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Area forecast discussion...updated 
National Weather Service Pendleton or
309 am PDT Wednesday Jul 29 2015

Updated aviation discussion

Short through Friday...upper high pressure ridge will
dominate the weather for the rest of the week with a strong warming
trend and very dry conditions. Highs on Wednesday are expected to be
in the lower to middle 90s lower elevations and 70s to 80s in the
mountains. Then temperatures will rise to 100-105 degrees in the
lower elevations on Friday and continue into the extended period.
These temperatures will be about 10-15 degrees above normal. There
is some monsoon moisture that will try to work its way northward
into the southwest County Warning Area on Friday in a southwest flow behind the
upper ridge. Have introduced isolated thunderstorms over mainly
Deschutes County on Friday afternoon and evening due to the presence
of negative lifted indice's...some cape and an increase in middle level moisture.
Any thunderstorms will be high based and will contain little
rainfall. Therefore this may become a fire weather concern as well
and will monitor it closely. 88

Long term...Friday night through Wednesday...models are in good
agreement in having strong high pressure over the Pacific northwest
from Friday night through at least Tuesday. Temperatures will be hot
with highs 95-105 in the lower elevations and in the upper 80s and
90s in the mountains. The GFS continues to show modest amounts of
moisture being circulated around the high and into the area,
assisted by circulation around a low out in the Pacific. This will
give US a slight chance of showers and thunderstorms in central
Oregon as far north as Redmond on Saturday then spreading from
central Oregon into the ochoco-John Day Highlands and northeastward
into the Blue Mountains and Wallowa County each afternoon and
evening Sunday through Tuesday. On Monday night and Tuesday, models
begin diverging as to the handling of an upper low in the Gulf of
Alaska. The GFS brings the low to the northern British Columbia
coast Monday night and then ashore Tuesday night. This keeps a
southwest flow over the area but moves the ridge axis eastward into
Montana. The European model (ecmwf) splits the low and keeps one low in the Gulf of
Alaska and sends the other low into central British Columbia Monday
night. This other low then moves to the Canadian rockies Tuesday
through Wednesday. This flattens the ridge to the south and develops
a trough over our area. Both solutions are cooler and would continue
a slight chance of thunderstorms so have temperatures Tuesday and
Wednesday dropping to 90-100 with middle 80s to lower 90s in the
mountains. Also have a slight chance of afternoon and evening
thunderstorms continuing each afternoon and evening on Tuesday and
Wednesday. Perry


Aviation...12z tafs...VFR conditions will generally clear skies
will continue across all taf sites for the next 24 hours. Winds will
remain below 12 kts. Perry


Preliminary point temps/pops...
PDT 92 58 98 63 / 0 0 0 0
alw 92 62 99 67 / 0 0 0 0
psc 94 58 100 62 / 0 0 0 0
ykm 91 58 97 61 / 0 0 0 0
hri 94 57 100 62 / 0 0 0 0
eln 92 56 97 59 / 0 0 0 0
rdm 91 49 97 55 / 0 0 0 0
lgd 88 50 94 54 / 0 0 0 0
gcd 90 49 96 53 / 0 0 0 0
dls 95 61 100 64 / 0 0 0 0


PDT watches/warnings/advisories...

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