305
FXUS66 KPDT 140519
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1019 PM PDT TUE OCT 13 2026
KEY MESSAGES
- LOCALIZED AREAS OF FROST AND FREEZE OVERNIGHT TONIGHT
- ABOVE AVERAGE TEMPERATURES LIKELY ON FRIDAY, WITH BREEZY
CONDITIONS IN THE BLUE MOUNTAINS AND GRANDE RONDE VALLEY
- CHANCES FOR RAIN RETURN EARLY NEXT WEEK.
DISCUSSION
QUIET WEATHER TODAY WITH SOME MID-UPPER LEVEL CLOUDS STARTING
TO COME INTO THE REGION FROM THE NORTHWEST, AS SHOWN BY VISIBLE
SATELLITE IMAGERY. CURRENT WATER VAPOR IMAGERY AND UPPER AIR
OBSERVATIONS SHOW A CUTOFF LOW OVER THE NEVADA-UTAH BORDER AND
A RIDGE OVER THE EASTERN PACIFIC. AS THIS RIDGE CONTINUES TO
MOVE EAST, IT WILL MOVE INTO THE REGION DURING THE NEXT DAY OR
TWO.
AS A RESULT OF THE RIDGING THROUGH FRIDAY, TEMPERATURES WILL
GRADUALLY INCREASE THROUGHOUT THE WEEK. TEMPERATURES OVERNIGHT
TONIGHT WILL BE A FEW DEGREES WARMER THAN LAST NIGHT, BUT AREAS
OF FROST AND FREEZE ARE STILL LOCALLY (IN COLDER PRONE
LOCATIONS) POSSIBLE (20-40%) IN LOWER ELEVATIONS. HOWEVER,
WIDESPREAD FREEZING TEMPERATURES APPEAR UNLIKELY (<10%). AS A
RESULT, A FREEZE WARNING IS NOT CURRENTLY EXPECTED FOR AREAS
STILL ELIGIBLE. TOWARDS THE END OF THE WEEK, AS THE NEXT SYSTEM
APPROACHES, HIGHS ON FRIDAY WILL REACH THE MID 70S TO LOW 80S
FOR LOWER ELEVATIONS AND THE LOW 60S TO 70S FOR HIGHER
ELEVATIONS, WHICH IS AROUND 10-20 DEGREES ABOVE NORMAL
(CONFIDENCE 90%). ADDITIONALLY, THERE IS EVIDENCE IN THE LONGER
RANGE CAMS (I.E. THE RRFS, EXPERIMENTAL MPAS-RRFS, AND
UNIVERSITY OF WASHINGTON WRF) THAT SUGGEST THE DEVELOPMENT OF
BREEZY CONDITIONS ACROSS THE BLUE MOUNTAINS AND GRANDE RONDE
VALLEY ON FRIDAY. CURRENT GUIDANCE SUGGESTS WIND GUSTS IN THE
30-40 MPH RANGE. HOWEVER, THE EXACT MAGNITUDE WILL BECOME
BETTER REFINED AS THE EVENT COMES INTO RANGE FOR MORE OF THE
CAMS.
AFTER FRIDAY, MODELS ARE IN SOMEWHAT GOOD AGREEMENT ABOUT THE
PRESENCE OF TWO TROUGHS COMING THROUGH THE REGION. THE FIRST IS
A WEAK SHORTWAVE TROUGH THAT WILL COME THROUGH THE NORTHWEST
DURING THE WEEKEND. THE TIMING AND AMPLITUDE DOES HAVE SOME
UNCERTAINTY BUT THERE IS GOOD AGREEMENT THAT THE PRECIP WILL BE
CONFINED TO THE CASCADES. THE SECOND TROUGH APPEARS TO BE A
DEEPER TROUGH THAT WILL COME THROUGH SOMETIME TOWARDS THE START
OF NEXT WEEK. LREF CLUSTER EOF'S SHOW THAT TIMING IS CURRENTLY
THE LARGEST SOURCE OF UNCERTAINTY FOLLOWED BY THE AMPLITUDE OF
THE TROUGH. DESPITE THE UNCERTAINTY, MODELS SUGGEST THAT THIS
WILL BE THE NEXT BEST CHANCE OF SEEING RAIN FOR MOST OF THE
AREA, WITH NBM PROBABILITIES OF MEASURABLE RAIN (>0.01 IN)
AROUND 70% IN THE BLUE MOUNTAINS AND 25-50% IN THE LOWER
ELEVATIONS. GARTY/26
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
VFR CONDITIONS ARE FORECASTED DURING THE TAF PERIOD AT ALL SITES.
WINDS ARE GENERALLY 7 KTS OR LESS AT ALL SITES. CIGS ARE
NOTHING OF CONCERN AT THE MOMENT DURING THIS PERIOD RANGING FROM
7000 FT AND HIGHER IN CEILING HEIGHT. VIS IS 6 SM AT ALL SITES
AS WELL. AMES/01
PRELIMINARY POINT TEMPS/POPS
PDT 64 36 68 37 / 0 0 0 0
ALW 65 41 69 41 / 0 0 0 0
PSC 67 34 71 36 / 0 0 0 0
YKM 65 39 70 41 / 0 0 0 0
HRI 66 36 70 38 / 0 0 0 0
ELN 62 35 67 37 / 0 0 0 0
RDM 66 27 69 30 / 0 0 0 0
LGD 63 31 68 34 / 0 0 0 0
GCD 64 33 70 37 / 0 0 0 0
DLS 70 41 74 45 / 0 0 0 0
PRELIMINARY POINT TEMPS/POPS
PDT 34 68 35 69 / 0 0 0 0
ALW 41 67 38 69 / 0 0 0 0
PSC 36 70 35 71 / 0 0 0 0
YKM 42 70 40 70 / 0 10 0 0
HRI 38 69 36 69 / 0 0 0 0
ELN 38 68 38 66 / 0 10 0 0
RDM 31 68 28 74 / 0 0 0 0
LGD 33 67 34 70 / 0 0 0 0
GCD 32 67 34 75 / 0 0 0 0
DLS 43 75 45 74 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...26/71/86
AVIATION...01/82
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