Area Forecast Discussion Issued by NWS Pendleton, OR
000
FXUS66 KPDT 162330 CCA
AFDPDT
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PENDLETON OR
425 PM PDT SUN JUN 16 2013
CORRECTED AVIATION DISCUSSION
.SHORT TERM...TONIGHT THROUGH WEDNESDAY. A LARGE UPPER LEVEL LOW OFF
THE COAST WILL INFLUENCE THE WEATHER FOR THE NEXT SEVERAL DAYS.
TEMPERATURES WILL BE COOLING ESPECIALLY TUESDAY AND WEDNESDAY ALONG
WITH INCREASING CHANCES FOR RAIN. CURRENT SATELLITE SHOWS CUMULUS
DEVELOPING OVER CENTRAL OREGON AND THE MOUNTAINS. AIRMASS IS
UNSTABLE SO EXPECT CLOUDS TO CONTINUE TO INCREASE WITH SHOWERS AND
ISOLATED THUNDERSTORMS THIS AFTERNOON AND INTO THE EVENING. WITH
WARM TEMPERATURES TODAY AND EXPECTED CLOUD COVER TONIGHT LOW
TEMPERATURES WILL BE ON THE MILD SIDE WITH UPPER 40S AND 50S. MODELS
INDICATE A REPEAT ON MONDAY WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING IN THE AFTERNOON. THE UPPER LOW WILL BE
MOVING INTO THE PACIFIC NORTHWEST LATER TUESDAY AND WEDNESDAY.
TEMPERATURES WILL SHOW A DRAMATIC COOLING TREND WITH HIGHS IN THE
60S TO MID 70S. MODELS ARE GENERATING A FAIR AMOUNT OF PRECIPITATION
OVER THE FORECAST AREA. WILL CONTINUE WITH SHOWERS AND THUNDERSTORMS
THROUGH THE PERIOD HOWEVER THINK THERE MAY BE A PERIOD OF STRATIFORM
RAIN AS WELL ESPECIALLY TUESDAY NIGHT OR WEDNESDAY. WESTERLY WINDS
WILL BE INCREASING OVER THE NEXT FEW DAYS AS THE LOW MOVES INLAND
HOWEVER NO SIGNIFICANT WINDS EXPECTED OUTSIDE OF ANY THUNDERSTORM
ACTIVITY. 94
.AVIATION...00Z TAFS...VFR CONDITIONS WILL OCCUR FOR THE NEXT 24
HOURS. A MID/UPPER LEVEL LOW OFFSHORE WILL SEND MOISTURE INLAND AND
CREATE UNSTABLE CONDITIONS WHICH WILL TRIGGER LIGHT SHOWERS MAINLY
OVER MOUNTAINS OVER THE NEXT 24 HOURS. ISOLATED THUNDERSTORMS WILL
DEVELOP LATE THIS AFTERNOON OVER THE CASCADE EAST SLOPES AND OVER
MOUNTAINS IN CENTRAL OREGON AND CONTINUE INTO THIS EVENING. RADAR
INDICATES A THUNDERSTORM 9 MILES NW OF MADRAS (KS33) AT THIS TIME
MOVING NORTH. THIS STORM MAY REACH KDLS BY AROUND 02Z IF IT HOLDS
TOGETHER SO WILL INDICATE VCTS AT KDLS FROM 02Z-04Z THIS EVENING.
THUNDERSTORMS WILL MOVE NORTHWARD THIS EVENING, BUT WILL DISSIPATE
BEFORE REACHING THE COLUMBIA BASIN OF OREGON. CLOUD BASES AND
CEILINGS WILL BE AT OR ABOVE 10000 FEET AGL, BUT THERE MAY BE BRIEF
PERIODS OF MVFR DUE TO REDUCED VISIBILITY IN BRIEF HEAVY RAIN IN THE
IMMEDIATE VICINITY OF THUNDERSTORMS. -TSRA EXPECTED AT KRDM AND KBDN
FROM 01Z-03Z. WINDS FOR REMAINDER OF THIS AFTERNOON AND INTO THIS
EVENING WILL BE TO 10-15 KTS. GUSTS TO 25 KTS AT KDLS, KRDM, AND
KBDN THROUGH 04Z. THUNDERSTORMS MAY HAVE WIND GUSTS TO 40-45 KTS.
POLAN
&&
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...A LARGE MID/UPPER
LEVEL LOW WILL BE OVER THE FORECAST AREA AND MOVING SLOWLY NORTH
WEDNESDAY NIGHT. WINDS ON THE SOUTH FLANK OF THE LOW WILL BE
WESTERLY THUS PRODUCING DOWNSLOPE WINDS AND SINKING MOTION EAST OF
THE CASCADES FOR DRY CONDITIONS ACROSS THE LOWER COLUMBIA BASIN,
NORTH CENTRAL OREGON AND CENTRAL OREGON. A DISTURBANCE PINWHEELING
AROUND THE LOW WILL MOVE OVER THE BLUE MOUNTAINS WEDNESDAY NIGHT AND
PROVIDE DYNAMIC LIFT IN ADDITION TO OROGRAPHIC LIFT FOR SHOWERS
LIKELY OVER THE BLUE MOUNTAINS, ESPECIALLY IN THE EVENING, WITH A
SLIGHT CHANCE OF THUNDERSTORMS AREAWIDE ON WEDNESDAY EVENING.
THURSDAY, WITH THE LOW CENTERED OVER NORTHERN WASHINGTON, WESTERLY
DOWNSLOPE WINDS AND SINKING AIR WILL PREVAIL IMMEDIATELY EAST OF THE
CASCADES FOR DRY CONDITIONS, BUT THE EAST SLOPES OF THE CENTRAL
WASHINGTON CASCADES AND THE NORTHERN BLUE MOUNTAINS AND WALLOWA
MOUNTAINS WILL SEE A CHANCE OF SHOWERS ON THURSDAY. THURSDAY NIGHT
AND FRIDAY THE LOW DRIFTS NORTH INTO FAR SOUTHERN BRITISH COLUMBIA
WITH THE PLACEMENT OF THE LOW CONTINUING WESTERLY WINDS ALOFT OVER
THE REGION FOR A CONTINUATION OF SINKING AIR AND DRY CONDITIONS
THURSDAY NIGHT AND FRIDAY. OVER THE WEEKEND THE LOW IN SOUTHERN
BRITISH COLUMBIA MOVES EAST INTO THE CANADIAN PRAIRIE PROVINCES.
THIS WILL ALLOW A FLOAT RIDGE OF HIGH PRESSURE TO BECOME ESTABLISHED
OVER THE PACIFIC NORTHWEST FOR DRY CONDITIONS THROUGH SUNDAY NIGHT.
POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 57 83 55 73 / 20 20 20 30
ALW 62 85 59 74 / 20 20 20 30
PSC 61 88 59 77 / 20 20 30 30
YKM 58 83 56 74 / 20 20 30 30
HRI 60 86 58 76 / 20 20 30 30
ELN 57 80 55 72 / 20 20 30 40
RDM 49 78 47 67 / 30 20 30 30
LGD 53 81 52 70 / 20 20 20 30
GCD 50 82 48 71 / 20 20 20 30
DLS 59 81 57 72 / 20 20 30 40
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
MONDAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
94/99/99