701
FXUS66 KPDT 121703
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1003 AM PDT Fri Jul 12 2024

Updated Aviation Discussion

.AVIATION...18Z TAFS...VFR conditions are expected for all sites
through the period with clear skies. However, haze will be produced
by smoke from wildfires but will not reduce surface visibility below
VFR at these sites. Feaster/97

&&


PREV DISCUSSION... /issued 312 AM PDT Thu Jul 12 2024/

.SHORT TERM...Friday through Sunday...The heat is back on as warm
summer conditions promote another round of heat related products
while fire weather season also persists with a fire weather watch
for dry thunder still in effect, and some lingering concerns for
breezy winds over the weekend and into next week.

High pressure ridging will continue to meander a bit further
eastwards today and center itself over the Four Corners region
while a Pacific trough off of California will rise slightly
northwards, keeping the overall flow southwesterly to westerly and
generally stagnant overall. This will allow our temperatures to
remain on the warm side and limit overnight recoveries of cooler
lows. With the NBM showing a 40-90% chance of highs greater than
or equal to 100 on Saturday for our population centers and lower
but still noteworthy chances of 20-60% on Sunday while lows only
get down into the 60`s, HeatRisk values will bounce back into the
moderate to major category for the weekend. This is enough of a
signal that a heat advisory was issued to account for the hot
temperatures - though not quite as warm as the stretch we just
went through, concerns will still be present for heat related
illness.

Onto the fire weather side of the forecast, the westerly flow will
help to promote periods of breezier conditions through the Cascade
Gaps. Kittitas Valley remains a problem spot for sustained winds
expected to hit 15-20+ mph, but the duration remains in question
and if it will line up with minimum afternoon RH values long
enough. If a red flag warning were to be necessary, Sunday is the
most likely day when the NBM shows an 80-90% chance of wind speeds
25+ mph in this area, along with the Columbia Gorge into portions
of the lower Columbia Basin. Confidence is still low at this time
though precluding the need for a fire weather watch. On the
subject of a fire weather watch - the watch for the southern
Blue/Strawberry Mountains remains in effect for Saturday into
Sunday, but confidence has lowered here also. Models show the weak
shortwave that is moving in and the vorticity associated with it
has dropped just a bit further south, pulling a bit more of our
isolated thunder chances back down. Still some models show the
chance at a few cells and cannot rule it out enough to fully
cancel the watch at this time. Will need to monitor the afternoon
model runs to see if any new changes occur to our probabilities to
change confidence. Goatley/87


.LONG TERM...Monday through Friday...Models continue to be in good
agreement through the long term forecast periods. The Four Corners
high will remain in place but an upper level trough over the eastern
Pacific will keep enough westerly flow over the region to prevent
monsoon moisture from impacting the forecast area. High temperatures
will continue to run around 10 degrees above normal. About the only
real concern will be the locally breezy conditions that develop each
afternoon and evening along the east slopes of the Cascades and the
threat that poses to fire spread. Otherwise, pretty much a typical
summer weather pattern in store for next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  96  60  98  62 /   0   0   0   0
ALW  99  65 101  67 /   0   0   0   0
PSC 100  65 103  65 /   0   0   0   0
YKM  99  63 101  62 /   0   0   0   0
HRI 100  64 103  66 /   0   0   0   0
ELN  98  65  98  65 /   0   0   0   0
RDM  95  53  98  55 /   0   0   0   0
LGD  96  58  98  60 /   0   0   0   0
GCD  99  59 102  62 /   0   0   0  20
DLS  99  63 101  65 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from noon today to 10 PM PDT Sunday for ORZ041-044-
     049-503-505>508-511.

     Fire Weather Watch from Saturday afternoon through Sunday
     evening for ORZ642-644.

WA...Heat Advisory from noon today to 10 PM PDT Sunday for WAZ024-
     026>029-521.

&&

$$

SHORT TERM...87
LONG TERM....91
AVIATION...97