Our latest 7 Day forecast is quite chilly (4 more days), then shows a dramatic warm up. That seems to stick out a bit compared to other Portland station’s forecasts:
First the chilly weather, I see the 00z NAM is showing -5 to -6 temps at 850mb late Friday night and early Saturday morning. Pray for skies remaining mostly cloudy Friday night because all my fruit trees are in full bloom right now and I don’t want a late season frost. With a few leftover showers Saturday morning, there could be sticking snow down around 2,000′.
The ECMWF has been leading the way showing a quicker exit of the cold upper trough later Saturday and Sunday. Plus it and the Canadian model have been sticking to a stronger ridge for Monday and Tuesday. Now the 00z GFS is also quite similar.
This means we actually get a thermal trough west of the Cascades at least on Monday…note the WRF-GFS for Monday at 7am:
You can see a decent easterly gradient through the Gorge and over the Cascades. My chart for May shows easterly flow, 850 mb temps about +10 Monday afternoon, plus full sunshine = 77-81 degrees. That’s why I pushed forecast high temps up a bit.
Not sure how long it’s going to last, GFS wants to get “all troughy” on us while the ECMWF and Canadian rebound the ridging a bit for the latter half of next week.
Chief Meteorologist Mark Nelsen