Nate almost a hurricane; Maria remains disorganized
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
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And this just adds to my confusion.
As far as I know, it's air coming off of the mountain range down south across the border. It's up pretty high and it's also pretty warm, so it rides along up in the troposphere minding its own business. Meanwhile the great vast hot plate of Texas warms air at the surface that tries to rise. But it can't, because there's this big stable mass on top. This is why Steve McCauley up at WFAA is always talking about 'The Cap.' It prevents convection from working up to a high enough altitude where it's cool enough for water to condense into rain drops.
The air that rises has to go some place, so thanks to the coriolis effect it spirals down out towards the edge in a clockwise fashion.
In other words, if you took a few thousand feet off of those mountains, the ridge might not show up as often.
Please correct me if I'm wrong.
Is Nate's track still in play? Not hard left Mexico?
Quebeccer's put mayo on fries too, like all the abominable French. Vive le ketchup libre!
The ground is still perfect to gather & radiate heat. It's still dry & lacking in vegetation. The excessive heat begs to feed a high.
You can also see the ridge broke after an atmospheric lag from when ENSO went neutral breifly this summer. It went La Nina again. La Nina = no rain for TX.
ESPI was right on about this recent plunge. ESPI since went back neg. Don't expect this to be a real strong La Nina, nothing less than -1 for any length of time. Maybe in the spring it will go neutral again.
No, but I must admit you weren't far from my mind at the time. I would have used an example, but being the gentleman that I am, I refrained.
35mph ENE winds in one and 30mph ESE in the other.
ADT seems right.
Apparently not, although the bulk of the models still veer hard west. Its in light steering and models therefore are more prone to track error.
What we wouldn't do for a good ol' fashioned el nino around these parts.
I think you need a compass..;) It looks like its tracking due west to me.
That's un-American!
Skye, have you been following the flooding in the Northeast? It is really being under-reported. It is enfolding to be one of the most catastropic flooding they have ever had. If you could find info on it, it could be of interest. The situation is getting worse by the hour. They expect thousand of homes and businesses to be destroyed.
The "Small Details" Gro, no pun intended :-b
Irene wanted to go N.
Maria wants to go W.
May have a bit of a growth next image...
You must be having a relapse
You're hallucinating!
yeah see that is strange, we have had countless rain events bigger than 1.3, in fact I had 1.62 on Monday, and 2.89 on Tuesday, as a more recent example. St. Petersburg had nearly 6 in on Tuesday.
Well, I'm not sure how rainfall was last year in your area, but rainfall last year around here and the situation reminds me of how it was last year here. Always high moisture and instability but the rain always fell short of forecast or what it should have been. It seemed almost unreal how little rain there could be sometimes, for example, we would have PWAT at like 2.3 with cool mid level temps, but convection still wouldn't build to more than some scattered activity.
This year, we pretty much always get more rain than forecast. We had days days where widespread 2 to 4 has fallen with isolated higher totals but they had only a 60% or 70% chance in the forecast. Forecasters never forecast above 70% here for some reason.
I makes me wonder i MET's here use there forecast numbers as based on "% chance of heavy rain of 1 inch or more" rather than chance of precip. Because % chance of precip means probability of getting 0.01 inches or greater. But many days they know almost everyone well get at least 1 to 2 inches more, lol
and at the Pub at international plaza as well. its still gross lol
Just shows how poorly organized the system is and would suggest more that this no longer has a defined closed surface circulation and may be a vigorous tropical wave.
I stand corrected. For some reason my browser showed me the cached version of yesterday's 00Z run. Sorry about that.
Leave it to you to catch that! Wondered where you have been. Glad to see you are back.
I wish we had HHs in there or a buoy further south, it seems like a TW, but we don't have any definitive data to support that theory. :\
We gotta another system forming behind MARIA!
Night! may you sleep with Maria and TWs.
What a nightmare! XD
Agree which would favor a more Westerly movement than NHC is showing IMO!
Was gonna say that, but had to step away from my desk. ("We have to go outside. Now.")
Not a fan of ketchup on fries. Tartar sauce is OK, though!
'Night, all. Turn the lights off when you leave.
I bet I know where it will go.
Link
This info is totally amazing! And I actually understand a lot of it. Also the graphs below were great.
All I know is it almost always rains during the livestock shows at the fair. Do you think its all the cows burping & passing gas, like apperntly the goverment does:)
I do the fairboard & 4-H thing, 26yrs now. Check in is Fri & Have to judge classes on Sat. So it WILL rain in our part of Missouri this weekend! We need it too, so I am willing to judge wet goats (phew) etc.
Saw at least 2 died. Part of DC is flooded, along with a large swath of NE. Some people still don't have power after Irene..one of the bigger power companies.
Is it 1993 Mississippi river flood bad?
I'm in agreement on a more westward track than currently indicated. No way in hell does the system gain 5 degrees of latitude before reaching 65 degrees west given the incredibly fast steering flow the system is currently caught in and will continue in during the next 24 hours or so. In fact, it seems the main core of Maria is now further out west around 56 to 58 west tonight.
Good to see you too Gro. Life is calling big time. Just started a cabinetry design business a couple weeks ago, needed a new car "I HATE car shopping". Toughiness rules for now, ciao.
Link (hit Trop Points to see it seems to be all southerly winds over the forecast points!
Based on what I saw on TWC (Yeah yeah, I know, but I don't have the time to spend 200 hours looking at models, steering charts, etc) it seems like itll either drift west (if its weaker), or get caught up by one of the troughs and move NNE (if its stronger). But then if it feels the trough, itll get shear and weaken then lose it's steering again! This storm could be a potential forecasting nightmare, but it seems due to the TX ridge, it will not threaten TX. Either northeastern gulf coast, or southern gulf coast of mexico. Any thoughts on this??
edit: Going to vote no due to tangling with troughs and dry air, and cold water upwelling due to sitting in place
So I look at the Eastern US Infrared loop to see what it is...
Link
Am I actually being sprinkled on by some part of Lee? There's certainly a low there.
Weird. Too bad we didn't get any real rain. We're in a drought here too. Just not the epic proportions of Texas' drought.
Buoys reports dont support that. Still ENE winds in one and in the other ESE, the center is south and in between them.
It is very bad, some of the towns may be under 20 feet of water. There are thousands of people stranded on the highways. No way to get to them. Most of the midwest is flat. The area up there is very mountainous. The valley areas are being hit very hard. They have evacuated a couple of hundred thousand people already and they expect more rain this week. It will be catastrophic in many places. The topography is very different there. They were mostly unprepared for it.
2:00 AM AST Fri Sep 9
Location: 13.4°N 55.5°W
Max sustained: 40 mph
Moving: W at 21 mph
Min pressure: 1005 mb
Just looked at nearly every loop format.......i'm not sure where the COC is at now...my guess would be further west than the main blog which has been the position all day!
Where you are you should be an expert:) I went to college up there from Kansas. Year of the dam break & big flood.
I was amazed. They served pototes 3 or 4 differnt ways at every meal. Moms from there so I knew about the potatoes, but It was differnt. We used bread or biscuts & gravy. They used potatoes. (Now my favorite)
Got to go up & see the potato sheds, thats not the right word. They were amazing! Went on snow mobils way up in the mountians & Was amazed when I wrecked it & tried to stand up in the snow & sank to my waist! Tried to Ski but kept going down the mountian backwards. Came home & designed some "Ski Kansas" T Shirts with Yucca, Cactus & All.
See, I said "snow" twice this is weather related:) OK, not the right weather Sorry
Good Luck with your new business. Times are tough.
GFDL and HWRF shift right
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