Saturday, February 21, 2009

Got Snow?

12 to 18 inches now on the way...

Short term /7 am Sunday morning through 6 PM Sunday/... significant winter storm to affect the County Warning Area sun and Sunday night...as energy dives into 500mb closed trough over the Great Lakes and begins to tilt it negative and close it off over eastern New England. This will allow for development of coastal low S of Long Island Sun morning. Models in good agreement on general scenario...but differ on exact track and timing. Agree with HPC assessment that a 12z Euro/GFS blend...slightly to skewed the less intense /and lower quantitative precipitation forecast/ Euro is the way to go...as it actually captures a nice consensus of many models and ensembles. Expecting precipitation to begin across southern New Hampshire and SW ME in the late morning...and across rest of the County Warning Area midday to early afternoon. Will likely see some rain mix in on the ME coast and seacoast New Hampshire...in fact...precipitation might start as rain...and could stay rain for a few hours on the coast from Casco Bay south into coastal New Hampshire. This will keep snowfall totals down in this area...enough to only put up an advisory in these areas. For the rest of the area...the track...and rapid intensification will lead to significant...and sometimes heavy snow. In the foothills and mountains...where southeast upslope flow will enhance snowfall...a foot to a foot and half of snow is likely in some spots by early Monday. Also...once the low passes late Sun night...will see west winds kick up...with gusts of 25-30 miles per hour expected after midnight...which could lead to some blowing and drifting of snow.