Upcoming Week - October 29-November 5

[Andrew92]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.


Evaluating last week

This past week two tropical cyclones developed, Sandy and Tony, and I predicted them both to occur. Sandy took place originally in the Caribbean while Tony was over open waters, never a threat to land. On that regard, I did a great job on Tony, identifying it is an out-to-sea storm. However, I greatly overestimated its intensity. I thought Tony might sneak in and become a hurricane! It instead only peaked at 50 mph. I was also a good two days off on the timing of this storm, predicting it to develop on Wednesday and dissipate by Sunday; instead, it developed Monday and dissipated on late Thursday to early Friday. So overall, I didn’t do so well with Tony, but I did at least see a disorganized system developing, something I have struggled with a lot in the past.

But the main event for this past week was Sandy. I did a little better overall on this storm, though I was way off again on the intensity portion. The track was overall very-well predicted along with the timing of events. I predicted the Jamaica landfall for Wednesday and the Cuba landfall for early Thursday, which both happened. Sandy did reach the Bahamas a little earlier than I thought, but still took a track that generally skirted the East Coast through the weekend. Yes, I know it is forecast to head inland by tomorrow night or Tuesday, but that’s a different story – the point was I predicted it to be offshore of the United States, though a lot closer to Bermuda than where it is now. So overall, I executed the track well. But I greatly underestimated the intensity. Sandy first became a tropical storm a day before I thought it would, and intensified a lot faster in the Caribbean than I expected. I thought Sandy would be struggling to organize as a moderate tropical storm, but she nearly became a category 3 hurricane, with a pressure definitely supporting that intensity of 954 mb as she hit Cuba. I guess on one front, I nailed her being a minimal hurricane during the weekend, at least by wind speed. But the evolution of Sandy to become as strong as she got prior to then, and weakening to get there instead of strengthening as I thought would happen knocks this part of the prediction down a couple pegs. That said, my warning was well-advised for Jamaica, Cuba, the Bahamas, the East Coast, and Bermuda, given the immense size of this storm; though I didn’t think about Sandy hitting Haiti either.

Overall, my grade for Sandy is a C+ and my grade for Tony a D+. Sandy was the bigger deal to try to pin down, as Tony was never a threat overall. Therefore, I will indeed give myself a C+ for this past week.

Sandy is about to try something possibly never seen before. Will it pull it off? Let’s take a look.

Current situation and models

Sandy is of course the big game in town. She looks poised to make landfall along the coast of either New Jersey or points south to Ocean City, Maryland, late tomorrow night or very early on Tuesday. However, the point of landfall will not be the only focal point for this storm. Sandy is a storm with tropical storm force winds reaching out 520 miles from the center. Being that Sandy is a minimal hurricane by wind speed, hurricane force winds extend out quite a bit shorter from the center, but still a quite respectable 175 miles. Because of this, lots of high tides and storm surge can be expected when Sandy makes the turn northwest and makes landfall, even if it does so as an extratropical storm. Sandy is also not forecast to weaken before landfall, and if anything will likely strengthen just a bit.

Otherwise, the big threat from Sandy will be a large early of very heavy rainfall over the next couple days in the Northeast. With the northern Appalachians possibly helping to produce a bit of orographic effect, coupled with Sandy already being the ogre in size that she is, a major storm appears to be in store for many areas of this part of the country, reaching into New England and Canada by Tuesday and Wednesday. Even areas as far west as western Pennsylvania, West Virginia, eastern Ohio, and Ontario west of Toronto could receive some effects from wind and rain from this massive storm. Sandy is also not forecast to move all that quickly as an extratropical storm, and by late Friday could still be over Maine or the Canadian Maritime Provinces as it re-curves around an area of high pressure. Conditions in this part of the country could rival or even be worse than those seen by Hurricane Irene last year.

Elsewhere, the tropical Atlantic is shaping up to be quiet this upcoming week. The GFS and Euro do not show any threatening disturbances looming. About the only area I saw that could possibly threaten to develop would be way out over the eastern Atlantic, of subtropical nature. Even this feature looks short-lived and weak, while not threatening any land.

Recent history

I would first like to point out that if Hurricane Sandy does not become extratropical before making landfall, it would be the first hurricane to make landfall north of North Carolina since a hurricane hit New Jersey from this angle in September 1903. I can only imagine what this hurricane might have looked like. Perhaps it was another storm like Sandy. I would also like to point out that October hurricanes are quite rare reaching into North Carolina. Since 1960, only Isbell in 1964, Gladys in 1968, and Irene in 1999 have hit or brushed North Carolina. In fact, only Isbell went inland, and was more like a dying tropical storm by that point anyway. Then again Hazel also occurred in October back in 1954, so it certainly is possible for a storm like this to punch into North Carolina during that month. But Sandy is occurring further north. Hazel is the only October storm since 1950 that has hit areas further north than North Carolina during this month. Sandy is truly reaching uncharted territory, if she isn’t there already.

OK, so what other storms have developed (and were not previously active) this upcoming week? How about:

Inga in 1961
Jenny in 1961
An unnamed storm in 1964
Lois in 1966
An unnamed hurricane in 1969
Katrina in 1981 (NOT the famous one!)
The Perfect Storm in 1991
Florence in 1994
Katrina 1999 (also NOT the famous one!)
Michelle in 2001
Noel in 2001
Ida in 2009
Tomas in 2010

That’s a total of 13 storms in the last 52 years, or an average of one new tropical storm this upcoming week every four years. The last one happened two years ago, so it would not be a surprise after Sandy leaves the picture to have no new storms this week. Surprisingly, ten of these storms went on to become hurricanes, but only Michelle was a major hurricane, in the western Caribbean. Six of these 13 storms occurred in the Caribbean, with five of them in the western part; only Tomas developed east of there and then re-curved near Haiti and Jamaica. Inga was an erratically moving storm for a few days in the Bay of Campeche. All of the other six storms formed over the subtropical latitudes of the open Atlantic. Only the Perfect Storm hit land of these storms.

So what does this all tell us?

Sandy is one of a kind. I mean, if you are looking for an analog for this storm, do you consider Hazel? That storm did follow a similar path, but lashed North Carolina on its way inland. The 1903 storm I mentioned, just based on the fact that it is coming in from that angle into New Jersey potentially, something almost unheard of? This storm is closer to the wind speed of the 1903 storm, but likely closer to the pressure of Hazel simply due to its massive size. However, these two storms are not likely to be what Sandy is looked upon like.

As strange as it sounds, the Perfect Storm might be what Sandy is compared to. Think about it; that storm was aided by another previously-formed hurricane (Grace) providing energy for a cutoff frontal low that headed towards the East Coast. Well, Sandy and a disturbance that has been moving across the Midwest are combining to create this massive “Frankenstorm” event, as it is popularly being dubbed. The one key difference is that the Perfect Storm finally moved inland as a weakening storm over Nova Scotia, while this will be a quite intense storm moving onshore over the Mid-Atlantic States. This will undoubtedly produce massive flooding over the Northeast, especially if this storm is still in the area by Thursday and Friday as expected by the National Hurricane Center. Flooding in the form of heavy rain, storm surge, and high waves will likely be the legacies left by Sandy, but the winds will likely cause their fair share of damage too. I mean, when you have tropical storm winds extending out 520 miles from the center, and hurricane force winds 175 miles, from a minimal hurricane, you’ve got a big problem on your hands. When you factor in that some of the higher inland elevations could come into play from the flooding standpoint – I don’t mean to hype anything – but this could not only be comparable to Irene from last year, but could this be an event like Agnes or Floyd? Or even the Johnstown Floods of years’ past? It really does make me wonder, and I will definitely be praying hard for this part of the country. Fill up your sandbags and be more prepared than you think you have to be if you live in this part of the country!

When looking elsewhere, a storm of subtropical origin could certainly be considered for this upcoming week. However, even that is a low chance historically. The GFS and Euro just do not show this potential system, far out over the open Atlantic and a non-threat to land, as anything strong or noteworthy. Therefore, I just can’t get excited about seeing Valerie this upcoming week.

The prediction

It is going to be a long week for the Northeast. I predict Hurricane Sandy will turn north by tomorrow morning and northwest by the late afternoon. Sandy will become extratropical in the evening, but will still be a large, powerful storm with maximum winds of 75-80 mph at landfall at close to midnight somewhere between Atlantic City, New Jersey, and Ocean City, Maryland. Weakening will occur after landfall and continue on through the storm’s life over the northeast, but winds will not be the most destructive factor with this storm, even though they will reach well inland into West Virginia and western Pennsylvania. Massive storm surge and high waves will batter the Mid-Atlantic States reaching up to New York City. Long Island Sound will also be a quite angry body of water due to this storm. Heavy rainfall will also cause major flooding inland, especially in the more rugged areas of the northern Appalachians, the Adirondacks, and into northern New England. As an extratropical storm, Sandy will re-curve very slowly northward by Tuesday night and Wednesday, and then northeast on Thursday, but still be near the Maine-Canada border by Friday. Sandy will finally leave the United States for good on Saturday, and Canada on Sunday. Confidence is 60%.

If you are poised to be impacted by Sandy this upcoming week, it is absolutely imperative for you to remember that this is NOT an official forecast! This is only my opinion, and official information should be obtained from the National Hurricane Center and your local National Weather Service office. Please also listen to your local authorities for what to do if and/or when this storm hits your area and heed all the advice they give you. This is a potentially very dangerous storm, the likes of which have not been seen in quite a long time. Thank you.

Elsewhere, I predict no tropical or subtropical cyclone activity this week in the Atlantic. Confidence is 85%.

-Andrew92

[Andrew92]

And it's time to evaluate.

Sandy was of course the big player this past week. As the week was beginning, Sandy was poised to make an unusual turn northwest into the Mid-Atlantic States, and I predicted a landfall near midnight on Monday somewhere between Atlantic City, New Jersey, and Ocean City, Maryland. Indeed, landfall occurred in this window, near Cape May in far southern New Jersey. However, Sandy sped up more than I thought before landfall, which occurred at about 8:00 PM. This would be a pretty decent prediction for later in the week, but not quite as good for so early in the week. I was also incorrect on Sandy’s strength; some intensification was likely to about 80 mph, but 90 mph seemed like a stretch. Of course, Sandy did weaken to 80 mph, but the wind speed wasn’t the big deal of course. The flooding was a much bigger story with this hurricane, or superstorm as it became as it made landfall – another thing I nailed, her becoming extratropical just before landfall. Indeed, a large storm surge inundated New Jersey and New York, especially New York City. Record tides that I’m not sure I would have been quite capable of conveying in this type of prediction occurred even. On top of it, there was lots of heavy rainfall inland as this storm slowly re-curved over Pennsylvania and upstate New York – though I missed the snowfall threat in West Virginia. I was accurate in the effects reaching into Ohio even, though I didn’t see the wind whipping up Lake Michigan even as it happened! Sandy actually weakened over land quite a bit quicker than I thought and the effects of rainfall were less pronounced than I imagined later in the week. Still, this was quite a disastrous storm as it was. Overall, the only blips were the slight timing discrepancy in regards to landfall, intensity being a little off (but hardly mattering given the size of this storm), and missing the snowfall threat. I did a pretty good job on what Sandy would do to the Northeast as a whole.

Sandy was also the only player in town this past week. This was another accurate projection on my part. Though a subtropical area was brought up by models, it never came to fruition, and I wasn’t ready to buy it either. Overall, I give myself a very respectable B+ for this past week.

New week coming up shortly.

-Andrew92