textproduct: Pendleton

KEY MESSAGES

1. Dry conditions will persist through the week.

2. Slight Chances of dry thunderstorms Wednesday and Thursday.

3. Diurnally breezy winds and low RHs.

DISCUSSION

Satellite and radar continue to advertise mostly clear and dry conditions across the region thanks to the upper level ridge situated near the four corners. Areas of smoke and haze are still present with winds generally from the southwest, pushing smoke transport across Central Oregon through Northeast Oregon. Air Quality continues to be sub-par through noon on Friday as an Air Quality Advisory is issued (via the Oregon Department of Environmental Quality) for counties near Central Oregon and the Eastern Mountains.

Very low potential (up to 5% chance) for dry thunderstorms to develop from Central Oregon through the Eastern Mountains during peak day-time heating hours today and tomorrow. Guidance is in good agreement that a small pocket of low to mid level moisture will move over the previously mentioned areas through the next 24-hours with models struggling to forecast for the MUCAPE values for the lifting mechanism. GFS, NAM, and the ECMWF are all over the place with MUCAPE values with NAM being the most aggressive with 300-500 J/kg, GFS putting almost nothing developing, and the ECMWF somewhere in the middle. Regardless, chances remain very low and are not expected to be widespread if storms develop.

Through Friday: The upper level ridge will push slightly more to the west (>85% chance) with a trough just situated to the northeast. Diurnal wind breezes will continue, with breezier winds near the mountain gaps and parts of the Basin. Dry conditions persist with minimum relative humidity values dropping to the mid-teens to lower 20 percent range and with slightly enhanced diurnal breezes with the upcoming shortwave, elevated fire weather conditions will persist at least through this period.

Saturday: The approaching shortwave will bring tight pressure gradients to move-in to the region, allowing for breezy to locally windy conditions to develop. NBM advertises 50-70% chances of winds exceeding wind advisory (>45 mph gusts) Saturday across the Kittitas Valley, Simcoe Highlands, and parts of the Columbia Basin. Wind highlights have not been issued, but additional monitoring may be needed as the event gets closer. On the fire weather side, minimum relative humiditys recover slightly into the 20 to 30 percent range, but its put off by the stronger developing winds. A Fire Weather Watch has been issued for the Columbia Basin and the eastern part of Wallowa County following the anticipation of overlapping breezy winds and low relative humidity levels. Additional fire wx highlights are possible as more guidance comes through with increased confidence of an issuance.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

VFR condition to prevail through the period. Smoke impacts were seen around the RDM/BDN area, with BDN currently reporting lower CIGs. Will continue to monitor for now, but will leave MVFR or lower CIGs out of the forecast. Otherwise, winds will become breezy at site DLS in the afternoon, with periodic gusts at sites RDM/BDN. Winds will be light through the period at all other sites. Lawhorn/82

Preliminary Point Temps/PoPs

PDT 55 87 54 92 / 0 0 0 0 ALW 61 90 60 94 / 0 0 0 0 PSC 58 92 56 95 / 0 0 0 0 YKM 57 91 58 95 / 0 0 0 0 HRI 59 90 58 94 / 0 0 0 0 ELN 54 86 56 92 / 0 0 0 0 RDM 47 88 48 94 / 0 0 0 0 LGD 55 92 55 98 / 0 0 0 0 GCD 54 94 55 100 / 0 0 0 0 DLS 59 85 59 94 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Fire Weather Watch from Saturday morning through Saturday evening for WAZ691-693. OR...Air Quality Alert until noon PDT Friday for ORZ041-049-050-502- 503-505-506-509>511. Fire Weather Watch from Saturday morning through Saturday evening for ORZ691-693.