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 061138 AAA
AFDPDT

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PENDLETON OR
438 AM PDT WED MAY 6 2015

UPDATED FOR AVIATION DISCUSSION

.SHORT TERM...TODAY THROUGH FRIDAY. WATER VAPOR IMAGERY SHOWS
UPPER LOW MOVING OUT OF BRITISH COLUMBIA INTO THE PACIFIC
NORTHWEST EARLY THIS MORNING. THE LOW WILL BE CENTERED OVER OREGON
LATER IN THE AFTERNOON. MODEL FORECAST SOUNDINGS SHOW DECENT LAPSE
RATES. EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. THE
ACTIVITY WILL LIKELY BE MORE CONCENTRATED OVER THE MOUNTAINS.
MODELS STILL INDICATE -28 AT 500MB SO THE STRONGER SHOWERS MAY
PRODUCE SMALL HAIL. SURFACE GRADIENTS WILL PRODUCE LOCALLY BREEZY
NORTHWEST WINDS TODAY. SHOWERS AND STORMS WILL CONTINUE INTO THE
EVENING THEN DIMINISH OVERNIGHT AS THE ATMOSPHERE BECOMES MORE
STABLE AND THE LOW MOVES SOUTHWARD. BY THURSDAY THE LOW HAS MOVED
INTO CALIFORNIA WITH AN UPPER RIDGE BUILDING INTO THE REGION WITH
A NORTHERLY FLOW. EXPECT CLEARING SKIES DURING THE DAY WITH WARMER
TEMPERATURES. GRADIENTS CONTINUE TO PRODUCE BREEZY NORTHERLY
WINDS. UPPER RIDGE REMAINS IN PLACE FRIDAY WITH CLEAR TO PARTLY
CLOUDY SKIES.

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...WEAK YET AMPLIFIED RIDGE
OF HIGH PRESSURE WILL DOMINATE THE AREA FOR THE WEEKEND.  TEMPERATURES
WILL BE IN THE MID 70S TO LOWER 80S...WITH MID 60S TO LOWER 70S
MOUNTAINS.  ANOTHER LOW PRESSURE SYSTEM IS EXPECTED TO SET UP OFF THE
OR/CA COAST ON SUNDAY NIGHT INTO MONDAY.  MOISTURE WILL BEGIN TO IMPACT
THE EAST SLOPES OF THE OREGON CASCADES BY SUNDAY EVENING.  RIGHT NOW
SHOWER COVERAGE IS VERY LIMITED.  SUNDAY NIGHT INTO MONDAY COVERAGE
WILL INCREASE TO THE NORTHEAST MOUNTAINS AS THE LOW MOVES CLOSER TO
THE COAST. BY MONDAY AFTERNOON THE LOW IS EXPECTED TO BE SET UP
RIGHT OVER THE OR/CA COAST PROVIDING GOOD SOUTHERLY FLOW TO CENTRAL
OREGON...AND SOUTHEAST FLOW TO NORTHEAST OREGON.  THIS HAS THE SETUP
FOR DECENT THUNDERSTORMS ACROSS THE SOUTHERN PORTION OF THE CWA.
GFS STALLS THE LOW OUT THROUGH TUESDAY...SHIFTING THE CENTER ABOUT
150 MILES ENE FROM MONDAY`S POSITION...SETTING UP ANOTHER
POTENTIAL DECENT DAY FOR THUNDERSTORM ACTIVITY. WILL CONTINUE TO
MONITOR THE SYSTEM AND MAKE UPDATES. WEBER

&&

.AVIATION...12Z TAFS...VFR CONDITIONS EXPECTED OVER THE NEXT 24
HOURS. SOME BRIEF CLEARING THIS MORNING...BEFORE DAYTIME HEATING AND
WEAK INSTABILITY WILL ALLOW SCATTERED SHOWERS AND POSSIBLE
THUNDERSTORMS BETWEEN 18Z-6Z. RIGHT NOW CONFIDENCE IS MARGINAL...AND
WITH STEEP LAPS RATES ANYWHERE SHOWERS DEVELOP...CAN`T RULE OUT
THUNDER.  HOWEVER HAVE ONLY GONE WITH A TEMPO -TSRA FOR KDLS...AND A
PROB30 GROUP FOR KYKM...AND KBDN.  OTHERWISE CONFIDENCE IS ONLY
ENOUGH TO HAVE VCTS FOR OTHER TAF SITES.  HIGHEST PROBABILITY OF
THESE THUNDERSTORMS WILL BE BETWEEN 21Z-01Z. WINDS WILL RANGE FROM 5-
15 KTS...WITH SOME AREAS GUSTING TO 25 KTS.  GUSTY WINDS ARE
POSSIBLE NEAR THUNDERSTORMS AS WELL.  WEBER

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  62  39  68  41 /  20  20  10   0
ALW  65  42  70  43 /  20  20  10   0
PSC  68  42  75  43 /  20  10   0   0
YKM  65  40  73  43 /  30  20   0   0
HRI  67  40  73  41 /  20  10   0   0
ELN  62  38  71  41 /  40  20   0   0
RDM  58  32  64  33 /  30  30  10   0
LGD  59  39  64  39 /  20  20  10  10
GCD  59  34  64  35 /  20  20  10  10
DLS  66  41  75  44 /  20  20   0   0

&&

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

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

$$

94/89/89



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