Holding a Steady Course

May 13, 2008

SnapshotODOT sent out this info today in a news release.  Of course McKenzie Pass closes each winter.  It’s Highway 242 between Belknap Springs and Sisters…the most direct route between Eugene and Bend/Redmond areas.  The opening date varies from year to year.  Looks like the big snow year of 1999 was the latest opening ever, in mid summer.

Now, what about the subject for the post.  Well, as I was preparing for the 10pm show, I was thinking that I’ve reached the "info saturation stage" for our approaching weather "event".  Our hot weather has been well forecast by models, so well that only minor forecast details have changed in the last 2 days.  What can happen in these data-rich Internet days is a sort of information overload.  Every few hours new info comes in.  It could be MOS temps from 3 different models, 850mb temp forecasts, or surface temp forecasts from each different model and it’s respective runs.  For example…Thursday:  MOS from GFS, NAM, and NGM (00z) show a high of either 86, 83, or 80, respectively.  Surface temps from the GFS show 88, from NAM, 79.  So lots of numbers are always flying around in weather circles.  My special chart shows a high of 88-91.  It’s pretty reliable in general.  What’s the point?  Well, for 3 days we’ve shown a 90 Thursday and 95 Friday on our 7 Day forecast.  My theory has been increasingly one of "hold it steady" the last few years.  In my younger days (1990s), I would flip flop with each new model run, adjusting temps every 12 hours.  Now I figure there’s no need to change unless models make an obvious change.  Basically numbers are whacking you on the side of the head constantly in this business, so you need to focus your sights forward.  Pretty deep eh?  So I didn’t change the 7 day forecast yesterday or today for the Thursday-Sunday period.  If the marine push starts slightly faster Saturday evening, then Sunday may only be in the 70s, or maybe Saturday will stay in the 80s…but no need to change for now.

I did notice one thing:  It’s going to be crazy warm in the mountains Friday-Saturday.  Temps in the "free-air" at 2000′ will be above 70 degrees from Friday morning through Saturday evening!  This elevation has been in the 40s the past few days.  The snow pack is definitely going to collapse a bit, especially up on Mt. Hood where .50" of rain has fallen since this morning.

Otherwise my thinking hasn’t changed since last night’s post.  We’re going from 70 or so tomorrow to about 90 Thursday afternoon.  We start with east wind Friday and a thermal trough all the way out at the Coast, then it goes calm by late afternoon…with +22 deg C. 850mb temps, that’s the perfect setup for mid 90s.  Conceivably it could even be warmer…if it was early-mid June, 100 would be more likely…Mark Nelsen