Nate almost a hurricane; Maria remains disorganized

By: Dr. Jeff Masters , 9:05 PM GMT on September 08, 2011

Share this Blog
23
+

An Air Force Reserve hurricane hunter aircraft is in Tropical Storm Nate, and has found winds much stronger than the storm's satellite appearance would suggest. At 2:17 pm EDT, the aircraft measured winds at their flight level of 1500 feet of 93 mph, which would ordinarily support upgrading Nate to a Category 1 hurricane. Surface winds measured by the SFMR instrument were about 70 mph, suggesting that Nate is indeed very close to hurricane strength. However, latest visible satellite loops show that if Nate is a hurricane, it's only half of a hurricane. Nate's low-level center is exposed to view, due to northeasterly upper-level winds that are creating a moderate 10 knots of wind shear. This shear is keeping all of Nate's heavy thunderstorms pushed to the south side of the center, and the northern half of the storm almost cloud-free. Sustained winds at Buoy 42055, about 140 miles to the northwest of the center of Nate, were just 28 mph at 3:50 pm EDT this afternoon. Water vapor satellite loops show that there is a large area of very dry air from Texas to the north of Nate, and this dry air is keeping the northern half of the storm dry.

Nate will meander in the Bay of Campeche for several days, and the computer models are sharply divided on what happens early next week to the storm. A ridge of high pressure is expected to build in to the north of the storm, potentially forcing it westwards to a landfall in Mexico. However, our two best-performing models last year, the GFS and ECMWF, predict that a weak trough of low pressure expected to move across the U.S. early next week will be strong enough to turn Nate northwards towards an eventual landfall along the northern Gulf Coast. We will have to wait until the NOAA jet makes its first mission to sample the steering currents in the Gulf of Mexico to get a better idea on how probable this northern path might be; their first flight will be tonight, and the data will make it into the 8 pm models runs that will be available first thing Friday morning. As far as intensity goes, the very dry air to Nate's north should begin being less of a problem for it by Friday, when the upper level winds shift more to blow from the southeast, and the shear drops to the low range, 5 - 10 knots. Since the storm is moving very slowly, it will upwell cooler waters from the depths that will slow intensification, though.


Figure 1. Afternoon satellite image of Nate.

Tropical Storm Maria
Tropical Storm Maria barely survived as a tropical storm today, but is now making a bit of a comeback. Satellite loops show that Maria has been badly ripped up by the 10 - 20 knots of wind shear affecting it. The low-level center has been exposed to view most of the day, and surface arc-shaped clouds have been racing away from the storm to the west this afternoon, indicating that dry air has been getting into Maria's thunderstorms and disrupting the storm. However, the areal coverage and intensity of Maria's thunderstorms have increased a little in the past two hours. Maria is passing close to buoy 41040, which measured sustained winds of 36 mph, gusting to 45 mph, at 2:50 pm EDT.

Wind shear is predicted to fall to the low range on Friday as Maria approaches the Lesser Antilles. In addition, as I noted in this morning's post, Maria will be encountering an atmospheric disturbance known as a Convectively-Coupled Kelvin Wave (CCKW) that is currently passing through the Lesser Antilles Islands. There is a great deal of upward-moving air in the vicinity of a CCKW, and will help strengthen the updrafts in Maria's thunderstorms, potentially intensifying the storm. None of our models are detailed enough to "see" CCKWs", so we may see more intensification of the storm than the models are calling for. I believe Maria will continue to organize and arrive in the Lesser Antilles Islands as a tropical storm with 50 - 60 mph winds. The latest run of the GFDL model predicts that Maria will be a Category 1 hurricane on Saturday afternoon when it moves through the Virgin Islands, and a Category 2 hurricane Sunday night when it moves through the Turks and Caicos Islands. This is on the high end of what is possible, and I think it more likely that Maria will be a tropical storm with 50 - 60 mph winds in the northern Lesser Antilles, 60 - 70 mph winds in the Virgin Islands and Puerto Rico, and a Category 1 hurricane in the Turks and Caicos Islands--assuming passage over Puerto Rico and the eastern tip of the Dominican Republic does not significantly disrupt the storm. A lower intensity, as forecast by NHC, is certainly quite possible, as Maria may continue to struggle with the dry air and wind shear besetting it.

The latest computer model runs have been trending more southwards, and the Northern Lesser Antilles, Virgin Islands, Puerto Rico, the Turks and Caicos Islands, and the Bahama Islands are all at high risk of a direct hit by Maria. The models are split on how strong the steering influence a trough of low pressure along the U.S. East Coast will have once Maria approaches the U.S. East Coast. Most of the models foresee that Maria will turn north before arriving at Florida, and potentially threaten North Carolina, Bermuda, or Canada. The latest run of the GFDL model, though, brings Maria through the Bahamas to a point just 100 miles southeast of Miami as a hurricane on Tuesday afternoon. While this forecast is an outlier, and it is more likely that Maria will turn north before reaching Florida, it will be another two days before we will have a fair degree of confidence on when Maria will curve to the north.

Lee's rains trigger historic flooding in New York and Pennsylvania
An extreme rainfall event unprecedented in recorded history has hit the Binghamton, New York area, where 7.49" of rain fell yesterday. This is the second year in a row Binghamton has recorded a greater than 1-in-100 year rain event; their previous all-time record was set last September, when 4.68" fell on Sep 30 - Oct. 1, 2010. Binghamton has also already broken its record for rainiest year in its history. Records go back to 1890 in the city. The rain has ended in Binghamton, with this morning's rain bringing the city's total rainfall for the 40-hour event to 9.02". The Susquehanna River at Binghamton has risen to 25.69', its highest level since records began in 1847, and is now spilling over the flood walls protecting the city, according to media reports. In Hershey, Pennsylvania, Swatara Creek is 19' over flood stage, and more than 9' above its record flood crest. Widespread flash flooding is occurring across the entire area, and over 120,000 people have been evacuated from their homes.


Figure 2. Seven-day precipitation amounts from Tropical Storm Lee and its remnants. Image credit: NOAA/AHPS.


Figure 3. The Susquehanna River at Binghamton has crested this afternoon at its highest flood height on record, 25.69'. Records at this gauge go back to 1847. Image credit: NOAA/AHPS.


Figure 4. In Hershey, Pennsylvania, Swatara Creek is 19' over flood stage, and more than 9' above its previous record flood crest. The river is forecast to crest at 27.2' (green lines are the predictions.) Records at this gage go back to 1930. Image credit: NOAA/AHPS.

The extreme rains are due the the remains of Tropical Storm Lee interacting with a stationary front draped along the Eastern U.S. Adding to the potent moisture mix last night was a stream of tropical moisture associated with Hurricane Katia that collided with the stationary front. You don't often see a major city break its all-time 24-hour precipitation record by a 60% margin, according to wunderground's weather historian, Christopher C. Burt, and he can't recall ever seeing it happen before. It's worth noting that the Susquehanna River Binghamton stream gage, which has been in operation since 1847, is due to be shut off in 3 weeks due to budget cuts. Here's the note at the USGS web site:

NOTICE (03/23/2011)--Data collection at this streamgage may be discontinued after October 1, 2011 due to funding reductions from partner agencies. Although historic data will remain accessible, no new data will be collected unless one or more new funding partners are found. Users who are willing to contribute funding to continue operation of this streamgage should contact Rob Breault or Ward Freeman of the USGS New York Water Science Center at 518-285-5658 or dc_ny@usgs.gov.

I'll have an update in the morning.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 77 - 27

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40Blog Index

A tropical wave is interacting with a strong upper level low just northeast of the islands that is producing the disorganized showers and storms as wind shear is clearly disrupting the tropical wave, without this upper level low there we could have had four named storms in existence.
Member Since: Posts: Comments:
18Z GFS Init:

Member Since: August 14, 2008 Posts: 4 Comments: 4978
Member Since: Posts: Comments:
Quoting Gearsts:
How is the Convectively-Coupled Kelvin Wave causing the rain over PR?

Sorry, meant that other wave/disturbance over the eastern caribbean. Fixed it :P
Member Since: Posts: Comments:
Big difference in the convection between 20:45:


and 21:15:


Looks like that coc is fully convection wrapped, and in short order too.
Member Since: June 27, 2011 Posts: 0 Comments: 179
Quoting bigwes6844:
omg u cant be serious! u think it has a chance to weaken big time before it gets to us. (if necessary)


There's no guarantee that it's even going to hit the Northern Gulf, especially when the model consensus has shifted back to the Mexico solution. I certainly can't give you an idea on strength until we know where Nate is going first.
Member Since: Posts: Comments:
Quoting spinningtop:
seriousy now is there a chance maria hits east coast florida?


An itsy-bitsy teeney, weeney chance..
Member Since: Posts: Comments:
Quoting WeatherNerdPR:
Thanks doc. That CCKW is making PR look quite gloomy.
How is the Convectively-Coupled Kelvin Wave causing the rain over PR?
Member Since: Posts: Comments:
Quoting spinningtop:
seriousy now is there a chance maria hits east coast florida?


yes
Member Since: Posts: Comments:
ALSO DON'T FORGET MARIA COULD INTERACT WITH SOME OF THE LARGER ISLANDS OF THE LESSER ANTILLES LIKE MARTINIQUE DOMINIQUE AND GUADELOUPE... THAT CAN CHANGE THE TRACK LOCALLY!!!! IT HAPPENED WITH 1995 IRIS AND MARILYN..
Member Since: Posts: Comments:
Quoting mrpuertorico:
wow if you read the nws forecast for maria it sounds like she is going to die but dr.m's says restrengthening now i am really confused not sure what my saturday is going to be like :(


Forecasting IS NEVER 100% CERTAIN. The NHC has its point of view on Maria, and Dr Masters also have his own logic. Only future will tell who's more accurate :) SO LET'S WATCH!!!
Member Since: Posts: Comments:
Quoting CaicosRetiredSailor:
Although preparing, I am hoping the NHC forecast of Maria being "only" a Tropical Storm when it reaches the Turks and Caicos, prevails rather than Jeff Masters thinking it will be up to Hurricane strength... time will tell.


I'd prepare for a hurricane none the less. Not a lot of difference between a strong TS or weak hurricane.
Member Since: Posts: Comments:
Quoting MississippiWx:


The Texas ridge is displaced to the south over Northern Mexico and should stay there for the next several days. Its placement even keeps South Texas from receiving a direct hit from Nate. The end result will be one of 2 extremes. Either Southern Mexico or the Northern Gulf Coast will take the direct hit.
omg u cant be serious! u think it has a chance to weaken big time before it gets to us. (if necessary)
Member Since: Posts: Comments:
Someone asked how to put up shutters on a stucco house. Here's a good link for 'Do-it-yourself' installation:

Do-It-Yourself Shutters
Member Since: Posts: Comments:
Thanks doc. That wave/disturbance is making PR look quite gloomy.
Member Since: Posts: Comments:
Thanks Dr.
I'm curious about the last bit of your blog.
Bold Part From Blog.
NOTICE (03/23/2011)--Data collection at this streamgage may be discontinued after October 1, 2011 due to funding reductions from partner agencies. Although historic data will remain accessible, no new data will be collected unless one or more new funding partners are found. Users who are willing to contribute funding to continue operation of this streamgage should contact Rob Breault or Ward Freeman of the USGS New York Water Science Center at 518-285-5658 or dc_ny@usgs.gov.
.
This seems very petty to me. How much can it cost to have someone go check a gauge? Unless there's some waste involved and someone has a full-time job checking this one gauge, or something of the sort. Otherwise...why not just cut back during slow times to once a week, and go out as needed during other times?
Member Since: Posts: Comments:
Live video of the large (13k acres) wildfire burning NW of Houston near the Magnolia area. This fire has already destroyed a couple hundred homes and over 5000 people have been evacuated.

Link
Member Since: Posts: Comments:
Convection has filled in over the center, at least temporarily.

Member Since: Posts: Comments:
I liked Dr Masters update! VERY INTERESTING. THANKS. MARIA WILL BE INTERESTING TO WATCH TONIGHT!
Member Since: Posts: Comments:
Quoting bigwes6844:
so this thing has a chance that it will go to LA instead of TX? WHY!!


The Texas ridge is displaced to the south over Northern Mexico and should stay there for the next several days. Its placement even keeps South Texas from receiving a direct hit from Nate. The end result will be one of 2 extremes. Either Southern Mexico or the Northern Gulf Coast will take the direct hit.
Member Since: Posts: Comments:
18z GFS has begun initialization Link
Member Since: Posts: Comments:
Quoting Sfloridacat5:
For a couple days,Florida was right in the middle of the cone for Irene.

So I don't put much confidence in any long range cone.
it will take a developer around jamaica to get to fl. this yr acc to climatology
Member Since: September 11, 2010 Posts: 1 Comments: 4780
Quoting GTcooliebai:
GFS Ensembles are split on both storms. Is it safe to assume if Nate goes North, Maria goes North, and if Nate goes west, Maria goes west. The former weaker Bermuda High, the latter stronger Bermuda High.


I dont think so..I think it depends on where the high is set up in the GOM and the Bermuda high set up for the east coast..If Nate goes west, then you look at having a higher chance of Maria hitting the east coast..I read somewhere that the east coast should be lucky that Lee formed and traveled NE, if not, we would have had a Katia landfall on the east coast..If Nate goes NE as Lee did, then I'm thinking you will see an out to sea scenario with Maria..Has anyone wonder if the models do well with several storms in formation at the same time..might be throwing off the models?
Member Since: August 19, 2006 Posts: 13 Comments: 15750
so this thing has a chance that it will go to LA instead of TX? WHY!!
Member Since: Posts: Comments:
wow if you read the nws forecast for maria it sounds like she is going to die but dr.m's says restrengthening now i am really confused not sure what my saturday is going to be like :(
Member Since: Posts: Comments:
43. Asta
Quoting redwagon:

Why would Nate weaken right as he sticks his straw into the warmest most undisturbed waters of the GOM?


Good question.. I don't see that happening, the water in the GOM is a warm storm jacuzzi right now.. and I haven't sen any models that show those blocking highs in Texas moving any time soon.. anyone else have anything different to share??
Member Since: Posts: Comments:
Quoting P451:
Wind reports in knots. Not much coverage down there unfortunately.



*note: Tropical storm positions are not frequently updated. Wind reports ARE frequently updated.



Seems that a NE, then NNE, then N, and maybe now even a bend W of N movement has occurred throughout the afternoon.



Those winds that you are showing haven't been updated all day. They have all shown the same readings ever since you first posted them 3 or 4 hours ago.
Member Since: Posts: Comments:
Quoting KaNaPaPiJoSa:
My 14 year old son was excited to see a Tropical Storm named after him...Nate


My wife is Maria and my son is Nate (13)...

..Katia Ahem... No way she's not mine, but she's coming looking for her Daddy in the UK!!
Member Since: Posts: Comments:
Dr. Masters-

The European hasn't predicted a Northern Gulf Coast landfall since yesterday's 00z run.
Member Since: Posts: Comments:
Nate certainly is an odd one! Thanks for the update Doc.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Is there anything we should be watching behind Maria in the atlantic?
Member Since: Posts: Comments:


Athens Pa

Link
Member Since: Posts: Comments:
Quoting P451:
HPC
Days 3-4-5-6-7



*Note, HPC does not place tropical symbols on their day 6 and day 7 maps. This does not indicate a dissipation of Nate into a low. This is just how they do things.
Is that a backdoor cold front?
Member Since: Posts: Comments:
Quoting P451:
HPC
Days 3-4-5-6-7



*Note, HPC does not place tropical symbols on their day 6 and day 7 maps. This does not indicate a dissipation of Nate into a low. This is just how they do things.

Why would Nate weaken right as he sticks his straw into the warmest most undisturbed waters of the GOM?
Member Since: Posts: Comments:
For a couple days,Florida was right in the middle of the cone for Irene.

So I don't put much confidence in any long range cone.
Member Since: Posts: Comments:
31. Asta
Seems the blocking Highs over texas and the Mid Atlantic will prevent Nate form going to Texas...
So, perhaps Maria will follow the path of Irene and Nate will follow the path of Lee?? anybody else see this as a possiblity?
Member Since: Posts: Comments:
a four day surf event on the east coast they are lucky
Member Since: September 11, 2010 Posts: 1 Comments: 4780
Thank you, Dr. Masters!
Member Since: Posts: Comments:
Quoting ncstorm:


GFS Ensembles are split on both storms. Is it safe to assume if Nate goes North, Maria goes North, and if Nate goes west, Maria goes west. The former weaker Bermuda High, the latter stronger Bermuda High.
Member Since: Posts: Comments:

Viewing: 77 - 27

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.