More Interesting Weather

February 13, 2007

Snapshot_19Quite a wet 48 hours beginning Wednesday morning.  A very wet and strong westerly jet punches into the Northwest USA by tomorrow evening.  Looks like 2 waves of moisture. First one is tomorrow afternoon/evening, then the 2nd and wetter one arrives during the day Thursday.  Our model here (RPM-WRF) AND the MM5-UW generate a tremendous amount of orographic rainfall.  As I mentioned at 10pm, I wouldn’t be surprised to see 3-5" rainfall totals in the mountains, and up to 1.50" in the metro area.  Luckily there is very little snowfall on the ground below 3,000′ and rivers are obviously quite low after 5 weeks of mainly dry weather.  The strong westerly flow then lifts north Friday-Saturday for warmer and sunnier weather, especially Saturday. 
00z GFS has now come around to the ECMWF prediction of a cool trough moving inland Sunday, so forget about a nice day then.  That leads us into a pattern change to what you see above.  Chilly and lots of mountain snow coming up beginning next Tuesday.  Of course it’s too early to know if this is a pattern change and "make-up" time for all the dry weather.  Or is it just a brief blip in our split-flow pattern which has been persistent for over a month?  The happy weather days may be back again!…Mark