Fire Weather Watch 14, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
202 PM PDT Tue Jul 13 2021

.DISCUSSION...13/12Z NAM/GFS/EC in.

Lots of marine stratus offshore. Mostly clear skies prevail over
the inland areas and the coast, except for areas of smoke mostly
emanating from the Jack and Bootleg fires. Expect the marine
stratus to move back onshore later this afternoon and into the
coastal valleys tonight.

Today will be the last really hot day of this high heat cycle.
High temperatures today will be about 10-15 degrees above normal
over northern California with the lower Klamath Valley seeing
highs in the 100-105 degree range. Most populated areas inland
will see highs 5-10 degrees above normal, ranging from the middle
90s to around 100 degrees. Excessive Heat Warnings and Heat
Advisories remain in effect. See NPWMFR for details.

Today will also mark the 24th consecutive day of 95+ degrees here
at the Medford Airport, the longest such streak on record. The
forecast high on Wednesday is 95 degrees, so it may increase to 25
days tomorrow. Thursday will be cooler and the streak is forecast
to end that day. To escape the heat (and the smoke, for that
matter), the coast will see highs in the lower 60s to lower 70s.
The sunniest areas will be from Port Orford to Gold Beach.

The strong upper ridge that has been dominating the weather
picture over the area will move out Wednesday, and it will be
replaced by a weak trough. This will bring in the relatively
cooler weather. While it will remain hot, inland high temperatures
will be around 10 degrees above normal Wednesday and around 5
degrees above normal Thursday. Friday will be cooler still, with
highs 0-5 degrees above normal.

However, a strong ridge will build over the intermountain states
beginning Saturday, and this will force the trough offshore
initiate a warming trend inland. By next Tuesday, inland high
temperatures will approach the values currently forecasted for
Wednesday. So, the break will last from Wednesday into Saturday,
then it's back to hot.

No thunderstorms are forecast over the coming week, but some of
the GEFS model ensemble members are hinting at the return of
convection as early as next Monday. The models are currently
forecasting consistent southwest flow over the area through the
extended period, but if the offshore trough digs a bit deeper,
this could turn the flow more southerly, thus opening the door for
monsoonal moisture to enter the area. At this time, the chances of
thunderstorms look minimal, but this will be monitored over the
coming days.

&&

.AVIATION...For the 13/18Z TAF Cycle...Over the coastal waters,
along the coast, widespread IFR cigs with areas of IFR vsby a little
offshore will fill into the coastal valleys again tonight.

Inland, clouds will not be an impact over the next 24 hours.
However, smoke from the Jack Fire east of Roseburg, and Bootleg Fire
northeast of Klamath Falls, is creating areas of MVFR/IFR visibility
with some higher terrain restrictions. This will prevail mostly to
the southeast and south of those fires today into this evening,
encompassing a large portion of south-central Oregon into far
northern California. Sven

&&

.MARINE...Updated 200 PM PDT Tuesday 13 July 2021...A strong
thermal trough near the coast will continue to produce strong north
winds and steep wind-driven seas across the area. Gales and very
steep seas will continue south of Cape Blanco, peaking in strength
during the afternoons and evenings. The thermal trough will weaken
Wednesday night into Thursday, and winds and seas will decrease at
that time. Sven

&&

.FIRE WEATHER...200 PM Tuesday 12 July 2021...Little change is
expected for the rest of this week, other than gradual cooling
Wednesday-Friday with slightly higher relative humidities in the
afternoons. It will remain dry through the weekend.

The main concern is a high Haines again into this evening (and also
Wed pm/eve) with a Haines 6 expected within the perimeter of the
Bootleg Fire with pyrocumulus likely. Given the high potential for
extreme fire behavior, a Red Flag Warning remains in effect until 8
pm PDT Wednesday. Most active burning period, though, is expected to
be from 2-8 pm.

For those folks in evacuation zones near the Bootleg Fire, we want
to stress how dangerous of a situation this is, and you will be much
safer well away from the fire. If you live in a level 2 evacuation
zone, consider evacuating early, or at the very least go over your
fire evacuation plan and gather your go kits so you can leave at a
moment's notice.

Hot, dry, breezy and unstable conditions are also expected across
much of the remainder of the area inland from the coast this
afternoon/evening and again Wednesday afternoon and evening. This
could result in increased fire behavior on the other actively
burning wildfires in the area. While we still expect breezy
conditions out there along with low RH, winds probably won't be
quite as gusty as they were yesterday, so no Red Flag Warning. Right
now, we're just headlining in the FWF. Wednesday, we could see an
uptick in winds in the afternoon and evening due to slightly
stronger winds aloft (at 700 and 600 mb) and tighter pressure
gradient. As a result a few locations in fire zone 625 could briefly
reach red flag conditions. However, a larger portion of fire zone
285 could reach Red Flag conditions for at least a few hours, and a
Fire Weather Watch will be in effect.

Meanwhile, the thermal trough pattern along the south Oregon coast
will continue into Wednesday, this will result in moderate to
locally poor overnight recoveries at the mid slopes and ridges in
fire zones 618, 619, western 620 and western fire zone 280 in
California. Guidance suggest breezy east to northeast winds, except
for fire zone 280.

The upper trough that will bring some cooling into the area is
expected to remain parked over the eastern Pacific with the ridge in
the vicinity of the four corners. This will result in a more south
to southwest flow, but more importantly could bring in an increase
of monsoonal moisture, thus increasing the concern for at least
isolated thunderstorms mainly east of the Cascades. Keep in mind
since were still several days out from this, the specifics on
locations, timing etc. will vary from day to day. At this point
it's something will monitor closely. -Petrucelli

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning until 8 PM PDT Wednesday for ORZ624.
     Heat Advisory until 8 PM PDT this evening for ORZ029>031.
     Heat Advisory until 8 PM PDT this evening for ORZ024-026.

CA...Excessive Heat Warning until 8 PM PDT this evening for
        CAZ080>082.
     Heat Advisory until 8 PM PDT this evening for CAZ083>085.

Pacific Coastal Waters...Small Craft Advisory until 11 PM PDT
        Wednesday for PZZ350-356-370-376.
     Gale Warning until 11 PM PDT Wednesday for PZZ356-376.

15/15/04