Area Forecast Discussion
Issued by NWS Pendleton, OR

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FXUS66 KPDT 221001 CCA
AFDPDT

Area Forecast Discussion...Corrected
National Weather Service Pendleton OR
252 AM PDT Sat Jul 22 2017

.SHORT TERM...Today through Monday night. Dry westerly flow aloft
today with sunny skies. A front moving into southern BC will
continue to bring scattered clouds to the Washington Cascades this
morning. 850mb temperatures increase today with building upper
level ridge and high temperatures will be 3-7 degrees warmer than
yesterday. An upper level low will be approaching the northern
California coast Sunday. Instability will be increasing over
central Oregon and expect cumulus development in the afternoon.
Could have isolated thunderstorms over the southern Cascades
late. Remainder of the forecast area will have another sunny day
with highs in the 90s to near 100. Warmest temps will be in the
Columbia basin. Surface gradients indicate a little more wind
Sunday especially Kittitas valley and gorge. The upper low will
slowly move into northern California and southern Oregon Sunday
night and Monday. This will increase the coverage of showers and
thunderstorms. Mainly impacting central and northeast Oregon. To
the north of this area it will be partly cloudy and continued
warm.  94

.LONG TERM...Tuesday through Friday...Mid/upper low along northern
California coast continues to spread mid level moisture and
associated elevated instabiity into central and NE Oregon. This sets
the stage for a good chance of thunderstorms Tuesday and Wednesday
in the highlands/mountains of central Oregon and the Blue Mountains.
As the low enters the forecast area it opens up to a negatively
tilted trough with its amplitude dampening as the trough moves NE
through the forecast area. Wednesday night the upper trough swings
through far NE Oregon and exits the region by daybreak Thursday
followed by a drier SW flow aloft. The dry SW flow aloft will
persist on Thursday through Friday, which results in dry conditions
through the remainder of the long term. Tuesday looks to be the
warmest day with high temperatures in the mid to upper 90s.
Wednesday onward will be slightly cooler with highs in the mid 80s
to lower 90s through Friday.  Polan

.FIRE WEATHER...Low amplitude ridging will result in dry
conditions and a warming trend through the weekend. The next
significant fire weather concern will be thunderstorms for the
first half of next week. Models are coming into a little better
agreement with mid/upper level low pressure digging along the
northern CA coast Sunday into Monday, then opening into a trough
and moving east/northeast Tuesday and Wednesday. With the flow
becoming more toward the southwest, sufficient moisture and
instability will work into the region for some thunderstorm
development. Initial storms would likely develop across Central OR
Sunday evening, pushing east to the southern Blues Monday, then
into northeast OR Tuesday/Wednesday. With limited deep layer
moisture initially, will keep thunderstorm wording at slight
chance through Monday. Looks like the greatest risk will be on
Tuesday, and will use chance wording for thunderstorms. Given
significant uncertainty remaining will not issue any watches.

&&

.AVIATION...VFR conditions will continue for the next 24 hours
across all TAF sites.  Polan


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  92  64  98  63 /   0   0   0   0
ALW  94  68  99  66 /   0   0   0   0
PSC  96  66 101  64 /   0   0   0   0
YKM  94  65  99  62 /   0   0   0   0
HRI  95  66 100  64 /   0   0   0   0
ELN  91  63  92  58 /   0   0   0   0
RDM  91  56  97  57 /   0   0   0  20
LGD  89  57  95  57 /   0   0   0  10
GCD  92  58  97  60 /   0   0   0  20
DLS  95  67  97  65 /   0   0   0   0

&&

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

$$

94/99/99


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