Weather Service Report

FXUS66 KPDT 270329 AAA

Area Forecast Discussion
National Weather Service Pendleton OR
825 PM PDT SUN JUN 26 2016

.UPDATE...High pressure continues to dominate the areas weather with
dry conditions that will persist into the beginning of the work
week. Slight adjustments were done to temps tonight and the present
short term forecast appears on track.


.AVIATION...vfr conditions will continue across all taf sites for the
next 24 hours.


.PREV DISCUSSION... /issued 425 PM PDT SUN JUN 26 2016/ 

SHORT TERM...Tonight through Wednesday...A ridge of high pressure
over the western U.S. will continue to dominate the weather through
the short term with hot temperatures. A small weather disturbance
riding over the ridge on Monday could provide just enough
instability and moisture to trigger some thunderstorms over portions
of the forecast area in the late afternoon and overnight. Following
that the high pressure ridge will keep weather systems away form the
region through wednesday and a dry forecast.  

LONG TERM...Wednesday Night through Sunday night...The flow begins
to turn more southwesterly Wednesday night out ahead of an
approaching shortwave disturbance. This will act to gradually
increase moisture over our forecast area into Thursday. As the
shortwave and associated vort max move onshore Thursday there will
be a slight chance of thunderstorms over the eastern mountains
during the afternoon and evening. At this time the atmosphere is
forecast to be moderately unstable with SBCAPE values near 1000 J/Kg
and LIs ranging from negative 1 to negative 4 extending from
southern Deschutes county northeast to Wallowa and Columbia
counties. With 0-6KM bulk shear values near 30 KTs a strong storm or
two cannot be ruled out. Behind this weak disturbance a front will
move through the area with drier...cooler and more stable air
advecting in from the west. On Friday this boundary will likely be
located somewhere over our CWA. Right now there remain differences
in the speed and timing of this boundary in the guidance. The latest
12z GFS would put this boundary right along our far SE CWA border by
Friday afternoon...which would significantly limit any
shower/thunderstorm activity. Meanwhile the latest ECMWF and CMC
stall this boundary over the central portion of our forecast
area...leaving the southern and eastern portion of our area in the
warm, moist, unstable sector. For now leaned the forecast toward the
slower ECMWF/CMC solution and continued with a slight chance of PM
thunderstorms in the above mentioned areas. Heading into next
weekend the latest guidance has come into better agreement that a
deeper, long wave trough will move into the Pacific Northwest. This
would bring cooler temperatures, (but still near to above average)
breezy conditions, more cloud cover and at least a slight chance of
showers along the East Slopes of the Washington Cascades both
Saturday and Sunday.

Temperatures remain well above average Thursday and Friday with
daytime highs in the upper 80s to upper 90s in the valleys/basins
and 70s to mid 80s mountains. As mentioned above a cooling trend is
now forecast by Saturday and Sunday. Expect highs in the 80s each
day in the lower elevations...with 70s mountains. 77


PDT  59  94  63  93 /   0   0   0   0 
ALW  61  94  68  94 /   0  10  10   0 
PSC  58  96  63  95 /   0   0   0   0 
YKM  57  96  62  96 /   0   0   0   0 
HRI  57  95  64  95 /   0   0   0   0 
ELN  54  91  61  92 /   0   0   0   0 
RDM  51  88  53  89 /   0   0   0   0 
LGD  51  92  57  89 /   0  20  20   0 
GCD  53  92  56  90 /   0  10  10   0 
DLS  61  96  65  93 /   0   0   0   0 


.PDT Watches/Warnings/Advisories...



Return to Home page

Western Regional Climate Center,