Area Forecast Discussion
Issued by NWS Pendleton, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KPDT 040538 AAA
AFDPDT

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
1040 PM PDT THU SEP 3 2015

...UPDATED AVIATION DISCUSSION...

.UPDATE...A SHORTWAVE CURRENTLY MOVING THROUGH THE REGION IS
BRINGING SOME LIGHT SHOWERS TO THE CASCADES AND THE EAST SLOPES
AND VALLEYS IN WASHINGTON. HAVE REMOVED THE MENTION OF THUNDER
FROM THE FORECAST DUE TO RAPID STABILIZATION OF THE ATMOSPHERE
WITH THE LOSS OF DAYTIME HEATING. SHOWER ACTIVITY HAS ALREADY
DIMINISHED FROM EARLIER THIS EVENING...AND WILL CONTINUE TO DIMINISH
OVERNIGHT. ALTHOUGH SOME AREAS WILL SEE PARTIAL CLEARING
OVERNIGHT...CLOUD COVER WILL BEGIN TO INCREASE AGAIN BY MORNING.
DESPITE RADIATIONAL COOLING ALLOWING FOR MUCH COLDER TEMPERATURES
THAN WERE EXPERIENCED LAST NIGHT ACROSS THE CENTRAL AND EASTERN
MOUNTAINS...HAVE RAISED MINIMUM TEMPERATURES A FEW DEGREES HIGHER
THAN THE AFTERNOON FORECAST DUE TO THE INCREASED INSULATION
EXPECTED FROM THE CLOUD COVER. COBB

&&

.AVIATION...06Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE
PERIOD. SKIES WILL BE MOSTLY CLEAR THIS EVENING...BUT EXPECT
INCREASING MID LEVEL CLOUDS AS A STORM SYSTEM APPROACHES THE AREA.
BY DAYBREAK EXPECT CIGS AT 4-6 THOUSAND FEET AT KBDN AND KRDM WITH
VCSH. KPDT AND KDLS WILL SEE VCSH AFTER 05/00Z. SOUTHEAST WASHINGTON
TAF SITES KALW...KPSC AND KYKM SHOULD NOT SEE PRECIPITATION UNTIL
AFTER 05/06Z FRIDAY NIGHT. WINDS ON FRIDAY WILL BE MOSTLY NORTHERLY
5 TO 15 KTS.  82

&&

.PREV DISCUSSION... /ISSUED 216 PM PDT THU SEP 3 2015/

SHORT TERM... TONIGHT THROUGH SUNDAY...AN UPPER LEVEL LOW PRESSURE
SYSTEM CONTINUES TO SPIN DOWN THE WA/OR COAST THIS EVENING.  RIGHT
NOW THE MOST FAVORABLE SHOWER ACTIVITY WILL BE ALONG THE EAST SLOPES
OF THE WASHINGTON CASCADES THIS EVENING.  HOWEVER...THERE MAY BE
ENOUGH MID LEVEL MOISTURE FOR SOME ISOLATED SHOWERS ACROSS CENTRAL
AND NORTHEAST OREGON THIS EVENING.

BY FRIDAY AFTERNOON...THE LOW SHOULD BE CENTERED OVER THE CA/OR
BOARDER AND A MOIST SOUTHERLY FLOW WILL BE IN PLACE.  AS THE LOW
SLOWLY PROGRESSES TO THE NORTHEAST EXPECT CENTRAL...NORTHEAST
OREGON...AND SOUTHEAST WASHINGTON WILL BE IN THE DEFORMATION ZONE.
THIS WILL ALLOW FOR SEVERAL ROUNDS OF PRECIPITATION OVER ABOUT 36 TO
48 HOURS. MODERATE RAINFALL MAY OCCUR AT TIMES...ESPECIALLY ACROSS
SOUTHEAST CROOK...ALL OF GRANT...AND SOUTHERN UMATILLA...UNION...AND
WALLOWA COUNTY.  48 HOUR TOTALS WILL RANGE FROM AROUND A TENTH OF AN
INCH TO A QUARTER OF AN INCH ACROSS THE BASIN...FROM A QUARTER OF AN
INCH TO THREE QUARTERS OF AN INCH ACROSS THE HIGHER ELEVATIONS.

THERE MAY BE ENOUGH INSTABILITY ALONG CENTRAL AND NORTHEAST OREGON
FOR THUNDERSTORMS ON FRIDAY.  RIGHT NOW SPEED SHEAR IS VERY HIGH
ALONG THE NORTHEAST MOUNTAINS...AND INSTABILITY IS MARGINAL.  THIS
WOULD MAKE IT LESS LIKELY FOR THUNDER ON FRIDAY ACROSS NORTHEAST
OREGON. FOR NOW HAVE JUST GONE WITH THUNDER OVER THE EAGLE CAPS.
BETTER SHEAR AND INSTABILITY FOR NORTHEAST OREGON CAN BE EXPECTED ON
SATURDAY.  SO A SLIGHT CHANCE OF THUNDERSTORMS WILL CONTINUE FOR
THAT PERIOD.

BY SUNDAY A NORTHWESTERLY FLOW WILL SET IN ALLOWING FOR CONDITIONS
TO DRY OUT.  THE EAST SLOPES OF THE CASCADES MAY SEE SOME SHOWERS AS
THE NEXT ROUND OF MOISTURE APPROACHES ON SUNDAY AFTERNOON. WEBER

LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...A SHORTWAVE TROUGH WILL
MOVE ACROSS THE REGION SUNDAY NIGHT WITH LIMITED MOISTURE. THERE
WILL BE JUST A SLIGHT CHANCE FOR SHOWERS ALONG THE WASHINGTON
CASCADE CREST AND OVER FAR NE OREGON. OTHERWISE EXPECT JUST A FEW
CLOUDS AROUND AND COOL TEMPERATURES. FOR THE REST OF THE WEEK EXPECT
DRY WEST TO NORTHWEST FLOW. SKIES WILL BE MOSTLY CLEAR A MAJORITY OF
THE TIME. HIGH TEMPERATURES WILL MODERATE FROM BELOW NORMAL MONDAY
TO ABOVE NORMAL BY WEDNESDAY AND THURSDAY. LOW TEMPERATURES WILL BE
CHILLY DUE TO GOOD RADIATIONAL COOLING AND LONGER NIGHTS. THE
VALLEYS WILL BE PARTICULARLY COOL WITH HIGHER MOUNTAIN LOCATIONS
LIKELY SEEING SOME FREEZING CONDITIONS. 78

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  44  69  48  71 /   0  10  30  50
ALW  48  73  53  68 /   0  10  30  60
PSC  46  76  54  77 /   0  10  10  40
YKM  45  68  49  72 /  20  10  10  10
HRI  46  74  52  76 /   0   0  20  40
ELN  43  70  48  71 /  20  20  10  10
RDM  37  61  36  65 /  20  50  70  20
LGD  36  66  40  62 /  20  20  60  70
GCD  35  67  39  65 /  20  50  70  70
DLS  49  76  53  77 /  20  20  20  10

&&

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

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON

$$

82/


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.