MAweatherboy1's Blog

Storm Train Lined Up For The East

By: MAweatherboy1, 12:59 AM GMT on December 23, 2012

Good evening. I'm watching the potential for a few storms on the East Coast in the next 1-2 weeks. The first event will be occurring Christmas Eve night into early Christmas day. I'm hesitant to call this a storm as it will really be no more than a weak area of low pressure drifting off the East Coast and strengthening slightly as it pulls away from New England. Models have been a bit variable on the track and intensity of the system. The Euro has generally shown a warmer, weaker, more northerly solution than the GFS. However, tonight's 18z GFS run came in north of previous runs, and it was also weaker. This implies a warmer solution with very light precipitation and limited snowfall accumulation if any. The NAM has also shown some large variations, and I am hesitant to trust anything it says. Overall, I lean towards a weak low pressure system traveling just south of the CT and RI coasts, providing southern New England a light precipitation event, but perhaps enough to give some a white Christmas, defined as one inch or more of snow on the ground. This is what my local NWS is thinking:



I actually disagree with them quite a bit. My map is shown below. I realize its sloppy, I just threw it together real quick using MS Paint, but you get the picture:



The next storm will come in not long after as we get into the Wednesday night/Thursday timeframe. This is a real storm, and will provide significant impacts for many. At this point, there remain large uncertainties on the track. With the exception of its 0z run last night, the Euro has been pretty steady forecasting the storm to pass through western and central New England before pushing offshore, providing rain to most of the NE with snow well inland. The other models such as the GFS had been showing a more easterly track, which a snowier solution. I have been hesitant to buy these solutions considering the NAO is going positive, which makes it very difficult for storm to bomb out off the NE coast. Indeed, most 12z and 18z guidance, particularly the GFS, has trended west. With the Euro and GFS now in decent agreement, I have fair confidence on the general setup of this storm. I reserve the right to make major changes if the models flip flop again, but here's my early thinking. Again, I know its sloppy and feel free to laugh at me but you get the point:



The potential exists for another storm around the 30th or 31st, but it's just too early to get into any details regarding that storm at this point.

I hope this blog was semi-informative. I'll be keeping the comments section updated with new information in the coming days. Merry Christmas!!!!!!

MAweatherboy1

2012 Atlantic Hurricane Season Recap

By: MAweatherboy1, 1:59 AM GMT on December 01, 2012

The 2012 North Atlantic Hurricane Season is officially over. By many standards, 2012 was an exceptional year in the Atlantic basin as we witnessed the development of a whopping 19 named storms, 10 of which became hurricanes, with 1 becoming a major hurricane. These numbers, particularly the 19 named storms, would be remarkable in any season, but especially in this one as preseason predictions from nearly all official agencies were in the 10-14 storm range due to the expected arrival of El Nino, which is notorious for hindering development in the Atlantic, towards the middle and end of the season. To put it plainly, El Nino missed the memo and the rest is history. This marks the third straight year 19 or more storms have formed in the Atlantic basin, truly a remarkable statistic. I am not going to write comprehensive reports on all the storms this year as I do not have the time, diligence, or knowledge to complete them. They will be left to the experts. However I will point out several things I found particularly interesting about this year.
1. A very early start. 2012 was remarkable even before the season officially began on June 1st as we witnessed the development of two systems, Tropical Storm Alberto and Tropical Storm Beryl. Beryl started out subtropical, but eventually gained tropical status and ended up becoming the strongest May cyclone on record to make landfall in the United States as it was just under hurricane status and had a clearly evident ragged eye by the time it made landfall on the east coast of Florida. As the climate warms, I expect events like this to become more frequent in the future, and I strongly support the idea of the NHC moving the official start of the Atlantic season to May 15, the same as the East Pac, to heighten awareness of early season storms.


Figure 1: Even before Alberto and Beryl made headlines, the Atlantic attempted to start early in the form of Invest 92L. In the image above 92L is more than likely a tropical storm, however, it's good appearance was rather short lived, so it will likely not be identified as a storm by the NHC in the post-season.


Figure 2: Tropical Storm Beryl nearing landfall. The ragged eye is evident. While there is some evidence supporting an upgrade to hurricane status in post season analysis, I do not feel it will be enough to justify the upgrade.

2. The forecasting conundrum of Debby. Every single tropical system, no matter what, is a challenge to forecast. There is no such thing as an “easy” storm to track. 2012 however saw arguably the greatest tropical forecasting challenge ever, Tropical Storm Debby, one of two storms to develop in June, the other being high latitude minimal hurricane Chris. Debby as a storm was really nothing noteworthy, just a minimal to moderate strength poorly organized tropical storm in the Gulf of Mexico. What was noteworthy about it was the complete inability of the computer models to pick up on its eventual track into Florida, as the vast majority indicated a track west into Texas or Louisiana, many insisting on this solution even as it became apparent there was absolutely no way Debby could turn west in time to head for TX or LA. The NHC didn’t fare much better as their original track also went with this solution and they had to end up pulling a complete 180. The one major model exception was the GFS, which, despite complete disregard by most of both the professional and amateur forecasters, absolutely nailed the track into Florida. Debby will likely go down as a good learning experience, as we may now be able to better predict future storms that are in similar positions.


Figure 3: A disorganized Debby nears landfall in Florida.

3. The improvement of the GFS. Before this season began the American GFS model received an upgrade, giving it high expectations heading into the season. Whether this upgrade really helped or it just got lucky, the GFS generally had an excellent year forecasting in the Atlantic. It of course got started out on a good note by being the only major model to predict Debby’s improbable journey to Florida, but performed solidly for the rest of the year as well, often outperforming its archrival the European ECWMF model, which after years as king struggled at times this year. The GFS also showed better skill than usual in the long range. While there were some ghost storms as always it generally did a good job of at least indicating the formation of something that would develop well in advance. One major exception occurred towards the end of the season with Hurricane Sandy. The GFS, like most of the models, did do a good job predicting Sandy’s formation and strengthening, but it insisted for days that Sandy would harmlessly recurve out to sea, while the ECMWF accurately predicted from quite early on that this storm would impact the United States. This was an exception, however, as this year generally belonged to the GFS. Time will tell if this is a one year fluke or a long term trend. For now I still say the ECWMF is king, but the GFS is not far off.
4. A silent July. After a ridiculous four storms combined between May and June, the Atlantic took the month off in July. The MJO completely left the building, and when that happens early in the season it is very difficult to get development, and indeed, the basin could not muster even one named storm this month. Still, by the end of the month we had seen the emergence of the yearly African wave train, setting the stage for an active August and September.
5. A number of weak storms and a lack of strong ones. While this season was certainly remarkable for its number of named storms, it was really nothing special in the intensity department, as evidenced by only 1 major hurricane, Michael, which barely and briefly made the mark. Hurricane Sandy was also noteworthy for its intensity, as even though it fell short of major hurricane status it was remarkable in terms of its extremely low pressure off the East Coast of the United States, far lower than Michael’s pressure at any time. These two were exceptions, however, as we saw several fairly pathetic storms this year, including Helene, Joyce, Oscar, Patty, and Tony. I don’t really have an explanation for why we seem to be getting more weak storms, as last year also had several, but it could be partly due to how much easier it is to pick up weak storms far out at sea now in the satellite era, with pitiful Tropical Storm Joyce being my best example for this year, as well as Tropical Storm Florence which formed far from land areas. We also watched multiples storms struggle in the Caribbean due to high trade winds, including Ernesto until just before landfall, and the system that eventually spawned Helene, another very weak storm. Even storms that became hurricanes such as Leslie and Nadine struggled quite a bit from low instability in the Atlantic. Dry air also caused problems for several storms this year, including Isaac.


Figure 4: Small and weak Tropical Storm Joyce moves over the open Atlantic. This storm never would have been detected before the satellite era.


Figure 5: Hurricane Michael prowls the Atlantic near peak intensity. Michael was a very interesting storm, as it became a major hurricane despite virtually no model support and very little forecaster confidence. He is my favorite storm of the year.

6. Hurricane Isaac. The United States escaped once again this year without a major hurricane making landfall on its shores, but we far from escaped tropical impact. While Debby and Beryl both provided US impacts, the first place in the United States to feel the true fury of the 2012 season was the Gulf Coast, in particular Louisiana and the New Orleans area. These places received significant impacts from Hurricane Isaac, which ironically made landfall near New Orleans on the 7th anniversary of Hurricane Katrina’s landfall. For much of its life, Isaac was a storm characterized by a struggle with land, dry air, and trade winds. Even as it entered the Gulf of Mexico it refused to strengthen, despite expectations from forecasters. However, as it neared the Gulf Coast it became apparent that while the winds were not increasing, the pressure was falling and the wind field was greatly expanding. This created a significant storm surge threat. Isaac was also an extremely slow mover as it came ashore, sitting in Louisiana for multiple days, dumping tremendous amounts of rain. While not the main impact factor, strong winds and some wind damage also occurred as just before landfall the actual winds themselves began to catch up with the falling pressure and expanding wind field. While nowhere near as bad as the infamous Katrina, Isaac certainly caused plenty of damage on the Gulf Coast.


Figure 6: A strengthening Isaac nears landfall on the Gulf Coast.


Figure 7: Isaac's torential rains submerged this car in Mississippi.

7. Never Ending Nadine. Another memorable storm from the 2012 season was Hurricane Nadine. Nadine is certainly most memorable for its longevity as a tropical cyclone, forming on September 11 and not dissipating until October 4, although there was a brief period from September 22 to part of September 23 that saw the storm lose tropical characteristics, causing the NHC to briefly suspend advisories. Despite nearly a month as a tropical cyclone, Nadine was not noteworthy in terms of intensity, as it only managed to achieve Category 1 status with 90mph winds, or impacts to land as it remained over open water for much of its lifespan, providing only minor impacts to the Azores as it became post-tropical for the second and final time. Still, Nadine goes down as tied for the second longest named storm ever in the Atlantic, stubbornly refusing to quit despite several periods of unfavorable conditions. In the future, just as I expect more early season storms, I also expect more storms like Nadine, as the warming climate is creating sea surface temperatures capable of supporting tropical cyclones over an increased portion of the Atlantic basin.


Figure 8: Nadine meanders through the Atlantic as a hurricane on September 30, nearly 3 weeks after it first formed. Shortly after this image was taken Nadine began to weaken for the final time.

8. Superstorm Sandy. In addition to Isaac, the other storm to have a significant impact on the United States was Hurricane Sandy. Sandy initially wreaked havoc in the Caribbean, hitting Jamaica as a hurricane then rapidly intensifying to a strong Category 2 storm before hitting Cuba, where it caused significant damage and several fatalities. It also caused damage and fatalities in both Haiti and the Bahamas. Initial forecast tracks seemed to indicate Sandy would eventually recurve after leaving the Caribbean, as several models, especially the GFS, supported this. However, as it reached Cuba and the Bahamas, it became increasingly clear that a very unusual weather pattern was going to allow Sandy to do what practically no storm in its position had done before: turn NE as if it was going out to sea but then swing back NW and hit the US. Initial speculation for a landfall point indicated New England as a likely spot, but it soon became evident that this would be more of a Mid-Atlantic storm, and indeed, the forecast track stayed very steady on a New Jersey or Delaware landfall for days before the landfall. Meanwhile, forecasters watched in awe as model run after model run of virtually every model we have brought Sandy’s central pressure below the 950mb mark. Many dismissed this at first, but it soon became clear that a true superstorm was evolving; Sandy’s pressure would fall, and though the winds would not significantly rise, the wind field would expand dramatically and create one of the largest and most dangerous storms ever. These fears came true as mission after mission by NOAA and Air Force Reserve hurricane hunting aircraft showed the pressure plummeting, below 950mb and down to around 940mb. Extensive preparations and evacuations occurred along the Mid Atlantic coast, and Sandy made her greatest impacts on October 29. The main points of the storm were the high tide cycles, first one in the morning that proved to be fairly uneventful, but another one in the late evening that proved to be much more destructive. Water rushed into low lying areas of New York City, flooding subways and buildings, as well as the site of the World Trade Center. High above Manhattan a crane snapped atop a high rise building and dangled precariously far above the ground, forcing an evacuation of the ground below. This really became one of the iconic images of the whole event for me. Another major story from Sandy was the sinking of the vessel HMS Bounty off the Outer Banks of North Carolina in rough seas churned up by massive Sandy, which had become the largest recorded tropical cyclone in the Atlantic basin. It also took the record for lowest pressure off the East Coast, easily surpassing other well-known storms such as the perfect storm of 1991 or last year’s Hurricane Irene. Sandy certainly ended up as the highlight this season, and she serves as a great reminder that no matter what point in the season it is, we can never take our eyes off the tropics. Sandy also stirred up a significant debate over whether climate change was partly to blame for her destruction, and whether we should expect more events like it in the future. The logical answer seems to be yes, as warming seas and rising sea levels increase the risk for future storm surge events. I do not think climate change should be blamed for steering Sandy into the US; that was the result of an incredibly rare combination of weather factors, but the warmer water farther north than usual certainly enhanced her impacts.


Figure 9: Hurricane Sandy carves a path of destruction through the Caribbean. There is likely sufficient evidence to upgrade Sandy to a major hurricane while it was in the Caribbean during post-season analysis.


Figure 10: Massive Hurricane Sandy moving up the East Coast. The size of Sandy was incredible, as it had the largest swath of tropical storm force winds ever recorded.


Figure 11: A crane, snapped by the fury of Sandy's winds, dangles precariously above Manhattan after the storm.


Figure 12: One of many examples of Hurricane Sandy's damage, this one from New Jersey.

Odds of retirement for each storm:
Alberto: 0%, Beryl: 10%, Chris: 0%, Debby: 5%, Ernesto: 10%, Florence: 0%, Gordon: 0%, Helene: 0%, Isaac: 65% (Very close call on this one, Isaac was certainly a destructive storm but there is a case to be made that he shouldn’t be retired. In the end I think the retirement-happy WMO will take him off the list though.), Joyce: 0%, Kirk: 0%, Leslie: 0%, Michael: 0%, Nadine: 5%, Oscar: 0%, Patty: 0%, Rafael: 0%, Sandy: 95% (Sandy deserves to be retired beyond any doubt in my opinion, but I can’t go with 100% due to the very slight chance the WMO deem Sandy’s damage occurred when the system was post tropical and thus Sandy doesn’t really get credit for it. I would find this ridiculous but it’s not impossible), Tony: 0%

I've had a great time blogging with you all here this year. I've really learned a lot thanks to all my fellow posters here at WU, as well as Dr. Masters. Regarding the future I will still be around in the offseason tracking winter storms and any tropical systems that threaten in the West Pacific or Southern Hemisphere, and I definitely look forward to another Atlantic season next year. Against my better judgment I will be releasing my 2013 season forecast sometime late this winter or early next spring.

* Note- All information on storms in this blog is preliminary and could change as official Tropical Cyclone Reports are released by the National Hurricane Center. There is also the unlikely possibility that a post-season storm will form and skew some of my numbers a little.

Have a great weekend!

MAweatherboy1


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

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About MAweatherboy1

Average 20 year old weather nerd. Plymouth State University Meteorology, Class of 2018. NOAA Hollings scholar. Summer 2016 intern at NWS Boston.