight into Friday
morning. As is often the case with thermal troughs, the strongest
winds will be on the first night, but RH recovery should be OK
(generally moderate in the 40-60% range). It`ll be drier the second
night, Friday night into Saturday morning, but with slightly less
wind. Poor RH recovery of 25-35% is forecast for the upper
slopes/ridges of western Siskiyou County, the west slopes of the
Cascades and the coast ranges.
While temperatures will warm along the southwest Oregon coast due to
offshore flow Friday, most of the area will be slightly cooler
(compared to today) behind the dry front. The upper ridge will shift
over and then to the east of the area on Saturday. This will be the
warmest day inland, but onshore flow should begin a cool down along
the coast.  Meanwhile, a strong upper trough will set up near the
Alaska panhandle. The upper trough will deepen in the Gulf of Alaska
on Sunday with a stronger southwest flow setting up over the area.
Winds aloft are expected to increase, especially east of the
Cascades where they could experience moderate to occasionally strong
winds in the afternoon and early evening. The good news is relative
humidities will be higher.
Eventually, this upper trough will send a frontal system to the
coast Sunday night into Monday. This should bring a transition to a
wetter pattern for most of the area that will last through mid next
week. Confidence is pretty high for wetting rain along and west of
the Cascades. Meanwhile 700mb winds could be between 30-40 kts east
of the Cascades which could result in moderate to strong winds.
-Petrucelli/Spilde
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...CA...None.
PACIFIC COASTAL WATERS...Small Craft Advisory until 2 AM PDT Saturday
     for PZZ350-356-370-376.
Hazardous Seas Warning from 11 AM this morning to 2 AM PDT
     Saturday for PZZ356-370-376.
&&
$$
MAS/MAS/MAS

NWS MFR Office Area Forecast Discussion