textproduct: Pendleton

KEY MESSAGES

1. Warm and dry conditions over the weekend

2. Pattern change start of the week will bring cooler temperatures and chances of thunderstorms.

DISCUSSION

Current radar shows a few small returns over the central Cascades but otherwise nothing. Satellite shows mostly clear skies with some lingering mid to high level clouds over the region. Today will remain mostly dry and clear as the leading edge of the upper level high continues to push across the region.

Dry and warming conditions will persist through the weekend with above seasonal average temperatures. In house calculations show temperatures will reach upwards of 15 degrees above normal by Sunday. Temperatures today will remain in the upper 50s to low 60s with 70-90% confidence. Saturday will see temperatures increase to the upper 60s to low 70s across much of the region with 60-80% confidence. By Sunday the axis of the ridge will be overhead allowing for Sunday and Monday to be the warmest days of the period with highs reaching low to mid 70s with 70-90% confidence.

Models show the pattern to begin to break down as an upper level low begins to push in from Canada and another low pushes in from the south off the Pacific. With this pattern, NBM raw ensembles and deterministic models are picking up on increased instability forming to the southern portion of the region. NBM raw ensembles show a greater than 60% chance of the region seeing CAPE values nearing 200 J/kg with just enough shear and orographic forcing there could be enough instability to pop of a thunderstorm or two (10-15% confidence). This convergence of two upper level lows will bring temperature back towards near seasonal normal as well as heightened winds on Tuesday. While there is uncertainty in the pattern, ensembles do show near 50% confidence in a wind event occurring Tuesday which could lead to possible headlines of wind gusts nearing 45 mph or greater through the mountain gaps and wind prone areas.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

VFR conditions and winds generally 10 kts or less are expected through Saturday as high pressure builds into the region.

Preliminary Point Temps/PoPs

PDT 59 35 67 41 / 0 0 0 0 ALW 59 40 67 45 / 0 0 0 0 PSC 63 36 70 40 / 0 0 0 0 YKM 62 35 68 42 / 0 0 0 0 HRI 63 36 70 41 / 0 0 0 0 ELN 57 34 64 40 / 0 0 0 0 RDM 61 28 71 35 / 0 0 0 0 LGD 57 33 66 39 / 0 0 0 0 GCD 57 33 67 37 / 0 0 0 0 DLS 64 40 72 46 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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