271  
FXUS66 KPDT 222132  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
232 PM PDT SAT SEP 22 2018  
   
SHORT TERM...TONIGHT THROUGH TUESDAY
 
AN UPPER LEVEL TROUGH WILL  
CONTINUE TO MOVE ACROSS THE PACIFIC NORTHWEST TONIGHT AND SUNDAY.  
MEANWHILE A COLD FRONT, CURRENTLY EXTENDING FROM WALLOWA COUNTY TO  
SOUTH-CENTRAL DESCHUTES COUNTY, WILL CONTINUE TO DRIFT EAST-  
SOUTHEAST ACROSS THE REGION. THIS FRONT SHOULD BE OUT OF NORTHEAST  
AND CENTRAL OREGON BY EARLY SUNDAY MORNING. ISOLATED TO SCATTERED  
SHOWERS WILL CONTINUE ALONG THIS FRONT. ALSO SCATTERED SHOWERS WILL  
CONTINUE TO SPILL OVER THE CASCADE CREST INTO THE CASCADE EAST  
SLOPES TONIGHT INTO SUNDAY MORNING. A DRY NORTHWEST FLOW WILL  
DEVELOP ACROSS THE REGION SUNDAY AFTERNOON AND SUNDAY NIGHT AS AN  
UPPER RIDGE BUILDS OFFSHORE. THIS DRY NORTHWEST FLOW WILL PERSIST  
MONDAY THROUGH TUESDAY. HIGH TEMPS WILL BE COOL SUNDAY, BUT WILL  
WARM SLIGHTLY MONDAY THEN JUMP 5-7 DEGREES TUESDAY. LOW TEMPS WILL  
BE COOL EACH MORNING. THE CENTRAL OREGON ZONE COULD SEE WIDESPREAD  
LOW TEMPS AT OR BELOW 32 DEGREES MONDAY MORNING. 90  
   
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
 
MODELS ARE SIMILAR  
THROUGH THURSDAY DEPICTING A REX BLOCK OFFSHORE AND WITH A LOW OFF  
THE CA COAST. THIS WILL PRODUCE STABLE NORTHWEST FLOW WITH THE MAIN  
STORM TRACK IN CANADA. DRY CONDITIONS ARE EXPECTED UNDER MOSTLY  
CLEAR SKIES. WINDS WILL BE LIGHT AND WARMING TREND EXPECTED WITH  
HIGHS IN THE 70S TO LOWER 80S IN LOWER ELEVATIONS. MODELS DIFFER  
FRIDAY AND SATURDAY. THE GFS SWINGS A COLD FRONT SOUTH ALONG THE  
CANADIAN COAST FRIDAY REACHING WA SATURDAY WHILE THE ECMWF SWINGS  
THE CUTOFF LOW OFF THE CA COAST NORTHEAST INTO WA SATURDAY THEN EAST  
ACROSS WA. TIMING AND STRENGTH OF THE FRONT OVER THE AREA VARIES  
MODEL TO MODEL AND RUN TO RUN. GFS GIVES WA AND OR A STRONGER SHOT  
OF COLD AIR WHILE THE EC GIVES A GLANCING BLOW. BOTH MODELS ARE  
SUGGESTING AT A REINFORCING SHOT OF COLDER AIR POSSIBLE NEXT  
WEEKEND. NEITHER MODEL SHOWS ANY PRECIPITATION EXCEPT NEAR THE  
CASCADES SO I CONTINUED THE DRY FORECAST BUT CONFIDENCE IS LOW.  
COONFIELD  
 

 
   
AVIATION...00Z TAFS
 
VFR CONDITIONS EXPECTED AT ALL TAF SITES  
THROUGH THE NEXT 24 HOURS. MID AND HIGH LEVEL CLOUDS WILL DECREASE  
OVERNIGHT. WIND GUSTS TO 20 KTS DECREASING AFTER 03Z. 76  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 46 67 42 69 / 0 0 0 0  
ALW 50 68 45 70 / 0 0 0 0  
PSC 47 71 43 73 / 0 0 0 0  
YKM 41 71 40 74 / 0 0 0 0  
HRI 47 70 41 72 / 0 0 0 0  
ELN 44 67 42 73 / 10 0 0 0  
RDM 31 65 27 70 / 0 0 0 0  
LGD 41 65 35 68 / 20 10 0 0  
GCD 40 66 34 69 / 20 10 0 0  
DLS 49 70 45 76 / 10 0 0 0  
 

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

 
 

 
 
90/76/76  
 
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