Trinidad, Washington Weather Forecast Discussion

344
FXUS66 KOTX 141748
AFDOTX
Area Forecast Discussion
National Weather Service Spokane WA
1048 AM PDT Sun Sep 14 2025
.KEY MESSAGES...
- Cooler today with widespread rain. Highest totals across
  southeast Washington and southern Idaho Panhandle. Isolated
  afternoon thunderstorms.
- Warm and dry Tuesday and Wednesday.
&&
.SYNOPSIS...
A weather system arrives today bringing cooler temperatures,
breezy west to southwest winds, and widespread precipitaiton.
High pressure rebuilds Tuesday and Wednesday with a brief return
of warmer and drier conditions.
&&
.DISCUSSION...
Sunday and Monday: An upper-level trough and an associated old front
will move across the Inland Northwest today. Water vapor imagery and
model consensus depict the trough to become negatively tilted as it
tracks onshore. Deep southerly flow ahead of the system is advecting
ample moisture into the Inland Northwest, with precipitable water
values exceeding 0.80 inches Sunday morning. Models have come into
much better agreement for the base of the trough to travel across
northern Oregon, providing sufficient lift for widespread
precipitation this morning into the early afternoon. This will
transition to scattered convective showers this afternoon and
evening, with showers lingering over the Idaho Panhandle into Monday
morning.
While models have trended wetter, considerable spread remains in
National Blend of Models (NBM) QPF. The 25th-75th percentile range
is 0.05-0.50 inches for northeast Washington and north Idaho. Lower
totals, from 0-0.15 inches, are expected in the lee of the Cascades
due to downsloping effects off the Cascades. The highest totals are
favored across southeast Washington and the southern Idaho
Panhandle, closer to the base of the trough, with a 25th-75th
percentile range of 0.10-0.90 inches. CAMs indicate the greatest
instability and steepest lapse rates will also be focused in these
southern areas, with the NBM giving a 15-20% chance of
thunderstorms this afternoon. Instability decreases farther
northward, with less confidence (5-15% chance) in thunderstorms
Sunday afternoon.
Southwesterly winds will increase with the morning precipitation,
with sustained speeds of 10-20 mph and gusts of 20-30 mph.
Monday night through Friday: High confidence exists in an
upper-level ridge building over the region late Monday, becoming
centered over the area Tuesday and persisting through
Wednesday. A thermally- induced surface pressure trough is
expected to develop west of the Cascades, supporting breezy
easterly winds across central Washington into Tuesday. The
thermal trough will shift east of the Cascades by Wednesday,
allowing winds to return to a west/southwesterly direction.
Forecast confidence decreases late in the week. Ensembles agree on
another upper-level trough affecting the region but show significant
spread in its track and strength. This will be the next period to
monitor for breezy winds as the ridge breaks down, however, forecast
uncertainty remains too high for specifics at this time. /vmt
&&
.AVIATION...
18Z TAFS: Radar shows rain within the hour to
GEG/SFF/COE/PUW/LWS, with good enough confidence to have the
rain be in prevailing for all but LWS. For GEG/SFF/COE/PUW,
there is moderate confidence that showers will bring ceilings
down to MVFR from ~19-24Z, with MVFR ending earlier for PUW.
Winds have already picked up from the southwest with sustained
winds of 10kts or more at GEG/SFF/COE, and the potential to gust
to 20kts throughout the afternoon. There is a 10-20 percent
chance for thunderstorms in far southeast Washington and the
southern Idaho Panhandle that includes PUW/LWS, but
probabilities are too low to include them in TAFs at this time.
By 18Z tomorrow, rain will have ended for the TAF sites.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Moderate confidence in MVFR conditions with rain at
KGEG/KSFF/KCOE and low confidence at KPUW with rain. Low
confidence in thunderstorms at PUW/LWS Sunday afternoon and
evening.
-----------------------
Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance
For additional probabilistic information for NWS Spokane
airports, please refer to the Aviation Dashboard on our webpage:
https:/weather.gov/otx/avndashboard
&&
.Preliminary Point Temps/PoPs...
Spokane        68  50  72  50  82  52 /  80  40  10   0   0   0
Coeur d`Alene  69  52  69  50  82  54 /  70  60  20   0   0   0
Pullman        64  46  67  45  78  49 /  80  60  10   0   0   0
Lewiston       72  55  74  53  83  57 /  80  60  10   0   0   0
Colville       72  43  74  41  82  42 /  70  50  20   0   0   0
Sandpoint      70  47  67  46  80  48 /  60  70  50   0   0   0
Kellogg        68  51  63  50  80  55 /  60  70  40   0   0   0
Moses Lake     73  47  75  49  83  50 /  70  20   0   0   0   0
Wenatchee      73  52  77  56  81  58 /  60  20   0   0   0   0
Omak           73  50  80  53  84  55 /  60  40   0   0   0   0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Air Quality Alert until noon PDT Monday for Central Chelan
     County-Northeast Mountains-Okanogan Highlands-Wenatchee
     Area-Western Chelan County.
ID...None.
&&
$$

NWS OTX Office Area Forecast Discussion