textproduct: Pendleton

KEY MESSAGES

1. Dry and above seasonal temperatures through the weekend

2. Thunderstorms chances central OR Cascades through Sunday

DISCUSSION

Current radar shows a few convective cells riding along the ridgetops of the Cascades. Ground observations do not show any rainfall has occurred and the lightning detection network has not picked up on any lightning strikes. Satellite does show some areas along the OR Cascades and central OR with some cloud cover as well as along the foothills of the Blues. These clouds are moving to the northeast and drying out quickly. The remaining areas are under clear skies. Some Cu fields are beginning to form to the south of the region and into Grant and Wasco Counties with some larger Cu popping up along the border of Deschutes and Lake Counties.

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. 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. 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. Monday will an increase in temperatures in the same areas as previously mentioned with temperatures in the mid to upper 80 and low 80s elsewhere with 80-90% raw ensembles agreement.

Models show the center of the upper level low still off the coast of California with the leading edge continuing to affect the central OR area with south to south flow aloft. This is a prime environment for thunderstorms to return over the central OR Cascade crests. SPC has the area in general thunderstorm chances and the NBM probability of thunder for 12 hours is 15-25%. Forecast soundings for today (Saturday) show MUCAPE between 500-1000 J/kg, lapse rates between 7- 8 C/km, lifted indices between -5-(-7), and effective bulk shear near 20 kts. Sunday chances again decrease to 5-10% with the upper level low being shown to be a bit deeper south with less influence to the region. However, cannot rule out the possibility of a thunderstorm or two developing over the crests.

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. Models do not show a hint of a pattern shift until next weekend at the earliest. 90

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

VFR conditions to prevail through the period. There will be around a 10-15% chance for an isolated thunderstorm or shower to impact sites RDM/BDN tomorrow afternoon into the early evening. Otherwise, all other sites will remain dry. Winds will be light through the period. Lawhorn/82

Preliminary Point Temps/PoPs

PDT 51 83 52 83 / 0 0 0 0 ALW 54 83 56 83 / 0 0 0 0 PSC 52 88 52 89 / 0 0 0 0 YKM 54 86 55 88 / 0 0 0 0 HRI 51 86 51 87 / 0 0 0 0 ELN 49 82 51 83 / 10 0 0 0 RDM 42 81 43 80 / 20 0 0 0 LGD 47 79 48 78 / 0 0 0 0 GCD 47 80 45 78 / 0 20 10 0 DLS 57 88 57 84 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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