Special Weather Statement, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
234 PM PDT Tue Aug 9 2022

.SYNOPSIS...An upper low currently offshore will bring another
round of active weather east of the Cascades through this evening.
Dry weather will return Wednesday and is expected to last through
early next week. Afternoon temperatures will remain above seasonal
norms for interior locations into early next week, with hot
temperatures possibly returning mid to late next week.

&&

.DISCUSSION...The upper remains off the northwest California coast
this afternoon, but a look at the high and mid level water vapor
image shows a dry air mass moving into areas west of the Cascades
and most of Siskiyou County. Therefore the concern for
thunderstorms in these areas remain low through this afternoon.

Meanwhile, moisture, instability and trigger are in greater supply
along and east of the Cascades, and this is where most, if not all
of the thunderstorm activity will be. A heavier cell popped up in
central Lake County  around 11 am pdt, and picked up steam as it
quickly marched north along highway 31 near Summer Lake and Silver
Lake. A quick look at a couple of observations at For Rock and
Christmas Valley showed a quick drop in temperatures, a quick rise
in relative humidity and gusty outflow winds.

As previously mentioned, the focus for storms (some of which could
be strong or severe) into this evening will be east of the Cascades,
although could not rule out isolated storms along the Cascades into
this evening. Upper level winds remain fairly strong which means,
storms that do form will be quick movers and and moving from south
to north. The combination of forward momentum and stronger winds
aloft could result in some storms producing moderate to strong
outflow winds. Additionally, since the moisture source is rich, there
is the concern storms can also produce locally heavy downpours.

Also of note, winds are also expected to be strong enough in the
Shasta Valley to reach advisory criteria and a Wind Advisory remains
in effect for this area. Please see NPWMFR for more details.

Tonight, the upper low will move north towards the southwest Oregon
coast and centered west of Gold Beach over the marine waters early
Wednesday morning. The track of the low and the the fact there is
plenty of energy out ahead of it gives reason for concern for at
least isolated thunderstorms to pop up over the marine waters, and
the coastal mountains in southwest Oregon this evening. Also enough
energy is present for storms to result in gusty winds and locally
heavy downpours. This idea is being supported by several of the high
resolution CAM (convective allowing models) and the deterministic
GFS and NAM. This thinking is also being supported by the fact there
is convection already showing up northeast of the upper low over off
the northwest California coast. Meanwhile, thunderstorms coverage
east of the Cascades will start to shift northeast later this
evening and tonight, with most, if not all out of our forecast area
by early Wednesday morning.

We'll finally start to turn the corner Wednesday as the upper low
continues to move north taking the best chance for thunderstorms
north and east of our forecast area, and it should be the start of
what could be along stretch of dry weather. Of note, a few showers
are possible Wednesday morning over the marine waters.

Thursday through next weekend will be dry with temperatures above
seasonal norms for interior locations as the aforementioned upper low
weakens as it moves towards Vancouver Island with a southwest stable
flow aloft over the area.

Not much change is expected into early next week, but the ECMWF and
GEFS ensembles suggest upper ridging building back into our area
towards the middle of next week, which will result in hotter
temperatures for interior locations and a southerly flow which could
usher in increasing mid level moisture into at least the southeast
part of our forecast area. Stay tuned. -Petrucelli

&&

.AVIATION...09/18Z TAFs...A mix of LIFR to MVFR ceilings are
currently spread out along the coast, over the coastal waters, into
the coastal valleys, and the Umpqua Basin. While daytime heating
will cause the stratus to burn back towards the immediate coastline
by this afternoon, the low offshore will keep those clouds up along
the coast, likely for the duration of the TAF period. MVFR/IFR
ceilings are likely to push inland again late this evening and
tonight, affecting similar areas as this morning.

VFR will prevail for most other locations today, although showers
and thunderstorms could produce brief periods of poor visibilities
and lower ceilings along and east of the Cascades. Some storms may
produce strong gusty winds and heavy rain. There is also the
potential for some severe storms as there are large pockets of
instability east of the Cascades this afternoon into this evening.
Gusty prevailing winds are also likely through this afternoon and
evening, with areas of mountain wave turbulence possible.

-BPN/Smith

&&

.MARINE...Updated 200 AM PDT Tuesday, 9 August, 2022... Weak to
occasionally moderate south winds and light seas, dominated by a
fresh northwest swell, will persist through Wednesday night, with
showers and isolated thunderstorms possible this evening and
tonight. North winds are likely to return late in the week and
increase into the weekend. Conditions may be hazardous to smaller
crafts south of Cape Blanco this weekend as the north winds
steepen seas. -BPN/Smith

&&

.FIRE WEATHER...Updated 130 PM PDT Tuesday 9 August 2022...
Thunderstorms with abundant lightning on dry fuels and gusty
outflows of 30+ mph will drive fire weather concerns from the
Cascades east for the remainder of this afternoon. A Red Flag
Warning is in effect for FWZs 284/285 in northern California as
well as 617/623/624/625 in southern Oregon. There is a very low 5%
chance that one of these storms in Northern Klamath or Lake
County intensifies and winds or hail becomes severe.

Meanwhile, gusty southerly winds and low relative humidity
conditions are ongoing in west-central Siskiyou County, the Siskiyou
Mountains, and the southeastern portion of Jackson County. A Red
Flag Warning is in effect for FWZs 280/281 in northern California as
well as 621/622 in southern Oregon. This includes the higher
elevations of the McKinney fire. The strongest winds will be in the
Shasta Valley.

Overnight tonight along the coast we have added thunderstorms to the
forecast. For now, the models are keeping these storms along the
western portions of FWZs 615/618, which makes sense since they are
being driven by the dynamics of the core of the Low Pressure center
offshore. These storms are largely expected to form a line and move
SW to NE scrapping the coast. There is strong agreement that the
stronger cells will remain well offshore, but there should be a few
showers that move along the coast, which could intensify and produce
a few stray lightning strikes.

Wednesday the thunderstorm risk will shift well to the east.
However, it will be replaced by very dry conditions across most of
NorCal and east of the Cascades in Oregon. Lingering windy
conditions over portions of the east side are driving the Fire
Weather Watch. Previously the watch included FWZs 624/625 in Oregon
and FWZ285 in NorCal. This has been amended dropping zone 625, while
retaining portions of zones 624/285. This watch has not been
upgraded yet because of the ongoing Red Flag Warnings; look for this
with tonight's update.

FWZ 625 was dropped because winds are not expected to remain
elevated long enough to meet criteria; although the HREF (reliable
hi-res ensemble guidance) does indicate a 10% chance for RFW
conditions meeting criteria occuring along the higher terrain in the
southeast portion of the zone.

Looking well ahead to the start of next week, Sun.-Tues. at least,
high pressure has a very high chance of building in over the region.
This should cause a thermal trough to develop along the coast, which
is often accompanied by reduced RH recoveries with weak offshore
flow along the coast at night, and gusty north winds in the
afternoons. Plus just plain hot conditions with temps trending
towards triple digits in west side valleys.  -Miles

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning until 9 PM PDT this evening for ORZ624-625.
     Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for ORZ624.
     Red Flag Warning until 9 PM PDT this evening for ORZ617-623.
     Red Flag Warning until 9 PM PDT this evening for ORZ621-622.

CA...Red Flag Warning until 9 PM PDT this evening for CAZ284-285.
     Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for CAZ285.
     Red Flag Warning until 9 PM PDT this evening for CAZ280-281.
     Wind Advisory until 5 AM PDT Wednesday for CAZ081.

Pacific Coastal Waters...
     None.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>