410
FXUS66 KPDT 160258
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
758 PM PDT MON OCT 15 2018
UPDATE
CLEAR SKIES AND LIGHT WINDS ARE EXPECTED TO PERSIST
THROUGH TONIGHT AND TUESDAY. PATCHY FOG POSSIBLE NEAR RIVERS.
CURRENT FORECAST ON TRACK. COONFIELD
AVIATION...06Z TAFS
MOSTLY CLEAR SKIES WITH WINDS LESS THAN
10 KT THROUGH THE NEXT 24 HOURS. PATCHY BR POSSIBLE NEAR THE KPSC
AFTER 10Z BUT MINIMAL IMPACTS. 76
PREV DISCUSSION
/ISSUED 219 PM PDT MON OCT 15 2018/
SHORT TERM...TONIGHT THROUGH THURSDAY..AN UPPER LEVEL RIDGE OF
HIGH PRESSURE CENTERED OFF THE COAST WILL CONTINUE TO SHIFT
INLAND AND SETTLE OVER THE PACIFIC NORTHWEST. THIS WILL STRENGTHEN
AND LOWER THE SUBSIDENCE INVERSION ASSOCIATED WITH THE HIGH
PRESSURE. THIS WILL RESULT IN MORE WARMING IN THE HIGHER
ELEVATIONS THAN AT THE LOW ELEVATIONS THROUGH TUESDAY AS SOME
COOL AIR REMAINS TRAPPED BENEATH THE INVERSION. TEMPS WILL CLIMB A
FEW DEGREES EACH DAY WITH VALLEY HIGHS IN THE 60S TO LOW 70S.
NIGHTTIME LOWS IN THE UPPER 20S/LOWER 30S IN THE MOUNTAINS TO
UPPER 30S/LOWER 40S IN THE VALLEYS.THERE COULD BE SOME SPOTS OF
FOG DEVELOPING UNDER THIS PATTERN BUT MAINLY NEAR OR AROUND LARGE
BODIES OF WATER LIKE LAKES AND RIVERS OR IN SMALL MOUNTAIN
VALLEYS. WINDS WILL BE VERY LIGHT THROUGH THE SHORT TERM PERIOD,
ALONG WITH DRY CONDITIONS UNDER MOSTLY CLEAR SKIES.
LONG TERM...THURSDAY NIGHT THROUGH MONDAY...UPPER LEVEL RIDGE
LOOKS TO REMAIN IN CONTROL THROUGH AT LEAST SUNDAY WITH MOSTLY
CLEAR SKIES, LIGHT WINDS, MILD DAYTIME HIGHS AND CHILLY OVERNIGHT
LOWS. WITH HIGH PRESSURE EXPECTED TO REMAIN OVERHEAD WE WILL SEE
AN INCREASINGLY STAGNANT AIRMASS WITH STRONG SUBSIDENCE INVERSIONS
KEEPING AFTERNOON MIXING HEIGHTS FOR THE LOWER ELEVATIONS LESS
THAN 2000 FEET. AS POLLUTANT AND MOISTURE LEVELS UNDER THE
INVERSION CONTINUE TO BUILD SHOULD SEE AN INCREASE IN MORNING
PATCHY FOG COVERAGE ESPECIALLY SATURDAY AND SUNDAY WITH THE RIDGE
AXIS DIRECTLY OVERHEAD, BUT OVERALL COVERAGE AND DURATION WILL BE
LIMITED BY A COMBINATION OF DRY/WARM GROUND CONDITIONS AND STILL
REASONABLE MID OCTOBER SUN ANGLES. HAVE KEPT ANY MENTION OF HAZE
OUT OF THE FORECAST FOR NOW, AS SIGNIFICANT VISIBILITY REDUCTIONS
IN HAZE WILL BE LARGELY DRIVEN BY LOCAL BURN DECISIONS. THERE ARE
SOME TIMING DIFFERENCES IN THE MODELS REGARDING THE EVENTUAL SHIFT
OF THE RIDGE TO THE EAST WITH A RETURN TO A MORE ACTIVE PATTERN,
GIVEN THE SPREAD IN SOLUTIONS FROM MONDAY AFTERNOON TO WEDNESDAY
HAVE KEPT THE FORECAST DRY FOR NOW THROUGH TUESDAY MORNING. PECK
PRELIMINARY POINT TEMPS/POPS
PDT 35 61 36 62 / 0 0 0 0
ALW 37 64 39 64 / 0 0 0 0
PSC 35 66 36 66 / 0 0 0 0
YKM 36 66 36 67 / 0 0 0 0
HRI 34 66 36 66 / 0 0 0 0
ELN 33 65 36 67 / 0 0 0 0
RDM 27 68 30 70 / 0 0 0 0
LGD 33 65 36 68 / 0 0 0 0
GCD 34 67 37 69 / 0 0 0 0
DLS 37 67 38 69 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
76/76/76
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page