MATTNOYES.NET - Weather Website & Blog

NOAA: Up to 5 million dollars in emergency aid to New England states for red tide damage

NOAA’s Fisheries Service today announced the states of Massachusetts and Maine will each be eligible for up to $2 million and New Hampshire will be eligible for up to $1 million in disaster aid to assist the shellfishing industries affected by this year’s closures due to the harmful algal bloom, commonly known as a red tide.

Mount Washington Valley Ski Area Opening Dates

Just got this from the Mount Washington Valley Chamber of Commerce:

Opening Dates

 

Attitash Ski Resort -- Opening Date: November 22

Black Mountain -- Opening Date: December 12

Cranmore Mountain Resort -- Opening Date: Tubing Hill opens November 28, Skiing begins December 6

Great Glen Trails -- Opening Date: December 6 for the Atomic Sprints

Jackson Ski Touring Foundation -- Opening Date: December 1 (weather permitting)

King Pine --Opening Date: December 12

Wildcat Mountain --Opening Date: November 29

Sunday night prospectus - November 16, 2008 - Winter will not wait

Last week's prospectus looked at the transition to a wintry pattern that was slated for this week, and the potential for a coastal storm development around the middle of this upcoming week.  The reality a week later is that we're ready for a trough that will continue to dig and amplify over the Eastern United States this week, dumping cold air across the Northeast.  The intense shortwave energy riding the fast westerlies will continue to drop over New England, and the aforementioned strong storm will indeed develop, but it appears just far enough offshore to preclude major storm development for New England.  This doesn't eliminate the chance for accumulating snow in the next seven days, however - rather, I think it will be very difficult for many areas NOT to accumulate snow between now and next Sunday's prospectus.

But let's start with the here and now, which features one installment of cold air to New England, with many more yet to come.  Westerly low level winds have instigated lake effect snow squalls, and these will carry east, enhanced by upslope flow against the western slopes of the Green Mountains tonight and Monday.  By later Monday, mean layer flow in the lowest several thousand feet of the atmosphere favors carrying some of the snow showers into the Berkshires, as well, though accumulation there should be limited, while the favored locales of the Southern Greens, on the other hand, could pick up a few inches by Monday night.

Also of interest is a pronounced wind shift dropping across the North Country Monday afternoon and evening, and the remainder of New England Monday night.  This shift in surface wind represents a cold front, providing a formidable shot of Canadian cold for Tuesday and the midweek.  The passage of this front in Northern New England Monday afternoon should bring some snow squalls - and a few of these will probably be intense in the Green Mountains.  Lifted index values are positive, but rise about 3 or 4 with the passage of the front, and the pressure rises 3 to 4 mb in the North Country after its passage, while there's plenty of mid-level instability.  These parameters appear to favor a weak windex event, though relative humidity parameters in the lowest levels are a bit dry for a decent event.  Nonetheless, orographic lift should make up for this in favored locales.

Tricky forecasting on Tuesday, though not for all parameters.  For example, temperature and wind seem pretty straight-forward with good cold advection underway.  What's trickier, though, is the precipitation forecast.  I hate looking at a situation like this, because I realize from a couple of days out that a big bust is possible right up to the event on Tuesday.  And the event is this:  The major storm we looked at as a potential last week will be coming together southeast of New England.  Though that's not a big deal for us in and of itself, there are problems here, because there's a ton of vorticity moving overhead, and how that vorticity interacts, combined with diffluence aloft and a mid-level speed max at 500 mb, as well as the approach of the trough axis at the jet stream level, creates a bulls-eye of upward vertical motion in all of the guidance products.  The tricky part is that there's not really a well defined surface feature to cling to here - perhaps a weak Norlun-type troughing that takes place, but it's really driven by a complex pattern aloft, and nailing down where that lift will take place is going to be very difficult.  Nailing down just how ripe the conditions will be for precipitation will be equally if not even more tricky, but so important given the temperatures through the column will support snow.  The NMM and GFS both do very little with this setup, but the higher resolution WRF and SUNYSB MM5 go to town with accumulating snow for Eastern MA - with the WRF starting in Southern ME then sweeping south down the coast, and the MM5 focusing on the South Shore and Cape Cod, where some ocean enhancement aids development of a snowburst.  At this point, I can see good evidence aloft to support such a snow burst, and following the guidance shows Eastern New England will be the closest to this burst, but further detail may remain difficult even right up to the event!

Wednesday looks to be the peak of the cold as the storm really deepens to our east, dragging down a shot of dense, cold air.  NMM temp forecasts of max temps in the teens high terrain north to lower or middle 30s south look reasonable and with the wind chill we can knock about another 10 degrees off.  Though the cold may relent a bit toward the end of the week, the longwave trough holds tough, and this raises eyebrows by next weekend.  The GFS and many of its Ensemble members are rather insistent upon a strong shortwave digging out of Central Canada, dropping south in the fast jet stream flow and amplifying over the Midwest, then shooting east across the Ohio Valley and south of New England.  This prompts coastal storm development in an airmass that would be cold enough for a mostly snow event except for areas warmed by a coastal front.  The timing would be later Saturday through Saturday night as a moderate to strong nor'easter.  Of course, we know the GFS is not the be all and end all of medium range forecasting, though good agreement among the Operational and Ensemble members certainly is of interest and warrants respect.  Those of you who've read my posts for a long time know that I always go with what the upper level pattern supports when there is uncertainty, especially in the medium range, and while the precipitation pattern on the GFS Ensembles may say a moderate to strong event, the 500 mb mean prog is not so supportive.  In fact, the GFS Ensemble mean 500 mb height fields look very similar to the ECMWF and especially the GGEM and GGEM Ensembles, which indicate some digging of the upstream shortwave, but also a lingering trough axis east of New England.  This keeps a faster and less amplified flow from the Ohio Valley through New England, meaning less deepening of the shortwave and resultant surface storm.  This is the solution I think should be followed for now, which actually can mean a colder scenario for more of New England, because the chance of a coastal front is much less with what essentially becomes a clipper going near or just south of the South Coast of New England, dropping a swath of accumulating snow on its northern side, which could drop anywhere between two and six inches on the way by.  Of course, at nearly a week out and with a changing and fast flow pattern, there's lots of room for change here, but I would favor the faster and less amplified solution for now.

That disturbance does reinforce the upper level trough over the Northeast, which means the cold continues coming on strong.  The Friday after Thanksgiving brings another strong shortwave worth watching, then by the first week of December, another strong shortwave coming off the Pacific will try to dig over the Plains and Midwest, and may bring another scenario that can be watched for coastal development.

Please do offer your thoughts in the comments section.

See you back here throughout the week.
Matt

NOAA: Commerce secretary determines red tide disaster in Massachusetts, Maine and New Hampshire

U.S. Commerce Secretary Carlos M. Gutierrez today determined that the economic effects of closing some shellfish fisheries due to a harmful algal bloom, commonly referred to as a red tide, in ocean waters off Massachusetts, New Hampshire, and Maine has caused a commercial fishery failure.

NOAA: NOAA advises New England mariners to watch for migrating right whales

Right whales.

High resolution (Credit: NOAA)

NOAA’s Fisheries Service advises all mariners and fishermen to keep a sharp look out for North Atlantic right whales in southeast U.S. waters from Nov. 15 through April 15.

Each year, pregnant female North Atlantic right whales migrate southward more than 1,000 miles from their feeding area off Canada and New England to the warm, calm coastal waters off South Carolina, Georgia, and northeastern Florida to give birth and nurse their young. These waters are the only known calving area for the species.

Sunday evening prospectus, November 9, 2008 - A colder pattern ahead

A mild reprieve of the past few days will be a distant memory in short time as a well-defined Eastern United States trough will take hold.  In time, this may result in an accumulating snow event for much of New England by the middle of next week, but that's a long way out, and remember what this Sunday prospectus is - just my view of the weather that lay ahead from a relaxed, big-picture, Sunday spin-up perspective.  The week will bring the need to get down and dirty with the details, some of which will clarify and some of which will muddy the view, meaning it will be necessary to rely on this big-picture perspective for clarity.

The water vapor loop shows a very active continent this evening, with a couple of well defined shortwaves spinning east toward New England - one set to cross the region overnight Sunday night into Monday morning, and another likely to pass on Monday night.  Each pinwheels beneath a strong upper low spinning across extreme Southern Canada, and each will deliver slightly cooler air to New England.  Farther west, a strong upper low is evident moving across the Four Corners region of the Southwestern United States, while a series of strong upper level disturbances are racing into Western Canada from the Northern Pacific.  The Southwest U.S. low will dissipate but move over New England on Thursday as a vorticity lobe with warm and moist advection, and a substantial chunk of Aleutian Low energy will move through New England next weekend.

The short-term forecasting challenges will come from the most immediate shortwaves, and the cold air that follows them.  With cold air streaming east, lake effect snow will begin off of Lake Ontario, and though this often means only limited consequences for New England, indications are we should get a decent spray into Northern VT on Monday.  The challenge will be boundary layer temperatures, which appear to stay too warm for snow - at least for appreciable snow - in the valleys, including and especially the Champlain Valley.  The mountains, however, and the higher terrain from Montpelier north to Jay Peak, should find upslope flow with a west wind enhancing the lift, and cold enough air above about 2000 feet during the day Monday, then lowering to about 1000 feet Monday night, to produce accumulating snow.  Total amounts won't be blockbuster, for sure, but a few inches are likely in places like Jay Peak between Monday and Monday night.  Elsewhere, a westerly, downsloping flow will limit precipitation chances, keeping scattered instability produced showers the most likely precipitation form both Monday morning with the first vorticity axis, then again Monday night with the second.

Confluent mid and upper level flow takes over for midweek, ensuring subsidence and therefore surface high pressure will dominate.  Cool temperatures but dry conditions are expected.  Meanwhile, another impressive storm will take shape from the Northern Plains to the Upper Midwest, though it won't be anything like the last blockbuster blizzard of this past week, largely because an abundance of Gulf Moisture will remain untapped, with the southern stream shortwave remaining just a bit too far south and a bit too progressive to interact.  Instead, that southern energy rides into New England later Thursday, with quickly increasing clouds from Wednesday night into Thursday and a good chance of at least some rain developing in the southwestern half of New England by the time the day is out Thursday.  At first I was somewhat skeptical of this - and to be completely honest, I think this timing is one that still could change as we near it and the details become more clear - but the 850 mb warm advection is pronounced at the same time the vort max moves through, and this shortwave does have a history of Pacific moisture with some weak Gulf interaction, so some showers seem like the wise way to go for now.

Next weekend the trough associated with the Midwest energy really digs, and this ejects Gulf of Mexico moisture and energy northward so that after a break early Friday, heavy rain is likely Friday night into Saturday morning.  Rain is likely to exceed an inch for many spots, with some two or three inch amounts possible, at least given this cursory glance.  One thing that may alter this is if the system progresses a bit quicker, as the energy aloft will start piling east, and will shift the moisture axis east, too, by late morning or midday Saturday.  Thereafter, cold air surface and aloft means some drying but also some instability for scattered rain and snow showers as another shot of cold comes on.

What I find the most intriguing of this week's cursory glance, however, is the setup for midweek next week.  A series of strong northern shortwaves dig across the Upper Midwest and Great Lakes, and this not only keeps shots of cold air coming at the Northeastern corridor, but also gradually shifts the mean trough axis on the longwave pattern just a little farther west with time.  By next Wednesday, this takes a similar baroclinic setup to what we have coming up next weekend, but moves it slightly farther east and thereby introduces the possibility for at least weak coastal storm development with much of New England (interior) on the cold side of the system.  We're talking a week and a half out here, so we'll see what verifies, but the pattern does look favorable.  Additionally, the Ensembles are showing signatures I usually like to see to support such a scenario, including cold 850 mb temperatures (-4 C anomaly), baroclinicity along the coast and just east of  New England, and, though not nearly as important but still an important signal, a moderate swath of precipitation in the means, on the cold side of the storm.

So, plenty to watch - and what does seem likely is that the Northeast remains colder than normal at least until around Thanksgiving, while warmth will build in the west with time.

Matt

Quite a storm developing off the Mid-Atlantic coast...core expected to pass south of New England

The storm off the Mid-Atlantic coast has become very well defined this afternoon and continues to ramp up.  There are a few impressive features on this cyclone and I wanted to take a moment to contemplate them and work them out in a post this afternoon.

First, have you checked out the buoy observations on the western side of the storm circulation?  Wow!  58 mph gust just east of Hatteras, and 54 mph gust at the buoy east of Virginia Beach!  Seas correspond, registering at 14-18 feet with an 11 second period.  Meanwhile, winds near the center of the storm are much lighter, which corresponds well to an extratropical storm with a wind field removed from the center and driven primarily by pressure gradient forces, in this case the product of the bridged surface ridge from Nova Scotia over New England then down the Appalachian Mountains.  For now, the storm looks like it will remain extratropical in the next 12-18 hours, which is certainly supported by the dry air wrapping around the southern and eastern side of the storm and directly into its core.  This has suppressed any deep convective activity near the center, and instead an impressive swath of mostly stratiform rain has been thrust north and west of the circulation.  This is the band of rain that will affect New England in the coming 36 hours.

There appears to be decent agreement among the guidance on the storm reaching peak intensity tonight, well south of New England, and expanding its wind field far enough north to get Cape Cod and the Islands into an easterly wind with gusts to 40 mph - perhaps a few 45 mph gusts in the most exposed east-facing locales - then the wind field diminishes rather quickly on Thursday.  Meanwhile, aloft, the slug of warm and moist advection responsible for the rain outruns the surface/mid-level center (the storm becomes stacked) and therefore weakens as it drifts north and northeast in the steering flow on Thursday.  From Northern VT to far Nrn NH, little precip is expected, with heavier amounts farther south and east.  The ample tropical and Atlantic moisture feed, coupled with a mid-level baroclinic zone, will provide sufficient lift for as much as 2" of rain Wed Ngt and Thu in some of Eastern MA - esp on Cape Cod - with 1"-2" more widespread in Eastern New England.  Even along the Mid-Coast of Maine, though the rain may be weakening as it drifts up the coast and the Maine Turnpike on Thursday, a secondary max of precipitation may occur with a re-infusion of tropical moisture later Thursday and Thursday night.

This isn't quite the whole story on this storm, though, as there may be a few surprises with it Thursday.  Though the agreement among the guidance is to weaken the wind field, there is also remarkable agreement on transitioning the core from its present state of asymmetric warm core to a symmetric warm core storm later Thursday.  This is a big deal!  One of the traits we look for in a tropical transitioning storm is this symmetry and warm core.  Though the storm will be passing over water that's still 75 to 80 degrees over the Gulf Stream, it's unlikely to remain in such favorable conditions for long.  Nonetheless, later Thursday we may see a flare up of thunderstorms around the center with a renewal of wind, this time contracted near to the center.  Definitely something interesting to watch from a scientific perspective, and important for mariners and surfers, as well, as this may enhance and prolong waves on the southern waters/South Coast into Friday.

As for the sensible weather, the most successful viewpoint on the next few days is to view the airmasses as fluids - something we should always do in the field of meteorology, but an outlook that will really help to grasp the forecast for the coming days and latch onto what I think will be the right solution.  The bottom line is that we have one fluid from the Mississippi Valley to the Southeast US (warm air), another fluid from Eastern Canada and New England through Ontario (cool, but not cold air), and another over the Rockies (chilly).  It's interesting to note that the dewpoint of the air north of New England today is in the middle and upper 40s, so while it may be cooler than the stuff producing highs in the 70s and 80s over the Ohio Valley and Midwest, it's not a really cool or dry airmass, and this is part of the reason that, even with a northeast wind, I'm not going exceptionally cool for most of New England - not below the middle 50s - on Thursday, and by Friday the wind abates as a weak trough between the Upper Midwest low and our coastal low very sluggishly moves to and through New England from the southwest.  Of course, with very light winds either side of this trough as New England finds ourselves in a col between systems, clouds will be stubborn on Friday and low level differential advection will probably bring drizzle and areas of light rain, especially east ahead of the trough, which comes with weak warm/moist advection on the leading edge of the Southeast US air.  Saturday may start gray even though Central/Southern/Western areas are transitioning to the warmer side of the trough, but an increasing southwest wind ahead of the approaching occlusion/cold front will break the clouds up, and with warm air in place, at least Central and Southern areas will see enough breaks to warm considerably into the 60s.  By Sunday, cold advection is underway in installments, with the first installment not all that chilly, and the combination of drying for sunshine, and downsloping flow, resulting in a fair day with bubbling instability Cu.  Cool air continues building in for the start of next week.

Matt

Replacement of ETA-based MOS guidance with NAM-based MOS guidance

For those of us who follow the guidance products, this is an important update regarding ETA MOS data, from the National Weather Service:

TECHNICAL IMPLEMENTATION NOTICE 08-89
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
255 PM EDT MON NOV 3 2008

TO:    SUBSCRIBERS:
     -FAMILY OF SERVICES
     -NOAA WEATHER WIRE SERVICE
     -EMERGENCY MANAGERS WEATHER INFORMATION NETWORK
     -NOAAPORT
     OTHER NWS PARTNERS...USERS AND EMPLOYEES

FROM:   JASON TUELL
     CHIEF...SCIENCE PLANS BRANCH
     OFFICE OF SCIENCE AND TECHNOLOGY

SUBJECT: REPLACEMENT OF ETA-BASED MOS GUIDANCE WITH NAM-BASED
     MOS GUIDANCE: EFFECTIVE DECEMBER 9 2008

REFER TO: PUBLIC INFORMATION STATEMENT...COMMENT PERIOD RELEASED
     JULY 21 2008.

EFFECTIVE TUESDAY DECEMBER 9 2008 WITH THE 1200 UNIVERSAL 
COORDINATED TIME /UTC/ CYCLE RUN...THE NWS WILL REPLACE THE 
MODEL OUTPUT STATISTICS /MOS/ GUIDANCE BASED ON THE ETA MODEL 
WITH MOS GUIDANCE BASED ON THE NORTH AMERICAN MESOSCALE /NAM/ MODEL.