Dorris, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

623
FXUS66 KMFR 080540
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
940 PM PST Fri Mar 7 2025

...Updated AVIATION discussion for 06Z TAFs...

.DISCUSSION...Satellite image shows clear skies over the forecast
area, with the exception of a very think layer of high cirrus that
is barely visible in the satellite image.

It will be dry the rest of the afternoon through the weekend and
possibly into the early part of next week. The operational models,
and a majority of the ensemble members, and clusters are in good
agreement showing a split flow with the upper low splitting off from
the main flow and moving southeast into southern Cal Sunday night
into Monday. Typically split flows that track in the above mentioned
areas will not result in precipitation for our area. A few of the
individual ensembles show what would amount to trace amounts of
precipitation Sunday night into Monday morning, but the precip field
basically gets washed out, meaning trending towards nothing. This is
something to be expected in a split flow pattern. Would not be
surprised if the upper pattern remains consistent (which it has the
past few days), the ensembles will trend drier as well over time. As
is typical the NBM does not appear to take this into consideration
due to perhaps a bias correction as opposed to what the upper
pattern is being depicted by the various operational models,
individual ensemble members, and the clusters which all favor the
split flow patten mentioned above.

Therefore were going with a dry forecast through the weekend, and
would not be surprised if it remained dry into the start of next
week. The only exception could be Saturday night into Sunday morning
where there are some signs the marine layer could deepen enough for
a slight chance of drizzle over the marine waters and close to the
coast. When the models show a broad area of very light QPF over the
marine waters, typically this can result in a low marine cloud deck
with areas of fog or patchy to areas of drizzle.

The operational models and individual ensemble members are trending
drier on Tuesday and it could actually end up dry because we could
see brief upper ridging as the upper trough outside of 130W begins
to dig with the surface low deepening.

The main event for the forecast period will be Tuesday night. There
is still the potential for a strong low to develop late Tuesday
afternoon and night, then move inside of 130W Tuesday night into
Wednesday. The only difference is there`s good agreement the track
of the low is farther northwest. If this remain the case, then the
odds of wind impacts will be less, but non the less still exist and
precipitation amounts will be lower. The net result will be a strong
front reaching the coast Tuesday night, then moving inland during
the day Wednesday.

The operational ECMWF shows the rapidly deepening low, and the GFS
while weaker is trending towards the stronger ECMWF solution. We
also looked at the ECMWF ensemble surface low locations and the
spread is rather tight given how far out in the forecast this is,
and many of the members show the individual low placement farther to
the northwest. However the general consensus is for the low to
rapidly deepen. It`s still a long ways out there and the track and
strength of the low will vary. Thus, it will be something we`ll
continue to monitor in the days to come. Despite the difference in
the track noted above, we could still be dealing with a combination
of wind, rain and mountain snow, but the odds have lowered.

Right now, it appears as if main impacts will be coastal/Shasta
Valley and east side winds, widespread moderate to heavy rain
(heaviest coast ranges and into NorCal) and snow in the mountains.
Snow focus areas should be in NorCal mountains and over the Cascades
Tuesday night through Wednesday. This could still be an impactful
snow event on I-5 at Siskiyou Summit due to favorable upslope flow
that could bring moderate to heavy snow. Some east side areas could
get into the action since snow levels will be lowering Tuesday night
through Wednesday.

This storm could also result in moderate to strong winds along the
coast, Shasta Valley, east side, and possibly the Rogue Valley due
to favorable southeast flow. A look at the ECMWF EFI also shows
values that could be considered somewhat outside of the
climatological norm, but now it`s less so than what it was showing
yesterday at this time.

The cooler and wetter pattern is in the cards for the the latter
part of next week through next weekend. -Petrucelli


&&

.AVIATION...08/00Z TAFs...Clear skies and stable conditions support
continuing VFR levels across northern California and southern Oregon
tonight. Confidence has decreased in the chances of sustained
periods of low flight levels along the Oregon coast and in the
Umpqua Valley. While guidance shows signs of ceilings developing,
those signs have decreased over time. Periods of LIFR conditions
remain in the TAFs for North Bend and Roseburg, but with slight to
moderate confidence. Anything that develops overnight should clear
out on Saturday morning.

VFR conditions will continue across the area through the day
Saturday. An approaching front is expected to split, keeping showers
to the north and south. Gusty winds are possible along and near the
coast on Saturday afternoon. Areas of low level wind shear may
develop over elevated terrain west of and along the Cascades on
Sunday evening, with winds at 2000 feet from 180-200 degrees at
speeds of 35-40 kts. Currently, area terminals do not look to be
affected. -TAD

&&

.MARINE...Updated 200 PM PST Friday, March 7, 2025...High
pressure over the area today will bring dry weather and relatively
light winds and seas. This evening into Sunday, a front will
approach the area, then weaken and move onshore late Sunday night.
Drizzle, lower visibility, and increased south winds and steep
combined swell and wind-driven seas are expected this evening
through Monday morning.

Tuesday night into Wednesday, a rapidly deepening low pressure
system may move inside of 130W and track near the coast or just
north to northwest of the area. This would result in a potential for
strong south winds and very steep seas for the coastal waters.
However, confidence is low on the track and intensity of this
system, so we will continue to monitor and update with details.
-BPN


&&

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

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 10 AM Saturday to
     11 AM PST Monday for PZZ350-356-376.

     Small Craft Advisory from 4 AM Saturday to 11 AM PST Monday for
     PZZ370.

&&

$$