textproduct: Pendleton

KEY MESSAGES

1.Dry and warm through the weekend becoming hot Monday *Heat Advisories Issued*

2. Breezy to windy across the region through Wednesday

3. Isolated fire weather concerns today becoming widespread Tuesday *Fire Weather Watch Issued*

DISCUSSION

Current satellite shows mostly clear skies over the region with some lingering high clouds over Kittitas and Yakima down through central OR. The cloud coverage will assist with keeping the overnight lows a bit on the warmer side through the morning. With overnight lows providing little relief from the warmth overnight and high temperatures tomorrow reaching well into the 90 degree range through many area, the HeatRisk models show portions of central OR, the Columbia River Gorge of WA & OR as well as the Kittitas and Yakima Valleys to be in moderate to high risk Monday so an heat advisory has been issued between 10 AM to 10 PM. Confidence in the temperatures nearing the low to mid 90s in these areas is >90%.

Models show an upper level shortwave will makes its way across the top of the ridge Monday afternoon. This will cause a slight increase in the winds today through the gaps. Winds today will be breezy with sustained winds of 10-15 mph and gusts to 25 with 50-70% of the NBM and HREF raw ensembles in agreement. By Tuesday models show the upper level shortwave to deepen across the low causing the pressure gradient across the Cascades to tighten even more. Winds Tuesday will be sustained at 15-25 mph with gusts nearing 40 mph with 60-90% of the raw ensembles in agreement. Winds will settle slightly Wednesday to a more normal diurnal flow with sustained winds settling back to 10-15 mp with gusts of 20-25 mph.

With the winds on Tuesday being elevated and the area being under dry and warm conditions, there is elevated fire weather across portions of the Columbia Basin. A fire weather watch is in effect for both the OR & WA Basin Tuesday morning through Tuesday evening for winds and RHs. WSUP viewer for 15 mph winds and 20% RH are well in the 60-90% range on Tuesday.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

VFR conditions expected through the forecast period. Winds will be light and variable across all TAF sites today with the exception of DLS where winds will develop and reach 15-20 kts gusts by the afternoon. Wildfire smoke will also be a possible issue for DLS through the period until the wind shifts causing haze to filter towards PDT. The haze is not expected to bring flight categories down at this moment and will continue to monitor.

FIRE WEATHER

There is 60-90% probabilities of the daytime RHs of 20% and winds of 15 mph that will cause an elevation of fire weather concerns for the Columbia River Basin. Grasses are conducive to spread and are in the 60-80% chances of occurrence. Fire Weather Watches for Wind and Low RH have been issued for the Columbia Basin zones WA691/OR691 Tuesday morning through Tuesday Evening.

Preliminary Point Temps/PoPs

PDT 92 61 90 52 / 0 0 0 0 ALW 92 66 91 55 / 0 0 0 0 PSC 96 64 95 55 / 0 0 0 0 YKM 99 63 92 54 / 0 0 0 0 HRI 95 65 92 55 / 0 0 0 0 ELN 95 63 82 52 / 0 0 0 0 RDM 91 55 90 47 / 0 0 0 0 LGD 88 54 88 49 / 0 0 0 0 GCD 90 52 92 48 / 0 0 0 0 DLS 99 69 87 57 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Heat Advisory from 10 AM this morning to 10 PM PDT this evening for WAZ024-026-027. Fire Weather Watch from Tuesday morning through Tuesday evening for WAZ691. OR...Heat Advisory from 10 AM this morning to 10 PM PDT this evening for ORZ041-511. Fire Weather Watch from Tuesday morning through Tuesday evening for ORZ691.