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
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