Area Forecast Discussion
Issued by NWS Pendleton, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KPDT 220007 AAA
AFDPDT

Area Forecast Discussion...Updated
National Weather Service Pendleton OR
500 PM PDT Sat Apr 21 2018

Updated AVIATION discussion

.SHORT TERM...Tonight through Tuesday...A cold front has exited to
the east, with a mid level shortwave crossing central/northern WA.
Precip is diminishing across the immediate east slopes of mainly
the WA Cascades, with partly to mostly sunny skies elsewhere early
this afternoon. Breezy to windy conditions prevail across most lower
elevation locations this afternoon, with wind speeds remaining under
advisory criteria. Mostly clear skies and decreasing winds will
prevail into this evening, with a gradual increase in clouds
overnight as another weak shortwave approaches the area. Expect
chilly temperatures overnight, with lows in the lower/mid 30s for
the lower elevations. Some freezing temperatures will be possible
across the lowest elevations, but with coverage and duration
limited, will not issue a freeze warning. A shortwave will cross the
area Sunday, exiting Sunday night. Moisture/lift is very limited,
thus will keep dry conditions area wide. Highs Sunday will be
similar to today. Models in good agreement for early in the week,
with ridging amplifying across the interior Pacific Northwest for
dry conditions. After a chilly start early Monday, temperatures will
warm to slightly above normal later Monday, with highs in the mid to
upper 70s for the lower elevations Tuesday.

.LONG TERM...Tuesday night through Saturday night...ECMWF, GFS and
Canadian models 12Z runs are very similar through Thursday afternoon
showing a large mid-upper level ridge of high pressure for dry
conditions through Wednesday and most of Thursday. A closed mid-
upper level low pressure system wobbles eastward toward the
California and southern Oregon coasts Wednesday and Thursday. By
Thursday question concerning when the ridge breaks down allowing the
low to move inland. The models diverge in how they move the low with
the track of each low going in different directions. ECMWF is the
model that tracks the low northeast and across the forecast area
and brings increasing moisture into central and eastern Oregon
Friday. Weighted the ECMWF solution a bit more than the GFS and
Canadian models. AS such have a chance of rain showers and a
slight chance of afternoon thunderstorms in the Oregon forecast
zones. Chance of showers continues Friday night and Saturday.
Dynamic forcing/lift Friday fairly strong with the low so slight
chance of Thunderstorms will be possible through Friday night in
central and NE Oregon. Saturday/Saturday night the ECMWF model
shows the low squarely over the interior Pacific Northwest so
Saturday looks to have a good chance of showers. Do not have any
mention of thunderstorms for Saturday.

&&

.AVIATION...00Z TAFs...VFR conditions over next 24 hours. FEW-SCT
060-090 trough remainder of this afternoon. Higher clouds 150-200
move east of Cascades to TAF sites tonight. Winds will be 10-18kt
until sunset and then diminish to 5-10kt this evening becoming
mainly drainage winds around 5kt overnight. Clearing skies Sunday
morning. Lighter winds 5-10kt during the day on Sunday.  Polan

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  33  61  34  67 /   0   0   0   0
ALW  38  63  38  69 /   0   0   0   0
PSC  36  65  36  71 /   0   0   0   0
YKM  36  63  36  69 /   0   0   0   0
HRI  36  65  35  70 /   0   0   0   0
ELN  33  61  33  66 /   0   0   0   0
RDM  27  61  27  68 /   0   0   0   0
LGD  33  58  33  63 /   0   0   0   0
GCD  33  60  32  67 /   0   0   0   0
DLS  39  66  39  72 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

$$

80/99/99



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.