603
FXUS66 KMFR 030002
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
502 PM PDT Wed Sep 2 2026

.KEY MESSAGES...

* An unusually strong system for early September is producing
  widespread rainfall, along with gusty winds at the coast and
  across the East Side.

* Temperatures will be 15 to 25 degrees cooler than normal today
  and Thursday.

* Cooler conditions with shower chances persisting into early next
  week.

* Isolated to scattered thunderstorms expected on Thursday and
  again Sunday.

&&

.DISCUSSION...Widespread rain is ongoing across the region, and
will continue through this evening. So far, amounts have been
somewhat modest, but even these modest amounts are much more than
we would typically see during the first few days of September.
Precipitation will taper off from west to east as the afternoon
and evening wear on and the front passes.

By Thursday, the cold front will be in south eastern Oregon and
weakening, while the upper level trough settles in overhead.
Showers and cooler temperatures will linger over the area for as
long as the trough remains overhead, which looks to be through
around Monday. In addition to the showers, a few thunderstorms
will probably develop over southern Oregon and northern California
Thursday through Sunday afternoons, mainly as a result of
increased instability due to the cold air aloft. The available
instablity is weak, so strong storms are not expected, but some
lightning is not out of the question as the CAPE touches the
-10C to -15C level. The NBM Tstorm probability is also 15-20%
across the majority of the area.

Although the air is unusually cold with this system, our
overnight low temperature forecast with the NBM/NDFD is likely too
cold, especially in some of the valleys east of the Cascades.
Lingering cloud cover from a low being overhead should keep
temperatures from dropping too low. For example, the NBM has 28
for a low at KLMT with a 30% probability of precipitation in the
region and a 6400 foot snow level Thursday night. Other
deterministic guidance has lows in the mid to upper 30`s at KLMT.

The upper level low will hang around until Monday, then there is a
chance that brief period of ridging will bring warmer, more
seasonable conditions back to the region. This would be short
lived, however, as ensemble guidance suggests another trough could
enter the area with another round of cooler temperatures and
precipitation chances.

&&

.AVIATION (00Z TAFs)...

A front making its way through the region is bring widespread
rainfall today and this evening. This will also result mainly MVFR
ceilings through this evening. Then, expect a mix of MVFR and VFR in
showers overnight and Thursday. Coastal areas are likely to maintain
MVFR and may see local IFR at times. Rainfall may also result in
reduced visibilities.

&&

.MARINE...Updated 1200 PM PDT Wednesday, September 2, 2026...South
gales and very steep and hazardous seas will continue until the
front passes onshore late this afternoon. While winds will diminish
behind the front, they will remain gusty with steep combined seas
continuing through Thursday night. Conditions improve further on
Friday, with winds shifting to the north, then remain relatively
calm through the weekend and into early next week.



&&

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

PACIFIC COASTAL WATERS...Gale Warning until 7 PM PDT this evening for
     PZZ350-356-370-376.

Small Craft Advisory until 2 AM PDT Friday for PZZ350-356-370-
     376.

&&

$$