March madness usually refers to the tournament of
64 65 68 NCAA teams competing for a title. This particular March not a single team from the western US made it into the sweet-16, so instead we’ll focus on another March madness and title.
NWS Spokane also has a nice graphic detailing the onslaught of records.
Most locations in extreme eastern Washington and the Idaho Panhandle took home the trophy for wettest March on record. Upstream, Portland Oregon also had its wettest March on record and Quillayute, WA with 21″ last month was just a tad shy of 23+” set in 2007.
In additional several locales, including Kellogg, ID and Moscow, ID had one of the wettest months on record (for any month of the year). Kellogg’s 9.01″ is the fifth wettest month on record (the top three are all December’s or November’s), while Moscow’s total inches (not official as of 1 Apr) should be in the top 7 wettest months on record (all other records are Nov, Dec or Jan). All this thanks to the same persistent longwave pattern that brought incredible warmth to the eastern 2/3rd of the country. The image below shows the ramifications of being on the business end of the trough off the PNW coast.
Somewhat more interesting is the fact that the first 10 days of the month were dry, meaning that about 95% of that precipitation fell in the last three weeks. Close as most of the region gets to a Noah’s ark type setting…hence the madness.
Southeastern Idaho did not intercept the cavalcade of systems and had ambiguously normal months while much of WY/UT/CO were extremely dry. Likewise, the southeastern part of the INW was above normal in terms of temperature by a couple of degrees while eastern WA/OR and Idaho panhandle were below normal.
Streams and Rivers in the Idaho reached historically high levels for early spring. The Palouse River in Potlach, ID and Palouse, WA reaching its highest level (7350 cfs, 17.74″ since Jan 1997) and the highest flows observed for the station (40+ years) outside of the months of Jan and Feb which I suspect tend to be rain-on-snow driven runoff events. March 2011 was also a very wet month and had (now) the second highest March flows on record for the Palouse River (pictured with new water bball court and advanced-level tire swing).
April 1 SWE numbers from SNOTEL are now up and show a good recovery from a pathetic start to winter. The central mountains of Idaho are right at “normal”, while much of the Idaho panhandle and western Montana are 10-20% above normal. The southeastern part of the INW near Yellowstone is 10-15% below normal.
Observations tell us that 9 out of 10 La Nina’s result in above normal April 1 SWE for both the central mountains and panhandle of Idaho. Technically, we had a weak La Nina this winter.