National Weather Service Text Product Display

Area Forecast Discussion
Issued by NWS Pendleton, OR
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 222233 AAA
AFDPDT

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PENDLETON OR
333 PM PDT WED MAY 22 2013

UPDATED FOR AVIATION DISCUSSION

.SHORT TERM...TONIGHT THROUGH SATURDAY...A DEEP CLOSED LOW CONTINUES
TO SPIN OVER CENTRAL WASHINGTON.  SNOW WILL GRADUALLY DECREASE
ACROSS NORTHERN KLICKITAT COUNTY ABOVE 2500 FEET INTO EARLY THIS
EVENING.  WINTER STORM WARNING REMAINS IN EFFECT TIL 8 PM.

THE COLD AIRMASS ASSOCIATED WITH THIS SYSTEM WILL BRING TEMPERATURES
DOWN TO THE UPPER 20S ACROSS THE SOUTHERN FOOTHILLS OF THE BLUE
MOUNTAINS AND GRANDE RONDE VALLEY OF OREGON.  A FREEZE WARNING HAS
BEEN ISSUED FOR THESE AREAS. CENTRAL OREGON WILL ALSO FREEZE UNDER
THE EFFECTS OF THE UNSEASONABLY COLD AIR...BUT FREEZE WARNINGS ARE
NOT NORMALLY ISSUED FOR THOSE AREAS UNTIL AFTER JUNE 1.

SHORT TERM MODELS IN GOOD AGREEMENT WITH UPPER LOW WOBBLING AROUND
THE PACIFIC NORTHWEST THROUGH FRIDAY AND THEN LIFTING OUT FRIDAY
NIGHT.  AS SUCH...VERY COOL AND SCATTERED SHOWERY CONDITIONS WILL
PREVAIL THURSDAY. SHOWERS WILL LIKELY SHOW AN INCREASE ON LATE
THURSDAY NIGHT AND FRIDAY AND THE LOW TRACKS NORTHEAST FROM CENTRAL
OREGON TO NORTHERN IDAHO. A DRIER WESTERLY FLOW SHOULD PREVAIL FOR
ALL AREAS ON SATURDAY...EXCEPT THE CREST OF THE WA/OR CASCADES AND
THE EASTERN MOUNTAINS WHERE A FEW SHOWERS WILL LINGER.

LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY NIGHT...UPPER LEVEL
TROUGH WILL CONTINUE TO CIRCULATE OVER THE PACIFIC NORTHWEST FOR THE
EXTENDED.  IT DOES SHOW SIGNS OF WEAKENING AND WARMER AIR
INTRUDING...BUT OVERALL UNSETTLED WEATHER CAN BE EXPECTED EVERY
DAY...WITH THE BETTER CHANCES OF SHOWERS AND POSSIBLY THUNDERSTORMS
TO BE OVER THE MOUNTAINS.  MODELS DO HINT AT A WEAK WAVE TO PUSH
THROUGH SATURDAY EVENING...WHICH MIGHT GENERATE A FEW MOUNTAIN
THUNDERSTORMS ACROSS NORTHEAST OREGON. AS THE CENTER OF THE LOW
PUSHES NORTHWARD FOR THE MAJORITY OF THE WORK WEEK...THE FORECAST
AREA FOR THE MOST PART WILL BE IN A ZONAL FLOW.  THIS WILL SUPPORT
NEAR NORMAL TEMPERATURES...BUT ALSO A CHANCE FOR SHOWERS EACH DAY.
MODELS DO HINT AT ANOTHER POTENTIALLY STRONG COLD FRONT TO MOVE
THROUGH ON WEDNESDAY AFTERNOON.  THE SYSTEM THAT IS MOVING IN LOOKS
TO HAVE A SLIGHT NEGATIVE TILT...ALONG WITH CAPE VALUES AND LI`S
INDICATE THE POTENTIAL FOR THUNDER.  THEREFORE HAVE MADE A SLIGHT
CHANCE MENTION INTO THE FORECAST FOR WEDNESDAY.  WEBER


&&

.AVIATION...00Z TAFS...VFR CONDITIONS AND OCCASIONALLY MVFR
CONDITIONS WILL PREVAIL THIS EVENING AND TONIGHT WITH AN UPPER LOW
PRESSURE SYSTEM THAT WILL CAUSE NUMEROUS RAIN SHOWERS AND A POSSIBLE
EVENING THUNDERSTORM. VISIBILITIES COULD BE REDUCED TO BELOW 6 MILES
AT TIMES DURING SOME OF THE HEAVIER RAIN SHOWERS AND CIGS BELOW 030
AT TIMES AT ALL TAF SITES. WINDS WILL ALSO BE BREEZY AND GENERALLY
10 TO 20 KTS AT MOST TAF SITES THIS EVENING AND THEN THEY WILL
BECOME LIGHT TONIGHT AND GENERALLY LESS THAN 10 KTS BY 06Z-12Z.
EXPECT SIMILAR CONDITIONS TOMORROW WITH LIGHTER WINDS IN THE
AFTERNOON. WEBER


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  34  59  42  60 /  20  20  20  50
ALW  36  63  44  61 /  20  20  20  40
PSC  37  65  45  66 /  20  20  20  40
YKM  36  63  43  65 /  60  20  20  40
HRI  34  65  45  63 /  20  20  20  50
ELN  34  61  41  63 /  60  30  30  40
RDM  25  55  35  55 /  20  20  50  40
LGD  30  57  38  54 /  30  30  30  50
GCD  28  54  35  51 /  30  30  30  50
DLS  38  62  46  62 /  20  20  50  50

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 3 PM PDT THIS AFTERNOON ABOVE
     4000 FEET FOR THE ORZ502-503.

     FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM PDT THURSDAY
     ORZ049.

     FREEZE WARNING FROM 2 AM TO 9 AM PDT THURSDAY ORZ508.

WA...WINTER STORM WARNING UNTIL 8 PM PDT THIS EVENING ABOVE 2500
     FEET FOR THE WAZ521.

     WINTER WEATHER ADVISORY UNTIL 3 PM PDT THIS AFTERNOON ABOVE
     4000 FEET FOR THE WAZ030.

&&

THREAT INDEX
THURSDAY : GREEN
FRIDAY : GREEN
SATURDAY : 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

$$

79/89/89
National Weather Service National Headquarters
