Monday, February 12, 2007

VALENTINES DAY STORM OUTLOOK

Here is my second call for the Valentine's Day storm. EH Boston, I feel your pain. I think you will be able to take off Wednesday night for Italy. That is when we will likely be a the peak of the storm, but we could be seeing a mix of rain and sleet at this time. You should get off though, maybe a delay.

I decided to base my snowfall forecast more on the GFS because it is pretty much in the middle of the road between the NAM and the EURO. The NAM brings this storm very close to the coast and actually has it pass right over the cities of Providence and Boston. I don't think this will happen. There will be just too much cold air on the onset and the model isn't seeing this for some reason. The arctic front will be pushing through early Tuesday morning with perhaps a snow shower or snow squall. Then the cold air will be really getting entrenched and the cold front will basically become stationary south of New England. Storms like this love to travel along a stationary front and I don't see this one being the exception. If the NAM were to verify about 3/4 of the storm would be rain for HAR-ORH-PVD-BOS, with limited accumulations.

The GFS has a more offshore component, which I like. It, however, does throw lots of warm air off the Atlantic all the way past Route 128 and close to 495 for a change to freezing rain, sleet and rain. I like that but I think that with a position that the GFS is showing where the storm is, SE of Nantucket, the warm air from the ocean will not make it that far inland. We have had a very cold stretch the past 20+ days and that will help us. Ocean water temperatures one month ago were in the low to mid 40's. Now they are in the mid to upper 30's. That is much less heat energy to get involved and change over the storm for many. Usually the rain/snow line with these storms never gets past Burlington or Wakefield. Then it will collapse back to the SE and possible envelop the Cape as well with the last burst of snow.

The EURO shows a plain out BLIZZARD for all of SNE, except the Cape and Islands. If the EURO were to verify, all the snow accumulations would be way underdone. I would have to bump them up by 4-8" for most. However, if the NAM were to verify, I would have to move up the line of a couple inches all the way to BOS-PVD. As you can see, this forecast, like all, will eventually turn into a NOWCAST. We will see what we get.

Here are the basics....

Timing:

Tuesday Night: Snow overspreads the area for all of SNE. Progressively becomes steadier and heavier. A quick inch or two on the Cape before a change to rain occurs. It will start to mix with sleet south of Plymouth, MA. NW of here, it should stay as all snow with as much as 2-4" south of Boston to Plymouth and 3-6" by the Wednesday morning commute just NW of BOS-PVD.

Wednesday Early PM: Then it gets interesting. That line of mix to rain will gradually move up into PVD and the 128 corridor of BOS. This will limit accumulations in this area. I do however, expect it to stay all snow NW of Bedford, Lawrence, Hopkinton, and Hartford.

Wednesday Late PM: The mix/rain line gets as far north as it will get as outlined above and now heads back to the SE very fast. This will be the peak of the storm. Out in Worcester county and most of the rest of NH, VT...snowfall rates will be approaching 2-3"/hr. Combined with winds of 35-45mph sustained, gusting to 60mph, with near whiteout conditions, this is when interior SNE may achieve Blizzard of '07 criteria. Snow will start to accumulate again inside of Route 128 and head back to Boston and Providence.

Wednesday Night - Early Thursday Morning: Storm is winding down, precipitation moving from SW to NE. Pretty heavy backlash snows could be going on for NE Massachusetts in Middlesex, Essex, and Suffolk counties with perhaps rates of 1-2"/hr. before abruptly ending. NNE will wind up with about 1-2 FEET once all said and done from VT to NH to interior ME. Some places may pick up close to 30" in the mountains of interior ME.

Thursday Afternoon: Breaking in the clouds in CT and entering MA. Very windy and very cold with another arctic blast. Anything slushy will flash freeze and turn to cement. Heads up...get your shoveling done early.

SCHOOL CLOSINGS???

I do think there will be school closings across SNE. I would say that anywhere NW of Route 128 and west of Framingham, Natick, will see a close for Wednesday. Inside 128 and for interior MA and north of PVD, there will likely be delays with scattered closings. The Cape....school will be in session. Then for Thursday there may be delays in NW MA and southern NH. In fact if southern NH gets closer to 20", there may be closings again due to uncleared sidewalks.

PROJECTIONS FOR SELECTED CITIES

In Massachusetts....Boston 6"....Woburn 8"....Worcester 13"....Springfield 10"....Plymouth 4"....Cape Cod 2" (washed away)...Pittsfield 16"

In New Hampshire....Nashua 12"....Manchester....13"....Concord 15"....North Conway 19"....Keene 20"....Berlin 21"....Laconia 14"

In Connetticut...Hartford 10"...Litchfield 11"....Waterbury 6"....Norwich 4"

In Rhode Island....Providence 5"....Pawtucket 6"....Newport 2"....9 miles N of PVD 6"

In Vermont....Bennington 17"....Killington 24"....Middlebury 16"...Burlington 13"

Thats all for now, any questions or critisisms, I would greatly appreciate. Take care.

2 comments:

E.H. Boston said...

I am sticking with my forecast from yesterday afternoon.

Central New England and NNE may see up to 30" though.

Cape...1-2" then washed away.

E.H. Boston said...

MY WOBURN UPDATE...

TEMP: 19
CONDTITIONS: LIGHT SNOW ~ LOOKS TO TAPER FOR A WHILE

ACCUMULATION SO FAR: ~ 2" of Sleet/Snow

Wind: From the NORTH-NORTHEAST