800 FXUS66 KPDT 061652 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 852 AM PST Sat Feb 6 2021 .MORNING UPDATE...Region continues to be under a persistent northwest flow aloft while an upper level ridge sits over the eastern Pacific. Today, shortwave will move across the forecast area and produce another round of mountain snow in the WA Cascades, northern Blues, and the Wallowas. Total snow accumulations with this system will below advisory criteria, with 1-3" possible in the passes and in the lower elevations of Wallowa valley. Low level jet associated with shortwave passage will also mix down to the surface late this morning and produce windy conditions across the forecast area. Currently, the Kittitas valley, Lower Columbia Basin/Gorge, and the foothills of the Blues are under a wind advisory through this evening for this event. Winds and snow showers will decrease overnight as shortwave exits the region, with breezy conditions expected to persist through Sunday. Lawhorn/82 && .PREV DISCUSSION... /issued 237 AM PST Sat Feb 6 2021/ SHORT TERM...Today through Monday...Models continue to show that a northwest flow will persist through the short term with a gradual cooling trend. Another shortwave will slide across the forecast area today bringing some more light snow amounts below advisory levels to the Washington Cascades and northern Blue Mountain region. It will also increase winds back up into advisory range with sustained winds 25 to 40 mph and gusts to around 50 mph through this evening before decreasing a little overnight. Snow showers will linger through Sunday with winds still windy but a little below advisory levels. Lingering snow showers will begin to decrease on Monday and winds continue to decrease. Temperatures today will again be warm around the Basin generally in the mid 50s and 40s in the mountains. Temperatures will cool Sunday and into Monday with Monday Columbia Basins highs only in the low to mid 40s and 30s in the mountains. This cooling trend will continue into the extended forecast period. LONG TERM...Tuesday through Saturday...Models have trended colder during the long term, with likely the coldest air of the season expected by late week. Cooling trend continues on Tuesday with region under drier Northwest flow with ridge amplifying offshore and large polar low southern Canada. For Wed and Thu most guidance has now trended the low and trough to retrograde west and keeping ridge offshore. This would also bring a backdoor cold front dropping south across the PacNW and possibly a few snow showers, mainly over the mountains, although amounts look to be limited with moisture lacking. For Friday into weekend, model guidance varies significantly with the ensemble guidance even struggling to get a handle of overall pattern. Scenario that seems to be favored is for west to northwest flow to develop over the region while low remains planted over southern Canada and north-central US. A combo of upper lows are then progged to undercut offshore ridge and work onshore. The first low is tracking further south and could impact the region Thu night into Friday, although best chance looks to be into southern OR and northern CA. Second low is trending further north with a more westerly, moist onshore flow expected to develop and could impact the PacNW over the weekend. This system looks a bit wetter than the first and NBM is suggesting relatively higher POPs over the region. Could be a bit of breezy northerly winds associated with the backdoor front Wed/Thu, otherwise, lighter winds expected. Highs Tuesday in the mid 30s to mid 40s. Becoming 5-15 degrees below normal Wednesday (upper 20s to 30s) as the polar low and long wave trough creep west and Arctic air infiltrates the Inland Northwest. Expect temps 10-25 degrees below normal Thu-Sat with highs in the 20s to low 30s and lows generally in the teens with single digits possible in the mountains. Lowered lows/highs 2-3 degrees below NBM Wed night onward based on EC, CMC and GFS ensemble means colder than what current NBM guidance suggesting. AVIATION...12Z TAFs...Persistent northwest flow aloft will bring mountain snow through the period, with dry and VFR conditions expected at the taf sites. Cloud cover will be sct-bkn 040-080. Strong westerly winds 20-35g35-45kts expected. 10-20g20-30kts at BDN/RDM. Slagle...84 && .PRELIMINARY POINT TEMPS/POPS... PDT 53 36 44 30 / 10 10 10 10 ALW 54 36 47 31 / 20 20 20 20 PSC 57 37 51 30 / 0 0 10 0 YKM 56 32 49 28 / 10 0 0 0 HRI 56 37 50 30 / 0 0 10 0 ELN 51 32 43 26 / 30 20 10 10 RDM 48 23 45 21 / 0 0 0 0 LGD 44 32 39 26 / 30 20 20 20 GCD 46 29 42 24 / 10 10 10 10 DLS 53 39 49 34 / 20 10 10 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Wind Advisory until 7 PM PST this evening for ORZ041-044-507-508. WA...Wind Advisory until 7 PM PST this evening for WAZ024-026-028-029. && $$ MORNING UPDATE...82