816
FXUS66 KPDT 130542
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1042 PM PDT THU JUN 12 2025
UPDATED AVIATION DISCUSSION...
AVIATION...06Z TAFS
VFR CONDITIONS TO PREVAIL THROUGH THE
PERIOD. AREA WILDFIRES MAY PRESENT SOME SMOKE IMPACTS TO SITES
DLS/PDT/ALW/PSC THROUGH THE PERIOD, BUT CONFIDENCE TOO LOW TO
INCLUDE IN THE TAF. A WEAK SYSTEM WILL
BE MOVING THROUGH THE AREA THIS EVENING, ALLOWING FOR A LOW
CHANCE OF RAIN (20-30%) ACROSS KPDT/KALW WITH VERY LOW CHANCES
(5-10%) FOR KPSC. BREEZY WINDS 12-20KTS WITH GUSTS 20-30KTS WILL
CONTINUE TO IMPACT SITE DLS THROUGH THE PERIOD. WINDS WILL
INCREASE TO 12-15KTS WITH GUSTS TO 25KTS AT SITES RDM/BDN BETWEEN
22Z-03Z. OTHERWISE, LIGHT WINDS, 12KTS OR LESS, WILL PREVAIL
THROUGH THE PERIOD AT MOST SITES. LAWHORN/82
PREV DISCUSSION... /ISSUED 158 PM PDT THU JUN 12 2025/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT
BREEZY TO LOCALLY
WINDY SOUTHWESTERLY TO NORTHWESTERLY WINDS ARE PRESENT ACROSS MUCH
OF THE COLUMBIA PLATEAU REGION THIS AFTERNOON, DRIVEN BY CROSS-
CASCADE PRESSURE AND TEMPERATURE DIFFERENCES OF ROUGHLY 5-9 MB AND
15-25 DEGREES, RESPECTIVELY. COUPLED WITH RHS IN THE TEENS TO
TWENTIES, THIS IS DRIVING ELEVATED FIRE WEATHER CONDITIONS THIS
AFTERNOON. HAVE OPTED NOT TO ISSUE ANY RED FLAG WARNINGS DUE TO
VERY LIMITED COVERAGE OF OVERLAPPING WIND/RH CONDITIONS WITHIN
DECLARED FIRE WEATHER ZONES.
WINDS THROUGH THE KITTITAS VALLEY HAVE BEEN JUST BELOW ADVISORY
CRITERIA (SUSTAINED WINDS OF 30 MPH OR GUSTS OF 45 MPH).
CONFIDENCE IN REACHING CRITERIA IS MEDIUM (40-60%) SO HAVE HELD
OFF ON ISSUING ANY WIND HIGHLIGHTS.
LOOKING AHEAD, ENSEMBLE NWP IS IN EXCELLENT AGREEMENT THAT A
COUPLE SHORTWAVES VISIBLE OFFSHORE IN THE PACIFIC WILL MOVE
ONSHORE OVERNIGHT THROUGH FRIDAY. FORCING FROM THE FIRST
SHORTWAVE MAY BE ABLE TO TAP INTO SOME WEAK ELEVATED INSTABILITY
OVERNIGHT AND GENERATE ELEVATED SHOWERS ALONG A LINE FROM CENTRAL
OREGON TO SOUTHEAST WASHINGTON. CONFIDENCE IN LIGHTNING IS LOW
(10% OR LESS) GIVEN MEAGER CAPE PROFILES IN FORECAST SOUNDINGS.
FRIDAY AFTERNOON, HAVE INTRODUCED A SLIGHT CHANCE (15%) OF
THUNDER FROM CENTRAL OREGON EAST THROUGH THE BLUE MOUNTAINS.
INSTABILITY IS LIMITED (300 J/KG OR LESS) IN FORECAST SOUNDINGS,
BUT FORCING FROM THE SECOND SHORTWAVE COUPLED WITH NEGATIVE MID-
LEVEL (700-500 MB) THETA-E LAPSE RATES AND SUFFICIENTLY MOIST MID
LEVELS MAY BE ENOUGH TO GET ISOLATED SHOWERS AND THUNDERSTORMS.
CONFIDENCE IN OCCURRENCE OF THUNDER SOMEWHERE WITHIN THE
AFOREMENTIONED REGION IS MEDIUM (50%), LOWER THAN AVERAGE.
BREEZY TO LOCALLY WINDY SOUTHWESTERLY TO NORTHWESTERLY WINDS WILL
AGAIN BE PRESENT FRIDAY, ALSO IN TANDEM WITH LOW RHS. HOWEVER,
HIGH TEMPERATURES IN THE 70S TO LOWER 80S SHOULD KEEP RHS JUST
HIGH ENOUGH TO AVOID RED FLAG CONDITIONS. WILL NOTE ELEVATED FIRE
WEATHER CONDITIONS ACROSS MUCH OF THE COLUMBIA PLATEAU AGAIN.
DRY CONDITIONS ARE FORECAST FOR SATURDAY INTO SATURDAY NIGHT.
PLUNKETT/86
LONG TERM...SUNDAY THROUGH WEDNESDAY
ENSEMBLE NWP SUGGESTS
SOME FORM OF A TROUGH WILL BE PRESENT THROUGH THE PERIOD, WITH ALL
CLUSTERS OF ENSEMBLE MEMBERS INDICATING SOME FLAVOR OF A
SHORTWAVE FOR SUNDAY INTO MONDAY. HAVE HELD OFF INTRODUCING
THUNDER INTO THE FORECAST FOR SUNDAY AND MONDAY AT THIS TIME DUE
TO MEDIUM CONFIDENCE (40%) IN ALL INGREDIENTS NECESSARY FOR
CONVECTION.
LOOKING AHEAD TO TUESDAY AND WEDNESDAY, ENSEMBLE CLUSTERS SHOW A
MORE ZONAL PATTERN ALOFT WITH ABOVE-NORMAL 500-MB HEIGHTS TO OUR
SOUTH AND BELOW-NORMAL 500-MB HEIGHTS TO OUR NORTH. WESTERLY WINDS
THROUGH THE CASCADE GAPS ARE EXPECTED, WITH A SLIGHT CHANCE TO
CHANCE (15-50%) OF SHOWERS ALONG THE CASCADES. PLUNKETT/86
PRELIMINARY POINT TEMPS/POPS
PDT 53 80 49 81 / 10 10 0 0
ALW 58 80 53 81 / 10 10 10 0
PSC 54 84 53 84 / 10 0 0 0
YKM 51 82 50 83 / 0 0 0 0
HRI 54 83 51 84 / 10 0 0 0
ELN 50 76 50 80 / 0 0 0 0
RDM 41 74 40 79 / 10 10 0 0
LGD 51 76 46 79 / 40 20 10 0
GCD 48 78 44 81 / 30 20 10 0
DLS 52 75 52 80 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
SHORT TERM...86
LONG TERM....86
AVIATION...82
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