876
FXUS66 KMFR 081610
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
910 AM PDT Tue Jul 8 2025

.DISCUSSION...Last night`s storms brought over 1,300 cloud to
ground strikes, and most were concentrated in Jackson County.
Today`s temperatures will be slightly cooler compared to yesterday
with highs mainly in the upper 80s and low 90s. The main changes
this morning were to increase afternoon winds, especially in the
Shasta Valley.

This afternoon will bring more thunderstorm chances, and this will
be highest in northern Klamath and Lake counties. The threat for
isolated thunderstorms spreads west through the Rogue Valley and
south into western Siskiyou County. The thunderstorm chances for
today and Wednesday will be reviewed this afternoon. Temperatures
are still on track to be near normal Wednesday and Thursday with
an increase Friday into the weekend. -Hermansen

&&

.MARINE...Updated 845 AM PDT Tuesday, July 8, 2025...Conditions
have improved for all areas and will continue through Wednesday,
then the thermal trough returns for the latter half of the week with
steep seas possible. -DW/Hermansen

&&

.PREV DISCUSSION... /Issued Issued by National Weather Service
Eureka CA/

DISCUSSION...This morning will be warmer with more west side
locations seeing lows in the 60s, but afternoon temperatures will
not be as warm as yesterday`s. An upper low near San Francisco
will be moving towards Southern Oregon later today into
Wednesday, and this will bring breezier conditions in the
afternoons. Another thunderstorm chance comes in the afternoon.
This will be focused on northern Klamath and Lake counties at a
25-35% chance while a line of 15-25% chances extends to the
southwest into Siskiyou County.

The last thunderstorm chance of this string comes Wednesday and
is concentrated in central Lake County and eastern Klamath County.
Forecast CAPE values in this region will be near 250-350 J/kg.
Surrounding areas have CAPE up to 200 J/kg, so will look at this
as the CAMs come in to see if the coverage needs to be extended.

In the long term ridging will start to build into the weekend, and
this will bring a return of heat the area. There is currently a 70-
90% probability to see 100 degrees in Medford from Friday through
early next week. For now, dry conditions are forecast during that
time frame. -Hermansen

AVIATION...12Z TAFs...After overnight thunderstorms, the marine
layer has moved into the coast, settling over the Brookings and
North Bend terminals. The layer is shallow, with mostly LIFR
ceilings/visibilities and some periods of fog. Improvement in
visibility and some lifting to IFR ceilings is possible this
afternoon, but the low ceilings will likely remain embedded most of
the day. An area of low pressure will be moving through North CA
tonight and through Wednesday morning. Soundings show some deepening
of the marine layer in response, and this may introduce some
variability in ceiling heights along the coast. There is a high
chance for IFR ceilings and potentially some periods of MVFR. LIFR
ceilings are also expected, but the duration is in question with a
potentially deepening marine layer. The low will kickoff additional
thunderstorms this afternoon mainly across northern Klamath/Lake
Counties.

FIRE WEATHER...Isolated to widely scattered thunderstorms (15
to 35%) continue this afternoon/evening as the low edges closer
to the coast. East Side areas north of the Sprague River Valley
and NW of Abert Rim (northern sections of FWZs 624/625) have the
highest probabilities of thunderstorms (25-35%), so we have
upgraded the Fire Weather Watch to a Red Flag Warning (2-11 pm
PDT) there, but isolated activity could extend back to the SW
across the Cascades to northern and western Siskiyou County.
Models show the convection beginning in our area, then lifting
north into Deschutes County, so there are some uncertainties in
quantity of lightning prior to the storms exiting to the north.

By Wednesday, an upstream "kicker" trough will cause the low off the
Cal coast to move onshore. This will maintain a slight chance to
chance of thunderstorms across SE portions of the forecast area,
but especially from Modoc County northeastward into southern Lake
County. We have added a Fire Weather Watch to the SE portion of FWZ
624 and southern part of FWZ 625 (2-8 pm PDT) for abundant
lightning on dry fuels. The trough axis pushes east of the area
fairly quickly Wednesday evening, so felt confident enough that
convection would be ending earlier in the evening.

Following the trough passage, drier westerly flow aloft moves in
Wednesday night and the thunder risk ends. Expect slight cooling
Wed/Thu over inland areas, but northeast winds provide warmer
weather to the south coast. A return of hotter weather is expected
Friday into the weekend with fairly typical late-day summertime
breezes, but also dry afternoon humidity and poor to moderate RH
recovery at night. -Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 2 PM this afternoon to 11 PM PDT this
     evening for ORZ624-625.

     Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for ORZ624-625.

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$