weatherwiz Posted February 28, 2012 Share Posted February 28, 2012 A very messy and long duration storm system is expected to impact much of New England mid-week. This storm system will be impacting the region in two parts. The first part will be associated with very strong lift associated with a low-level and mid-level warm front that will slowly be lifting northward from the southwest. As the warm front drifts northeastward winds will try and turn more towards the southwest. These southwest winds associated with a low-level jet which will be anywhere from 35-45 knots will be smashing right into colder and much more denser air. This will really help to enhance lifting and with increasing moisture this will lead to the development of snow and a period of heavy snow. The second part of this system will be associated with the parent low pressure system which will be drifting eastward from the Ohio Valley region. Right now confidence on how the second part of this system will produce and where precipitation will occur is on the lower side. This is due to the fact that computer models are offering up different solutions regarding the strength and track of the parent low. There are some models that want to slide the energy south of southern New England, this solution would mean a bit stronger of a system and also mean extra snowfall for a larger part of the region, especially areas down across CT/RI. Some models slide the energy right through CT/RI meaning all the precipitation, which would be virtually snow except for the south coast, would be confined to MA and southern VT/NH. As of right now I would lean towards this type of solution. This will be a very complex and complicated forecast not only b/c we are dealing with a two part system but b/c there are alot of factors involved that could make or break the forecast. The forecast snowfall map will include totals from both parts combined...the discussion will be broken down into two parts to lessen any confusion. Part One: The onset of part one looks to begin anywhere from late morning to early afternoon on Wednesday. The further south and southwest you live, the earlier the onset will occur. With the approaching low level and mid level warm fronts istentropic lift will rapidly increase along with moisture, this will lead to a rapid development/blossoming of the precipitation shield across the region. Thanks in large part to a strong area of high pressure situated over Canada/northern ME this will provide us with a great deal of cold air damming in the lower levels of the atmosphere just above the surface. Several computer models are also in agreement that the low level and mid level warm fronts will not move any further north than just north of the CT/MA border. Until these fronts do move northward precipitation will be all snow for everyone, especially north of the CT/MA border, however, across CT/RI we will begin to see a transition to freezing rain/sleet/rain, especially with the precipitation rates begin to lighten up. Several computer models are also in agreement that the lift involved here will be fairly strong thanks to tightly packed temperature contours at 925 and 850mb (~2000-5000ft ASL) leading to a great deal of isentropic lift. This will mean we will see a several hour period of moderate to heavy snow with snowfall rates possibly as high as 1-2'' per hour. Due to some warmer boundary layer temperatures the snow may be quite wet in nature across CT/RI. South of the CT/MA border (including RI) as the precipitation rates begin to lessen up and the low level/mid level warm fronts move northward expect a brief transition to sleet across the coastal areas then a changeover to rain. Across inland CT expect a transition to freezing rain and it's quite possible we could see some minor ice accretions. This potential will have to be watched closely. Transition Between Part One and Part Two: The transition period will be rather interesting, especially for central New England. It appears for areas like CT/RI that once part one is over that is it for any meaningful precipitation as the stronger lift will be to the north of these areas. During the transition period while the energy to our west slides east it's possible that there could be periods of light snowfall across southern VT/NH and MA as there is some leftover moisture available and increasing lift thanks to the energy sliding east. Precipitation rates here may not be all that strong enough to produce any accumulations but it will make it difficult to know when part one ends and when part two begins. It isn't completely impossible that someone could pick up an additional 1-2'' in the transition period. Part Two: Part two as of now appears as if it will affect mainly southern VT/NH/MA where it would certainly tack onto the snow that fell from part one. One key player to round two for these areas is the potential for a pre-frontal trough setting up across these areas which will enhance the low level moisture in place. The impacts from part two will likely occur from very late Wednesday night/early AM Thursday and last through much of the day on Thursday. Snowfall rates won't be as heavy as part one but snowfall rates could reach 1'' per hour at times. Precipitation from round two should begin to taper off during the evening hours of Thursday and overnight. With everything said above this is what I am expecting for snowfall accumulations as well as some ice accretions possible across a narrow area. Link to comment Share on other sites More sharing options...
bboughton Posted February 28, 2012 Share Posted February 28, 2012 I'd be really happy if that verified. Link to comment Share on other sites More sharing options...
NorEastermass128 Posted February 28, 2012 Share Posted February 28, 2012 Good luck Wiz. Looks good! Link to comment Share on other sites More sharing options...
weatherwiz Posted February 28, 2012 Author Share Posted February 28, 2012 Thanks! At least Kevin can't yell at me this time for humping the GFS. Link to comment Share on other sites More sharing options...
ctsnowstorm628 Posted February 28, 2012 Share Posted February 28, 2012 Ballsy to go 6-9 for BOS down to TAN. I think it'll be tough for SE mass to pick up 6"+ but CT looks good...except for coastal regions where 3-5" is probably a little high. Overall good job! Link to comment Share on other sites More sharing options...
weatherwiz Posted February 28, 2012 Author Share Posted February 28, 2012 Ballsy to go 6-9 for BOS down to TAN. I think it'll be tough for SE mass to pick up 6"+ but CT looks good...except for coastal regions where 3-5" is probably a little high. Overall good job! I went with a NAM/Euro/Ukie/GGEM/SREF blend. I'll look over the 12z stuff when I get home from the Whale game. I looked at soundings for HFD off 12z NAM and it looked even colder here at least then past runs. Link to comment Share on other sites More sharing options...
weatherwiz Posted February 28, 2012 Author Share Posted February 28, 2012 Biggest update to the forecast: 1) Lowering snowfall totals across the CT/RI shoreline drastically. These areas have been placed in the 1-3'' contour, although it's very possible nobody here received more than 1-1.5'' of snowfall. Computer models are indicating that surface winds and winds just above the surface will become more southerly in nature more quickly, thus bringing in marine air much faster warming the boundary layer more quickly. This will result in a much faster changeover from snow to rain and reducing snowfall totals. Across inland areas of CT/RI some minor ice accretions are possible as a period of freezing rain is likely as the snow begins to transition over to freezing rain and sleet in some spots...the further south you go the better chance you have of turning over to all rain eventually. Link to comment Share on other sites More sharing options...
ineedsnow Posted February 28, 2012 Share Posted February 28, 2012 looks great! Biggest update to the forecast: 1) Lowering snowfall totals across the CT/RI shoreline drastically. These areas have been placed in the 1-3'' contour, although it's very possible nobody here received more than 1-1.5'' of snowfall. Computer models are indicating that surface winds and winds just above the surface will become more southerly in nature more quickly, thus bringing in marine air much faster warming the boundary layer more quickly. This will result in a much faster changeover from snow to rain and reducing snowfall totals. Across inland areas of CT/RI some minor ice accretions are possible as a period of freezing rain is likely as the snow begins to transition over to freezing rain and sleet in some spots...the further south you go the better chance you have of turning over to all rain eventually. Link to comment Share on other sites More sharing options...
weatherwiz Posted February 28, 2012 Author Share Posted February 28, 2012 Thanks! We'll see what verifies though These totals are REALLY banking on a major thump from the front end, especially across CT. Link to comment Share on other sites More sharing options...
ctsnowstorm628 Posted February 28, 2012 Share Posted February 28, 2012 Thanks! We'll see what verifies though These totals are REALLY banking on a major thump from the front end, especially across CT. 6-9" is reallyyyyy ballsy along the MA border in the CT valley lol Link to comment Share on other sites More sharing options...
codfishsnowman Posted February 28, 2012 Share Posted February 28, 2012 well it is nice to see that forecasted but living here i know all too well how to get boned from every which direction in every type of synoptic set up however swfes in the dead of winter tend to be the least dissapointing although heading towards this point in the season i am not so sure but I do sure like wizs forecast for my area. Link to comment Share on other sites More sharing options...
nzucker Posted February 29, 2012 Share Posted February 29, 2012 You should probably include more contouring for elevation on the map, Wiz. In a long-duration event with light to moderate precipitation, higher elevation areas are going to receive far more snowfall. I might take the 3-5" contour up the CT River Valley towards Springfield and give some more potential for higher totals in NE CT which might benefit from the orientation of the cold air and its higher elevation. Link to comment Share on other sites More sharing options...
Quincy Posted February 29, 2012 Share Posted February 29, 2012 very rough map...didn't put a TON of analysis into it, but the jackpot looks like the Berkshires and ORH hills...could also see an icy zone set up near the CT/MA border... Link to comment Share on other sites More sharing options...
weatherwiz Posted February 29, 2012 Author Share Posted February 29, 2012 You should probably include more contouring for elevation on the map, Wiz. In a long-duration event with light to moderate precipitation, higher elevation areas are going to receive far more snowfall. I might take the 3-5" contour up the CT River Valley towards Springfield and give some more potential for higher totals in NE CT which might benefit from the orientation of the cold air and its higher elevation. You're right... it's just I don;t know how to make a map just to include higher elevations. Link to comment Share on other sites More sharing options...
weatherwiz Posted February 29, 2012 Author Share Posted February 29, 2012 Final: Link to comment Share on other sites More sharing options...
N. OF PIKE Posted February 29, 2012 Share Posted February 29, 2012 good job and map wiz Link to comment Share on other sites More sharing options...
ctsnowstorm628 Posted February 29, 2012 Share Posted February 29, 2012 Final: Nice looking map bud Link to comment Share on other sites More sharing options...
weatherwiz Posted February 29, 2012 Author Share Posted February 29, 2012 Thanks guys! I finally came to and removed much of eastern MA from the 6-9'' totals Link to comment Share on other sites More sharing options...
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