701
FXUS66 KMFR 161140
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
440 AM PDT Tue Jun 16 2026

.Updated AVIATION Discussion...

&&

.AVIATION...16/12Z TAFs...Aside from some high clouds streaming over
the area, little change is expected to VFR flight levels in this TAF
period. Gusty north winds (20-30 kt) are expected to return to the
coast today while other areas will see typical diurnal breezes.
Patches of IFR stratus are possible at the coast north of Cape
Blanco this afternoon, between 18-21z, with potentially more
coverage overnight tonight.

&&

.PREV DISCUSSION... /Issued 254 AM PDT Tue Jun 16 2026/

KEY POINTS...

* Hot temperatures continue today, with Heat Advisory in effect
  until tonight. Temperatures trend somewhat cooler on Wednesday
  with a more noticeable cool down Friday into the weekend.

* Elevated fire weather concerns Thursday -- dry and unstable
  conditions.

* Increasing signal for thunderstorms for latter half of week,
  possibly as early as Thursday, but most likely on Friday. Focus
  for activity expected over northern California and east of the
  Cascades.

DISCUSSION...Fairly quiet morning with satellite imagery only
showing some high level clouds streaming over the region. It`ll
be another hot day across the region, though the heat wave will
begin to ebb for areas west of the Cascades today, most notable
along the coast north of Cape Blanco and into the Umpqua Basin.
The upper level pattern responsible for this heat features a
strong high pressure just offshore over the eastern Pacific, that
will weaken and expand eastward today, eventually settling into
the Great Basin region by Thursday. Meanwhile, weak energy will
linger off the coast of California and meander westward around
this high pressure while it expands/shifts eastward. This energy
comes into play for the latter half of the week. In the meantime,
a Heat Advisory remains in effect through this evening due to a
moderate risk of heat related illnesses. Be sure to take
precautions to protect yourself from the heat. If you plan to seek
relief in area waterways, please remember that the water is still
quite cold, and cold water shock is a real thing. Temperatures do
trend cooler for the latter half of the week, but will remain
above normal (mid-upper 90s West/upper 80s-low 90s East) until the
weekend. So instead of being 15-25 degrees above normal like
yesterday, it`ll "cool" to only 10-15 degrees above normal.

The upper level pattern shifts on Thursday. That meandering weak
energy combines with a few other weak shortwaves passing through in
the westerlies and carves out a weak open trough over the eastern
Pacific by Thursday afternoon. Temperatures tick upward a few
degrees on Thursday under southerly flow, and it`s possible we see
another triple degree day here in Medford on Thursday. The larger
concern however, is the thunderstorm potential that comes with this
pattern transition. It`s almost a guarantee that heat waves conclude
with a thunder threat, and it seems this event is no different.
Moisture and instability increase on Thursday, and there are some
weak shortwaves passing through, but moisture is pretty marginal on
Thursday. It`s more likely that there will be some cumulus buildups
with a stray shower across northern California. By Friday, however,
the trough nudges closer and moisture looks more favorable for
thunderstorms. Currently, it looks like the focus would be across
northern California and east of the Cascades, but model guidance
shows some potential convection over the Siskiyous, which could
bring some storms into southeastern Jackson County. We`ll keep an
eye on model trends to see if thunderstorm chances expand westward
with time.

The trough axis moves through the region Friday night, taking the
moisture and instability east of our region for Saturday. It`s
possible some isolated activity lingers across far eastern
Lake/Modoc counties early Saturday afternoon. The coolest
temperatures of the forecast period are expected over the weekend as
this trough passes through. Afternoon highs will still be above
normal, but only on the level of 5-10 degrees.

MARINE...Updated 100 AM PDT Tuesday, June 16, 2026...A thermal
trough pattern will persist through Thursday. Conditions will
worsen this afternoon as northerly winds strengthen, reaching
gales south of Cape Blanco and seas become very steep and
hazardous. Very steep seas could spread north of Cape Blanco
around mid-week, but the worst conditions are expected south of
Cape Blanco. Conditions could improve late Thursday into Friday as
the thermal trough pattern weakens, but steep seas are likely to
persist into the weekend.

FIRE WEATHER...Updated 200 AM PDT Tuesday, June 16, 2026...The
heatwave will begin to ebb today for areas west of the Cascades,
most notable along the coast north of Cape Blanco and into the
Umpqua Basin. Meanwhile, temperatures remain hot east of the
Cascades and across northern California. With the moderating
temperatures west of the Cascades, conditions will be less critical
today, but it will still be dry and breezy this afternoon.

A weak marine push will bring improving recoveries tonight compared
to recent days, but this improvement will be shortlived. The thermal
trough will remain along the coast through Wednesday, then push
inland on Thursday. This will maintain broad north through east flow
across the midslopes/ridges, and poor recoveries are expected again
Wednesday night. As the thermal trough shifts inland Thursday,
expect another uptick in temperatures across the region.
Additionally, this pattern will bring dry and unstable conditions
across northern California and east of the Cascades.

Meanwhile, an open trough develops offshore over the eastern Pacific
on Thursday, moving inland late Friday and east of the region on
Saturday. This pattern sets up the potential for thunderstorms
during this time frame, focused across northern California and east
of the Cascades. Chances for thunderstorms are highest on Friday,
but could begin as early as Thursday. Moisture remains fairly
marginal for Thursday, but instability is present. Could just be
some cumulus buildups with a stray shower or even an isolated
thunderstorm in the afternoon. As the upper level low moves closer
to the coast on Friday, the chance of showers and thunderstorms
increases. Current guidance maintains the best chances across
northern California and east of the Cascades, but there is the
potential for as far west as Jackson County. By Saturday, the best
moisture/instability shifts east, leaving some lingering chances
along/east of the Warners/Winter Ridge.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory until 11 PM PDT this evening for ORZ024-026-029.

CA...Heat Advisory until 11 PM PDT this evening for CAZ080>085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 AM PDT this
     morning for PZZ350-356-370-376.

     Gale Warning from 11 AM this morning to 2 AM PDT Thursday for
     PZZ356-376.

&&

$$