331  
FXUS66 KPDT 240523 AAA  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
1030 PM PDT SAT MAR 23 2019  
 
UPDATED AVIATION DISCUSSION  
   
UPDATE
 
BAND OF MOISTURE/LIGHT RAIN CONTINUES TO MOVE FROM  
SOUTHEAST OREGON NORTHWEST INTO THE LOWER COLUMBIA BASIN. THE  
UPPER LOW WILL CONTINUE TO PUSH INTO NORTHERN CALIFORNIA TONIGHT  
WITH MOISTURE BEING FUNNELED ACROSS EASTERN OREGON INTO CENTRAL  
WASHINGTON. THE SYSTEM MAY BE A LITTLE SLOWER TO MOVE OUT ON  
SUNDAY. MAINLY UPDATES TO POP AND QPF AND BUMPED UP OVERNIGHT  
LOWS.  
 
THERE ARE HYDRO CONCERNS ABOUT THE AMOUNT OF MOISTURE THAT WILL  
CONTINUE ACROSS NORTHEAST OREGON WITH SNOW LEVELS NOT LOWERING AS  
FAST AS ORIGINALLY THOUGHT. PER RFC, THE HIGHER POPS AND QPF WERE  
INCORPORATED AND FORECAST POINTS ALONG THE UMATILLA RIVER, GRANDE  
RONDE RIVER AND TOUCHET RIVER WILL SEE STRONG RISES, BUT AT THIS  
TIME SHOULD REMAIN BELOW FLOOD STAGE. 93  
 

 
   
AVIATION...06Z TAFS
 
MVFR CIGS AT TIMES OVERNIGHT AND THROUGH THE  
MORNING HOURS AT PDT/ALW/PSC AS BAND OF SHOWERS CONTINUE TO SPREAD  
NORTHWEST FROM OREGON INTO WASHINGTON. THE UPPER LOW WILL SHIFT EAST  
ON SUNDAY WITH SHOWERS ENDING FROM WEST TO EAST AND VFR CONDITIONS.  
WINDS WILL 10-15 KTS TONIGHT, THEN UNDER 10 KTS ON SUNDAY. 93  
 

 
   
PREV DISCUSSION
 
/ISSUED 430 PM PDT SAT MAR 23 2019/  
 
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT. A LOW PRESSURE SYSTEM  
WAS MOVING ACROSS OREGON AND WILL COMBINE WITH MOISTURE TO PRODUCE  
SHOWERS ACROSS THE REGION TONIGHT. THE BEST CHANCE OF PCPN WILL  
OCCUR OVER OUR SE CWA WHERE THE MODELS WERE GENERATING UPWARDS TO  
A QUARTER INCH OF PCPN THAT COULD FURTHER AGGRAVATE SWOLLEN  
RIVERS AND STREAMS. SOME SNOW ACCUMULATION IS POSSIBLE FOR  
ELEVATIONS AS LOW AS 3500K FEET TONIGHT. ELSEWHERE SCATTERED  
SHOWERS WILL PERSIST ESPECIALLY IN THE MOUNTAINS INTO SUNDAY WHILE  
THE BULK OF THE PCPN WILL SHIFT INTO THE EASTERN MOUNTAINS. SOME  
DRIER AIR WILL WORK ITS WAY INTO THE WESTERN SECTIONS TOMORROW  
BEFORE PUSHING EAST SUNDAY NIGHT. ANOTHER DISTURBANCE WILL  
APPROACH THE TWO STATE AREA MONDAY WITH INCREASING CLOUDS AND  
SHOWERS EXPECTED ALONG THE WA/OR CASCADES THAT WILL MIGRATE INTO  
THE REMAINDER OF THE REGION MONDAY AFTERNOON. THE SHOWERS WILL  
MOVE EAST WITH SOME DRYING EXPECTED MONDAY NIGHT. TEMPERATURES  
WILL REMAIN NEAR NORMAL THROUGH THE PERIOD.  
 
LONG TERM...TUESDAY THROUGH SUNDAY...AN ELONGATED UPPER LOW OFF THE  
PACIFIC NORTHWEST COAST WILL BE PUSHING A MOIST SOUTHWEST FLOW ALOFT  
OVER THE FORECAST AREA ON TUESDAY. A WEATHER DISTURBANCE WITHIN THE  
FLOW WILL MOVE THROUGH THE CWA TUESDAY NIGHT INTO WEDNESDAY. THIS  
WILL BRING AT LEAST SCATTERED SHOWERS OVER THE FORECAST AREA,  
ESPECIALLY IN THE MOUNTAINS WHERE UPSLOPE WILL BE THE GREATEST. THIS  
WILL BE OVER THE BLUES AND WALLOWA MOUNTAINS DUE TO THE SOUTHWEST  
FLOW. THERE WILL ALSO BE SCATTERED SHOWERS OVER THE CASCADES. SNOW  
LEVELS WILL BE AROUND 3000 FEET TO 4000 FEET FROM NORTH TO SOUTH.  
THEN THE MODELS BEGIN TO DIVERGE FROM EACH OTHER AFTER THIS POINT  
AND THE UPPER LOW WILL WEAKEN, BUT THE CANADIAN AND GFS KEEP A  
TROUGH OVER THE REGION WHILE THE ECMWF TRIES TO BUILD A RIDGE FOR  
THURSDAY. WILL GO WITH THE WETTER SOLUTION OF THE MODELS AND KEEP  
THE FORECAST SHOWERY AND UNSETTLED THROUGH AT LEAST FRIDAY. AFTER  
THAT THE ECMWF COMES MORE INTO ALIGNMENT WITH THE GFS AND ECMWF AND  
ALL WANT TO DRY CONDITIONS OUT WITH AN UPPER RIDGE TRYING TO BUILD  
OVER THE REGION. THUS WILL START A DRYING TREND ON SATURDAY AND  
CONTINUE IT THROUGH SUNDAY. TEMPERATURES WILL BE SLIGHTLY BELOW  
NORMAL WITH MAX READINGS IN THE 50S FOR THE LOWER ELEVATIONS. WINDS  
WILL BE BREEZY AT TIMES, MAINLY ON THE RIDGE TOPS, AND ESPECIALLY ON  
TUESDAY THROUGH FRIDAY. 88  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 39 56 37 55 / 70 50 0 20  
ALW 39 56 38 57 / 70 60 10 20  
PSC 41 59 37 57 / 50 50 0 30  
YKM 39 58 36 52 / 30 30 0 40  
HRI 42 60 37 56 / 60 50 0 30  
ELN 37 57 33 50 / 30 40 10 40  
RDM 27 56 32 51 / 30 0 10 70  
LGD 33 49 32 51 / 90 60 0 20  
GCD 32 52 35 54 / 90 30 0 40  
DLS 39 59 36 51 / 10 0 0 70  
 

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

 
 

 
 
93/93/93  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab OR Page
The Nexlab WA Page Main Text Page