829
FXUS66 KMFR 100532
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1032 PM PDT Mon Jun 9 2025

.UPDATE...Updated Aviation Discussion.


&&

.AVIATION...10/06Z TAFs...Along the coast, areas of IFR/LIFR
conditions will develop tonight from Cape Blanco northward and near
Brooking. These conditions will persist into Tuesday morning, then
expect improvement to VFR around 18-21z.

Inland, conditions will be VFR through early Tuesday afternoon.
Then, areas of MVFR and strong gusty winds are possibly near
thunderstorms Tuesday afternoon and evening. Isolated to scattered
thunderstorms are expected to develop south of the Umpqua divide and
from the Cascades east in southwest Oregon and across Siskiyou and
Modoc counties in Northern California Tuesday afternoon and evening.
There is a low (5%) risk for severe thunderstorms with damaging hail
and strong winds, including for Medford (KMFR), Klamath Falls (KLMT)
and Montague (KSIY).


&&

.PREV DISCUSSION... /Issued 830 PM PDT Mon Jun 9 2025/

DISCUSSION...It was an active day for Siskiyou County with
multiple strong storms and one severe storm that showed hail
potential. Overall things are starting to weaken, with an outflow
creating a few showers in western Modoc County and southern
Klamath County. There are also a few showers around southern
Jackson County, eastern Josephine County, and Lake County. There
is a marginal risk for more of the area tomorrow, focusing on
areas in Northern California and east of the Cascades, but going
as far west as central Jackson County. The main timing on this
will be between 2 PM - 8 PM with the main threats of hail and
gusty winds. These are expected to move east/northeast, although
some cells may move slowly or be nearly stationary as was seen
tonight. A trough axis will move overnight Tuesday night and
shower and storm chances will continue east of the Cascades before
drying out later Wednesday morning.

We got through the hottest day of the week today! 3 records were
broken today: Klamath Falls (Tie of 95 degrees from 1903), Medford
(104 degrees, previously 98 from 1918), and Roseburg (101
degrees, previously 94 degrees from 2015). That shows that for the
day of June 10th, Medford hasn`t seen this heat in a decade!
Between 2015 and 2024, only two years have seen 90+ degree highs
for this day (2015 and 2019), with all the other years cooler. The
ridge will be moving eastward tomorrow, and temperatures will
start to cool down. By that we mean we will be a couple degrees
cooler, but the streak of Heat Advisories are over for now.
Nonetheless, still take your precautions and stay in the shade if
outside during peak heating and stay hydrated. -Hermansen

MARINE...Updated 800 PM Monday, June 9, 2025...Steep seas and
gusty north winds will persist through Tuesday. Then, winds will
gradually lower Tuesday night into Wednesday but seas will remain
steep.

Then there is a potential for winds to increase further Thursday
through Saturday as the thermal trough restrengthens. This will
likely result in continued steep wind-driven seas. We will also
monitor for the potential of very steep seas late in the week.

PREV DISCUSSION... /Issued 421 PM PDT Mon Jun 9 2025/


DISCUSSION...It will be a bit more unstable this afternoon and
evening with with increasing mid level moisture that could set the
table for isolated thunderstorms into Monday evening. The trigger is
weak, but given the amount of instability, it won`t take much of a
trigger to get storms to develop. The best chance for storms are
expected to be in northern California, and southern Lake and Klamath
Counties. Sounding profiles suggest storms will be high based with a
very dry layer below it. Therefore any precipitation that comes out
of the storms will likely evaporate before reaching the ground. The
exception could be in portions of Siskiyou County where some
precipitation could reach the ground due to higher water content in
the column of the atmosphere.

Isolated storms will fizzle out between 8-9pm pdt with dry weather
expected tonight.

Tuesday will be more active with storms covering a larger portion
ofthe forecast area, with scattered storms possible later in the
afternoon and early evening hours. An upper trough will approach
from the west and put the area in a favorable position for isolated
to scattered thunderstorms along and east of the Cascades and
northern Cal, with the instability parameters greatest in Western
Siskiyou County northeast into Klamath and Lake County, and
southeast portion of Jackson County.

Given the position of the upper trough axis and stronger trigger
ahead of it could bring a heighten threat for isolated strong to
severe storms that will produce gusty winds near and withing storms,
and possible hail for the areas mentioned above. Also the amount of
available moisture will be higher, therefore storms will have a
better chance of producing locally heavy downpours for the same
areas. This will include most of Jackson County, including Medford,
Phoenix, Talent, White City, and Ashland. Steering flow will be from
the southeast, therefore storms will tend to move from southwest to
northeast. However, the steering flow will be on the light side,
thus, storms may not be quick movers, thus increasing the
possibility for localized urban flooding in areas that experience
heavier rainfall.

Storms are expected to continue into the overnight hours Tuesday,
with the upper trough axis to the west, but they are likely to be
isolated and confined to portions of Lake and Klamath County.

The upper trough axis is expected to be east of the Cascades later
Wednesday morning with a moderate to strong trigger and marginal
instability, therefore isolated storms could linger into at least
the mid morning hours Wednesday in portions of Lake and Klamath
County, then moving east of the forecast area as the upper trough
axis shifts east.

Other than the slight chance for storms for the areas mentioned
above Wednesday morning, we`ll be heading into a pattern of upper
troughing that will persist into Fathers Day weekend. The net result
will be cooler afternoon temperatures for the interior with values
near normal the latter part of the week into next weekend. Odds are
it will be dry during this time. -Petrucelli

FIRE WEATHER...Updated 200 PM Monday June 9, 2025...Dry and
mostly hot weather will continue for one more day. Isolated
thunderstorms are still a concern into early this evening, with most
centered in portions of northern Cal and southern Lake and Klamath
County. Sounding profiles suggest any precipitation that comes from
storms will not reach the ground. The exception may be in portions
of the Trinity Alps where some precipitation could reach the ground,
but even then it will be limited. The other concern will be gusty
and erratic winds near storms.

The main concern ahead will be isolated to scattered thunderstorms
in the afternoon and early evening hours into Tuesday. Details to
follow below.

Tuesday, the concern for isolated to scattered afternoon and early
evening thunderstorms will be higher. A stronger upper trough will
approach from the west, but the trend is for a slower arrival of the
upper trough axis. Even so, this will put the area in a more
favorable position for some storms be strong to severe since the
trigger is expected to be stronger along with greater instability.
So far, guidance is in pretty good agreement suggesting storms will
cover a larger potion of the area and the shear number of storms
will be higher. Due to the combination of instability, stronger
trigger and favorable dynamics, There is concern for storms to
produce gusty outflow winds, with hail possible with storms are end
up strong to severe. The one difference compared to the last couple
of days will be the amount of available moisture. PWATS (the amount
of moisture in a column will be higher, and the sub layer won`t be
as dry. Thus there could be a heighten concern for locally heavy
downpours. This will include most of Jackson County. Steering flow
will be from the southeast, therefore storms will tend to move from
southwest to northeast. However, the steering flow will be on the
light side, thus, storms may not be quick movers, thus increasing
the possibility for localized flooding in areas that experience
heavier rainfall.

Current fuel conditions suggest they could end up being more
receptive to new starts if we have a significant mount of lightning.
Please use extra care when participating in activities that may
create sparks or embers. These can ignite fires that can quickly
grow out of control, especially around abundant dry or unmaintained
fuels.

With the slower arrival of the upper trough axis, we could see
isolated storms linger Tuesday night into Wednesday morning, then
once the upper trough axis shift east later Wednesday morning, then
threat for storms will shift east of the area.

Wednesday into Fathers Day weekend, it will be dry with a cooling
trend with upper troughing setting up resulting in temperatures near
or slightly below seasonal norms. -Petrucelli

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT
     Wednesday for PZZ350-356-370-376.

&&

$$