038
FXUS66 KMFR 111009
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
309 AM PDT Fri Jul 11 2025

.DISCUSSION (Today through Thursday)...

Overview:

Overall, the main impact continues to be the upcoming heat wave
which will cause at least elevated fire weather concerns. That said,
not expecting critical fire weather conditions which would warrant a
Red Flag Warning at this time. Also noteworthy is the very small
chance for an isolated thunderstorm or two Sunday afternoon. This is
a very low confidence scenario and only showing up in very select
model guidance. This would be mainly for parts of northern
California albeit very low chance.

Further Details:

High pressure aloft will slowly slide west and expand over the
western CONUS the next several days. The flow over the PacNW will be
mostly west/northwesterly with only weak disturbances within this
flow. Notably on Sunday is a very weak disturbance on the northern
periphery of this high pressure. Very weak dynamics and minimal
MUCAPE values <200 J/kg will be noted. Moisture is lacking and
upper level jet dynamics are also unfavorable for upper level
divergence. Overall, this is a very weak setup for thunderstorms,
but given the likelihood reaching convective temperatures, this is
a non-zero chance day. However, at 5%-15% this is also not a
overly optimistic scenario for thunderstorms, but cannot rule out
one or two storms over mainly Siskiyou and Modoc counties Sunday
afternoon and early evening.

Given the general height rises over the area through the next
several days, we are looking at a prolonged stretch of hot weather
through at least middle of next week. We could see 5 days in a row
of at least 100 degrees for several of our low elevation areas that
are typically our hottest areas. For perspective, the record for
Medford of consecutive 100 degree days is 10 days in a row. This was
set in both 1967 and 1962. Last year we had a stretch of 7 days that
was good for 6th all time. While we may not reach 6 days in a row,
this is still a notable stretch of warm weather. Nailing down the
winds will be crucial through this stretch as RH values will be
critical for many areas. While we are not expecting the critical
overlap of both RH and wind that would warrant a Red Flag Warning,
this stretch will achieve at least elevated fire weather
concerns.

-Guerrero

&&

.AVIATION (06Z TAFs)...

Coastal IFR/LIFR along the coast north of Cape Blanco will expand
into the Coquille Valley overnight. Low clouds will lift and
clear in the late morning and early afternoon, with mainly VFR
returning along the coast. IFR/LIFR are expected to move onshore
again Friday evening. Gusty afternoon winds are expected along the
coast Friday afternoon/evening. Elsewhere, VFR will persist with
breezy late afternoon and evening northwest winds.

&&

.MARINE...Updated 300 AM PDT Friday, July 11, 2025...A thermal
trough will continue to strengthen over the next several days. This
pattern will bring gusty north winds and steep wind-driven seas to
the waters along with areas of gales and very steep seas south of
Cape Blanco. The strongest winds will occur south of Port Orford.
This pattern is expected to persist through early next week.

&&

.FIRE WEATHER...Updated 300 AM PDT Friday, July 10, 2025...

Above normal temperatures are expected today. Increasing heat
expected across the region this weekend into early next week as
upper level ridging builds in aloft and an thermal trough
develops at the surface. Meanwhile, expect fairly typical late-
day summertime breezes, but also dry afternoon humidity. Also, a
general easterly/offshore flow is forecast to develop over the
coastal mountains and Klamath/Siskiyou mountains each night, which
may result in moderate to locally poor RH recoveries, especially
over the ridgetops where overnight gusts could reach up to 25 mph.
This will not be a necessarily strong east wind pattern, but it
will be sustained for several days.

While there are no substantial threats for thunderstorms through at
least the middle of next week, a passing weak impulse will help
produce some weak instability over the area Sunday afternoon. As a
result, we will see some cumulus cloud buildups across the area,
and perhaps a stray shower or very isolated thunderstorm over
southwestern Siskiyou county. Most likely, the entire area will be
dry.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Extreme Heat Warning from 2 PM Saturday to 8 PM PDT Monday for
     ORZ024-026.

     Heat Advisory from 2 PM Saturday to 8 PM PDT Monday for ORZ023-
     025-029>031.

CA...Extreme Heat Warning from 2 PM Saturday to 8 PM PDT Monday for
     CAZ080-081.

     Heat Advisory from 2 PM Saturday to 8 PM PDT Monday for
     CAZ082>085.

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

     Small Craft Advisory until 8 PM PDT Saturday for PZZ350-370.

&&

$$