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 221755 AAB
AFDPDT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1050 AM PDT MON SEP 22 2014

UPDATED THE AVIATION DISCUSSION

.SHORT TERM...MORNING UPDATE...WRAP AROUND MOISTURE ASSOCIATED WITH
AN UPPER LOW TRACKING OUT OF SOUTHEAST IDAHO INTO WYOMING WILL
CONTINUE TO PRODUCE CLOUDS AND STRAY SHOWERS THIS MORNING OVER UNION
AND WALLOWA COUNTIES. ELSEWHERE THERE ARE A COUPLE OF SHOWER BANDS
MOVING NORTHEAST WITHIN THE SOUTHWEST FLOW ALOFT. THESE BANDS WILL
CAUSE A FEW LIGHT, BRIEF SHOWERS THIS MORNING AS THEY MOVE THROUGH
PORTIONS OF SOUTH-CENTRAL WASHINGTON, AND NORTH-CENTRAL AND CENTRAL
OREGON. INSTABILITY ACROSS THE REGION WILL CAUSE ISOLATE TO
SCATTERED SHOWERS TO CONTINUE THIS AFTERNOON OVER PORTIONS OF THE
AREA. THIS INSTABILITY SHOULD BECOME STRONG ENOUGH FOR ISOLATED
THUNDERSTORMS FROM CENTRAL OREGON EAST TO GRANT COUNTY, AND
NORTHEAST TO THE BLUE MOUNTAINS, GRANDE RONDE VALLEY AND WALLOWA
COUNTY. ALSO A STRAY STORM MAY DEVELOP OVER THE CASCADE EAST SLOPES
OF WASHINGTON, MAINLY IN NORTHWEST YAKIMA COUNTY AND WESTERN
KITTITAS COUNTY. UPDATES THIS MORNING WERE MADE BASED ON THE LATEST
RADAR AND SATELLITE TRENDS. 90

.LONG TERM...PREVIOUS DISCUSSION...UNCERTAINTY REMAINS IN THE
EXTENDED FORECAST...WITH CONTINUED DIFFERENCES IN THE MEDIUM RANGE
MODELS. A LONGWAVE TROUGH WITH ASSOCIATED COLD FRONT IS PROGGED TO
SLOWLY MOVE EAST ACROSS THE REGION THURSDAY EVENING WITH A
WIDESPREAD CHANCE OF SHOWERS. A SLIGHT CHANCE OF EMBEDDED AFTERNOON
THUNDERSTORMS ARE ALSO POSSIBLE FAVORING THE CENTRAL AND NORTHEAST
OREGON AS LAPSE RATES STEEPEN OVER THOSE REGIONS. A CHANCE OF
SHOWERS CONTINUES OVERNIGHT THURSDAY INTO FRIDAY WITH A SLIGHT
CHANCE IN THE COLUMBIA BASIN AS THE SHORTWAVE IMPULSE EMBEDDED
WITHIN THE LONGWAVE TROUGH MOVES EAST OF THE AREA. SIGNIFICANT
UNCERTAINTY CROPS UP IN THE WEEKEND FORECAST AS THE ECMWF CONTINUES
TO ADVERTISE A CLOSED LOW OVER CALIFORNIA SATURDAY AND SUNDAY THAT
EJECTS NORTHEASTWARD ACROSS THE AREA NEXT MONDAY. MEANWHILE...THE
GFS SUGGESTS THAT THE TROUGH WILL CONTINUE ITS EASTWARD PROGRESSION
THIS WEEKEND PLACING US UNDER A RIDGE BY SUNDAY EVENING. ENSEMBLE
SPREADS BTWN THE GFS AND ECMWF REMAINS SIGNIFICANT...MUCH LIKE THE
EARLIER RUN. HAVE OPTED TO CONTINUE WITH THE COMPROMISE FROM THE
PRIOR FORECAST AND COORDINATE MINOR CHANGES WITH NEIGHBORING OFFICES
UNTIL A MUCH MORE CLEAR CUT SOLUTION PRESENTS ITSELF. TEMPERATURES
DURING THE FORECAST PERIOD WILL NEAR TO SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR ACROSS SOUTHERN WASHINGTON AND THE LOWER COLUMBIA
BASIN OF OREGON AND NEAR TO SLIGHTLY BELOW NORMAL OVER CENTRAL AND
THE HIGHER ELEVATIONS OF NORTHEAST OREGON.

&&

.AVIATION...CLOUDS AND SHOWERS WILL CONTINUE MOVING IN AND
DEVELOPING RESPECTFULLY ACROSS THE REGION WITH LCL MVFR CONDITIONS
FOR THE NEXT 24 HOURS AND OCCASIONAL AREAS OF MVFR IN AND NEAR SHOWERS.
ISOLD TSRA ARE POSSIBLE NEAR TAF SITE KRDM AND KBDN FROM 22Z-02Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  85  60  81  55 /  10  20  10  10
ALW  86  64  83  60 /  10  20  10  10
PSC  88  62  84  57 /  10  10  10  10
YKM  84  58  81  57 /  20  10  10  20
HRI  87  57  84  53 /  10  10  10  10
ELN  85  58  79  56 /  20  10  10  20
RDM  83  51  78  49 /  20  20  10  10
LGD  83  56  82  48 /  20  30  20  10
GCD  86  53  83  50 /  30  30  10  10
DLS  83  56  80  56 /  20  10  10  20

&&

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

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

$$

90/98/97







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