Nate almost a hurricane; Maria remains disorganized

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

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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

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Any chance the same thing happens with these two that happened with Lee and Katia? Gulf storm makes it north which then kicks the Atlantic storm out to sea?
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1776. Gearsts
Maria very lackluster with the winds, looks like a TD.
Member Since: August 2, 2010 Posts: 0 Comments: 1808
1774. Patrap
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1772. Patrap
Maria




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1771. Caner
... and reciprocated...

3 posts today, 3 political attacks, i count you no great loss.
Member Since: June 27, 2011 Posts: 0 Comments: 179
Is this accurate-local mets/Crown Weather and Henry Margusity all are saying Maria=OTS. Do you agree?
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Quoting RitaEvac:


Should be some good surf up and down the East coast!
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1768. Patrap
Early morn Viz, Nate



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Maria sure has blown up widespread convection this morning, that's a lot of heat being released
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LOL compare NATE with MARIA. Girls definitely run the world
Member Since: October 6, 2007 Posts: 0 Comments: 6254
1765. Caner
I cannot get over how tiny Nate is...

just put a ruler on my screen and juxtaposed him off the coast of LA, and the tiny size is striking.
Member Since: June 27, 2011 Posts: 0 Comments: 179
Quoting Caner:


Disregarded everything after. If you feel the need to preface the comment with political diatribe, it gets flushed, sorry.

and you've been flushed from my screen cause if you didn't know, politicians make the calls on how much $$$$ NOAA/NWS get and not you. Oh and If you want to look back, Dr. Masters did comment on this exact thing in a previous blog.
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1763. ncstorm
Quoting BioWeather:


Thank you! Ewww that's ugly.


if this was just the NOGAPS depicting this path, I would discount it but the Euro is showing it curving back hitting NC as well..not very strong though on the Euro as far as intensity
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We fought hard but, Green Bay was the better team!
There are still 15 games left...
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Quoting ncstorm:


Here you go..

Link



Thank you! Ewww that's ugly.
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Quoting Cotillion:
Hurricane specialist John Cangialosi said Katia would change from a tropical system to a larger storm once it was over open sea and would head for ScotlandA warning from the NHC, an article on the BBC about Pat Tillman who tragically died in the line of duty and a lot of coverage on the upcoming 9\11 anniversary.

A very American touch here as of late.


Thank you Cotillion, you reminded me of how interconnected we all are and how fragile it can be to ride on the surface of this pale blue dot.
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1758. Caner
Quoting Chucktown:
This is from this mornings NWS disco here in Charleston.

THEN...MEDIUM RANGE GUIDANCE HAS
TRENDED TOWARD A STRONG COLD FRONT PROGRESSING THROUGH THE REGION
LATE NEXT WEEK. TIMING OF FROPA REMAINS UNCERTAIN...BUT LOW CHANCE
POPS ARE JUSTIFIED THURSDAY AND FRIDAY. THIS FRONT WILL ASSIST IN
STEERING MARIA OFF THE EAST AND SE COAST OF THE COUNTRY DURING THE
MIDDLE AND LATTER PARTS OF THE WEEK.

TEMPERATURES SHOULD AVERAGE SLIGHTLY ABOVE NORMAL UNTIL COLD FROPA
LATE WEEK.



I'm more curious as to whether the trough's passage will exert a pull on Nate, wobbling down there in the Gulf.
He's just waiting for a nudge in any direction.
Member Since: June 27, 2011 Posts: 0 Comments: 179
1757. ncstorm
Quoting 7544:


thanks is that a new and the latest run ?


yep 06Z..
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Quoting PensacolaDoug:
Nate still appears tightly wound


Unlike some of the bloggers here.


LOL, good one!
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1755. 7544
Quoting ncstorm:


Here you go..

Link



thanks is that a new and the latest run ?
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1754. Patrap
Quoting Dakster:
Hey, how about those Saints last night? Patrap must be proud!


Was a grest game.. even ran outta Frescsa and SC.
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This is from this mornings NWS disco here in Charleston.

THEN...MEDIUM RANGE GUIDANCE HAS
TRENDED TOWARD A STRONG COLD FRONT PROGRESSING THROUGH THE REGION
LATE NEXT WEEK. TIMING OF FROPA REMAINS UNCERTAIN...BUT LOW CHANCE
POPS ARE JUSTIFIED THURSDAY AND FRIDAY. THIS FRONT WILL ASSIST IN
STEERING MARIA OFF THE EAST AND SE COAST OF THE COUNTRY DURING THE
MIDDLE AND LATTER PARTS OF THE WEEK.

TEMPERATURES SHOULD AVERAGE SLIGHTLY ABOVE NORMAL UNTIL COLD FROPA
LATE WEEK.

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1751. ncstorm
Quoting BioWeather:


Oh! I was going by the spaghetti plots. They look very different. I take it they may be changing? How can I see the NOGAPS? The link on my WU page brings up a blank screen.


Here you go..

Link

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1749. 7544
morning all looks like maria is still moving west ?
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1748. Caner
LCP on GEOS-13 now illuminated by daylight.

Strong convection building in Nate's NE quadrant, that is a first for him...



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Quoting Caner:


Just glad to hear you get your news from 'faux' news, and are an avid reader...

incidentally, your political opinions are not welcome

So your saying we don't need NOAA/NWS??????
Or you just saw it was from Faux News and you just started typing and not read my opinion???
I called it Faux and not Fox cause I no they are full of garbage.
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SLU,
I saw that this morning but was a bit apprehensive of saying so. there seems there are two parts to maria, (PUN NOT INTENDED) one centre is moving westnorth west and the other tracking west. maria needs to consolidate
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1745. Vero1
I don't like the stationary High sitting off the Carolina/Georgia.



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The difference with MARIA between yesterday and today is just AWESOME
Member Since: October 6, 2007 Posts: 0 Comments: 6254
kman,

any more waves you see developing soon making their way even further westward?
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Nate hanging in there at 55 knots:

AL, 15, 2011090912, , BEST, 0, 202N, 925W, 55, 998, TS, 50, NEQ, 40, 50, 0, 0, 1010, 150, 40, 0, 0, L, 0, , 0, 0, NATE, M,
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Nate still appears tightly wound


Unlike some of the bloggers here.
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Can't stay on this morning. Back later.
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1739. Caner
Quoting AussieStorm:
WU is mentioned in this article from Faux News Opinions.

Any opinions?
Mine is that we need the NOAA/NWS. Big Business would be in it for commercial reasons and not life saving ones. Plus business only looks at the bottom line $$$$.


Just glad to hear you get your news from 'faux' news, and are an avid reader...

incidentally, your political opinions are not welcome
Member Since: June 27, 2011 Posts: 0 Comments: 179
Quoting wayfaringstranger:


I don't think any weather models can see this kind of change coming right?


They typically do not but the human observer can see the conditions setting up that tend to encourage a center shift. This system had all the classic signs from early this morning including a weak center on the SW edge of what convection there was then a big blow up to the N and NE of that center. Once that happened it was only a matter of time before the center jumped to the convection.
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Good morning, TGIF!

So I have a question. Why does the NHC think Maria is going to turn North when the weakness wasn't strong enough to pull Nate to the North? Maria is condiderably more South than Nate so i would think she would feel the affects of the weakness even less. Then they say because the High is going to build back in Nate is going West to Mexico but Maria turns sharply North around the same time. I would think the High building back in would push her to the West. I guess this is why weather watching is just a hobby for me!
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Quoting wayfaringstranger:


From FL, yes at the moment. From NC/SC? No. I still stand by my original opinion that Maria decides to make a NC visit and not a nice visit either. So send a letter to Maria?

Nate, I still feel is up in the air. I think that if anything the storm is still pretty stationary and IMO I still feel a TX/MX border impact is likely. At 8 am, the results from yesterday late evening flights in the GOM were suppose to be reported and factored into the track forecast. I don't think it has been yet.


Models really shifted east last night. What makes you think NC is still in the picture.
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1735. Dakster
Hey, how about those Saints last night? Patrap must be proud!
Member Since: March 10, 2006 Posts: 0 Comments: 10537
Quoting wayfaringstranger:


From FL, yes at the moment. From NC/SC? No. I still stand by my original opinion that Maria decides to make a NC visit and not a nice visit either. So send a letter to Maria?

Nate, I still feel is up in the air. I think that if anything the storm is still pretty stationary and IMO I still feel a TX/MX border impact is likely. At 8 am, the results from yesterday late evening flights in the GOM were suppose to be reported and factored into the track forecast. I don't think it has been yet.


Maria - a West Side Story - west Atlantic anyway ;-)
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Quoting kmanislander:
Good morning

Maria appears to be yet another sheared system that we have seen relocate the center near or over the Islands. Once the big convective blow up occurred it was only a matter of time before the area of lowest pressure would shift underneath the cloud deck to the NE of the surface low.

This has resulted in a significant track shift to the right which will keep the system offshore the majority of the Leewards and clear the island chain much faster than previously estimated.


I don't think any weather models can see this kind of change coming right?
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Quoting ncstorm:


Actually the Euro, NOGAPS and CMC have a more western shift with the NOGAPS riding up the east coast..The GFS and UK are still on the eastern route ..


Oh! I was going by the spaghetti plots. They look very different. I take it they may be changing? How can I see the NOGAPS? The link on my WU page brings up a blank screen.
Member Since: Posts: Comments:
WU is mentioned in this article from Faux News Opinions.

Any opinions?
Mine is that we need the NOAA/NWS. Big Business would be in it for commercial reasons and not life saving ones. Plus business only looks at the bottom line $$$$.
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1730. Gearsts
Time: 12:28:30Z
Coordinates: 13.8167N 55.1333W
Acft. Static Air Press: 841.7 mb (~ 24.86 inHg)
Acft. Geopotential Hgt: 1,583 meters (~ 5,194 feet)
Extrap. Sfc. Press: 1011.0 mb (~ 29.85 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 81° at 41 knots (From the E at ~ 47.1 mph)
Air Temp: 15.6°C (~ 60.1°F)
Dew Pt: 11.1°C (~ 52.0°F)
Peak (10s) Flt. Lvl. Wind: 42 knots (~ 48.3 mph)
SFMR Peak (10s) Sfc. Wind: 44 knots (~ 50.6 mph)
SFMR Rain Rate: 12 mm/hr (~ 0.47 in/hr)
(*) Denotes suspect data
Member Since: August 2, 2010 Posts: 0 Comments: 1808
Good morning

Maria appears to be yet another sheared system that we have seen relocate the center near or over the Islands. Once the big convective blow up occurred it was only a matter of time before the area of lowest pressure would shift underneath the cloud deck to the NE of the surface low.

This has resulted in a significant track shift to the right which will keep the system offshore the majority of the Leewards and clear the island chain much faster than previously estimated.
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Hmm...I see Maria is finally beginning to slow down.
When did she start to slow down?
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Quoting BioWeather:
Good morning all! I see the models have shifted a little for Maria this morning AND she woke up a little angrier than yesterday. How is everyone feeling about the new model runs with her shifting further away from the US? Do you agree?


From FL, yes at the moment. From NC/SC? No. I still stand by my original opinion that Maria decides to make a NC visit and not a nice visit either. So send a letter to Maria?

Nate, I still feel is up in the air. I think that if anything the storm is still pretty stationary and IMO I still feel a TX/MX border impact is likely. At 8 am, the results from yesterday late evening flights in the GOM were suppose to be reported and factored into the track forecast. I don't think it has been yet.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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