Meteorologist Larry Cosgrove's thoughts...
WEATHER SUMMARY THROUGH NEXT 72 HOURS
With the American forecast schemes now clearly trending toward earlier predictions on ECMWF, GGEM, and UKMET runs, it is time to deal with the growing storm threat shaping up over TX. The faster rate of development make this matter imperative, since much of what transpires in the U.S. will occur within the next 72 hours. In a nutshell, we have a rare event called triple phasing taking place. A disturbance in the southern branch strengthens, and incorporates energy from the polar jet stream (in this case a shortwave entering ND). This combinant feature, fed by a huge moisture fetch and widespread intense convection, grows to the point where cA values in Canada are pulled into the circulation, and an existing Grand Banks vortex (50/50 Low) is forced to retrogress into the St. Lawrence Valley, in effect being captured by the explosive impulse. This last leg of phasing all three of the existing high level windstreams looks to occur Monday night, after which time the resultant monster gyre will slow down as it approaches LBR, its final destination.
Because the circulation and dynamics with the TX/Gulf States feature will be so strong, low level cold air from a moderately strong cell of high pressure in QC will be drawn as far south as lower Appalachia and the Piedmont. So while the relatively mild temperatures of Saturday may give residents of N GA, W SC, W, C NC and SW VA a false sense of security, the track of the cyclone and the rapid rise in UVVs on Sunday will produce frozen precipitation, with potential for heavy wet snow in the higher elevations. This in-situ type of wedge from cold air damming could give winter-starved Southerners one last shot at snow and ice before the Winter of 2004-2005 slides into history. Further south, FL looks to be hammered by a combination severe weather + excessive rainfall event, with the low and frontal structure passing in very close proximity to the Sunshine State.
Of course the usual question marks are in place concerning the track and rain/snow line of this cyclone. I like to place the surface reflection of a storm along the leading edge of 500MB height falls. The existing blizzard over eastern Canada (with formative cAk vortex) has shifted the mean trough axis to about 75 W Longitude, so any new cyclogenesis will have to proceed to the right of that demarcation. Since the ultimate destination of the phased storm is the QC Eastern Townships, the low moving up the coastline should bend back somewhat to collocate with the new motherlode. This is why I am insisting on a path of deepest pressure falls through RI, MA, and NH into E QC. So while much of the Interstate 95 corridor gets blasted by what appears to be (and should turn out to be!) a blizzard, anyone living to the right of a Guilford CT....Barre VT....Quebec City QC line is going to experience a change to rain.
Two things stand out about this particular system: the phasing aspect AND the convective appearance, with intense UVV and Omega fields showing upon all of the forecast schemes compacted around the low and its inverted trough (linking the circulation with a the vestigial low in the Great Lakes). Sharp vertical transfer will channel cold air to the surface and keep the rain/snow line along the immediate coast, while at the same time produce staggering snowfall rates that will leave heavy accumulations across the Appalachian Mountains and coastal plain. During Monday night, the sudden drop in 500MB heights and added vorticity should make for an excellent display of thundersnow across N MD....N DE....PA....NJ....NY....W CT....W MA....VT. Then as the low takes on vortex characteristics, winds will increase dramatically by Tuesday morning. Lake-effect snow squall generation should maximize under the vast motherlode, which on Day 4 should effectively cover much of the Midwest and Northeast, driving colder air into the Deep South.
Where would I rank the potential of this system? At least in the same category as the January 22 2005 storm, but more likely comparable to such memorable events as March 1962, December 1992, and January 1996. Keep in mind that much of the snow produced will be wet-ratio type, which can greatly affect power transmission and roof integrity.
Larry Cosgrove is an EXCELLENT meteorologist, especially in winter situations. He posted a map and thoughts yesterday that appear as if they may be right on. He was one of the first to pick up on the historic possibilities of this storm.
http://www.easternuswx.com/bb/index.php?showtopic=23216
Well, that's not good.
=8-0
Oh good grief .. my area got 33 inches of snow that storm
Oh please please please tell me this storm isn't that bad
Purdy Please
Does everyone have enough milk, bread and toilet paper? lol. I sure am glad I hadn't put the shovels and other equipment back in the basement. We're ready for the fun. Now, if they would just cancel school so I don't have to set the alarm clock, things would be great.
January 1996 in NYC rocked.