Video: Earl passes North Carolina…damage may occur in bursts for New England
September 2nd, 2010The first weathercast, showing water vapor imagery to identify the disturbance that will kick Earl northeast:
Tracking the Tropics: More details on Earl, of course. A rundown of Fiona and Gaston-gone, too.
Now-casting: The latest analysis of Earl, and how it applies to New England
September 2nd, 2010Update: Hurricane Earl is passing the Outer Banks of North Carolina,
producing wind gusts in excess of 50 mph along immediate shorelines, but
very little wind just 30 miles inland. The hurricane has encountered
strong winds aloft, which have disrupted its inner core and weakened the
storm. As the hurricane moves north overnight and early Friday, it will
encounter the Gulf Stream and may strengthen briefly again, before
encountering more wind aloft and cooler ocean temperatures.
The track will likely be over the waters southeast of Nantucket, passing
between 50 and 100 miles to the southeast of the Island. There are
indications from numerous guidance products that a void of wind may
develop on the northwest quadrant of the storm, at the time it passes
Nantucket. This void would develop as the storm begins its transition
from tropical to non-tropical. Having said that, wind gusts in excess
of 110 mph will still be present on the southwest and all eastern sides
of the storm center. Additionally, heavy bands of rain developing on
the northwest quadrant of the storm may focus stronger winds aloft,
driving them to the surface.
The end result is to find rain developing at the South Coast between
noon and 2 PM, and the NH Seacoast between 5 and 7 PM, becoming heavier
within 3 hours of starting. Heavier bursts and bands of rain will focus
stronger wind gusts to 39+ mph, primarily along the coastal communities
and those within 30 miles of the coast from the NH/ME border southward.
On Cape Cod and the Islands, the Hurricane Warning remains in effect for
the possibility of drawing these stronger winds to the ground in heavier
rain bursts, as well. In a circumstance like this, the end result is
not the same as it is for a Gloria (1985) or Bob (1991). Instead, we
tend to see damage done rather randomly, where and when the heavier rain
occurs, and especially between 11 PM Friday and 5 AM Saturday.
Occasionally, a storm undergoing non-tropical transition can develop
strong winds on the backside of the circulation. I believe this may be
the case across the far South Shore, Cape Cod and the Islands between 1
AM and 5 AM Saturday. After most of the storm blows from the east, then
northeast...this would come as winds snap direction to blow from the
northwest, on the backside of the storm as it starts to pull away.
Believe it or not, this may bring the greatest threat for damage from
wind for Southeastern MA.
Rainfall amounts will be 3"-6" Southeast MA with urban and poor drainage
flooding, 1"-3" farther inland...less than 1" west of Worcester.
Storm surge of 2'-4' will mean splashover, minor and perhaps pockets of
moderate coastal flooding, though the storm passes with a receding tide.
Rip currents are building now and will continue through the weekend.
Saturday may still feature a 10-20 mph wind from the west, so line
repair may be slightly hindered, but weather will be quiet, and winds
will decrease with fair weather expected Sunday and Labor Day.
Overall - pockets of damage rather randomly dispersed, with a heavier
concentration and more widespread nature on the Outer Cape and Nantucket.
-Matt
Portahut — The Foundation
September 2nd, 2010Invitation to Likely Extended Livestream Session Friday to Saturday
September 1st, 2010Many of you have discovered my website for the first time - or the first time in a long time - over the past few days. One of the big things I like to do is fire up the Livestream video window on my Weather Analysis Page (many of you are reading this on that page right now...the video window appears above these posts). When the Livestream is active, I'm broadcasting live from my laptop, and we all come together using the Chat feature to share observations and damage reports.
At this point, I'm planning to livestream on Thursday evening and night as a test run for Friday's extended session. I expect to have the Livestream active by early evening Thursday.
If Earl takes the path it looks like he will to give New England a blow, it appears I'll be working from about 12 Noon on Friday to 12 Noon on Saturday, straight through. I plan on live streaming that whole time, so please plan on checking back in to follow the stream.
There are two locations to access the livestream:
1) On my Weather Analysis Page, below the radar image.
2) Directly through the Livestream host page.
Either way, I hope we can share reports and observations of an amazing storm together.
See you soon...literally!
Matt
Technical: Nobody said it was easy…even when the guidance makes it look that way
September 1st, 2010First, I'll share a quick story that fellow weather fanatics will appreciate and the rest will not. This evening I delivered one of my forecasts on NECN for Earl, and tossed back to the anchor when I finished. Little did I know, Ed Rappaport, Deputy Director of the National Hurricane Center and a man I've respected and practically idolized since childhood, was standing by on satellite link to do a live interview. The first question our anchor asked: "So what can we expect from this storm?" Ed's response: "Your meteorologist just gave an excellent description of where we stand with Earl." Yeah, maybe I'm bragging a little bit, but the point of the story isn't to brag. It's actually intended for those of you who read these posts from your college dorm room or your room at home, waiting for the day you'll be on the television delivering the forecast. Never in my wildest dreams as a child, teenager, college student or professional did I ever think Ed Rappaport would hear a word I said, let alone like what I had to say! So, keep after your goals and stay passionate.
Now, that's warm and fuzzy but the cold pricklies from 4 million New England households will be punishing if I did an excellent job explaining a completely wrong forecast. Not to mention my fun Labor Day Weekend Plans have been scrapped in favor of working a 24 hour shift Friday to Saturday, so I'll be pretty miffed if this storm rides out south of us, I blow the forecast, and I still work 24 hours to get cold pricklies. Needless to say, the pressure is on (pun intended).
Here's where I think we stand:
- Model guidance now nearly overwhelmingly agrees on a pass southeast of Nantucket, with the bulk of that guidance still tightly clustered along a 40 N, 70 W track, passing about 50-100 miles southeast of Nantucket. There are eastern outliers, but they are the relatively shallow, barotropic tropical models and I am discounting them. There are western outliers, but one is the NOGAPS. Come on. :) And then there is the GFS and ECMWF camp - closer to Nantucket than 40/70...in fact, very nearly over the island when you consider the eyewall.
- There are synoptic issues to contend with: 1) The Midwest trough just keeps getting deeper and deeper with each successive model run, meaning the flow near the East Coast is more amplified. 2) In response, the Western Atlantic ridge keeps getting higher and higher in the forecasts. 3) The guidance, by and large, analyzed the ridge too weak in the 12Z runs.
- We still have that pronounced trough over Newfoundland, which encourages confluent flow over Northern New England, and a general west-southwest mid-level flow that argues against landfall.
- Earl looks like a number of storms that have made landfall in New England when you examine his track thus far, but the key absolutely is his track, motion and speed going by the Outer Banks. Any correlation to history is fun to look at but I want to see where he goes by the Carolinas
- Earl is a monster. An even stronger Category 4 monster at 11 PM than he was before. Monsters create their own environment and often have surprises. Additionally, monsters are harder to turn on a dime. Much harder. They penetrate higher into the sky and depend on a larger mean layer wind to turn. Interesting to note that most guidance are responding to 850-500 mb shear with their turn northeast quicker of Earl - the GFS is keeping Earl's motion more NNE instead, largely in response to the deeper 850-200 mb shear, which I think may be more reliable given the mammoth size and strength of Earl
So...this leaves us with a slight northwest adjustment to the forecast I've been focused on the last couple of days of a 40/70 or just inside 40/70 track. I made that adjustment starting with the first 4 PM broadcast today, by mentioning that I expect Earl to track very close to, if not even perhaps over Nantucket Friday night. The impacts are relatively similar, but as you can see in the public products I've posted on the Weather Analysis Page and on our NECN Team Blog, I adjusted by expanding tropical storm force winds a bit farther north and inland, and shifting the heavy rain axis to center over Eastern MA, where some flooding is possible.
As for all of the threats, etc., they've been addressed in the non-technical, public products, so I'm going to spare you from those since if you've read this far, you're interested in the technical aspects. I have a lot more detail on the expectations from a public perspective, but want to wait until tomorrow before releasing some of them to meter just how much info we put out at once, given the lingering possibility for track deviation.
Best,
Matt
Video: 9 PM Update on Hurricane Earl…and Tropical Storms Fiona and Gaston
September 1st, 2010It's all eyes on Earl, poised to move very close to New England on Friday. While the storm may take priority in the weather world, the heat New England has been sweltering in will continue on Thursday, after resulting in school closings from the Merrimack Valley of Massachusetts to Maine on Wednesday! Earl is expected to arrive to New England on Friday, and there are a myriad of concerns given the current forecast track (which has been quite consistent in the last 60 hours). Though not all of the preparedness tips can fit in any one weather broadcast, you can find a write-up of what I'm expecting and advice I have to prepare both here on my Weather Analysis Page, and on our NECN Weather Team blog.
Meanwhile...there's plenty going on in the tropics, so I certainly couldn't ignore it in the "Tracking the Tropics" segment!
Video: Late afternoon Earl update for New England
September 1st, 2010This was the 4 PM update on NECN. I added significantly more graphics later in the afternoon and evening, but the message was the same. A complete timeline is included. Not long after this update, Earl was bumped back up to a Category 4 storm.
I've posted more details than I could fit here in the broadcast on my Weather Analysis Page, and on our NECN Weather Team blog, WeatherNewEngland.com.
I will post another video update after the 9 PM show - please watch live if you can for the latest on NECN at 9 PM, 10 PM and midnight.
Hurricane and Tropical Storm Watches are up – here’s what to expect
September 1st, 2010For Latest Info from the National Hurricane Center, click here.
Hurricane Earl continues steam northwest toward the Carolinas, and still looks as though he will impact New England later Friday and Friday night. Though there is still room for wiggle in the track, the forecast track has been quite consistent for the past 48 hours, and we must make preparations for what we in the NECN Weather Center believe will be a pass extremely close to the Island of Nantucket.
Track and Timing:
The consistent trend has been to move the track slightly westward and toward the coast with time. Though we believe a track over Nantucket is most likely, it's not impossible that Earl tracks over the Cape. Either way, the impact is largely the same, though a farther westward track would spread wind farther inland Friday evening and night. Regardless, this is a quick storm - moving in morning to early afternoon Friday, and moving out by Saturday morning, leaving splendid weather for the remainder of the holiday weekend.
Storm Surge:
Nationally, the most lives are lost in hurricanes due to storm surge - a surge of ocean water that comes ahead of the storm and can raise tide levels substantially. Thankfully, most communities are unlikely to experience a substantial surge in New England. At this point, a one to one and a half foot storm surge is likely along the eastern shorelines of Massachusetts. If the storm tracks close to Cape Cod - inside of Nantucket Island - a quick and nasty storm surge is possible in Wellfleet Harbor and Provincetown Harbor as the storm prepares to depart.
Wind:
The worst wind will occur on Cape Cod, first from the east, then northeast, then north and finally northwest. We certainly believe hurricane force winds will occur at least in gusts on Cape Cod, though sustained hurricane force wind cannot be ruled out. This will result in widespread damage of tree limbs and power lines to the Outer Cape and Nantucket, with extensive damage still likely on the remainder of Cape Cod and Martha's Vineyard. Scattered damage is likely for the South Shore of MA, and South Coast of New England from Woods Hole west to New London, CT. Isolated damage is more likely to be the case for coastal communities from the North Shore through Cape Ann to Merrimack River, and for areas farther west along the Connecticut shoreline.
Advice: Evacuations may be needed on Cape - follow any and all orders. All Cape residents should prepare for extended power outages. Some roads may be blocked after the storm. All Eastern and Southern New England residents near the Tropical Storm or Hurricane Watch areas should remove lightweight lawn and patio furniture.
Waves:
Swell will build Thursday along the South Coast, and continue building through New England waters Thursday night. Mariners who need to move lobster traps, etc., should rush these tasks to completion along all New England coastlines Thursday morning, before seas build. Large waves will also increase rip-currents considerably throughout the holiday weekend.
Advice: Those who are not experienced, strong swimmers should use exceptional caution and limit how deep you wade into ocean waters through Labor Day. Those drawn to the coast during the storm should stay away from vulnerable sand dunes and other areas that may collapse into pounding ocean surf. Mariners should complete tasks, including checking all moorings between Merrimack River and New London, CT. Vessels should be secured with extra ropes and fenders.
Rain:
Heavy rain will fall along and northwest of Hurricane Earl's track. This places Eastern New England under the gun, and we're expecting 3"-6" of rain to fall later Friday through Friday night. This rain will cause ponding of water on roadways, poor drainage flooding, and some stream flooding. By Saturday and Sunday, as runoff enters river basins, some rivers may flood if enough rain falls. Minor to moderate flooding is possible on the Charles, Neponset, Taunton, Nashua, Shawsheen and Aberjona rivers.
Advice: Curtail travel later Friday and Friday night in heavy rain. Those along rivers should monitor conditions carefullly and be alert for gradual river rises this weekend.
Additional Information:
We will offer even more detailed information as the storm nears. Please tune into NECN for the latest, and of course, we'll get information out here on WeatherNewEngland.com, as well.
Good luck with your preparations.
Matt
Working on the Backcountry Skiing Booklist
September 1st, 2010TR: Rogers Pass Base Camp Skiing
September 1st, 2010September First is an important date for skiers. It marks the transition from “summer months” to “fall months,” which have much better potential for skiing. Year round skiers have been known to use September 1 as the start of a “new ski year.” Today I’m honoring the day by posting the long-delayed Part 2 of my Roger’s Pass Trip last March.
Click on the image to read more!
Gore Mountain Action (Circa 1984)
September 1st, 2010"Gore's 41 trails offer a variety of skiing. There are gentle slopes for beginners and challenging trails for the adventurous expert. But the mountain is especially known for its excellent intermediate trails, all of which are over 1 mile long. Gore also has the ski industry's most advanced lfit, the high speed triple chairlift. In addition there are 4 double chairs, a T-bar and a J-bar.
After that long run, come in, warm up, get a bite to eat and relax in one of Gore's two comfortable lodges. Enjoy hearty fare in the base lodge cafeteria, a beverage in the lounge, or stretch out and bask in the sun on the newly expanded sundeck."
Video: Earl takes the spotlight, but for some, a very nice Labor Day Weekend
September 1st, 2010Note: A technical discussion has been issued and can be found on my Weather Analysis Page, below this post.
There's no way around a Major Hurricane taking the spotlight in the weather world when it's drawing closer to the Eastern Seaboard. If the current forecast track holds, Earl skirts the Carolinas then may deliver hurricane force gusts to the Cape and Islands, and Tropical Storm force gusts to the shorelines from Merrimack River to New London, CT. There is still time for a change in track - for better or worse - but there is also good news in the forecast: outside of the storm, very little wind is expected, and the upcoming Labor Day weekend looks delightful Saturday through Monday.
General Weather Info, plus Earl:
Tracking the Tropics:
Technical: No change to the Earl forecast…for now.
August 31st, 2010OK, so the title isn't all that inspiring, and may not instill confidence. Frankly, I don't think an open-minded meteorologist can feel much confidence about this tropical forecast, but that doesn't mean we don't make one. I had a fantastic time on the livestream with those of you who stopped by tonight.
- Hurricane guidance continues to be - for the most part - tightly clustered around a track that would take Earl south of the 40N/70W position discussed here last night, and bring minimal influence to Southern New England. Seeing continued tight clustering around this solution would, for many, build confidence that this is going to shoot well south of New England and keep most of the wind with it.
- Unfortunately, hurricane guidance is designed for a tropical environment, and nothing north of the Outer Banks is a truly tropical environment. In this instance, one should really probably discount the BAMS and BAMM, the shallow and medium depth models, as neither is likely to perform accurately with the complexities encountered in this forecast. That at least removes the southeastern most outliers.
- The key player remains the upper level/mid level trough digging into Minnesota Thursday into Friday. I see a major problem with this feature that concerns me for the hurricane forecast - each run is doing exactly what we've seen with so many upper lows so far this season...slowing it and amplifying it. This *should* mean that we see a more meridional flow east of the trough, and less southwest flow to move Earl off to the northeast, allowing for a more northward motion.
- Interestingly, and just to throw a monkey wrench into the whole thing, the NAM came back at 00Z showing the deeper solution on the Midwest upper level trough, and through 42 hours, I truly believed this would be a forecast that would carry Earl directly into New England. Obviously, it didn't. Even though the longwave pattern is forecast to be more amplified, the hurricane is forecast to shoot east flatter. Hmmm...this puts the NAM in great agreement with the hurricane guidance but the longwave pattern doesn't sit right with me.
- Of course, the 12Z Tue ECMWF was an impressive solution, carrying Earl directly over Nantucket by holding the northwest periphery of the subtropical ridge. Though a bit less pronounced, the 00Z GFS does the same thing, and trended northwest with its storm track.
- For all the model-talk we can do, my concerns are very real-world based: We have an amplifying longwave pattern that favors a digging trough in the Midwest/Ohio Valley that just so happens to be coming in slightly more amplified with every run, and that favors slowing down an east component.
- Continuing in the real-world vein, history brings concern to the table as well. Earl has already passed through the Kelley-Noyes Wheelhouse gate #1 that I mentioned yesterday, passing through a 30 mile wide "High Risk" zone. That's hard to hit. If the current forecast holds past the Carolinas, he'll hit either a moderate or high risk zone again. This has me extremely concerned that history is trying to send us a message: direct landfall is still a possibility.
So, in the end, what's my forecast? Exactly the same as it's been. The free-thinking meteorologist in me says to watch out for all the bad signs. The uptight conservative side of me points to the overwhelming guidance taking the storm farther southeast. If I had the luxury to forecast based solely upon gut and instinct, I'd probably take the track closer to New England than the 40/70 mark I laid out yesterday. But when delivering a forecast to 4 million households, I really can't do that this far out, because the implications are huge and we're still 72 hours out, which is an eternity in the world of tropical-turned-extratropical meteorology. This leaves the most prudent and best forecast, in my estimate, to be the same one as yesterday. A position near or just inside (northwest) of 40 N and 70 W with hurricane force gusts possible on the Cape and Tropical Storm force gusts between Newburyport (Merrimack River) MA and New London, CT.
Looking forward to what I hope will be a day of revelations later Wednesday. If you missed yesterday's technical discussion, check it out on my Weather Analysis Page, where I also hope to post a quick update or two later Wednesday.
-Matt
Here it is: The updated list of 2010 Vermont ski swaps
August 31st, 2010Roadtrip!
August 31st, 2010Kate and I finished our summer jobs last week, so it’s time for a road trip! We packed up Kate’s car with rock climbing gear, mountain bikes, camping gear, and, of course, rock skis and left Hanover Saturday evening heading West.
By the time we got to the Buffalo, NY area, it was after midnight and we were getting a little tired, so we decided to head up to the Niagara Falls area and find a spot to camp for the night. Kate was scouting around our campsite without a headlamp and walked onto what she thought was an open green area. Turns out it was a swampy pit.
She dried out by morning though, and we cooked delicious bacon-egg-cheese-potato breakfast burritos in the middle of the Niagara Falls State Park in true dirtbag style.
It was a beautiful day though, and the falls don’t disappoint (although it’d be cooler if there weren’t casinos in the skyline!)
After our leisurely morning, we hit the road again, hoping to make it to Madison, WI in time for dinner with my one of my best friends and climbing buddy who is starting his PhD in Physics there. Unfortunately, we hit rush hour traffic going through Chicago.
Even with the traffic, we made it to Madison in time for a late dinner. It was a hot night, but sleeping on a mattress was nice!
Yesterday we drove across the flatlands of Iowa and Nebraska all day, finally getting into Boulder, CO around 11 pm MST. We found a campsite on some national forest land and fell asleep quickly in the cool mountain air. Stay tuned for some biking and climbing updates in the next few weeks!
Apple Computer and Black Diamond, Brothers in Quality?
August 31st, 2010Hurricane Mountain, NY: 8/21/10
August 31st, 2010![]() |
| (click map to enlarge) |
The Hurricane Mountain Chapter of ADK maintains the trail. The first mile is up and down, without much elevation gain until you get to the lean-to at Gulf Brook. After you cross the stream for the first time, you start to climb. The trail is narrow and rocky much of the way.
We passed a beaver dam that will start to flood a section of the trail if it gets even a little higher. The dam has already flooded a still healthy-looking birch forest so I think it’s a relatively new structure.
The High Peaks from Hurricane
As we neared the top, we hiked on rock slabs surrounded by boulders. The summit is expansive, all rock, with 360-degree views. These views rival any summit I’ve been on in the Adirondack Park. I'd love to be on top when there is better visibility, but even so we could see Whiteface to the Northwest, Giant Mountain to the south, the Great Range to the west and Lake Champlain to the east.
There is a fire tower on top that's no longer in use. It's slated to be torn down, but it still survives. A group called the Friends of Hurricane Mountain Fire Tower is working to save it. I hope they succeed, but if they do, the tower will need a lot of work.
Lake Champlain
When I hike, it's all about the view from the top, and this summit delivered in a big way.
Technical Discussion: You won’t find a more complete early New England Earl Assessment
August 31st, 2010- If this is more technical than what you're looking for, my video presentation from Monday evening's NECN broadcasts can be found on my Weather Analysis Page
- I've posted some simple, easy, inexpensive preparatory steps we all should consider at this early stage of the game on our NECN Weather Team Blog, WeatherNewEngland.com
Normally, I have a chronological progression to these technical discussions - a big build-up to the final forecast, where we put all of the pieces together. I won't let you down, but want to get a few highlights out in the open first:
- I expect Hurricane Earl to pass very close to New England's benchmark of 40N and 70W.
- If this track verifies, tropical storm force winds and hurricane gusts will be possible in Southeastern New England, particularly the Cape and Islands
- I am encouraging New England residents take easy, cheap, quick preparatory measures at this point. Once uncertainty decreases, more advice will follow.
- This is not a slam-dunk forecast. The typical delicate interactions that govern New England hurricane forecasts are at work again.
With those four major points laid out, let's review what we know...
- The time of greatest impact of Earl on New England will be later Friday through Friday night: The storm will accelerate north, then northeast, after passing the Outer Banks of NC and this should ensure the storm has departed most of New England by Saturday morning. While a slight slowing is possible, it should not be significant enough to jeopardize this timing forecast.
- Waves will increase at the South Coast of New England Thursday, well ahead of Earl. Those waves will bring a return of severe rip currents, and that danger will persist into the weekend.
- Mariners...especially the fishing community...should be back in port by Thursday evening, as seas will continue building on Friday, and wherever the exact track of Earl ends up, ocean conditions will deteriorate quickly on Friday. Getting in trouble on Friday may result in a suspended search operation by Friday night as conditions worsen
- A landfall is extremely unlikely directly on the New England coastline. Though not completely impossible, what seems far more likely is a close pass southeast of Nantucket and Cape Cod.
I say the above points are "what we know" because there would have to be some substantial deviations from the current forecast for these to change. The wave action is fairly straight-forward. The deteriorating marine conditions - particularly for the Southern waters - also seem fairly self-explanatory. The exact acceleration of Earl is dependent upon the mid-level flow between the sub-tropical ridge and the incoming northern stream trough digging across the Great Lakes, but this squeeze will increase later Friday and should serve to provide the classic "New England slingshot" effect (I just made that term up, but it sounds good, eh?).
While we're discussing things we've made up, several years ago, Tim Kelley and I decided to do an historical analysis of storms that made landfall on New England. Our end product was the creation of two critical gates storms that strike New England must pass through - no storm to miss these gates ever hit New England directly. We called these gates the "Kelley-Noyes Wheelhouse" and if Earl continues on his current track, he will pass directly through the first high-risk area of this wheelhouse. That's not a guaranteed direct landfall, rather...a miss seems to be a guaranteed non-landfall. So, historically, landfalling in New England is not off the table according to the Kelley-Noyes Wheelhouse.
Of course, each scenario is different, and a meteorologist must examine the synoptic setup at the time. In this instance, the upper level low that will be deepening and digging across Lake Superior by Friday will be large, and its influence on the jet stream will be pronounced. Also at play is the upper low north of the mouth of the St. Lawrence, up in Newfoundland. The interaction of both upper lows creates a fairly strong southwest flow at 300, 500 and 700 mb that would make it very difficult - in fact, impossible if the forecast mid-level winds are correct - for a hurricane to landfall directly into New England. Rather, that southwest wind should exert a northeast push starting just after the passage east of North Carolina. This is interesting, because some of New England's worst hurricanes, historically, have taken the exact path touted by the 00Z NAM - a due north motion off the Carolina coast. So, historically and speaking from the "Wheelhouse" theory, there is much to be concerned about...but given the forecast mid-level and upper-level winds, it's a very, very difficult case to make, and I think forecasting a recurvature prior to New England is warranted.
Having said that, the pattern does favor a pass near the 40 degree north, 70 degree west, New England "benchmark." True weather fanatics know this position well - the sweet spot for big winter storms in Southern New England, as this position typically delivers the heaviest wind and snow to the Boston/Providence corridor. With a hurricane, things work a bit differently, but this is still a precarious position to put a storm. Though I have no guarantee this position will be correct, it is extremely close to the NHC track, is a weighted solution toward the global models (hurricane models take the storm farther southeast) which I think is wise given the interaction of northern stream trough with subtropical ridge, and most important of all, was developed by and therefore fits perfectly the synoptic reasoning set forth above.
The first consideration many will have is to question just how substantial a storm passing through this location will be. Afterall, it's common knowledge in the weather world that heaviest wind should stay to the east of the storm track. Remember Ophelia of 2005? Referred to as "No-feel-ya" by Cape Codders and weather nuts, this storm for days looked like it would come across Nantucket. The night prior, NHC posted Tropical Storm Warnings for the Southern New England coast. I'd been beating the drum for TS force winds all that week, and was thrilled to see it was going to pan out. Interestingly, that was a Friday Night/Saturday event, too, and I remember distinctly being on the air both of those periods, able only to show the Doppler velocity plot of the storm center going 25 nautical miles southeast of Nantucket, but no wind whatsoever on the west side. Maximum gust ended up being 21 mph from the west-northwest in Hyannis well after the storm went by, associated with dry and cool advection. It was horrible. Having said that, Earl is not Ophelia. Earl is not a glorified wave named a tropical storm. Earl is a monster. A category 4 and possibly 5 monster with winds that extend hundreds of miles outside of the center. Even a decaying monster is still a force to be reckoned with, and that's what Earl will be when he came by.
Tim Kelley very accurately compared Earl to another E storm from several years ago - Edouard. Edouard was also a monster, and charged northeast, passing southeast of benchmark, even farther away from New England than I currently expect Earl to pass. Edouard brought 90 mph wind gusts to Cape Cod. The stakes are high.
This brings us to the question of just how strong Earl will be when he passes New England, presumably near this 40/70 position. I cannot stress enough that I think Earl's strength is being underforecast by the guidance and therefore by many forecasters - perhaps significantly. It's more than gut that leads me to say this...consider the facts: 1) Waters along the Mid-Atlantic are running between 4 and 9 F warmer than normal, 2) These warm waters have enough heat content to support a CATEGORY FIVE storm as far north as 37.5N if Earl sticks close to his projected path, 3) Though wind shear typically would account for some weakening, once Earl turns northeast, the shear will decrease as acceleration begins, not to mention shear should remain quite limited until about that point. In fact, the forecast is for remarkably low shear, increasing slightly from the southwest when Earl starts his recurvature, but hardly enough to account for the weakening forecast by intensity guidance. The ocean water temperature gradient is just south of the 40/70 benchmark position, and therefore, weakening prompted by ocean cooling won't even begin until Earl approaches his expected closest pass to New England.
If I'm right on this, these factors effectively negate many of the normal alterations storms undergo when they come into northern latitudes - including the transfer of wind to the east side. This should still be a fairly concentric, extremely powerful beast. It's for this reason that I believe at hurricane force gusts - if not sustained - are a distinct possibility on Cape Cod and the Islands, with tropical storm force winds expanding up most of the Eastern MA coastline and perhaps westward to New London along the South Coast.
Given the uncertainty that lingers on precise track - and my desire to find better guidance consensus on my thoughts of a 40/70 position and track - I don't want to put any precise numbers out, and this is also a huge reason why I haven't more definitively hit things hard in my broadcasts - there's still plenty of room for wiggle, as some of 00Z guidance (GFS, GGEM) indicates with a more sea-ward solution. But I think we have plenty to work with in the facts laid out above to introduce the possibility of 74+ mph gusts on Cape (hurricane force) and 39+ mph gusts (tropical storm force) in some of the remainder of the coastal plain, and we can continue to adjust as needed.
It's for all of these reasons that I began suggesting early preps be made in my Monday broadcasts. Everything I suggested were easy, cheap, no-brainer preps that should be done before the season even starts, but few every really do until we have to
This ought to be interesting, to say the least.
Matt
Video: Hurricane Earl – the major players and detailed projections
August 30th, 2010- A technical discussion will follow soon on my Weather Analysis Page.
- I've posted suggested Preparedness Tips for this stage of the game on our NECN Team Weather Blog, WeatherNewEngland.com
In my first weather segment on NECN's news at 9 PM, 10 and midnight, I tried to lay out the players in the Hurricane Earl forecast, and exactly why uncertainty exists in the forecast:
A half hour later, in the nightly "Tracking the Tropics" update, I squeezed about as much as I possibly could into the broadcast:




















