Hamburg, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

560
FXUS66 KMFR 272337
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
437 PM PDT Tue May 27 2025

.DISCUSSION...Updated Aviation section...

&&

.AVIATION...28/00Z TAFs...VFR prevails area wide late this
afternoon and this will continue for all inland areas tonight into
Wednesday. A weakening thermal trough and increasing onshore
flow will allow marine stratus to develop at the coast tonight,
including North Bend. Expect mostly MVFR ceilings, but areas of IFR
are possible, especially along the south coast near Brookings. These
clouds should break up to VFR late Wednesday morning. Some buildups
are expected over the mountains (Cascades/Siskiyous) east and south
Wednesday afternoon with isolated showers/thunderstorms possible
into the evening hours. -Spilde

&&

.PREV DISCUSSION... /Issued 248 PM PDT Tue May 27 2025/

SYNOPSIS...

* Mainly dry conditions with late July/early August temperatures
  expected this week, peaking Friday and Saturday. High temperature
  records could be tied across northern California.

* Weakening front expected late Wednesday into Thursday, bringing
  light rain to the coast, a slight chance of thunderstorms east of
  the Cascades, gusty winds and a slight cool down for Thursday.

* Significant cooldown expected late weekend into early next week
  with potential for precipitation (15-35%).

High pressure is building over the region today, then will amplify
on Wednesday while shifting eastward over the Intermountain West.
This amplification will be in response to a deep upper level
trough approaching the West Coast that will send a front through
the Pacific Northwest late Wednesday into Thursday. High pressure
returns on Friday, bringing the hottest temperatures of the
forecast period, followed by another shortwave trough late
Saturday into Sunday. Energy on the backside of this shortwave
trough will carve out a deeper, cut off low nearly right over
southern Oregon and northern California Monday into Tuesday,
resulting in a significant cool down with precipitation potential.

SHORT TERM...this afternoon through Thursday (5/29)...Aside from a
thin layer of cirrus streaming over the East Side and some cumulus
clouds developing over Modoc County, skies are clear across the
region this afternoon. Temperatures are running around 5 to 10
degrees warmer than this time yesterday, putting the region on track
for afternoon highs more typical of late July/early August. High
pressure is building over the area today and will amplify while
shifting eastward on Wednesday.

For most of Wednesday, high pressure will remain in control, but a
deep upper level trough will approach the west coast. This will
result in dry conditions for most areas, along with another warmer
than normal day (though slightly cooler than today`s readings). A
weakening front will move through Pacific Northwest late Wednesday
into Thursday. Ahead of the front, expect gusty afternoon winds on
Wednesday with gusts of 15-25 mph common. Additionally, guidance
indicates enough instability for a few thunderstorms to develop
Wednesday afternoon. The best chances for this would be from the
Trinity Alps, north up the Cascades and eastward across northern
Klamath/Lake Counties. There really isn`t a well defined trigger
coming through Wednesday afternoon since the main front isn`t
expected until overnight, but moisture and instability are there.
Storms should be isolated and diurnally driven, so lightning
activity will diminish around sunset.

Much like recent systems, the front associated with this trough will
weaken as it moves into our area, and the bulk of the energy and
moisture will be north of the forecast area. Even still, some light
precipitation is expected along the coast, mainly north of Cape
Blanco, but the inland extent of measurable precipitation (less
than 0.10") will be limited to areas west of Roseburg. We`ll see
another breezy afternoon on Thursday as well as continued cooler
temperatures with afternoon readings in the upper 70s/low 80s across
the area.

LONG TERM...Friday (5/30) through Tuesday (6/3)...Friday will be a
stark contrast compared to Thursday`s conditions as the ridge and
thermal trough return in full force. A sharp warming trend is
expected with afternoon temperatures a few degrees warmer than peak
summer values. Recent guidance seems to have trended downward
slightly with Friday`s temperature forecast, now showing highs
across forecast area (with the exceptions of the coast and
mountains) are expected to be in the upper 80s and low to mid 90s.
Values in the upper 90s with triple digit highs possible are most
likely across the valleys of Siskiyou County. Currently, HeatRisk
values show a moderate risk of heat-related illnesses focused over
Siskiyou and Modoc Counties, and this could be the region where some
heat-related headlines are needed. Will see how guidance trends over
the next 24 hours or so before deciding. It is worth noting,
however, that these values could tie a few daily records for May
30th (previously set in 1986) across northern California.

The focus of the heat shifts eastward on Saturday, and this will be
the warmest day of the forecast period for areas east of the
Cascades. Another day of records being tied is possible on Saturday
across northern California and east of the Cascades while
temperatures west of the Cascades cool slightly. Another shortwave
trough will pass through the region on Saturday, bringing another
round of gusty winds. Winds could be stronger with this trough, with
gusts of 20 to 30 mph possible Saturday afternoon. Unlike the system
expected on Wednesday, however, moisture and instability look
insufficient for thunderstorm development at this time for Saturday.

Sunday into next week, the pattern looks to transition to a
significantly cooler one compared to what`s expected this week,
resulting in temperatures more like late April. Energy from the
shortwave trough will carve out a deep upper level low over the
western US that will linger over the region well into next week. The
current forecast has precipitation chances in the 15-35% range for
Monday and Tuesday, highest east of the Cascades with snow levels
hovering about 6000 ft. To illustrate the potential "thermal
whiplash" that we may see next week, the current forecast has a high
temperature of 98 on Saturday. By Monday and Tuesday, models are
suggesting highs may not even rise above 70 degrees. Stay tuned as
details regarding this pattern change become more clear. /BR-y

AVIATION...27/18Z TAFs...A mainly VFR TAF cycle is forecast for
the next 24 hours with mostly clear skies and generally light wind
speeds. There will be a weak marine push late tonight into
Wednesday morning that could bring some MVFR ceilings to the
coast. Overall, expecting great flying conditions weather-wise
through this cycle.

-Guerrero/Hermansen

MARINE...Updated 230 PM Tuesday, May 27, 2025...Breezy northerly
winds across the southern waters will start to weaken through this
evening. Until then, steep seas continue south of Cape Blanco
through early tonight. Seas are also forecast to decrease late
tonight, with below advisory seas returning to all waters by early
Wednesday morning.

Westerly swell increases Wednesday night and northerly winds start
to increase on Thursday night under a more substantial thermal
trough pattern. Steep to very steep and hazardous seas are possible
across all waters Friday through the weekend. Current guidance also
shows periods of gale gusts south of Gold Beach in this timeframe.
Conditions may start to improve on Monday. -Guerrero/Hermansen

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT this
     evening for PZZ356-376.

&&

$$

MAS/MNF/ANH