Hurricane Maria

[donsutherland1]

So far, Hurricane Maria remains on course to reach Puerto Rico in about two days as a major hurricane (possibly a Category 4 storm). Two major hurricanes from the climatological data set for hurricanes within 100 nautical miles of Maria's 11 am position that made landfall on Puerto Rico were the 1928 Lake Okeechobee Hurricane (Hurricane #4) and Hurricane Hugo in 1989. After possible Puerto Rico landfall, Maria's longer-term fate remains unresolved.

On account of its trajectory, climatological odds of landfall on the U.S. Mainland have increased to nearly 50%. However, with extratropical cyclone Jose likely to make another anti-cyclonic loop that moves it closer to the U.S. coast, those odds likely overstate Maria's actual prospects of landfall at present. Instead, the gradually weakening Jose will likely possess a broad circulation that helps turn Maria more to the north and perhaps later northeast, which would result in lower prospects of landfall. Should Jose weaken more rapidly than anticipated, its ability to help steer Maria away from the U.S. East Coast would likely be reduced. Other synoptic features that are not currently modeled as major players could grow in importance, though.

The EPS and GEFS imply a much lower prospect of landfall. Only a handful of EPS members show landfall (one small cluster across Florida and another small cluster along North Carolina's Outer Banks). Many of the ensemble members already depict a northwest trajectory. With Maria still tracking west-northwestward and that motion likely to continue for the next 12-24 hours and perhaps a little longer, the ensembles likely understate the prospect of U.S. landfall. In fact, the NHC has adjusted its track to the left with the largest adjustments occurring over the next 48 hours. In short, all of this implies that Maria will likely make a wider turn than what most of the ensemble members are currently depicting.

Overall, my guess remains that Maria's U.S. landfall probability is about 40%. The southern-most EPS members may offer the most reasonable solution through the next 48-72 hours.

[CheeselandSkies]

5 minutes ago, donsutherland1 said:

So far, Hurricane Maria remains on course to reach Puerto Rico in about two days as a major hurricane (possibly a Category 4 storm). Two major hurricanes from the climatological data set for hurricanes within 100 nautical miles of Maria's 11 am position that made landfall on Puerto Rico were the 1928 Lake Okeechobee Hurricane (Hurricane #4) and Hurricane Hugo in 1989. After possible Puerto Rico landfall, Maria's longer-term fate remains unresolved.

On account of its trajectory, climatological odds of landfall on the U.S. Mainland have increased to nearly 50%. However, with extratropical cyclone Jose likely to make another anti-cyclonic loop that moves it closer to the U.S. coast, those odds likely overstate Maria's actual prospects of landfall at present. Instead, the gradually weakening Jose will likely possess a broad circulation that helps turn Maria more to the north and perhaps later northeast, which would result in lower prospects of landfall. Should Jose weaken more rapidly than anticipated, its ability to help steer Maria away from the U.S. East Coast would likely be reduced. Other synoptic features that are not currently modeled as major players could grow in importance, though.

The EPS and GEFS imply a much lower prospect of landfall. Only a handful of EPS members show landfall (one small cluster across Florida and another small cluster along North Carolina's Outer Banks). Many of the ensemble members already depict a northwest trajectory. With Maria still tracking west-northwestward and that motion likely to continue for the next 12-24 hours and perhaps a little longer, the ensembles likely understate the prospect of U.S. landfall. In fact, the NHC has adjusted its track to the left with the largest adjustments occurring over the next 48 hours. In short, all of this implies that Maria will likely make a wider turn than what most of the ensemble members are currently depicting.

Overall, my guess remains that Maria's U.S. landfall probability is about 40%. The southern-most EPS members may offer the most reasonable solution through the next 48-72 hours.

NHC really needs to create discussions like this and release them to the media, because U.S. landfall chances is the question on everyone's mind for each major tropical system, especially when it's beyond the reach of the cone.

[medville]

1 hour ago, Crazy4Wx said:

Then you need to brush up on your math. The first two time periods are 24 years..the third is 16 years. 

I still respectfully stand behind my original comment. Compare technology in 1951 to that of 2017. The tools are different now. Satellites can read your newspaper through the living room window. We have much more accuracy now. still within average. If we start having more and more years where we run out of alphabet names, we can start discussing above avg totals. 

 

[donsutherland1]

18 minutes ago, CheeselandSkies said:

NHC really needs to create discussions like this and release them to the media, because U.S. landfall chances is the question on everyone's mind for each major tropical system, especially when it's beyond the reach of the cone.

Thanks for the kind words.

I believe the NHC has started doing so. With Irma, the NHC went beyond the 120-hour period in its discussions. For example, the 9/4 11 am discussion read, in part:

4. There is an increasing chance of seeing some impacts from Irma in
the Florida Peninsula and the Florida Keys later this week and this
weekend. In addition, rough surf and dangerous marine conditions
will begin to affect the southeastern U.S. coast by later this week.
Otherwise, it is still too early to determine what direct impacts
Irma might have on the continental United States. However, everyone
in hurricane-prone areas should ensure that they have their
hurricane plan in place, as we are now near the peak of the season.

Overall, the trade-offs involved are difficult, as larger time horizons involve larger errors. The NHC received some criticism when Irma ultimately made Florida Keys landfall and then landfall on the southwestern portion of the Florida Peninsula after an earlier focus more on the Miami area. Even as the distance involved was relatively small and the overall forecast was good given the complexities involved, the impact of the actual point of landfall from what had earlier been anticipated was substantial. What could have been a catastrophic hurricane landfall turned out to be a damaging one. The worst damage was confined to the Florida Keys and a small portion of southwestern Florida rather than the greater Miami area. Overall, damage will wind up much less than the $100 billion-$200 billion disaster that Irma could have been. Going forward, will this relatively better outcome encourage a sense of complacency? It's difficult to know.

The NHC and NWS have a lot of survey data on how people respond to various forecasts and outcomes following the forecasts. Personally, I'm not sure if too many people view things in terms of probabilities (probably more do so here than in the general public). Instead, many likely see things in a more deterministic, binary fashion: a storm will make landfall or it won't. This is a very difficult challenge for forecasters.

 

[Windspeed]

50 minutes ago, CheeselandSkies said:

NHC really needs to create discussions like this and release them to the media, because U.S. landfall chances is the question on everyone's mind for each major tropical system, especially when it's beyond the reach of the cone.

 

 

I understand your point but I am going to have to disagree. NOAA has a research division with a plethora of peer-reviewed climatological data in literature and journals that are accessible online. Information that is available for good people like Don and others to present that in discussion on any forum or media worth their weight in salt.

The focus of the meteorologists at the NHC should be forecasting based on current synoptic pattern and modeling, and further working with other government agencies to provide advisories based on those forecasts. Perhaps what happened 83 years ago with a cyclone is helpful from a climatological standpoint; however, it isn't very helpful from a forecast standpoint. In fact, mixing climatology into a hurricane forecast discussion might even be misconstrued by the media. They have enough difficulty understanding 5-7 day forecast errors as is. You're shooting yourself in the foot mentioning something like 75% of major hurricanes made landfall at this position or impacted this region may set unrealistic expectations when the synoptic pattern or atmospheric steering features may be nothing like those previous examples.

Again, just forecast. Leave the climatological discussion outside of official forecast discussion.

[Eskimo Joe]

Hurricane warning issued for the U.S. Virgin Islands.

[Derecho!]

So the GFS has shifted West quite a bit, approaching Outer Banks at 210 hours. 

[hawkeye_wx]

6 minutes ago, Derecho! said:

So the GFS has shifted West quite a bit, approaching Outer Banks at 210 hours. 

Yeah, the 12z run made a couple adjustments with Jose's future.  First, it takes it a little farther east after the turn, which puts a bit more distance between Jose and Maria.  Then, it weakens Jose to nothing and rebuilds the ridge before Maria can escape.

This run ends up turning Maria away from the coast just before landfall, but this is beyond day 7, which means the GFS has no idea what the pattern will be then.

[Derecho!]

4 minutes ago, hawkeye_wx said:

Yeah, the 12z run made a couple adjustments with Jose's future.  First, it takes it a little farther east after the turn, which puts a bit more distance between Jose and Maria.  Then, it weakens Jose to nothing and rebuilds the ridge before Maria can escape.

Still might escape, it hovers just off the NC coast for forever and then starts moving NE. 

[Stormlover74]

6 minutes ago, Derecho! said:

So the GFS has shifted West quite a bit, approaching Outer Banks at 210 hours. 

Somehow it manages to not make landfall despite being within 50 miles of the NC coast and turning almost due east

[downeastnc]

6 minutes ago, Stormlover74 said:

Somehow it manages to not make landfall despite being within 50 miles of the NC coast and turning almost due east

the island there just north of the storm for 12-18 hrs is Emerald Isle probably one of if not the most developed island on the NC coast....

[Eskimo Joe]

Maria's eye is looking much better defined on radar since this time yesterday:

 

https://twitter.com/EricBlake12/status/909819042436927489

[Windspeed]

25 minutes ago, Eskimo Joe said:

Maria's eye is looking much better defined on radar since this time yesterday:

https://twitter.com/EricBlake12/status/909819042436927489

 

I would think so. It was a Tropical Storm this time yesterday...

[Ginx snewx]

Dominica looks like its the first Island to take the RFQ

http://www.meteofrance.gp/observations-meteo-antilles-guyane/martinique/972

[NJwx85]

The 12z guidance continues to indicate a track over the next several days just WSW of where Irma tracked. At least Maria is a more compact system, with the hurricane force winds only extending up to 60 miles away from the center, so unless the eyewall itself tracks over the islands, they should fare better. Puerto Rico is a different story with a possible landfall.

[Eskimo Joe]

Eye becoming visible on satellite.  Cat 4 by tomorrow AM?

[NJwx85]

4 minutes ago, Eskimo Joe said:

Eye becoming visible on satellite.  Cat 4 by tomorrow AM?

I'm thinking Cat 4 by tonight. She's totally bombing out now. And the small core will help the winds ramp up quicker. 

[wxmx]

7 minutes ago, Eskimo Joe said:

Eye becoming visible on satellite.  Cat 4 by tomorrow AM?

Or right now? Dropsonde in the SE eyewall up to 122 kts at the surface. 957mb in the latest vortex message

 

[Eskimo Joe]

Just now, wxmx said:

Or right now? Dropsonde in the SE eyewall up to 122 kts at the surface 

[Ginx snewx]

current motion on radar takes the RRFQ here in Berekua Dominica, looks ugly with funnelling surge and mountainous flooding behind them.

[hlcater]

VDM since recon seems to be broken. Main thing I noted was the relatively small 8nm diameter eye. This could help the storm continue to rapidly intensify, but will have to be replaced at some point down the road.

 

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 18th day of the month at 16:50Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5305 
Storm Number & Year: 15 in 2017
Storm Name: Maria (flight in the North Atlantic basin)
Mission Number: 2
Observation Number: 22 ( See all messages of this type for this mission. )
A. Time of Center Fix: 18th day of the month at 16:35:00Z
B. Center Fix Coordinates: 14°45'N 60°14'W (14.75N 60.2333W)
B. Center Fix Location: 56 statute miles (90 km) to the E (80°) from Fort-de-France, Martinique (France).
C. Minimum Height at Standard Level: 2,727m (8,947ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 104kts (~ 119.7mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 5 nautical miles (6 statute miles) to the SE (134°) of center fix
F. Maximum Flight Level Wind Inbound: From 218° at 101kts (From the SW at ~ 116.2mph)
G. Location of Maximum Flight Level Wind Inbound: 8 nautical miles (9 statute miles) to the SE (134°) of center fix
H. Minimum Sea Level Pressure: 957mb (28.26 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 10°C (50°F) at a pressure alt. of 3,045m (9,990ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 17°C (63°F) at a pressure alt. of 3,038m (9,967ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 12°C (54°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Closed 
M. Eye Shape & Diameter: Circular with a diameter of 8 nautical miles
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile

Remarks Section:
Maximum Flight Level Wind: 115kts (~ 132.3mph) which was observed 17 nautical miles (20 statute miles) to the E (89°) from the flight level center at 14:41:00Z
Dropsonde Surface Wind at Center: From 245° at 18kts (From the WSW at 21mph)

 

[Windspeed]

Visible says it all. This is a very small and intense vortex.

[dan11295]

Pressure down of 957 w/18 kt wind. Recon had 122 kt at surface. Looks like southern half of Dominica is going to have a rough night.

[NJwx85]

28 minutes ago, wxmx said:

Or right now? Dropsonde in the SE eyewall up to 122 kts at the surface. 957mb in the latest vortex message

 

I saw that, but since nobody else posted it yet I thought I was reading it wrong lol.

[shaggy]

1 hour ago, Stormlover74 said:

Somehow it manages to not make landfall despite being within 50 miles of the NC coast and turning almost due east

Not that this run of the gfs is a sure thing but a storm in that position for that long would fill the sounds and rivers up with a huge surge. TS Dennis sat out there for a few days in 1999 and the pamlico river at washington had 9 foot surge.

[JasonOH]

That sonde could have caught a gust since the wind increased so much in the final 4mb, but 110kt is easily believable for surface winds. Going to be Cat 4 very soon, if not already.

edit: NHC went with 110KT/956mb

[dan11295]

125 mph makes sense. Pressures don't yet support a Cat 4, even if it is in a relatively high pressure environment.

[Roger Smith]

The only good thing about this hurricane season is that some of us are learning a lot about the Leeward Islands.

Dominica is an independent nation state with just under 100k residents. About one third of those live in or near the capital Roseau which is on the southwest coast, so if the eye tracks across the island they would likely see very strong NE then NW winds and therefore not as protected from storm surge as one might initially suppose. I checked a news website and the island is on high alert with the government warning people to move away from coasts and rivers that might flood, remove potential flying debris etc. 

Martinique to south and Guadeloupe to north are both integral parts of France and populations of both islands are roughly similar (400k). Guadeloupe is actually two connected islands, Basse Terre and Grande Terre. I was reading that both Hugo and the 1928 "Okeechobee" hurricane devastated the economy of Guadeloupe. Martinique is the island that contains the volcano that erupted in 1902 killing 30k people and changing the location of their capital city in the process. That volcano is near the northern tip of Martinique.

Looks to me like Maria will soon be cat-4 and will have major impacts on all three of these islands (regions). I think the eye will go over central Dominica but this will expose southern parts of Basse-Terre region of Guadeloupe to cat-3 winds as the distance to the track is not that large. 

[AfewUniversesBelowNormal]

Only 1 storm didn't hit America, and it was furthest NW of the bunch, soon to be nonanalog.

 

 

 

La Nina still being underestimated, I think

[jojo762]

11 minutes ago, dan11295 said:

125 mph makes sense. Pressures don't yet support a Cat 4, even if it is in a relatively high pressure environment.

 

So, you're just going to ignore a dropsonde then that measured 140mph at the surface and 160+mph just above the surface?