Gale Watch 13, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
213 PM PDT Tue Aug 11 2020

.DISCUSSION...Expect hot, dry and breezy conditions for the rest
of today. It will be hot in absolute terms because we're very
close (just passed) to the hottest time of the year, and also in
relative terms because high temperatures are expected to be about
5 degrees above normal for most locations. A dry cold front will
provide the "breezy" part of the day, with many locations gusting
into the 30s(mph) east of the Cascades, and areas west of the
Cascades will gust well into the 20s(mph). A Red Flag Warning
continues into this evening for portions of Southern Klamath and
Lake Counties while a Fire Weather Watch continues for tomorrow
afternoon for portions of Modoc County.

Right in line with what was expected this afternoon, thunderstorms
have developed in Lassen County and have started to move into and
across far southeastern Modoc County. Most lightning with these
storms has so far been cloud-to-cloud, but there have been
several ground strikes as well. This convective activity should
continue into the evening, and is expected to spread a bit north,
reaching far southern Lake County by this evening.

Winds will trend lower, along with temperatures, on Wednesday, with
the exception of areas well east of the Cascades where stiff
afternoon breezes are expected again. Wednesday will feature the
coolest temperatures of the week. These relatively cooler
conditions will continue through Thursday (although afternoon high
temperatures will still be around normal for this time of year).

On Friday a warming trend will begin as a large upper ridge of high
pressure builds over the Desert Southwest and the thermal trough
pushes inland. At least a couple of afternoons with 100+ degree
temperatures are expected in the Rogue Valley and surrounding
areas, including the Shasta and Klamath Valleys of Siskiyou
County, and the valleys of Josephine, Curry, and southwest Douglas
Counties. At this time, it does appear that Excessive heat
headlines will likely be necessary Saturday and Sunday, and may
even extend another day or so into next week. Decisions on these
will be made in the coming days.

While hot conditions are very likely at this time, any details on
thunderstorm potential, which usually follows heat events like
this, are still uncertain. The models are starting to show some
convective potential, especially in western Siskiyou County, by
Saturday afternoon, where instability, lift, and moisture appear
to line up in the latest runs. Thunder may also be possible for
some areas Sunday afternoon as well, likely more in line with the
Cascades and East Side, but nailing down exact locations and
timing is very uncertain this far out. Stay tuned as we try to
hone in on the likely evolution of the pattern ahead of us.

-BPN/Keene

&&

.AVIATION...For the 11/18Z TAF Cycle...VFR will prevail across the
inland areas through the TAF period. The exception will be along
the coast early this morning. A narrow band of marine stratus hugs
the coast near Brookings. Coastal stratus is expected to return a
bit inland again tonight. There will be breezy to gusty winds
across the area this afternoon into the evening, especially east of
the Cascades and inland valleys west of the Cascades. -Sven

&&

.MARINE...Updated 110 PM PDT Tuesday 11 August 2020...The thermal
trough will continue to weaken today into Wednesday as an upper
level trough swings through the area and disrupts the pattern.
Conditions will gradually improve today, especially north of Cape
Blanco. However, winds and seas will remain hazardous to small craft
through tonight for areas south of Port Orford. Conditions will be
improved for all areas for a brief time early Wednesday morning and
afternoon.

The thermal trough will rebuild Wednesday evening and strengthen
into Friday. Conditions hazardous to small craft will return south
of Cape Blanco by late Wednesday afternoon. Winds and seas will
build further Thursday afternoon into Friday. Conditions hazardous
to small craft will likely spread north of Cape Blanco, and gales
will be possible south of Cape Blanco. Winds and seas will peak
Friday, then gradually diminish Saturday into Sunday.

&&

.FIRE WEATHER...Updated 200 PM PDT Tuesday 11 August
2020...Isolated thunderstorms are expected this afternoon and
evening from the Mount Shasta area east, edging into southern
Lake county this evening.

The main concern for Wednesday is gusty winds and low humidities
east of the Cascades. At this time, the critical area looks to be
Modoc County. A Red Flag Warning has been issued for that area.

Relative benign conditions are expected Thursday and Friday. While
temperatures will be warming and humidities will be decreasing,
winds will be lighter as well.

The possibility of thunderstorms creeps back into the forecast
Saturday, but chances look minimal at this time.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning until 9 PM PDT this evening for ORZ624-625.

CA...Red Flag Warning until 9 PM PDT this evening for CAZ285.

Pacific Coastal Waters...Small Craft Advisory until 5 AM PDT Wednesday for PZZ356-376.
     Small Craft Advisory from 5 PM Wednesday to 5 PM PDT Thursday
     for PZZ356-376.
     Hazardous Seas Warning until 5 AM PDT Wednesday for PZZ356-376.