Altamont, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

665
FXUS66 KMFR 302120
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
220 PM PDT Sun Mar 30 2025

DISCUSSION...A compact surface low is evident on satellite
imagery this afternoon, located directly west of Brookings as of
the time of this writing. This low is tracking just as the high-
resolution models depicted earlier today, and is on track to pass
just offshore of southern Oregon and move onshore around Cape
Blanco or perhaps a bit to the north. This low is responsible for
significant wind concerns today, and we have been watching
coastal and marine wind gusts spread north from Cape Mendocino
throughout the day so far. Winds at the marine buoys and points
along the coast have seen dramatic increases in very short
periods of time. Meanwhile, inland winds have responded to a
strong MSLP gradient, and enhanced with momentum transfer due to
showers and mountain wave effects, mid level winds have translated
to the surface as gusts. It has been a challenge to nail down the
details of where winds will occur, as changes in the low track by
just a few miles can and have been making significant effects on
various areas. For instance, the low tracking just slightly closer
to the coast has enhanced the inland winds, while simultaneously
reducing the expected winds along the coast north of Cape Blanco.
The strongest winds should weaken once the low passes, while
overall, winds will taper off through the evening. Numerous wind
headlines remain in effect for much of the area, and details on
these can be found at PDXNPWMFR. A High Wind Warning for coastal
areas and Wind Advisories for inland areas are in place into this
evening to highlight possible hazardous conditions. Additionally,
this front will bring slight thunderstorm chances (10-15%) along
the Oregon coast this evening and tonight with lesser chances for
inland areas west of the Cascades. And of course, any
thunderstorms are likely to produce additional periods of locally
gusty winds.

Impactful conditions turn from wind to winter on Monday and
Tuesday. With the front off to the north, a low pressure system
will draw closer to then move over the area. A cold air mass
moving with this system will bring cooler temperatures and lower
snow levels across the area. Southwesterly flow aloft will
continue to bring precipitation across the area. Snow levels are
forecast to drop to 2500-3500 feet through Monday and Tuesday,
with hazardous winter weather possible in certain areas. A Winter
Storm Watch has been upgraded to a Winter Storm Warning for areas
in Siskiyou County above 4500 feet, and will be in place from
early Monday morning through Tuesday evening. Peaks and ridgelines
in Siskiyou County could get 1 to 3 feet of snow through this
timeframe. Sawyers Bar Road west of Etna could see over 2 feet of
snow in places. A Winter Weather Advisory covers the Cascades and
Mount Ashland in the same timeframe, with 12 to 24 inches of
snowfall possible in these areas. A shorter Winter Weather
Advisory is in place for areas along I-5 south of Weed and Highway
89 from Tuesday morning through Tuesday evening. Snow levels are
forecast to reach their lowest in this period, possibly bringing
impactful snowfall to these highways and cities in this area.
Additionally, snow amounts to the east of the Cascades will just
reach advisory criteria, although spread out over Monday and
Tuesday. Another Winter Weather Advisory has been issued there,
with mention of more gusty winds that could result from the
expected showers.

For other areas, generally light to moderate precipitation
continues on Monday and Tuesday. Increased thunderstorm chances
(15-25%) are forecast for areas west of the west of the Cascades
on Monday afternoon. Curry and Josephine counties may see a period
of increased precipitation on Tuesday morning. Gusty southwest
winds are forecast to continue over elevated terrain, but that
change of direction will prevent further funneling into the Shasta
and Rogue valleys.

Active but less impactful weather continues on Wednesday, as an
upper trough moves over the area. Northwest flow along the back
edge of the trough could bring continuing showers and cool
temperatures on Wednesday and Thursday. As the upper pattern
continues to move eastward, a high pressure system could settle
over the area while low pressure remains over the southwest United
States. This rex block pattern (high pressure poleward/north of a
low pressure system) could bring a period of warmer temperatures
and drier conditions. Meteogram guidance supports this, with both
ECMWF and GFS outcomes showing an absence of precipitation for the
first weekend of April and only weak signals for the week beyond.
-BPN/TAD

&&

.AVIATION...30/18Z TAFs...A compact low pressure system is moving
northward through the coastal waters at this time. Mostly light
offshore east or southeast winds exist north of this system, but
where winds have aligned (here in the Rogue Valley), wind gusts have
already been in the 35-40kt range. Low-level wind shear still could
be an issue in those areas where winds have yet to increase (North
Bend/Roseburg) for the next few hours, but expect winds to surface
abruptly in those areas in the 21-23Z time frame with wind shift
from SE-SW. Similarly, gusty SE winds here at Medford and in Klamath
Falls will also shift to SSW this afternoon. Peak gusts will
continue to be in the 35-40 kt range. As the low moves northward and
eventually inland, winds will ease this evening/overnight. Expect
prevalent ceilings to be VFR through the TAF period, but also MVFR
at times with higher terrain obscured in areas of heavier
precipitation. -Spilde


&&

.MARINE...Updated 230 PM Sunday, March 30, 2025...A compact, but
potent low pressure system is moving through the coastal waters
currently. South and east of the low center, observations showed an
abrupt increase in southerly winds to gale force with gusts to 47kt
at Buoy 27 between 1 and 2 pm. To the north and east of the low,
winds were fairly light out of the ENE. Models are showing the low
moving onshore in between Cape Blanco and Newport by 5 pm PDT this
evening with a wind shift to SW behind it across the coastal waters.
Winds will remain gusty (and to gale force), especially in any
showers through this evening. Isolated thunderstorms are also
possible.

The next low pressure system will likely maintain steep to very
steep seas overnight through Monday and into Tuesday morning, with
peak seas of 13 to 18 ft at 12 seconds Monday night into early
Tuesday. Expect showers to continue, along with a slight chance of
thunderstorms. A tapering to steep seas follows late Tuesday morning
through Tuesday evening. Gradual improvement is expected to continue
Tuesday night into the end of the week with light to moderate
northerly winds. -Spilde


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 8 PM PDT this evening for ORZ023-024-026-
     029>031.

     Winter Weather Advisory from 11 PM Monday to 5 PM PDT Tuesday
     for ORZ027>031.

     High Wind Warning until 8 PM PDT this evening for ORZ021-022.

CA...Winter Storm Warning from 11 PM this evening to 5 PM PDT Tuesday
     for CAZ080-082-083.

     Wind Advisory until 8 PM PDT this evening for CAZ081-084-085.

     Winter Weather Advisory from 11 PM Monday to 5 PM PDT Tuesday
     for CAZ082-085.

PACIFIC COASTAL WATERS...Gale Warning until 8 PM PDT this evening for
     PZZ356-376.

     Hazardous Seas Warning from 8 PM this evening to 8 AM PDT
     Tuesday for PZZ350-356-370-376.

     Gale Warning until 8 PM PDT this evening for PZZ350-370.

&&

$$