801
FXUS66 KMFR 271114
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
414 AM PDT Sun Jul 27 2025

.DISCUSSION...

Satellite is showing pretty clear skies except for some coastal
stratus near Brookings and north of Port Orford. We`ll continue
with the thunderstorm theme yet again this afternoon as a deep
trough just off shore over helps destabilize the atmosphere.
The cloud to ground probabilities are looking good with the SPC
HREF showing a wide swath of 50 to 60 percent east of the Cascades
and the NBM is a little more conservative around 20 to 25 percent.
The one thing that looks a little different today is storm should
have a little more motion this time. Winds between the surface and
6km are southerly about 20 to maybe 25 knots.

Not a whole lot will change between Sunday afternoon and Monday
afternoon. It appears the probability of lightning decreases to 10
to 20 percent and covers a good chunk of the forecast area. We
would characterize the lightning threat as more isolated on
Monday afternoon and evening given the current lightning
probabilities. However, it should be noted these storms will hedge
towards the drier side of things. the level of free
convection(LFC) pushes up to about 10000 feet east of the
Cascades, which is on the higher side. Forecast soundings, suggest
low CAPE, but storm mode should be drier compared to yet. Given
the isolated threat, we might not issue a red flag, although
ironically the ignition threat and efficiency could actually
increase into Tuesday.

Heading further into the week, the aforementioned trough digs
into the west coast and keeps the shower and thunderstorm going
into Wednesday. The forecast soundings from the GFS suggest more
showers instead of thunderstorms, although the NBM probabilities
have a 20 percent chance of cloud to ground lightning near any
point Wednesday afternoon and evening.

We were concerned about the thunderstorm threat Wednesday night as
it appears the axis of the upper level trough digs into Oregon
Wednesday night and Thursday. There is still a fairly large
spread of where these showers or thunderstorms could kick up
overnight from as far north as Washington to as far south as our
CWA. Ensemble members also vary greatly on wetness at this time,
so uncertainty is high, although the threat remains Wednesday
night. GFS BUFKIT forecast soundings also build potential
instability quickly by Thursday morning ~10 to 11am.

Overall, its looking like a stormy week with a persistent threat
of thunderstorms over southern Oregon and northern California.


&&

.AVIATION...27/06Z TAFs...Along the coast, areas of IFR will develop
tonight into Sunday morning, mainly north of Cape Blanco and from
Gold Beach southward. These low clouds will clear to VFR late Sunday
morning.

Inland, overall, skies are VFR and will remain that way through the
TAF period. However, isolated to scattered thunderstorms Sunday
afternoon and evening, mainly from the Cascades east and across
NorCal. These could temporarily lower ceilings and/or visibility,
but the main risks with thunderstorms will be gusty outflow wind
gusts, cloud to ground lightning and even small hail.

&&

.MARINE...Updated 300 AM PDT Sunday, July 27, 2025...Sub-
advisory north winds and low seas of 5 ft or less, will persist
into early next week. Areas of fog and low stratus will also
persist through this time. Winds and seas may trend slightly
higher south of Cape Blanco Tuesday into Thursday, with low end
advisory winds possible.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 2 PM this afternoon to 11 PM PDT this
     evening for ORZ624-625.

CA...Red Flag Warning from 2 PM this afternoon to 11 PM PDT this
     evening for CAZ280-281-284.

PACIFIC COASTAL WATERS...None.

&&

$$