Area Forecast Discussion
Issued by NWS Pendleton, OR

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FXUS66 KPDT 120335
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
835 PM PDT Tue May 11 2021

.UPDATE...
Latest satellite imagery showed high clouds over the Cascades and
nearby areas and portions of Central Oregon. Everywhere else was
basically clear as high pressure was in control. Only made some
adjustments to temps (mainly upward) as the forecast is quiet and
currently on track.


&&

.AVIATION...
06Z TAFs...Variable high level cloudiness AOA 15kft AGL with
few/sct cu/altocu 10-15kft Wednesday afternoon. Wind 5-15kt,
highest Wednesday afternoon.

&&

.PREV DISCUSSION... /issued 346 PM PDT Tue May 11 2021/

.AVIATION...00Z TAFs...Variable high level cloudiness AOA 15kft AGL
with few/sct cu/altocu 10-15kft Wednesday afternoon. Wind 5-15kt,
highest Wednesday afternoon.

SHORT TERM...Tonight through Friday. Weak instability over the
mountains with scattered cumulus through sunset. Mainly the Blues
with upslope flow. Otherwise satellite showing mostly clear this
evening then increasing cirrus overnight. A weak short wave will
be moving across southern BC and the Pacific northwest. This will
result in the partly cloudy conditions later tonight and Wed. Dry
westerly flow aloft Thursday with mostly clear skies. Another
short wave moving across the region on Friday. This one appears
stronger and will result in partly cloudy skies with some weak
instability over the mountains. Warm temperatures the next few
days with highs in the 70s to lower 80s.

LONG TERM...Friday night through Tuesday...Models in good agreement
through much of the period. However, they begin to diverge
significantly on their handling of a deep trough next week.  The
deterministic models show a weak upper level trough moving through
the region Friday with a low developing over northern California. As
this low moves into central California, an upper level ridge
develops in it`s wake over the area.  This will result in a very
warm weekend with daytime temperatures 10-15 degrees above normal.
Thicknesses begin to fall as the aforementioned deep trough begins
to approach the coast. The ECMWF is the fastest model moving it over
northern Washington by Tuesday while the GFS continues to dig it
southward along the coast. In fact, the GFS keeps it offshore with S-
SW flow through the end of the week.  Ensembles favor a slower
solution with most members showing cooler temperatures delayed until
Tuesday. If the ECMWF solution pans out we will also have a good
chance for widespread rain. However, given the current discrepancies
have stuck close to NBM.  Earle

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  45  78  46  77 /   0   0   0   0
ALW  50  79  50  78 /   0   0   0   0
PSC  44  82  50  82 /   0   0   0   0
YKM  48  80  46  79 /   0   0   0   0
HRI  45  83  47  82 /   0   0   0   0
ELN  46  73  43  74 /   0   0   0   0
RDM  36  78  39  78 /   0   0   0   0
LGD  38  73  42  74 /   0   0   0   0
GCD  38  76  44  76 /   0   0   0   0
DLS  49  81  49  80 /   0   0   0   0

&&

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

$$

SHORT TERM...77
LONG TERM....94
AVIATION...84


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