221
FXUS66 KPDT 062319
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
419 PM PDT MON APR 6 2026
KEY MESSAGES
1. LOW CHANCES OF THUNDERSTORMS THIS AFTERNOON WITH CONTINUED WARM
CONDITIONS
2. WIDESPREAD BREEZY TO WINDY CONDITIONS TONIGHT THROUGH TUESDAY
* WIND ADVISORY IN EFFECT*
3. PATTERN SHIFT BRINGS UNCERTAINTY TO THE FORECAST BEGINNING
MIDWEEK
DISCUSSION
CURRENT RADAR SHOWS A FEW CONVECTIVE CELLS TRYING TO FORM IN THE
SOUTHERN PORTION OF DESCHUTES COUNTY. GUIDANCE DOES SHOW A 10-15%
PROBABILITY OF THUNDERSTORMS FORMING ACROSS THAT AREA THROUGH THE
REMAINDER OF THE AFTERNOON INTO THE EVENING. LATEST CAMS ARE
SHOWING INSTABILITY WITH MUCAPES REACHING 200-250 J/KG WITH SHEAR
ONLY IN THE 15-25KTS RANGE. GUSTY OUTFLOW WINDS WILL BE THE PRIMARY
CONCERN WITH THE THUNDERSTORMS WITH MODELS SUGGESTING UP TO 50 MPH
OUTFLOWS. DCAPE VALUES OF 300-500 J/KG SUPPORT THE OUTFLOW
PROBABILITIES.
TEMPERATURES TODAY WILL BE WARM WITH TEMPERATURES 15-20 DEGREES
ABOVE SEASONAL AVERAGE. COULD SEE SOME NEAR RECORD TEMPERATURES
ACROSS THE REGION TODAY. NBM SHOWS TEMPERATURES TO BE IN THE MID TO
UPPER 70S ACROSS THE BASIN, ADJACENT VALLEYS, GORGE, FOOTHILLS OF
THE BLUES, CENTRAL AND NORTH CENTRAL OR WITH 80-90% PROBABILITIES.
THERE IS ALSO SOME ISOLATED LOCATIONS WITHIN THE BASIN (HANFORD
AREA) THAT COULD SEE TEMPERATURES REACH AT OR NEAR 80 DEGREES.
TEMPERATURES WILL THEN BEGIN TO SETTLE TUESDAY AS THE NEXT SYSTEM
MOVES IN BRINGING TEMPERATURES BACK TO 5-10 DEGREES ABOVE NORMAL
WINDS WILL BE THE NEXT CONCERN FOR THE FORECAST PERIOD AS THE REGION
BECOMES SANDWICHED BETWEEN TWO UPPER LEVEL SYSTEMS. THE UPPER LEVEL
LOW TO THE NORTH WILL CONTINUE TO BREAK DOWN THE RIDGE AS IT MOVES
IN FROM THE NORTH LATER THIS EVENING. IN HOUSE PRESSURE GRADIENT
TOOL SHOWS A TIGHTENING OF THE SURFACE GRADIENTS ACROSS THE AREA
WITH A 10-14 MB SPREAD. THIS WILL BRING INCREASED WINDS TO THE
KITTITAS VALLEY WHERE A WIND ADVISORY IS IN EFFECT FROM 5 AM THROUGH
5 PM TUESDAY FOR 25-35 MPH SUSTAINED WINDS AND GUSTS TO 45 MPH (70-
80% CONFIDENCE). WINDS WILL BE BREEZY ACROSS THE SIMCOE HIGHLANDS AS
WELL AS THE FOOTHILLS OF THE SOUTHERN BLUES WITH 60-80% OF THE RAW
NBM ENSEMBLES IN AGREEMENT FOR GUSTS 30-35 MPH IN THOSE LOCATIONS.
WINDS WILL ALSO BE ELEVATED ALONG THE RIDGETOPS OF THE OCHOCO JOHN-
DAY HIGHLANDS, HORSE HEAVEN HILLS AND ALONG PORTIONS OF THE
NORTHERN BLUES.
MODELS BEGIN TO DIVERGE AFTER TUESDAY WITH THE NEXT PATTERN
SOLUTION. THE CUT-OFF LOW IN THE PACIFIC AND THE INCOMING TROUGH IS
PROVING DIFFICULT FOR MODELS TO RESOLVE. HOWEVER, THERE DOES APPEAR
TO BE COME CONGRUENCY WITH A SPLIT FLOW PATTERN OCCURRING WITH THE
TROUGH TO THE NORTHWEST AND THE INCOMING CUT-OFF LOW TO THE SOUTH OF
THE REGION. THIS WILL KEEP TEMPERATURES TO NEAT OR ABOVE NORMAL
WITH SLIGHT CHANCES (15-30%) OF PRECIPITATION MAINLY ACROSS THE
MOUNTAINS ANS THE SOUTHERN PORTION OF THE REGION (DESCHUTES, GRANT
AND CROOK COUNTIES THROUGH FRIDAY. NBM RAW ENSEMBLES ALSO KEEP IN 10-
15% PROBABILITIES OF THOSE SAME AREAS SEEING SLIGHT CHANCES OF
ISOLATED THUNDERSTORMS. THEREAFTER, MODELS BEGIN TO SHOW ANOTHER
TROUGH IS SET TO MOVE INTO THE REGION, HOWEVER, CLUSTERS ARE SHOWING
A TIMING AND POSITIONING SEPARATION BETWEEN ENSEMBLES. LOOKING AT
THE CPC GUIDANCE, TEMPERATURES LOOK TO BE AT OR SLIGHTLY ABOVE
NORMAL WITH ABOVE NORMAL SEASONAL PRECIPITATION FOR DAYS 6-10.
90
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. THERE REMAINS A
10% CHANCE OR LESS OF AN ISOLATED THUNDERSTORM IMPACTING SITES
RDM/BDN THROUGH EARLY THIS EVENING. WINDS WILL BE LIGHT, 12KTS
OR LESS, THROUGH THIS EVENING AT SITES PDT/ALW/PSC AND WILL
REMAIN LIGHT THROUGH THE PERIOD AT SITE YKM. WINDS OF 12-17KTS
WITH GUSTS 20-25KTS WILL CONTINUE AT SITES DLS/RDM/BDN, BUT
WILL BECOME LIGHT IN THE EVENING. WINDS WILL INCREASE AGAIN
12-20KTS WITH GUSTS 20-30KTS AT SITES PDT/DLS/ALW/PSC BY OR
AFTER 10Z AS A COLD FRONT APPROACHES AND PASSES THROUGH THE
REGION. WINDS WILL INCREASE FURTHER TO 20-25KTS WITH GUSTS
30-35KTS AT SITES DLS/PDT AFTER 16Z. EXPECT WIND SHIFTS AROUND
16Z FOR SITES PDT/ALW/PSC. OTHERWISE, LIGHT WINDS TONIGHT THEN
INCREASING TO THE 12-15KTS WITH GUSTS UP TO 25KTS AT SITES
RDM/BDN. LAWHORN/82
PRELIMINARY POINT TEMPS/POPS
PDT 47 65 35 65 / 0 0 0 0
ALW 50 65 39 65 / 0 0 0 0
PSC 47 69 37 68 / 0 0 0 0
YKM 42 66 35 67 / 0 0 0 0
HRI 49 68 36 68 / 0 0 0 0
ELN 38 57 32 62 / 10 0 0 0
RDM 37 68 32 68 / 0 0 0 0
LGD 43 65 34 65 / 0 0 0 0
GCD 42 68 34 67 / 20 0 0 0
DLS 46 65 39 70 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...WIND ADVISORY FROM 5 AM TO 5 PM PDT TUESDAY FOR WAZ026.
OR...NONE.
DISCUSSION...90
AVIATION...82
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