River Flood Warning 1, NWS Pendleton, OR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
1000 AM PST MON FEB 15 2016

UPDATED AVIATION DISCUSSION

.UPDATE...HEAVY RAIN CONTINUES TO FALL OVER THE WASHINGTON
CASCADES THIS MORNING...ESPECIALLY IN WESTERN KITTITAS COUNTY.
FLOODING HAS BEEN REPORTED IN THE ELK MEADOWS SUBDIVISION
NORTHWEST OF CLE ELUM...AND A FLOOD ADVISORY HAS BEEN ISSUED.
FLOODING HAS ALSO BEEN REPORTED ALONG CREEKS AND OVER ROADWAYS IN
ELLENSBURG...PROMPTING THE ISSUANCE OF A FLOOD WARNING. THE
RAINFALL IN KITTITAS COUNTY IS EXPECTED TO DIMINISH THIS
AFTERNOON. RIVERS AND STREAMS SHOULD THEN CREST THIS EVENING AND
WATER WILL BEGIN TO RECEDE OVERNIGHT. THE REMAINDER OF THE AREA
WILL BE MOSTLY DRY TODAY...EXCEPT FOR SOME LIGHT SHOWERS OVER THE
BLUE MOUNTAINS AND WALLOWA COUNTY. OTHERWISE...THE PREVIOUS
FORECAST REMAINS ON TRACK.  COBB

&&

.AVIATION...18Z TAFS...VFR CONDITIONS WITH VARIABLE MID AND HIGH
LEVEL CLOUDS WILL CONTINUE THROUGH 16TH/12Z. THEN CLOUD BASES LOWER
TO 5000-10000 FT AGL AT KDLS, KPSC, KPDT AND KALW BY 17TH/12Z-14Z.
KYKM, KRDM AND KBDN WILL BE UNDER THE INFLUENCE OF SINKING AIR
MOTION IN THE MID LEVELS (5000-15000 FT AGL) DUE TO WESTERLY FLOW
ALOFT PRODUCING DOWNSLOPE WINDS IMMEDIATELY EAST OF THE CASCADES.
HOWEVER KYKM, KRDM AND KBDN WILL SEE SOME THIN HIGH CLOUDS STREAMING
THROUGH THE MID/UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE PACIFIC
NORTHWEST OVER THE NEXT 24 HOURS FOR CLOUD BASES AT KYKM SCT-BKN
25000 FT AGL, THEN LOWERING TO SCT-OVC 12000-15000 FT AGL BY
16TH/17Z. CLOUD BASES AT KRDM AND KBDN WILL BE SCT-BKN 20000-25000
FT AGL THROUGH THE PERIOD, EXCEPT THAT OVERNIGHT SKIES AT KRDM/KBDN
WILL BE MOSTLY CLEAR. THE MAIN CONCERN WILL BE WINDS. SW-W WINDS AT
12-24 KNOTS GUSTING TO 30 KNOTS ARE EXPECTED THROUGH 03Z AT KPSC,
KALW AND KPDT.  POLAN

&&

.PREVIOUS DISCUSSION... /ISSUED 328 AM PST MON FEB 15 2016/

SHORT TERM...TODAY THROUGH WEDNESDAY...A WEATHER SYSTEM CONTINUES
TO DEPART THE REGION AND THE MOISTURE IS BEING PUSHED NORTHWARD BY
AN UPPER RIDGE THAT IS BUILDING ACROSS THE REGION. EXPECT A DRYING
TREND TODAY AND TUESDAY AS A RESULT. HOWEVER...THERE ARE STILL A FEW
SHOWERS OVER THE SOUTHERN WASHINGTON CASCADE EAST SLOPES. IT WILL BE
BREEZY TO WINDY IN AREAS BEHIND THIS SYSTEM...ESPECIALLY ALONG THE
CASCADE EAST SLOPES WHERE THERE IS A LEE SIDE TROUGH...AND OVER THE
EXPOSED OPEN TERRAIN OVER THE LOWER COLUMBIA BASIN AND ADJACENT
VALLEYS/FOOTHILLS OF THE BLUE MOUNTAINS. THE WINDS ARE NOT EXPECTED
TO REACH ADVISORY SPEEDS AT THIS TIME BUT IT NEEDS TO BE MONITORED.
A VERY MILD SOUTHWEST FLOW WILL PERSIST TODAY THROUGH TUESDAY WITH
MAXIMUM TEMPERATURE READINGS IN THE 60S IN THE LOWER ELEVATIONS AND
40S TO MID 50S IN THE MOUNTAINS. SOME RECORD HIGHS COULD BE BROKEN
TODAY AND TUESDAY AND WILL HAVE NEAR RECORD HIGH TEMPERATURES
HIGHLIGHTED IN THE FORECAST FOR AT LEAST TODAY SO FAR. A WEAK COLD
FRONT WILL DROP SOUTHWARD ON TUESDAY BUT THE MAIN EFFECT WILL JUST
BE MOSTLY CLOUDY SKIES. ON WEDNESDAY ANOTHER WEATHER SYSTEM WILL
MOVE INTO THE REGION WITH MOISTURE AND RAIN SPREADING FROM WEST TO
EAST GOING INTO THE EXTENDED FORECAST PERIOD. THERE IS STILL SOME
RIVERS THAT ARE EXPECTED TO REACH ACTION STAGE ALONG THE CASCADE EAST
SLOPES OF WASHINGTON AND OVER THE NORTHEAST MOUNTAINS DUE TO RECENT
RAINS AND SNOW MELT. FLOODING IS NOT EXPECTED THOUGH AT THIS TIME ON
ANY RIVERS IN THE CWA. A HYDROLOGIC OUTLOOK IS CURRENTLY IN PLACE AS
WELL AS A RIVER STATEMENT FOR THE RIVERS THAT ARE EXPECTED TO REACH
ACTION STAGE...I.E THE NACHES RIVER SO FAR. 88

LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...A TROUGH WILL BE
LOCATED OFFSHORE WEDNESDAY NIGHT. WARM SOUTHERLY FLOW AHEAD OF THIS
SYSTEM WEATHER SYSTEM WILL BRING MAINLY RAIN WEDNESDAY NIGHT.
THURSDAY THE TROUGH WILL MOVE INLAND WITH A CHANCE OF SHOWERS AND
LOWERING SNOW LEVELS TO AROUND 3500-4500 FEET. BREEZY TO WINDY
CONDITIONS WILL DEVELOP THURSDAY AS SURFACE PRESSURE GRADIENTS
TIGHTEN AND STRONGER WINDS ALOFT MIX TO SURFACE. A TRANSIENT RIDGE
WILL MOVE QUICKLY ACROSS THE REGION THURSDAY NIGHT...BUT SOME
SHOWERS WILL STILL BE POSSIBLE. MODEL SPREAD INCREASES FRIDAY AS THE
GFS BRINGS ANOTHER TROUGH AND FRONT THROUGH THE AREA WHILE THE ECMWF
KEEPS THE SYSTEM OFFSHORE UNTIL FRIDAY NIGHT. THIS WILL KEEP SOME
SHOWERS OVER EASTERN WASHINGTON AND OREGON FRIDAY AND SATURDAY. A
RIDGE WILL REBUILD ON SUNDAY AND MONDAY FOR MUCH DRIER WEATHER.
COONFIELD

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  64  46  60  43 /   0  10  10  10
ALW  65  50  60  46 /  10  10  10  10
PSC  66  46  62  43 /   0   0  10  10
YKM  63  42  58  42 /   0  10  10  10
HRI  66  44  62  43 /   0   0  10  10
ELN  58  43  55  38 /  10  10  20  20
RDM  62  38  61  42 /   0   0   0  10
LGD  58  42  57  41 /  20  10  10  10
GCD  59  40  58  39 /  10  10   0  10
DLS  63  47  60  46 /  10  20  10  10

&&

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

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

82/99/88/76