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Area Forecast Discussion (AFD)

Issued by Pendleton, OR (PDT)

FXUS66 KPDT 232111

Area Forecast Discussion
National Weather Service Pendleton OR
211 PM PDT Sun Jun 23 2019

.SHORT TERM...Tonight through Thursday...A flat ridge of high 
pressure will remain over the region through Monday for one last day 
of dry weather. Then an upper level low will take up position off 
the Pacific Northwest Coast and will begin to turn our upper level 
flow southwesterly Tuesday and then southerly on Wednesday. The low 
will add moisture and instability to the airmass leading to 
convective showers and thunderstorms mainly during the afternoon and 
evening hours of Tuesday and Wednesday. Temperatures will remain 
warm but a little below normal.  

.LONG TERM...Wednesday Night through Sunday...Wednesday night 
through Thursday night will see an upper low and trough over the 
Pacific Northwest. Moisture will be getting pulled into the area 
from the southwest. With cold air aloft from the low, lapse rates 
will be steep and there will be instability for convective showers. 
Have a chance of showers and a slight chance of afternoon and 
evening thunderstorms over the mountains and central Oregon and a 
slight chance of showers in the Columbia Basin. On Friday the upper 
low will move northeast into British Columbia and Alberta but a 
weaker trough will remain over the area. This will give the area 
another day of a chance of showers in the mountains and a slight 
chance in the lower elevations. A slight chance of afternoon and 
evening thunderstorms will be confined to northeast Oregon. 
Precipitation will taper off overnight. Saturday through Sunday will 
see the weak trough over the area with a few weak waves moving 
through the area. Models suggest some showers in the mountains but 
moisture appear to be limited, so have kept the forecast dry aside 
from a slight chance of showers along the Washington Cascade crest 
Saturday afternoon. Thursday and Friday will see temperatures in the 
70s with 60s in the mountains. Temperatures will warm a few degrees 
each day Saturday and Sunday ending up in the lower to mid 80s with 
70s in the mountains next Sunday. Perry 


.AVIATION...Previous discussion...18Z TAFs...Skies will be generally 
FEW-SCT above 050 for the next 24 hours. KALW and KPDT may be SCT-
BKN at around 060-080 due to clouds banking up against the Blue 
Mountains. Winds will be the main concern as west winds of 10-20 kts 
this morning will increase to 15-30 kts with higher gusts this 
afternoon and early evening. Winds will drop below 12 kts after 06Z-
10Z tonight. Perry


PDT  49  75  55  80 /   0   0   0  10 
ALW  53  78  57  83 /   0   0   0  10 
PSC  54  81  56  84 /   0   0   0   0 
YKM  48  77  55  77 /   0   0   0  10 
HRI  52  80  56  84 /   0   0   0   0 
ELN  48  71  52  73 /   0   0   0  10 
RDM  42  76  47  75 /   0   0   0  30 
LGD  45  73  49  77 /   0   0   0  30 
GCD  45  73  51  77 /   0   0   0  30 
DLS  53  77  57  77 /   0   0   0  10