textproduct: Pendleton

KEY MESSAGES

1. Dry and above seasonal temperatures through the weekend

2. Thunderstorms chances central OR Cascades through Sunday

DISCUSSION

Current satellite shows mostly clear skies with some lingering cirrus moving across the area. Radar is quite as there is no precipitation anywhere. Ground observations are showing temperatures are already reaching into the low 70s at 1030 this morning. Temperatures today are expected to reach the low 80s across the Columbia Basin of WA, the Gorge, foothills of the northern Blues and north central OR. Elsewhere will see temperatures in the mid to upper 70s with 90% confidence.

Models show the upper level high will remain overhead through the weekend. This will bring continued warm and dry temperatures. Looking at the in house temperature comparison, temperatures will be 10-20 degrees above seasonal normal through Monday. 80-90% of the HREF raw ensembles are in agreement with temperatures above 70 degrees today. Saturday, 80-90% of the raw ensembles show the vast majority of the region seeing min to upper 70s while the Basin and the Gorge will see above 80 degrees. Finally, Sunday 60-80% of the NBM raw ensembles show temperatures in the low to mid 80s for the Basin, Gorge, Yakima/Kittitas Valleys, the foothills of the Blues and central OR. Elsewhere will remain in the mid to upper 70s.

Models show the center of the upper level low to off the coast of California with the leading edge affecting the central OR area with south to southwest flow aloft. This is bringing in increased instability to the region with 500-1000 J/kg MUCAPE, lapse rates between 7-9 C/km, lifted indices of 4-7 and effective bulk shear nearing 30 kts. This is a prime environment for thunderstorms over the central OR Cascade crests. SPC has the area in general thunderstorm chances and the NBM probability of thunder for 12 hours is 10-20%. Chances increase to 15-20% Saturday as the upper level low continues to usher in warm air advection. Forecast soundings for Saturday show MUCAPE between 500-1200 J/kg, lapse rates between 7-9 C/km, lifted indices between 5-7, and effective bulk shear near 15 kts. Sunday chances again decrease to 5-10%.

Moving on into next week, models show the continuation of an upper level high over the region. This will keep conditions dry and warm through the long term with temperatures averaging above seasonal normal. 90

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

VFR conditions to prevail through the period. There is a less than 15% chance of showers and thunderstorms impacting sites RDM/BDN tonight, with a less than 20% chance tomorrow afternoon. Winds will be mostly be light through period, however site DLS will continue to see breezy northwest winds tonight. Lawhorn/82

Preliminary Point Temps/PoPs

PDT 51 82 51 83 / 0 0 0 0 ALW 55 82 55 83 / 0 0 0 0 PSC 51 87 52 88 / 0 0 0 0 YKM 54 84 53 86 / 10 0 10 0 HRI 50 84 51 87 / 0 0 0 0 ELN 50 79 49 82 / 10 10 10 0 RDM 44 79 43 82 / 10 10 10 0 LGD 46 77 47 80 / 0 0 0 10 GCD 47 79 47 80 / 0 0 0 10 DLS 56 84 56 88 / 10 10 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...None.