445
FXUS66 KMFR 081047
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
347 AM PDT Wed May 8 2024

.DISCUSSION...

Temperatures aren`t dropping much this morning as dewpoints stay
in the mid 30`s across a lot of valleys west of the Cascades. The
exception appears to be the Scott Valley with temperatures
currently around 32 to 34 with dewpoints in the upper 20`s. Other
than the patchy freezing conditions across the forecast area this
morning, concerns are minimal given the current temperatures.

High temperatures will trend about 10 to 15 degrees higher today
compared to Tuesday as high pressure continues to build over
southern Oregon and northern California. A thermal trough will
strengthen along the southern Oregon coastline this morning with
some north east flow developing along the coastal range. Brookings
and Somes Bar in south western Siskiyou County will be the warm
spots later today with both pushing into mid 70`s with Somes Bar
potentially hitting the 80`s. Overall, this is pretty typical for
temperatures this time of year as Medford`s average high is 72.

Temperatures will continue to trend warmer by Thursday as high
pressure strengthens off the coast and winds becomes more
widespread out of the east. This should result in further bump in
temperatures with the most notable jump around Roseburg and North
Bend with an anticipated high of 83 and 75 degrees respectively on
Thursday. This warm up will push highs well above their normals
for this time of year.

The thermal trough will move farther inland on Friday with sea
level pressure dropping about 10 mb east of the Cascades and the
1000-500 mb thickness` rising over locations farther to the east
as well. These days are usually some pretty warm days and the
temperature forecast shows this with some highs potentially
hitting 90 degrees. The NBM gives Medford a 15% chance of hitting
90 and Roseburg a 40% chance of hitting 90 on Friday. Not much
will change on Saturday, although the temperatures might trend
down a degree or two. It`s worth noting that the NWS` heat risk
algorithm is showing an elevated heat risk for populated areas on
Saturday, perhaps due to the unusually warm high temperatures for
this time of year. Given that low temperatures are falling into
the mid 50`s, this elevated risk seems overdone.

Towards the start of next week, the NBM is predicting a 5% chance
of precipitation across sections of northern California as a weak
short wave could be moving through around Sunday evening or
Monday evening. To elevate the thunderstorm threat, we pushed the
probability of precipitation higher for those times. Any shortwave
this time of year will have that threat of kicking off
thunderstorms around the forecast area.

Towards the middle of next week it appears high pressure will
still remains in control. Temperatures have a higher probability
being warmer than normal versus cooler than normal for the middle
of May.

-Smith


&&

.AVIATION...08/06Z TAFs...Expect VFR to prevail tonight through
Wednesday, though areas of MVFR are possible in portions of the
Umpqua Basin and Coquille Basin overnight into Wednesday morning.
These shouldn`t last much longer than 16 or 17Z Wednesday morning.
Expect gusty north to northeast winds again Wednesday afternoon,
peaking 20 to 25 kt at Roseburg/Klamath Falls and around 30 kt at
North Bend, easing during the mid-late evening. -Spilde

&&

.MARINE...Updated 215 AM Wednesday, May 8, 2024...A thermal trough
will expand strong north winds and steep to very steep seas
northward today. Worst conditions are expected south of Cape Blanco
with gales and very steep, wind-driven seas this afternoon through
early Thursday morning. Gusty north winds and very steep seas are
expected north of Cape Blanco. Current models show a high chance (55
to 100%) for north gales from Cape Blanco southward, highest (70 to
100%) beyond 5 nm from shore south of Gold Beach. The thermal trough
will weaken Thursday, but lingering steep to very steep seas are
possible. Lighter winds and seas expected Friday into the weekend. -
Spilde/Hermansen

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Warning until 10 AM PDT this morning for ORZ024-026.

CA...Freeze Warning until 10 AM PDT this morning for CAZ080-081.

PACIFIC COASTAL WATERS...Small Craft Advisory until 2 PM PDT this
     afternoon for PZZ350-356-370-376.

     Hazardous Seas Warning from 2 PM this afternoon to 5 AM PDT
     Thursday for PZZ350-370.

     Gale Warning until 5 AM PDT Thursday for PZZ356-376.

&&

$$