Weather Service Report


348 
FXUS66 KPDT 241801 AAA
AFDPDT

Area Forecast Discussion...Updated
National Weather Service Pendleton OR
1100 AM PDT Fri Mar 24 2017

Updated AVIATION Discussion

.SHORT TERM...Today and tonight...A warm front is lifting across the 
area this morning bringing widespread rain to the forecast area and 
snow in the higher elevations. This will be followed by a cold 
frontal passage late today and overnight. Precipitation will 
continue until the cold frontal passage and then decrease to showers 
overnight. Precipitation amounts will range from around a quarter 
of an inch in the lower elevations to upwards of an inch in the 
mountains. This will cause an upward trend in the flow of small 
streams and creeks especially coming out of the mountains. A winter 
weather advisory for snow has been issued for the higher elevations 
of the northern Blue Mountains. Forecast has been updated to 
increase chance of precipitation and for the advisories. 

.AVIATION...18Z TAFs...There may be periods of MVFR  due to 
lower CIGS and visibility in showers until mid-afternoon. There may 
be some locally breezy conditions on the ridge tops. Otherwise, 
winds will be fairly light, especially tonight with diminishing 
winds through overnight.  Polan

&&

.PREVIOUS DISCUSSION... /issued 300 AM PDT Fri Mar 24 2017/ 

SHORT TERM...Today through Sunday...A front has moved ashore and 
will cross our area today. This system has a generous amount of 
moisture and lower elevations could see up to a quarter inch of rain 
in the wetter locations and up to three quarters of an inch in the 
mountains. Snow levels are running about 5000 feet so above that 
elevation in the mountains there will be up to 6 inches of snow. 
Models also show 30 to 35 mph winds at 850 mb, so have bumped winds 
up to 10 to 20 mph in Central Oregon and the Grande Ronde Valley. 
The winds aloft will be decreasing through the day, so do not think 
winds will be quite that strong in the Columbia Basin. Tonight the 
front will move off to the east and leave a trough over the area. 
Showers will taper off in the evening and the lower elevations will 
see showers end. There will continue to be a chance of rain and high 
elevation snow showers overnight with snow levels around 4500 feet. 
The higher mountains could see another inch or so of snow. The 
trough will cross the area Saturday and a moist westerly flow will 
keep a chance of rain and snow showers in the mountains with snow 
levels around 4000 feet. The Columbia basin will be dry. Rain 
amounts will be fairly light and less than a tenth of an inch. 
Saturday night weak ridging will cross the area ahead of the next 
system. This will be a break between systems and dry weather is 
expected. The next system will begin crossing the Cascades Sunday 
morning and bring a chance of rain with snow above 4000-4500 feet by 
Sunday afternoon. Rain amounts look to be a tenth of an inch or less 
with this system. Temperatures will be in the mid 40s to mid 50s 
today then warm to the 50s with mid to upper 40s in the mountains 
saturday then drop back to the mid 40s to mid 50s on Sunday. Perry

LONG TERM...Sunday night through Friday night...The beginning of 
the extended period looks to be fairly wet as a weather system 
tracks across the region. Most of the rain will be in the mountains, 
but all areas should see at least 0.05-0.10 inch of rain, possibly 
more, in the lower elevations and perhaps a few tenths to a half 
inch or more in the mountains. Drying will begin taking place east 
of the Washington Cascades on Monday as the flow becomes more 
downslope off the Cascades but showers will persist over the eastern 
mountains and the Cascades. More significant drying will take place 
on Tuesday as the flow aloft becomes northwest. Conditions will then 
be dry through Tuesday night until another weather system moves in 
by Wednesday morning bringing substantial rain to the entire CWA. 
Models begin to differ with each other and from run to run by that 
time and so timing will be difficult. Have decided to keep at least 
a slight chance to a chance of showers in the forecast from that 
time onward through Friday night. Winds will become breezy in 
central Oregon on Wednesday of next week through Wednesday night. 
Otherwise, winds will be light through the period and temperatures 
will be near or slightly below normal. 88

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  52  39  54  36 / 100  40  30  10 
ALW  53  42  55  40 / 100  40  30  10 
PSC  56  41  59  38 / 100  10  10   0 
YKM  55  35  59  34 /  90  10  10  10 
HRI  56  40  57  37 / 100  10  10   0 
ELN  49  32  52  30 / 100  10  10  10 
RDM  52  32  53  33 /  30  20  20  10 
LGD  47  35  52  35 / 100  70  50  10 
GCD  50  33  52  34 / 100  50  30  10 
DLS  55  41  56  41 /  60  20  30  10 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory until 6 AM PDT Saturday for ORZ502.

WA...Winter Weather Advisory until 6 AM PDT Saturday for WAZ030.

&&

$$

91/99/83/88

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Western Regional Climate Center, wrcc@dri.edu