Area Forecast Discussion
Issued by NWS Pendleton, OR

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FXUS66 KPDT 282129 CCA
AFDPDT

Area Forecast Discussion...correction
National Weather Service Pendleton OR
221 PM PDT THU JUL 28 2016

Corrected spelling in Long term

.SHORT TERM...Tonight through Sunday...General Overview...Very
warm/hot and dry conditions will continue through Friday afternoon.
Highs will be in the mid 90s to lower 100s across the lower
elevations, and in the mid 80s to lower 90s mountains.  Winds will
pick up in the 15 to 20 mph range Saturday with a dry cold front (see
Fire Weather Discussion for further details) passage.  Temperatures
will still be quite warm on Saturday with highs in the 90s across
the lower elevations, and in the 80s mountains.  Sunday will be
breezy but should not be as bad as the winds on Saturday. Highs
will cool off further and be in the mid 80s to lower 90s, with mid
70s to lower 80s mountains.  No precipitation expected in the short
term, although there may be some cumulus buildups over the
mountains of northeast oregon on Saturday afternoon.

Technical Synopsis...High pressure to the south will continue to
shift west over southern CA/NV, keeping a very warm and dry west
northwest flow to the forecast area.  This pattern will persist
through Saturday afternoon.  On Saturday a trough of low pressure
will swing north across the WA/Canada border.  Dry air will still be
kept to the south over the interior Pacific Northwest.  Only
moisture looks to be very limited and isolated over the mountains of
northeast Oregon.  Pressure gradients will increase with this trough
passage and winds will increase out of the west (Fire Weather
Discussion).  This will also continue through Sunday, although the
gradients will not be as strong on Sunday.  Weber

.LONG TERM...Sunday night through Thursday...Only made minor changes
to the forecast...mainly on Monday night and Tuesday.  EC/GFS
continue to bring an upper level low pressure area across central WA
late Monday into Tuesday.  Have introduced a chance for
thunderstorms across the Cascades mainly north of Highway 12 for
this time period to account for the enhanced instability associated
with the upper level cooling.  As the upper level low pulls away
east northeast, have kept dry conditions across the rest of the
area, but will need to watch the forecast track of this low to
potentially modify the area of unstable conditions.  A dry west to
northwest flow will dominate the region outside of Monday night and
Tuesday.  Temperatures will be close to or slightly below normal,
but the forecast rising heights and thicknesses by Thursday will
likely bring slightly warmer air again.  The trof associated with
the upper level will kick up some wind on Tuesday, but light winds
will be the rule the rest of the days.

&&

.AVIATION...00z TAFS...VFR conditions mostly clear skies and light
diurnal wind patterns will prevail during the next 24 hours. Hot
temperatures between 18z-00z will push density altitudes to around
3k feet higher than actual ground elevation.

&&

.FIRE WEATHER...After a week of hot and dry conditions, an
approaching dry cold front will result in possible extreme fire
behavior this weekend. The cold front on Saturday will cause winds
to increase throughout the Columbia Basin down to Central Oregon.
The actual start of marine intrusion and increasing wind will begin
late Friday afternoon/evening in and around the Eastern Columbia
River Gorge and north central Oregon. The remainder of the Basin and
Central Oregon will observe increasing winds on Saturday with winds
around 12-25 mph in many areas. Although the winds on Sunday will
not be as strong...there will be 10-20 mph winds that could remain a
concern. The relative humidity Friday through Sunday will primarily
be 10-20 percent during the afternoon.  Red Flag Warnings will be
issued for the Eastern Columbia River Gorge and North Central Oregon
(Fire zones WA/OR639 and OR610) for Friday afternoon through
Saturday evening...and Fire Weather Watches for the Columbia Basin
down to Central Oregon (Fire zones OR640, WA/OR641, OR644, and
WA675) Saturday afternoon through Sunday evening.  Wister

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  64  99  64  93 /   0   0   0   0
ALW  70  99  71  94 /   0   0   0   0
PSC  68 102  68  97 /   0   0   0   0
YKM  68 102  68  95 /   0   0   0   0
HRI  66 102  68  96 /   0   0   0   0
ELN  64  96  63  88 /   0   0   0   0
RDM  55  98  54  91 /   0   0   0   0
LGD  58  95  58  93 /   0   0   0   0
GCD  59  98  59  94 /   0   0   0   0
DLS  68  99  66  87 /   0   0   0   0

&&

.PDT Watches/Warnings/Advisories...
OR...Red Flag Warning from 4 PM Friday to 9 PM PDT Saturday for
     ORZ610-639.

     Fire Weather Watch from Saturday afternoon through Sunday
     evening for ORZ640-641-644.

WA...Red Flag Warning from 4 PM Friday to 9 PM PDT Saturday for
     WAZ639.

     Fire Weather Watch from Saturday afternoon through Sunday
     evening for WAZ641-675.

&&

$$

89/79/79/85

!--not sent--!



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