488
FXUS66 KMFR 081551
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
851 AM PDT Mon Jul 8 2024

.DISCUSSION...A strong high pressure ridge remains in place
through Tuesday bringing a continuation of the very hot and very
dry conditions. High temperatures will be around 20 degrees above
normal for inland areas with record setting highs likely across
inland areas through Tuesday. We set several record high
temperatures yesterday, including at Medford (108 deg), Roseburg
(107 deg) Klamath Falls (101 deg), Alturas (102 deg), Montague
(109 deg) and Mount Shasta City (104 deg). Overnight lows will
remain warm and well above normal. So there will be only brief
relief from the heat during this long, multi-day heat wave. Excessive
Heat Warnings (NPWMFR) for areas west of the Cascades and Heat
Advisories for areas east of the Cascades remain in effect
through Tuesday evening

High pressure will weaken slightly Wednesday through the end of
the week. This will result in slightly less hot weather. However
temperatures will remain well above normal with highs expected in
the upper 90s to mid 100s across inland valleys.

In addition to the heat, wildfire smoke has moved over much of the
area due to south to southwest flow aloft. This pattern is likely
to persist this week.


&&

.AVIATION...08/12Z TAFS...Marine stratus is moving along the Oregon
coast from the north, bringing LIFR levels over North Bend and areas
north of Cape Blanco. These clouds will give way to clear skies and
gusty winds this afternoon, but are expected to return this evening.

Inland areas are expected to stay at VFR levels, although smoke from
the Shelly (Western Siskiyou County) and Salt Creek (Central
Jackson) fires could cause some local visibility concerns. Upper
level smoke from these fires is expected to move east over southern
Klamath County as well. -TAD

&&

.MARINE...Updated 800 AM Monday, July 8th, 2024...A thermal trough
will remain in place and dictate the sea state through the week.
Northerly winds will continue to build steep seas south of Cape
Blanco today and tonight. Winds will pick up in the outer waters
north of Cape Blanco on Tuesday and Wednesday, spreading steep seas
into that area as well.

The trough is expected to quickly strengthen on Thursday, bringing
gale gusts and very steep and hazardous seas to waters south of Cape
Blanco. Elevated wind gusts and steep, nearly very steep seas will
be present north of Cape Blanco. Chaotic seas are expected to
continue through Saturday before winds start to calm on Sunday.
-TAD


&&

.PREV DISCUSSION... /Issued 443 AM PDT Mon Jul 8 2024/

DISCUSSION...Excessive Heat Warnings for the west side and Heat
Advisories for the east side remain in effect through Tuesday
evening, with additional records likely to be set and highs across
our area commonly more than 20 degrees above normal. Slight
cooling, including that of low temperatures, will follow for
Tuesday night into Thursday night.

Day-to-day fluctuations in high temperatures this week will be a
bit wider west of the Cascades, and there is the additional
complicating factor that smoke in Siskiyou and Jackson counties may
hinder heating, at least by a degree or two. Readings will remain
near 100 through the week for the east side valleys. Meantime,
west side highs today will again be within a degree or two of the
extremes of this heat wave that were registered on Saturday and
Sunday. A few degrees of cooling follow on Tuesday then several
additional degrees less hot for Wednesday and Thursday. Our `cool`
day on Thursday will still be a noteworthy 10 to 15 degrees above
normal.

A southerly flow pattern late in the week is likely to bring a few
degrees of additional heating. Finally, early next week should
bring enough cooling with some maritime influenced air to bring
our above normal temperatures into the single digits above normal.

Speaking of maritime influence, northeast flow is keeping much of
Curry County clear this morning, while both to the north and to
the south, a shift from a northeast to a north flow has allowed
marine low clouds to move into the coast. Today through Friday,
these low clouds are expected to diminish each day and similarly
return for the night and morning hours. A stronger marine push is
more likely to persist Friday night into Sunday morning. The
northeast flow is weaker than it was last week, but still
sufficient for downslope warming at Brookings with highs in the
lower 70s to lower 80s.

The ridge over our area will nudge eastward during the next couple
of days. By Tuesday, a weak trough is expected to move inland. A
stronger trough will move into western Canada at mid-week with
another similar trough taking a similar track late in the week.
Thus, afternoon and evening breezes are expected to trend
stronger, especially east of the Cascades.

The trough may bring just enough moisture aloft for cumulus
clouds to develop on Tuesday and/or Wednesday, mainly in Siskiyou,
northern Klamath, and northern Lake counties.

Model agreement is quite good through Thursday, and there is
general agreement on a broader, stronger trough to approach the
west coast at the end of the week. The ridge now over our area is
expected to shift east then southeast during the week, to the
desert southwest. The relative position and interaction of the
trough to our west and the ridge to our southeast will determine
whether a risk of thunderstorms develops in our area east of the
Cascades during Saturday and/or Sunday. Instability may also
develop solely east, southeast, and/or south of our area. For
now, we will continue with the dry, stable NBM solution.

The inland push of this trough, early next week around Day7/8, should
bring us closer to a normal pattern than we have been in quite
some time.


FIRE WEATHER...Issued 300 AM Monday July 8, 2024...Heat, winds,
low humidities, and unstable conditions will each vary from just
below to just above critical thresholds through the week.

Heat and low humidity during today and Tuesday will still be near
to the peak of the extreme values reached during the weekend.
Meantime, winds early this week will mostly be just below
thresholds, with gusty afternoon and evening breezes that will be
impactful, despite also being quite typical. In general, expect
high temperatures today at 1 to 2 degrees hotter than Sunday, then
on Tuesday a few degrees of cooling for the west side and no
change on the east side. Meantime, winds trend a couple mph weaker
today, then get that nudge of strength back on Tuesday.

The ridge shifting east on Tuesday while a very weak trough moves
inland will bring the slight cooling, slightly higher moisture
(most noticeable near the coast), and also may bring a few
afternoon cumulus buildups for western Siskiyou and northern
Klamath counties.

For Wednesday and Thursday, expect the edge to be taken off of
the heat with a few to several degrees of cooling. Though no
longer as extreme, expect temperatures to still be well above
normal and accompanied by slightly stronger afternoon/evening
winds. Though not returning to today`s values, temperatures are
likely to trend slightly warmer for the end of the week. Then,
readings early next week are expected to be several degrees cooler.

Instability with an accompanying risk of thunderstorms could
develop east of the Cascades as early as Saturday. There is also
a contingent of model solutions that suggest a risk will instead
develop southeast and/or east of our area.
-BPN/DW

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Excessive Heat Warning until 9 PM PDT Tuesday for ORZ023>026.

     Heat Advisory until 9 PM PDT Tuesday for ORZ029>031.

CA...Excessive Heat Warning until 9 PM PDT Tuesday for CAZ080>082.

     Heat Advisory until 9 PM PDT Tuesday for CAZ083>085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Thursday
     for PZZ356-376.

     Small Craft Advisory from midnight tonight to 5 AM PDT Thursday
     for PZZ370.

&&

$$

CC/CC/CC