Hurricane Maria: NNW Of Bermuda Hurricane Watch Issued

[NorEaster27]

GFS still recurves this, we have a big trough moving in durring the middle of next week. If this is going to hit the US, it needs to do it down by florida.

[GaWx]

12Z Euro takes a very weak Maria WNW to the Turks/Caicos hour 120 and then recurves it through the Bahamas near 25N, 77W. If she can survive into the Caribbean, Maria's fate would be far from sealed. Her ~westerly heading doesn't suggest recurve east of the US climowise fwiw. Dissipation perhaps, but not a likely recurve east of the US per climo. If she can stay weak and stay pretty far south but not fall apart, she may get more interesting mid to late next week.

[dan88]

18z SHIPS is a bit more enthusiastic with this than it has been. It weakens it in the short term, keeping it as a depression for a while, but later brings it up to 76kt by the end of the period ( stronger than past couple days of runs)

[wxsmwhrms]

You can clearly see an exposed tight LLC near 13N, 52.5W, with new convection developing near it. It looks like it is moving through the roughest part of the shear right now based on satellite winds, with lighter easterly winds ahead of it. Will be interesting to see what NHC does with it this afternoon.

[donsutherland1]

12Z Euro takes a very weak Maria WNW to the Turks/Caicos hour 120 and then recurves it through the Bahamas near 25N, 77W. If she can survive into the Caribbean, Maria's fate would be far from sealed. Her ~westerly heading doesn't suggest recurve east of the US climowise fwiw. Dissipation perhaps, but not a likely recurve east of the US per climo. If she can stay weak and stay pretty far south but not fall apart, she may get more interesting mid to late next week.

IMO, I'm not sure the Euro solution concerning Maria's track sometime beyond 192 hours would work out if Maria is in the forecast position at 192 hours. The weakness in the ridging is forecast to be closing fairly quickly. After 216 hours, model forecast concerning Maria's continued progression notwithstanding, there could well be enough ridging to eventually trap Maria. If so, Maria could be turned back to the U.S., possibly after doing a Jeanne-like (2004) cyclonic loop. With Maria still showing little indication of gaining any latitude, the risk of a track farther west than previously modeled is growing. If Maria gets to the Bahamas by 168 hours, it will probably recurve. If, however, Maria is still meandering around there after 192 hours, especially close to 216 hours, then its prospects of recurving in time to avoid U.S. landfall will probably be reduced.

[dan88]

After hours of communication troubles, some recon data has finally come in.

42kt flight level, 38kt SFMR, 1005.4mb extrap, 10-12kt winds out of the SW observed. Can't see more where W-NW winds would be, as it appears this recon data is still missing.

[donsutherland1]

When it comes to Nate's future landfall, the 18z GFS provided clarity in joining the ECMWF in forecasting Mexico landfall. However, when it came to Maria's future, the GFS and ECMWF agreed only on recurvature. Significant differences persisted between the Euro's bringing Maria dangerously close to the U.S. before recurvature and the farther out-to-sea recurvature on the GFS. The Euro ensembles also point to the evolution of a pattern that could make the East Coast vulnerable to any tropical cyclones that might be around after about Day 9. Whether Maria is still around at the time will depend on whether it slows down and is missed by a trough that will be moving across eastern North America. For now, with the Euro being well outside the model consensus, I am not yet ready to adjust my track much closer to the East Coast.

[OHweather]

Maria forecast/discussion 2 (update to forecast 1):

Tropical Storm Maria remains highly disorganized, with pulsing convection noted north of the low level circulation on IR Satellite loops and microwave images. Because of the center being displaced from the convection, Maria has weakened some today as I expected last night. Maria is still heading just a tad north of due west, at 275/15, and has gained very little latitude since yesterday.

Track forecast reasoning remains essentially unchanged, although will have to be adjusting slightly south/west due to yesterdays day 1 forecast busting too far to the north. Maria is on the southern periphery of a subtropical ridge over the central Atlantic and will begin over the next 48 hours gradually turning more WNW and then NW with time as ridging to the north of the cyclone weakens over the western Atlantic due to Lee's remnants over the OH/TN Valleys and due to the upper level westerlies being farther south than normal over the western Atlantic due to a positive NAO.

However, given Maria will remain weak in the short term and given the cyclone has tracked farther left than anticipated in the near term, a track close to or over Puerto Rico and near but likely still north of Hispaniola will be forecast, which is farther south than yesterday's forecast. In addition, a track much closer to the central Bahama's will be shown. The GFS and its ensembles show Maria tracking north and being picked up by troughing associated with Lee's remnants before they pull out causing the system to recurve well off the US east coast. However, the ECM and its ensembles slow Maria down in the mid range and narrowly allow Maria to escape before troughing pulls out of the eastern US. While landfall is still not likely in my opinion, the 12z Euro ensembles show troughing along the east coast at day 6, in association with a (brief) -NAO/+PNA. However, the ensembles allow a strong Pacific jet to weaken the western US ridging after this, and show the pattern becoming much more zonal over the eastern US. Should Maria slow down more than expected this weekend into early next week, it is an outside possibility that Maria gets caught up in weak steering currents off the southeast coast. However, this would require Maria to significantly slow down which appears unlikely given there is a fairly fast flow surrounding the ridge that is steering it, and would also require ridging to build back in over the eastern US days 7-10. While both are possible, it is unlikely both will happen at the right times to bring Maria much farther west (into the southeastern US).

As for intensity, moderate shear and dry air are still causing problems for Maria, with convection exhibiting a pulsing pattern. The convection is also displaced from the center of circulation. These problems are expected to continue plegging the tropical storm over the next couple of days. With some decent low level ridging north of Maria, the steep pressure gradient produced may help to continue generating some TS force winds on the northern side of the circulation, assuming some convection continues to fire. So, will maintain Maria as a minimal TS for the next 48 hours. Thereafter, the global models attempt to weaken the shear over Maria and the GFS, CMC, and NOGAPS attempt to develop an upper level anti-cyclone over Maria, just as the system also begins to slow some. All of these global models and the vast majority of the hurricane models show some intensification starting about 48 hours out. The 12z Euro was not so optimistic. The GFS, CMC, NOGAPS and about 2/3rds of the ATCF guidance suggest a cyclone nearing or exceeding hurricane strength by day 5. Given that at the upper levels the Euro looks favorable once Maria approaches the Bahamas, will bring Maria up to a minimal hurricane by day 5, despite the ECM not showing much intensification.

Forecast track/intensity:

Initial (0z Friday)...13.2N, 53.6W...35 knots, TS

24 hours (18z Friday)...13.5N, 59W...35 knots, TS

48 hours (18z Saturday)...16N, 65W...35 knots, TS

72 hours (18z Sunday)...19N, 69W...45 knots, TS

96 hours (18z Monday)...22.2N, 72.7W...55 knots, TS

120 hours (18z Tuesday)...25.1N, 76W...65 knots, Cat 1

[dan88]

18z SHIPS is a bit more enthusiastic with this than it has been. It weakens it in the short term, keeping it as a depression for a while, but later brings it up to 76kt by the end of the period ( stronger than past couple days of runs)

00z SHIPS continues to be more enthusiastic with the system, bringing it up to 87kt by the end of the period.

[Wannabehippie]

Given that path, can Maria even survive to get to the states after passing over Hispaniola?

Maria forecast/discussion 2 (update to forecast 1):

Tropical Storm Maria remains highly disorganized, with pulsing convection noted north of the low level circulation on IR Satellite loops and microwave images. Because of the center being displaced from the convection, Maria has weakened some today as I expected last night. Maria is still heading just a tad north of due west, at 275/15, and has gained very little latitude since yesterday.

Track forecast reasoning remains essentially unchanged, although will have to be adjusting slightly south/west due to yesterdays day 1 forecast busting too far to the north. Maria is on the southern periphery of a subtropical ridge over the central Atlantic and will begin over the next 48 hours gradually turning more WNW and then NW with time as ridging to the north of the cyclone weakens over the western Atlantic due to Lee's remnants over the OH/TN Valleys and due to the upper level westerlies being farther south than normal over the western Atlantic due to a positive NAO.

However, given Maria will remain weak in the short term and given the cyclone has tracked farther left than anticipated in the near term, a track close to or over Puerto Rico and near but likely still north of Hispaniola will be forecast, which is farther south than yesterday's forecast. In addition, a track much closer to the central Bahama's will be shown. The GFS and its ensembles show Maria tracking north and being picked up by troughing associated with Lee's remnants before they pull out causing the system to recurve well off the US east coast. However, the ECM and its ensembles slow Maria down in the mid range and narrowly allow Maria to escape before troughing pulls out of the eastern US. While landfall is still not likely in my opinion, the 12z Euro ensembles show troughing along the east coast at day 6, in association with a (brief) -NAO/+PNA. However, the ensembles allow a strong Pacific jet to weaken the western US ridging after this, and show the pattern becoming much more zonal over the eastern US. Should Maria slow down more than expected this weekend into early next week, it is an outside possibility that Maria gets caught up in weak steering currents off the southeast coast. However, this would require Maria to significantly slow down which appears unlikely given there is a fairly fast flow surrounding the ridge that is steering it, and would also require ridging to build back in over the eastern US days 7-10. While both are possible, it is unlikely both will happen at the right times to bring Maria much farther west (into the southeastern US).

As for intensity, moderate shear and dry air are still causing problems for Maria, with convection exhibiting a pulsing pattern. The convection is also displaced from the center of circulation. These problems are expected to continue plegging the tropical storm over the next couple of days. With some decent low level ridging north of Maria, the steep pressure gradient produced may help to continue generating some TS force winds on the northern side of the circulation, assuming some convection continues to fire. So, will maintain Maria as a minimal TS for the next 48 hours. Thereafter, the global models attempt to weaken the shear over Maria and the GFS, CMC, and NOGAPS attempt to develop an upper level anti-cyclone over Maria, just as the system also begins to slow some. All of these global models and the vast majority of the hurricane models show some intensification starting about 48 hours out. The 12z Euro was not so optimistic. The GFS, CMC, NOGAPS and about 2/3rds of the ATCF guidance suggest a cyclone nearing or exceeding hurricane strength by day 5. Given that at the upper levels the Euro looks favorable once Maria approaches the Bahamas, will bring Maria up to a minimal hurricane by day 5, despite the ECM not showing much intensification.

Forecast track/intensity:

Initial (0z Friday)...13.2N, 53.6W...35 knots, TS

24 hours (18z Friday)...13.5N, 59W...35 knots, TS

48 hours (18z Saturday)...16N, 65W...35 knots, TS

72 hours (18z Sunday)...19N, 69W...45 knots, TS

96 hours (18z Monday)...22.2N, 72.7W...55 knots, TS

120 hours (18z Tuesday)...25.1N, 76W...65 knots, Cat 1

[GaWx]

Some historical climatology data with respect to the region in which TD 14 formed (11.8N 37.0W):

Since 1950, 8 tropical cyclones formed in the region bounded by 9.8N-13.8N/34.0W-40.0W on September 6 +/- 20 days. A day outside that range was Hurricane Chris (1988), which peaked at Category 1 and recurved and Hurricane Andrew (1992), which made U.S. landfall as a devastating Category 5 hurricane.

Of the eight relevant storms, 3 (37.5%) made U.S. landfall. Those storms were Inez (1966), David (1979), and Frances (2004). 5 (62.5%) avoided U.S. landfall. The landfall percentage is 50% higher than that for all tropical cyclones that formed in the 34W-40W region on September 6 +/- 20 days. IMO, from that pool of eight storms, there are five analog candidates at this time (shown chronologically):

1. Flossie (1978)

2. David (1979)

3. Danielle (1998) **the solution closest to that shown on the 9/6 18z GFS**

4. Erin (2001)

5. Frances (2004)

In terms of peak intensity, 87.5% of the eight storms grew into hurricanes and 62.5% were major hurricanes. 50% were either Category 3 or 4 storms at their peak. From the smaller analog pool, 40% of the tropical cyclones made U.S. landfall and all five storms were hurricanes. 60% of the possible analog storms were major hurricanes. Based on this information, historic climatology suggests that TD 14 will likely peak as a major hurricane. There is some chance albeit a smaller one than had been the case for Katia that the storm will peak at Category 4 strength.

Looking at these ten Don S. analogs, here is the average heading in degrees from birth to 53.6 W, where Maria was at 8 PM EDT today, as compared to Maria:

David (1979): 272; hit CONUS; made it to 81W

Maria (2011): 275

Erin (2001): 284; made it to 66W

Inez (1966): 287; hit CONUS; made it to 101W

Andrew (1992): 288; hit CONUS; made it to 92W

Danielle (1998): 289; made it to 74W

Frances (2004): 292; hit CONUS; made it to 85W

Frances (1976): 295; made it to 55W

Chris (1994): 300; made it to 63W

Flossie (1978): 305; made it to 62W

Hortense (1990): 325; made it to 52W

1) So, the only one of the ten that moved at a comparably low heading was David (1979). The four CONUS hitters averaged 285 deg. (range 272-292) while the six missers averaged 300 deg. (range 284-325). With only a 275 heading, you'd think it would fit in better in the hitters group. The continued low heading of Maria continues to tell me that a CONUS hit should still be considered a decent possibility, despite the lack of it on models, unless it were to dissipate in the tropics.

2) The five that had a sub 290 heading made it all of the way to 83W on average. In contrast, the five 290+ heading TC's made it only to 63W.

2) None of the ten dissipated prior to a recurve or CONUS hit. Four were only TS's at 53.6 W: Erin (2001), Inez (1966), Andrew (1992), and Flossie (1978). All four of these made it least to cat. 2 'cane status at a later time: Andrew cat. 5, Inez cat. 4, Erin cat.3, and Flossie cat. 2. All four CONUS hits were as 'canes.

3) So, if Maria were to never get to 'cane status and also were to recurve east of the CONUS, it would certainly be going against the climo based tendencies. I have a feeling that Maria may be getting a good bit more interesting down the road. We'll see. Keep in mind that I constantly said the opposite about Katia (saying 90% chance of recurve starting when it was still in the E ATL). My point in mentioning Katia is that I'm not one to overhype.

[phlwx]

GFS shows a safe recurve and hit for Newfoundland. Euro slows the storm down, has it fuse with the incoming East Coast trough the middle of next week, and then sends a hybrid type system NNW into Hatteras by Day 10.

[phlwx]

Hazel!!1!

The GFS shows a similar Carolina hybrid around 9/17 that goes NNE up the coast (slowly though).

[U_Thant]

Interestingly, the GFS develops this feature in situ, pretty much entirely baroclinically initiated (BI), although not as strongly as the ECM, which ingests a decapitated Maria into the developing....ROGUE STORM ™.

[peribonca]

Anyone know if recon is going to check this thing out today before it gets close to us in the Virgin Islands? Where is the supposed center?

[phil882]

Wow, deepest expansion of -80C temps Ive seen all season. That CCKW must be doing it's dirty work!

[phil882]

Yeah, nice colors. Too bad it looks like a Jackson Pollock and not a cyclone.

Well it's pretty difficult to tell what's going on without recon, but the falling preside mentioned by the NHC suggests it's strengthening. microwave also suggest modest banding with a circulation fully embedded in the center. What the CCKW is doing is slowing down the low level easterlies while reducing the upper level westerly flow. This also helps convective development as strong upper level difluent flow moves overhead. The models generally are very poor with CCKW progression, but the one that is moving across the Atlantic right now is a strong one.

[donsutherland1]

Overnight, the ECMWF shows a situation fairly close to a trapping scenario whereb, would come northward, but the weakness between twin ridges would close when Maria is approaching the North Carolina from the south. For Maria to be in such a position, it will have to avoid gaining much latitude so that it won't be caught and turned out to sea by a trough that will be moving through southeastern Canada over the next 4-6 days. Considering that Maria finally began to gain latitude overnight, I still think the Euro's scenario is probably less likely than recurvature. Given this development, even as my initial estimated position had a large error, with Maria passing more than 100 miles to the south, I expect that Maria will take a course that brings it closer to the future estimated positions. Some of the latter positions are close to the current model consensus. As a result, I will not make any changes to the track at this time.

Finally, in terms of intensity, as noted previously, when the shear relaxes and Maria decelerates, it should begin to strengthen. Maria has been decelerating overnight and it is moving into an environment with low and lessening shear. As a result, the satellite images suggest that the storm has begun to strengthen in recent hours. In fact, some of the satellite estimates show that Maria is now a T3.0 storm on the Dvorak scale vs. T2.5 6 hours ago.

Track Estimates:

15.0N 55.0W; Actual: 13.3N 55.0W; Error: 117 miles--26.5 hours in advance

20.0N 66.4W

25.0N 72.5W

30.0N 72.0W

35.0N 69.0W

[Srain]

RECON is flying around and so far no 'center' can even be located. Perhaps we have an open wave.

[wxsmwhrms]

RECON is flying around and so far no 'center' can even be located. Perhaps we have an open wave.

Well, the Euro pretty much forecast it to degenerate into a wave before regenerating as a TC N of Hispaniola. Maybe it will be right.

[GaWx]

RECON is flying around and so far no 'center' can even be located. Perhaps we have an open wave.

Since 1851, ~27 TC's are on record as having moved at a less than 280 degree heading from about where Maria first became a TD to ~54 W. Maria moved at ~276 degrees. Of those, a respectable eight (30%) dissipated before either a recurve or a non-island land hit. These eight dissipated at the following longitudes: 54W, 55W, 56W, 56W, 61W, 65W, 69W, and 82W. So, half of them dissipated pretty near to where Maria is currenty located (within 54W-56W). So, dissipation into an open wave would be quite believable from a climo perspective.

[phil882]

RECON is flying around and so far no 'center' can even be located. Perhaps we have an open wave.

There is definitely still a circulation. The tight center it had a few days ago is likely no more, but its restructuring currently and becoming much larger than size. So while it might not have very strong winds currently, this restructuring bodes well for its development in the long term.

[dan88]

It was upped to 40kt on the advisory, but it is likely that another upgrade will be needed for the 2pm intermediate advisory. Recon has found a large area of unflagged 45kt+ SFMR readings North of the center, with a peak thus far of 49kt.

[wxsmwhrms]

The 06Z GFS EnKF and FIMY REALLY like Maria, both make it into a pretty strong looking hurricane north of the Islands. They both like hard recurve, too.

[phil882]

The 06Z GFS EnKF and FIMY REALLY like Maria, both make it into a pretty strong looking hurricane north of the Islands. They both like hard recurve, too.

Given the convective restructuring today... Maria's prospects beyond the next 24 hours look good for intensification. I think its rather unlikely that this storm is going to dissipate like the ECWMF has been suggesting given that the circulation's overall size has become much larger, and the expanding outflow may overpower the small upper level low to its northwest, like the GFS has been suggesting. This is a different situation from Katia, which was smaller than the large upper level trough that was in its path, and I see a more favorable outcome for Maria in the long term than my forecast I issued a few days ago.

[donsutherland1]

The 9/9 12z Euro is now in good agreement with the GFS concerning Maria's track and likely recurve. It has also abandoned the scenario of degenerating Maria into a tropical wave and then regenerating it. That scenario was perhaps the principal reason the model was an outlier during previous runs.

[atownwxwatcher]

On the same token the ECM ensemble means from 12 Z is also further south then the operational ECM at 144 hrs....Not as deep on the trough in the Northeast either..

[phil882]

FWIW, the 18z NAM takes the center just north of Hispanolia in 72hrs on a WNW heading, very similar to Irene.

How many more times do meteorologists have to reiterate how bad using the NAM is for tropical cyclones before folks finally start listening and stop to mention it. In today's run you can see a large area of bogus 850mb vorticity to the south of the system affecting the motion of Maria and pulling it much further south than it should. You frankly just can't trust the NAM with most of its vorticity in the tropical Atlantic.

[Ed Lizard]

On the same token the ECM ensemble means from 12 Z is also further south then the operational ECM at 144 hrs....Not as deep on the trough in the Northeast either..

Question on ensemble means. If one takes the means of, say, 50 lower resolution to begin with models, since the troughs and ridges would not be in the same position on each perturbation, wouldn't the ensemble means tend to 'broaden' troughs and ridges and even if the strenth of the features was similar each run, wouldn't the different positions produce what appears to be weaker troughs and ridges?

[peribonca]

winds gusting to 30mph already in St Croix... looks on IR that it is getting it's act together just in time to knock down some of our trees