510
FXUS66 KPDT 190528
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
930 PM PST SAT JAN 18 2025
UPDATED AVIATION DISCUSSION
SHORT TERM...TODAY THROUGH MONDAY
A COLD PATTERN REMAINS IN PLACE
OVER THE FORECAST AREA THANKS TO A POLAR VORTEX CENTERED OVER THE
UPPER MIDWEST INITIATING PERSISTENT N/NW FLOW ALOFT INTO THE PACNW.
WE'LL SEE SOME HIGH CLOUDS UNDER THE AMPLIFIED NORTHERLY FLOW AT
TIMES OVER THE WEEKEND, BUT OTHERWISE EXPECT CLEAR AND DRY
CONDITIONS WITH LIGHT WINDS.
TEMPERATURES ARE STILL EXPECTED TO BOTTOM OUT DURING THE SUNDAY
NIGHT INTO MONDAY MORNING TIME PERIOD. THAT BEING SAID, DID ADJUST
THE LOW TEMPERATURE FORECAST DOWNWARD BASED ON HOW COLD IT GOT LAST
NIGHT, RUNNING SEVERAL DEGREES BELOW WHAT MODELS PROJECTED. AS A
RESULT, DON'T BE SURPRISED IF AREAS OUTSIDE OF THE BASIN SEE
WIDESPREAD SINGLE DIGITS, WITH BELOW ZERO TEMPS PREVAILING ACROSS
OUR USUAL COLD SPOTS SUCH AS THE BEAR VALLEY AND MEACHAM.
EXPECT THIS PATTERN TO PREVAIL UNTIL TUESDAY, WHEN A SHORTWAVE IS
EXPECTED TO MOVE IN AND BREAK DOWN THE NORTHERLY FLOW. SHOULD SEE A
GRADUAL WARM UP IN TEMPS THROUGH THE UPCOMING WORK WEEK AS A RESULT,
HOWEVER PRECIP IS NOT ANTICIPATED UNTIL LATER IN THE WORK WEEK.
EVANS/74
LONG TERM...TUESDAY THROUGH SATURDAY
GUIDANCE IS IN GOOD
AGREEMENT STARTING THE PERIOD OFF QUIETLY WITH A RIDGE PUSHING INTO
THE PACNW. A SHORT-WAVE WILL THEN BRIEFLY PUSH THROUGH THE FIRST
HALF OF TUESDAY BRINGING ZONAL WINDS ALOFT, BUT NOTHING TO SUGGEST
ANY MEANINGFUL PRECIP AMOUNTS TO OCCUR WITH THIS SYSTEM WITH POP
CHANCES STAYING NEAR 0 PERCENT AREA WIDE.
HOWEVER, THE MAIN SYSTEM TO WATCH THIS PERIOD WILL BE ON THURSDAY
GOING THROUGH SATURDAY. MANY GUIDANCE MEMBERS ARE IN AGREEMENT WITH
A TROUGH DIGGING JUST OFFSHORE BEFORE HEADING INTO THE CWA. TIMING
AND PRECIP COVERAGE AGREEMENT DIVERGES AMONG THE ENSEMBLES AS THIS
SYSTEM APPROACHES THE AREA. MODELS WANT TO HINT AT SNOW CHANCES FOR
LOWER ELEVATIONS, WITH 34% OF ENSEMBLES BRINGING LIGHT SNOW TO THE
FOOTHILLS OF THE BLUES AS EARLY AS FRIDAY MORNING AND 58% SUGGESTING
SNOW BY LATE FRIDAY AFTERNOON. MODELS, HOWEVER, HAVE PRETTY GOOD
AGREEMENT FOR MOUNTAIN SNOW IN THE WALLOWA AND BLUE MOUNTAINS BY
FRIDAY AFTERNOON, AS 81% OF MEMBERS ARE IN AGREEMENT WITH THIS
SCENARIO. ACCORDING TO THE NBM, CHANCES OF SNOW ACCUMULATIONS OF A
TENTH OF AN INCH BY SATURDAY MORNING FOR THE FOOTHILLS OF THE BLUE
MOUNTAINS IS 30-50%, WHILE FOR THE CASCADES, WALLOWAS AND BLUE
MOUNTAINS CHANCES ARE 40-60% FOR 2 INCHES OF SNOW ACCUMULATIONS. /95
AVIATION...06Z TAFS
WHILE MOST OF THE TAF SITES WILL HAVE MOSTLY
CLEAR SKIES THROUGH SUNDAY MORNING, AN EASTERLY SURFACE GRADIENT
WILL PROVIDE LOW LEVEL UPSLOPE FOR STRATUS CLOUDS BELOW 1000 FT AT
DLS IN THE EARLY MORNING...SIMILAR TO CONDITIONS EARLIER TODAY. ON
SUNDAY EVENING, A WEAK SHORTWAVE MOVING SOUTH WILL BRING
STRATOCUMULUS CLOUDS AT PDT AND ALW. DESPITE THE LACK OF MOISTURE
WITH THE EMBEDDED WAVE, I WOULDN'T BE SURPRISED IF LIGHT FLURRIES
ALSO DEVELOP. CONFIDENCE WASN'T HIGH TO INCLUDE IN THE TAFS,
HOWEVER. WINDS WILL BE LIGHT ACROSS THE BOARD THROUGH SUNDAY
AFTERNOON, INCREASING FROM THE NORTH DURING THE EVENING HOURS WITH
5-15 KTS. WISTER/85
PRELIMINARY POINT TEMPS/POPS
PDT 20 29 14 27 / 0 0 0 0
ALW 24 29 19 28 / 0 10 0 0
PSC 25 35 21 31 / 0 0 0 0
YKM 17 32 11 29 / 0 0 0 0
HRI 25 33 20 31 / 0 0 0 0
ELN 17 31 11 27 / 0 0 0 0
RDM 9 30 6 32 / 0 0 0 0
LGD 14 32 7 30 / 0 0 0 0
GCD 13 36 8 34 / 0 0 0 0
DLS 26 36 22 33 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
SHORT TERM...74
LONG TERM....95
AVIATION...85
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page