491
FXUS66 KMFR 240951
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
251 AM PDT Fri May 24 2024

.DISCUSSION...

An upper level wave is currently pushing into Oregon and we`ll see
widespread synoptic lift through the day. We`re anticipating some
mid and high level cloud cover with showers forming generally in
the northern sections of the forecast area with drier conditions
towards the south west. There is also a low (5-15%) chance of
cloud to ground lightning within 25 miles of any point east of the
Cascades later today. There isn`t a lot of available moisture for
potential instability, and cloud cover could inhibit convection as
well. Other than storms, it shouldn`t be as windy compared to
Wednesday when a wave swung through the forecast region, however
there should be some stronger breezes east of the Cascades and in
some of the valleys later today.

By Friday night, high pressure should begin to build as the wave
departs the region. Precipitation chances should generally
decrease into the later evening hours. There is some evidence that
the air has some instability on Friday night along the coast, so a
low chance of rain showers will persist there overnight.

Not much will change on Saturday as high pressure continues to
build and the flow pattern remains out of the west and northwest.
However, the air is cooler behind this wave, so we`ll see
temperatures trend a few degrees cooler compared to Friday. High
temps will remain 5 degrees cooler than normal for late May.
Conditions continue to dry into Sunday with temperatures moving a
few degrees higher and high pressure continuing to build.

By the start of next week, high pressure will remain in place with
highs shooting into the mid 80`s to upper 70`s within valleys west
of the Cascades on Monday. High temps will cool slightly into
Tuesday as another upper level wave likely pushes into Oregon and
much of the Pacific Northwest. Depending on when the wave actually
arrives, there is a threat of some thunderstorms on Tuesday
evening or perhaps Wednesday evening.

Once the upper level wave passes on Wednesday, we`ll probably see
high pressure build towards the end of next week. However, the NBM
still has some low chances of precipitation along the Cascades and
in the northern sections of our forecast areas. There is about a
10 to 15% chance of precipitation on Thursday evening and Friday
evening. A cluster analysis shows some ensemble members with an
upper level wave over us Thursday evening while some some have
high pressure well in control. Therefore, it`s pretty hard to say
what will happen towards the end of next week.

-Smith

&&

.AVIATION...24/06Z TAFs...VFR conditions are expected to continue
through the TAF period for inland areas, with breezier afternoon and
evening winds at all terminals.

An approaching weak frontal system looks to push the marine layer
and its accompanying lower stratus, currently well offshore, inland
ahead of it tonight. A brief period of MVFR conditions along the
northern Curry and Coos county coasts is likely later tonight.
Northwesterly breezes will pick up ahead of the front in the early
afternoon and continue into the evening as the front approaches, but
winds won`t be as significant as the system that passed through
earlier this week.

Showery, spotty precipitation will move onshore and inland Friday
afternoon and evening. Best chances will be in northern portions of
the region (northern Douglas, Coos, Klamath, and Lake counties) as
well as along the south OR Cascade crest. Additionally, there is
about a 10-15% chance for isolated thunderstorms developing later in
the afternoon into the evening in southern and eastern Lake and
Modoc counties. -CSP

&&

.MARINE...Updated 200 AM Friday, May 24, 2024...The current Small
Craft is due to end at 11 pm pdt with a brief break until Friday
afternoon while north winds gradually diminish in the expansion fan.
A weak front will move through the waters with moderate northwest
winds with gusts up to 25 kts possible this evening through Saturday
morning. Steep seas are expected in all waters, with another Small
Craft Advisory covering all waters today at 5 PM until Saturday at 5
PM pdt.

Past Saturday evening, upper level stability will guide conditions
into the middle of next week. Currently calm seas are forecast from
Saturday evening through at least next Tuesday.
-Petrucelli/Hermansen

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT early
     this morning for PZZ350-356-370-376.

&&

$$