FXUS66 KPDT 161113
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
413 AM PDT Thu Apr 16 2026

.KEY MESSAGES...
- Near to below freezing morning lows today and Friday in the
  lower elevations

- Breezy conditions continue through this evening

- Dry conditions will develop this evening, and persist into the
  weekend

&&

.DISCUSSION...
Today through Sunday morning: Satellite imagery
this morning shows an upper closed directly over the PacNW, with
the center of the circulation centered over northeast WA and
northern ID. The low's position has resulted in upslope light
snow showers continuing along the Cascade crest and the northern
Blues this early morning. A winter storm warning is still in
effect along the OR Cascade east slopes through 5AM this
morning, with only 1 to 2 more inches of additional
accumulations by then.

Light snow showers along the Cascade crest and northern Blue
mountains as well as breezy west to northwest winds in the lower
elevations will continue today as the forecast area remains
under the influence of the upper low. The low will continue to
push a colder airmass in the region, which will result in near
to below freezing temperatures across portions of the lower
elevations, especially those under clearing skies and light
winds. Of particular concern this morning will be the
Yakima/Kittitas valleys and the foothills of the northern Blue
mountains in OR, where there is mod-high confidence (65-85%) of
freezing temperatures this morning. Freeze warnings are in
effect for this morning for these areas.

Tonight, an upper ridge in the northeast Pacific will approach
the PacNW, bringing with it light winds and clearing skies
across the forecast area. These conditions will lead to better
chances for widespread freezing morning lows Friday, impacting
the growing areas of the lower elevations, especially where
there are freeze warnings in effect for Friday morning in the
lower Columbia Basin and adjacent foothills/valleys. After
Friday, dry conditions, light winds, and warming temperatures
will persist through Sunday.

Sunday, the upper ridge over the region will push east of the
region as an upper closed low develops in the Northeast Pacific,
then setting up offshore the PacNW and northern CA. There is
decent agreement amongst ensemble and deterministic model
guidance that precip will remain mainly west of the Cascade
crest early Sunday.

Sunday afternoon through Wednesday: Ensemble guidance stays in
good agreement the latter of Sunday in the low placing the
region under a southerly flow aloft. This places the region
under favorable conditions for increasing instability across
southern and central OR Sunday afternoon, translating to
isolated shower and/or isolated thunderstorms (confidence
55-70%).

After Sunday, uncertainty grows amongst ensemble members on the
position and evolution of the upper low as it swings into the
western CONUS early next week. There is consensus among cluster
solutions that the low will swing inland between northern CA and
southwestern OR Monday, and lift east to northeast into the
PacNW as it moves further inland (confidence 45-65%). For
Monday, the position of the low still along the shoreline would
favor another round of isolated to scattered thunderstorm
activity Monday afternoon (confidence 40-50%). However the low
tracks inland after Monday, there is growing confidence
(confidence 50-65%) in increasing precipitation chances from
south to north that will persist into the mid-week. Lawhorn/82

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...VFR conditions to
prevail through the period. Winds will increase to 12-15kts
with gusts up 25kts during the morning hours and persist late
into the afternoon and early evening at all sites. Light winds
will prevail tonight through tomorrow. Lawhorn/82

&&

.Preliminary Point Temps/PoPs...
PDT  54  30  58  34 /  20   0   0   0
ALW  54  35  58  38 /  30   0   0   0
PSC  61  33  63  35 /   0   0   0   0
YKM  59  30  62  36 /   0   0   0   0
HRI  59  33  62  34 /   0   0   0   0
ELN  50  30  57  33 /   0   0   0   0
RDM  49  20  58  28 /  10   0   0   0
LGD  46  27  54  32 /  50  10   0   0
GCD  45  23  55  31 /  40   0   0   0
DLS  56  34  64  38 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
WA...Freeze Warning from 11 PM this evening to 9 AM PDT Friday for
     WAZ026>028.
     Freeze Warning until 9 AM PDT this morning for WAZ026-027.
OR...Freeze Warning from 11 PM this evening to 9 AM PDT Friday for
     ORZ044-507.
     Freeze Warning until 9 AM PDT this morning for ORZ507.
     Winter Storm Warning until 5 AM PDT early this morning for
     ORZ509.

&&

$$

DISCUSSION...82
AVIATION...82