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 041002
AFDPDT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
300 AM PDT TUE AUG 4 2015

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...AN UPPER TROUGH WILL
REMAIN OVER THE REGION THROUGH THIS PERIOD THOUGH IT WILL SLOWLY
SHIFT EAST. AS SUCH WILL SEE THE UPPER FLOW GRADUALLY SHIFT FROM
SOUTHWESTERLY TODAY TO WESTERLY BY WEDNESDAY. THUS EXPECT DRIER AND
MORE STABLE AIR TO CONTINUE TO FILTER INTO THE REGION THROUGH THE
PERIOD. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE LARGELY RELEGATED
TO PORTIONS OF THE OCHOCO-JOHN DAY HIGHLANDS, THE JOHN DAY BASIN,
THE GRANDE RONDE VALLEY, THE SOUTHERN BLUES AND WALLOWA COUNTY THIS
AFTERNOON AND TONIGHT. BY WEDNESDAY, ONLY A FEW LINGERING SHOWERS
ARE EXPECTED OVER EASTERN PORTIONS OF THE SOUTHERN BLUE MOUNTAINS
AND WALLOWA COUNTY. ALSO A FEW SHOWERS MAY SLOP OVER INTO WESTERN
KITTITAS COUNTY FROM WESTERN WASHINGTON. SHOULD SEE BREEZY TO
LOCALLY WINDY CONDITIONS THROUGH THE CASCADE GAPS AND ACROSS THE
COLUMBIA BASIN BOTH DAYS. HIGH TEMPS TODAY WILL BE SIMILAR TO THOSE
THAT OCCURRED YESTERDAY, BUT AN INCREASE IN MARINE AIR SHOULD CAUSE
A FURTHER COOL DOWN OF 5-8 DEGREES ON WEDNESDAY. 90

.LONG TERM...THURSDAY THROUGH MONDAY...THURSDAY AN UPPER LEVEL LOW
IN SOUTHEAST BC WILL MOVE EAST OF ROCKIES PRODUCING WESTERLY FLOW
ALOFT OVER FORECAST AREA, WHICH GIVES WESTERLY DOWNSLOPE WINDS AND
SINKING AIR EAST OF THE CASCADES FOR DRY CONDITIONS. THURSDAY NIGHT
AND FRIDAY A FLAT RIDGE OF HIGH PRESSURE MOVES OVER REGION FOR DRY
CONDITIONS. HOWEVER, A MID/UPPER LEVEL LOW OVER NORTHERN CALIFORNIA
WILL BRING SOME MID LEVEL MOISTURE INTO SOUTHERN PART OF CENTRAL
OREGON FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS IN SOUTHERN
DESCHUTES COUNTY AND ALSO IN SOUTHERN CROOK COUNTY. FRIDAY NIGHT THE
NORTHERN FLANK OF THE LOW BRINGS INCREASING MID LEVEL MOISTURE INTO
CENTRAL OREGON AND THE NORTHEAST MOUNTAINS OF OREGON WITH DAYTIME
SURFACE HEATING ON SATURDAY RESULTING IN MARGINAL INSTABILITY FOR A
SLIGHT CHANCE OF THUNDERSTORMS IN CENTRAL OREGON AND THE BLUE
MOUNTAINS TO IDAHO. OVERNIGHT THROUGH SUNDAY MORNING THE WRAP
AROUND MOISTURE IS ON THE WANE AS THE LOW MOVES INTO IDAHO/MONTANA
FOR DECREASING POPS AND ONLY A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH SUNDAY MORNING. SUNDAY AFTERNOON THROUGH
MONDAY NIGHT SOUTHWEST FLOW ALOFT BRINGS MORE MOISTURE INTO EASTERN
OREGON FOR A CHANCE OF AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS
IN CENTRAL AND NORTHEAST OREGON.  POLAN

&&

.AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL DURING THE NEXT
24 HOURS. SKIES WILL SLOWLY CLEAR 8-12Z. SMOKE FROM A WILDFIRE OVER
THE BLUE MOUNTAINS MAY INVADE INTO THE KALW AREA OVERNIGHT...DUE TO
DRAINAGE SOUTHEAST WINDS UNDER THE INVERSION. WINDS WILL PICK UP
AGAIN TOMORROW AFTERNOON.  POLAN

&&

.FIRE WEATHER...RED FLAG WARNINGS ARE IN EFFECT FOR THE LOWER
COLUMBIA BASIN AND AREAS NEAR THE EASTERN COLUMBIA RIVER GORGE
THROUGH THIS EVENING. THESE AREAS ARE EXPECTED TO SEE BREEZY TO
WINDY CONDITIONS WITH LOW RH`S THIS AFTERNOON AND EARLY IN THE
EVENING. THESE WARNINGS MAY NEED TO BE EXTENDED INTO WEDNESDAY...AS
CONDITIONS MAY BE SIMILAR. THE DECISION ON WHETHER OR NOT TO EXTEND
THE WARNING WILL BE MADE LATER TODAY. THE THUNDERSTORM THREAT WILL
BE LESS TODAY, WITH ONLY PORTIONS OF OREGON ZONES 640, 642, 644 AND
645 SEEING ISOLATED CELLS. 90

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  91  56  85  53 /  10   0   0   0
ALW  93  63  86  59 /  10   0   0   0
PSC  95  57  89  56 /   0   0   0   0
YKM  88  55  83  52 /   0   0   0   0
HRI  94  57  87  54 /   0   0   0   0
ELN  87  58  80  55 /   0   0   0   0
RDM  88  45  82  40 /  10  10   0   0
LGD  88  48  81  48 /  20  10  10   0
GCD  90  50  86  46 /  20  20  10   0
DLS  88  60  81  58 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR ORZ639-641.

WA...RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR WAZ639-641-675.

&&

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

$$

90/99/99/90


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