Saturday, January 17, 2009

Sunday's Clipper

FINAL CALL (1/17/09 @ 2PM): Here is the final call for tomorrow's snowfall. We have a clipper coming out of the GL today and this will spread snow into New England between 3-7AM west to east tomorrow morning. Warm air is going to get involved BOS S&E as rain/mix will be the predominant precip type on the Cape where only a C-1" will fall before the changeover and temps max in the mid-upper 30s. Boston is good for 1-3" before marine influenced air infultrates the area, but only 5-10 miles NW of BOS should stay mostly snow and that is where a good 3-6" of snow will accumulate. Maine will get the storm in the GOM as it blows up and spits out the heaviest QPF in that area. This will lead to a good 6-9" from this clipper before we turn our eyes to a developing coastal near the Del Marva. Recent information now takes this storm further out to sea, but it is so close that we should keep an eye on it. At the very least, some rain and snow showers will be on the Cape with the second storm. But for now, it looks like a near hit, but not close enough for anything significant.

Friday, January 09, 2009

Dusk 'til Dawn Winter Storm

FINAL CALL (1/10/09 @ 8AM) Overnight the models shifted north with this storm and it now looks like the heaviest of snow will be north of the Mass Pike. I narrowed the bands of snow as well, instead of going with a regionwide 5-10" of snow, I have southern ME to southern NH and parts of northern MA in the band of heaviest snow with accumulations of 7-10". This now looks to be a widespread 4-8" of snowfall from Plymouth, MA to northern New England. South of Boston the snow will be denser and somewhat heavier as mixing could get as far north as BOS-ORH-HFD. North of here, we should stay all snow, but we have to be weary of this coming a bit further north. The Cape and Islands may even change to plain rain for a time during the peak of the storm. This will limit accumulations here to a lighter 2-5" of gloppy snowfall. Still starts from west to east 5PM to 8PM. Ends tomorrow morning and early afternoon around 10AM-1PM. Thats all for now. Enjoy.

FIRST CALL (1/9/09 @ 1PM) Winter storm watches are already up for all of SNE this afternoon. I am tending to agree with the NWS call for a widespread 5-10" of snow across most of SNE. The only wild card is the Cape and the Islands. This is where some mixing with rain could occur, at the very least the lowest ratio snows would be confined to with temperatures in the 31-34 degree range, while areas north to around BOS would see temperatures overnight Saturday in the upper 10s to low 20s, which would provide for light fluffy snowfall. Ratios will likely be in the 12 or 15:1 range here. The snow growth does look fair, but not the type of snow growth we saw with the NYE storm where we had a good deal of easily accumulable dendrites falling from the sky. The winter storm watch will likely be converted to a winter storm warning by late tonight if not by tomorrow morning for all of SNE and maybe even southern NH. I like my 5-10" call, but I have to add that areas along the CT/MA and RI/MA border to the Mass Pike would be the areas that would see the most snowfall from this storm. Right now I have them for a good 8-10", but there is the small possibility we get really good ratios and a tad bit more QPF and then I wouldn't be surprised if someone came in with a foot of snow from this one. Closer to BOS, I think Logan will likely pick up between 7-9", maybe more if we get this CCB band to really get cranking over eastern MA.

TIMING? This looks to be roughly a dusk 'til dawn type of snowstorm with most of the snow falling overnight Saturday. It should be a fun enjoyable storm. The snow will be light and fluffy and easy to move around Sunday morning as it tapers off from west to east. The sun will go to work on Sunday afternoon and black tops should be visible again by later Sunday and cleanup by local cities and towns should be coming to an end and then you will be able to enjoy the snowscape. It should arrive in western SNE between 3-5PM and quickly become moderate to heavy at times. Further east, I expect it to arrive last in the BOS metro area between 5-8PM. Snowfall rates should get up to 1"/hr during the peak of the storm, so travel overnight Saturday is going to be tough to say the least. I advise that if you can have a nice night in, just do it. Lots of motorists had a bad night this past WED with all the glazed over roads in the BOS metro area, I know I did and we don't need more claims to go to our insurance companies. So that's it for now.

One last note is that true ARCTIC air is coming for next week and by next THU and FRI, we could be talking about temperatures that struggle to make 15 degrees on THU and then stay in the single numbers on FRI. Get ready! It's coming. Overnight temperatures below zero for a lot of SNE next week? You betcha!

Monday, January 05, 2009

Messy Wednesday

Wednesday is going to be one of those days where forecasts will likely bust horribly. Right now this is what I'm thinking. We all will start as a brief period of snow snow early Wednesday morning (3-5AM) and it will gradually transition over to a wintery mix south of the Pike. A quick 1-3" is possible areas south of the Pike, including the city of Boston before the switch to sleet and then freezing rain, rain Boston. The area outlined in red slash marks for northern CT, RI, interior SEMA, southern ORH Co. to the Springfield area are all in line to see healthy amounts of ZR after the switch from snow. This is the area where Ice Storm Warnings may need to be issued and where a 1/2" or more of ice accretion is possible. This will be enough to do some damage to trees and power lines, so we will need to be aware of isolated to scattered power outages in this area. The good news is that the latest information is lessening our ZR threat and it looks like it could be more of a sleet issue, which would be a saving grace. NW of 128 and north of the Pike, the changeover will take longer, so 2-5" of snow is forecasted before a switch to sleet. North of Concord, NH to Keene will be areas that receive mostly if not all snow out of this one. Areas that do stay all snow will likely pick up a healthy 6"+ of accumulation. The ski resorts will welcome this with open arms with the last couple bigger storms being primarily SNE storms. Thereafter, we look to go into the ice box later this week and for the foreseeable future. Be sure to shovel this wet snow Wednesday because if you don't it will be cemented to your driveway for a few weeks at least.

Sunday, January 04, 2009

Winter Storm Wednesday?

Wednesday's forecast is looking very difficult to really pinpoint at this time. There will be a storm coming out of the OH Valley and moving towards BUF, deepening along the way, but it will not be able to just shoot up the St. Lawrence River Valley because of our blocking to the north. This will allow a secondary to pop out somewhere between LI and SEMA. This transfer of energy will likely keep the flow near the surface from the NNE, thus keeping surface temperatures near or slightly below 32F for the duration of the event, especially north of the Mass Pike and W of 495. However, midlevels will not stay cold enough for all snow in these regions and infact warm to levels where the snowflakes will switch to rain drops. If we can keep the surface layer of cold deep enough, then we would be looking at lots of sleet, but I think it is going to be a shallow pool of cold air in these places hit hard by the DEC 11th Icestorm, thus giving more freezing rain and ice to areas that do not need it. It looks like a quick inch or two south of the Pike before a switch to sleet then rain. But north of the Pike looks good for 2-4" of snow then sleet and then a half inch of ice NW of 495. It could spell trouble. I'll have a map tomorrow.