Tropical Storm Lee moving ashore; Katia continues northwest

By: Dr. Jeff Masters , 3. syyskuuta 2011 klo 13:53 (GMT)

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Tropical Storm Lee is marching steadily northwards towards landfall in Louisiana, and continues to slowly intensify. The storm's central pressure is now down to 993 mb, as measured by an Air Force hurricane hunter aircraft at 7am CDT. However, the center of Lee is now very close to the coast, and the storm doesn't have much time to intensify further before the center moves over land. The main impact from the storm on the coast thus far has been heavy rains. At New Orleans Lakefront Airport, 5.88" inches of rain had fallen from Lee as of 8 am CDT this morning. Top winds were 35 mph, gusting to 55 mph. Though Lee's top winds are rated as being 60 mph, it is difficult to find any land stations that have reported sustained winds of tropical storm force, 39 mph or greater. One station that has is at the tip of the Mississippi River Delta, where Southwest Pass measured sustained winds of 40 mph, gusting to 58 mph, at 7:03 am CDT. Upper-level winds out of the southwest are creating a moderate 10 - 20 knots of wind shear over Lee, keeping the storm's heavy thunderstorms pushed to the east side of the storm. Latest satelllite loops show Lee is becoming increasingly organized.


Figure 1. Radar-estimated rainfall from Lee from the New Orleans radar. Lee has dumped a large region of 4 - 8 inches so far (orange colors.)


Figure 2. Predicted rainfall for the 5-day period ending at 8 am EDT Thursday Sep 8, 2011. Lee is expected to bring a large swath of 4+ inches of rain all the way to New England. Image credit: NOAA/HPC.

Forecast for Lee
Lee's large size, ill-formed circulation center, and the presence of dry air on its west side due to an upper-level trough of low pressure make Lee look a lot like a subtropical storm on satellite imagery, with a broad center and the majority of the heavy thunderstorms in a broad band well removed from the center. Subtropical storms can undergo only relatively modest rates of intensification, and Lee is unlikely to become a hurricane. Also tending to slow intensification will be the fact that much of its circulation is over land. Damages from Lee are likely to be less than $100 - $200 million, with the greatest threats being fresh water flooding from heavy rains. Given that much of the region Lee will traverse over the next few days is under moderate to severe drought, the storm's rains may cause more economic benefit than damage. Since Texas is on the dry side of the storm, that state will see very little rainfall from Lee, except very close to the border with Louisiana. The rains from Lee appear to have mostly ended across extreme southern Louisiana, so the feared 10 - 15 inches of rain does not look like it will materialize there. One possible concern for Lee's rains will be the mid-Atlantic and Northeast, where recovery efforts from the devastating flooding due to Hurricane Irene may be hampered by the additional 2 - 4 inches that may fall from Lee's remnants by the middle of the week.Tornadoes from Lee are potential hazard today, as NOAA's Storm Prediction Center is highlighting the Northern Gulf Coast in their "slight risk" area for severe weather. A tornado watch is posted for the region, but no tornadoes have been reported as of 8 am CDT.

Lee is the 12th named storm this year, and came eight days before the half-way point of the Atlantic hurricane season. Climatologically, September 10 marks the half-way point. A typical hurricane season has just 10 - 11 named storms, so we've already had more than a whole season's worth of storms before reaching the half-way point. At this rate, 2011 will see 24 - 26 named storms, making it the 2nd busiest season on record, behind 2005. Lee's formation date of September 2 puts 2011 in 5th place for earliest date of arrival of the season's 12th storm. Only 2005, 1995, 1936, and 1933 had an earlier 12th storm.

Hurricane Katia
The latest set of model runs show very little change in the outlook for Hurricane Katia. Katia will continue its long trek across the Atlantic Ocean, and will not pose a danger to any land areas over the next five days. Katia is still struggling with dry air and wind shear that has risen to a high 20 - 25 knots. Latest satellite loops show a lopsided hurricane that is suffering from the impacts of dry air and wind shear on its southwest side.

The models now agree that the upper-level trough of low pressure bringing the wind shear to Katia will move away by Sunday, putting Katia in an environment with low to moderate wind shear. At the same time, ocean temperatures will warm to 29°C, a full 0.5°C over what Katia is experiencing today. These effects should allow Katia to intensify to a Category 2 hurricane by Monday. It is still unclear how much of a threat Katia may pose to the U.S., as this depends on the strength and timing of a trough of low pressure predicted to move off the U.S. East Coast 5 - 7 days from now. Our models do not have enough skill to predict how the steering currents will behave that far into the future. As I mentioned in yesterday's post, part of the problem is due to the inability of the computer models to agree on what will happen to Tropical Storm Talas in the Western Pacific. Talas hit Japan early on Saturday as a strong tropical storm, and is racing northwestwards towards Alaska. Talas is expected to transition into a powerful extratropical storm in the waters south of Alaska early next week. This extratropical storm will create a ripple effect downstream in the jet stream, all the way to North America, affecting the trough of low pressure off the U.S. East Coast expected to potentially recurve Katia when it approaches the U.S. The computer models are not very good at handling these sorts of interactions, leading to more than the usual amount of uncertainty in the long-range outlook for Katia. It will probably be another two days before the models will converge on a solution for the long-term fate of Katia. It's a good bet that locations on the U.S. coast south of North Carolina are in the clear, but residents from North Carolina to New England need to watch Katia. Dr. Bob Hart's Historical Tropical Cyclone Probability web page suggests shows that tropical storms in Katia's current position have a 15% chance of hitting North Carolina, a 22% chance of hitting Canada, a 12% chance of hitting New England, and a 58% chance of never hitting land. One almost certain impact of Katia on the U.S. will be large waves. Long period swells from Katia will begin affecting the Bahamas on Sunday night, then reach the Southeast U.S. by Monday morning. By Tuesday morning, the entire U.S. East Coast will see high surf from Katia, and these waves will increase in size and power as the storm grows closer. Given the slow movement of Katia as it approaches the coast, plus its expected Category 1 to 3 strength as it approaches, the storm will probably cause extensive beach erosion and dangerous rip tides for many days.


Figure 3. Satellite image of Tropical Storm Talas taken September 2, 2011, as the storm approached Japan. Image credit: NASA.

Jeff Masters

So far 4 (minou)
We're in a Lee-lull at the moment but winds have been strong and gusty this morning with blowing rain at times. I had to don my gullashes and wander around the overhang!
So far 4

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2121. KEEPEROFTHEGATE (Mod)
4. syyskuuta 2011 klo 03:31 (GMT)

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Member Since: 15.07.2006 Posts: 165 Comments: 52383
2120. KEEPEROFTHEGATE (Mod)
4. syyskuuta 2011 klo 03:30 (GMT)
Member Since: 15.07.2006 Posts: 165 Comments: 52383
2119. keisa90
4. syyskuuta 2011 klo 02:51 (GMT)
Winds have increased quite a bit here in Katy, Texas, just SW of Houston. I don't think Lee is finished yet.
Member Since: 16.08.2007 Posts: 0 Comments: 194
2118. Tazmanian
4. syyskuuta 2011 klo 02:36 (GMT)
Quoting 5Rockets:
About to sign out. You'll see how Katia goes where I said it would and you'll know I was always right.



sorry but your not all ways right
Member Since: 21.05.2006 Posts: 5089 Comments: 114074
2117. Chapelhill
4. syyskuuta 2011 klo 02:32 (GMT)
none of the ole' sayings hold true here any more...a sad day for my grandfather... but of course this has nothing to do with climate change. ;)
Member Since: 31.08.2006 Posts: 0 Comments: 394
2116. TideWaterWeather
4. syyskuuta 2011 klo 02:24 (GMT)
Cyclone OZ.....

http://www.ustream.tv/channel/live-severe-weather -webcam#utm_campaign=synclickback&source=http://ww w.crazymother.tv/&medium=4301091

http://tampaspinsweather.chatango.com/

Member Since: 12.09.2008 Posts: 0 Comments: 176
2115. UKHWatcher
4. syyskuuta 2011 klo 02:15 (GMT)
Quoting Muffelchen:


You should try living in the UK :-) We have such classic sayings as:
'If you don't like the weather, wait a minute' (Scotland) and:
'If you can't see the hills, it's raining. If you can see the hills, it's going to rain' (Yorkshire).

Keep yer heads down that side of the pond and stay safe...

Back to lurking!


In the West of Cumbria, Rain before Seven... Fine before Eleven...
Member Since: 14.09.2010 Posts: 0 Comments: 140
2114. Muffelchen
4. syyskuuta 2011 klo 02:12 (GMT)
Quoting pcola57:


Do you know what is the record low number for them Taz?
I sure don't know.


You should try living in the UK :-) We have such classic sayings as:
'If you don't like the weather, wait a minute' (Scotland) and:
'If you can't see the hills, it's raining. If you can see the hills, it's going to rain' (Yorkshire).

Keep yer heads down that side of the pond and stay safe...

Back to lurking!
Member Since: 21.08.2007 Posts: 0 Comments: 72
2113. Chapelhill
4. syyskuuta 2011 klo 02:11 (GMT)
YAWN on the east coast. Diff an interesting day!
Member Since: 31.08.2006 Posts: 0 Comments: 394
2112. rv1pop
4. syyskuuta 2011 klo 02:06 (GMT)
Quoting P451:


Of course not. It's what makes me (e)special(ly stupid)....
Hey, please, watch what you say about someone I honor and respect. Thank You
Member Since: 18.08.2007 Posts: 0 Comments: 191
2111. franck
4. syyskuuta 2011 klo 02:00 (GMT)
Models diverging. NGFDL and GFDL have Lee headin' to Texas!!
Member Since: 30.08.2005 Posts: 0 Comments: 1150
2110. Thundercloud01221991
4. syyskuuta 2011 klo 01:41 (GMT)
Quoting 5Rockets:
About to sign out. You'll see how Katia goes where I said it would and you'll know I was always right.


im confused... if you make a prediction that doesnt mean that people are going to yell and scream at you about it... they may not even say anything about it
Member Since: 1.08.2006 Posts: 28 Comments: 3716
2109. 5Rockets
4. syyskuuta 2011 klo 01:40 (GMT)
About to sign out. You'll see how Katia goes where I said it would and you'll know I was always right.
Member Since: 30.08.2011 Posts: 0 Comments: 60
2108. 5Rockets
4. syyskuuta 2011 klo 01:38 (GMT)
Permanently signing out. Last chance!
Member Since: 30.08.2011 Posts: 0 Comments: 60
2107. Skyepony (Mod)
4. syyskuuta 2011 klo 01:36 (GMT)
Haven't much speculated aloud about Lee after it looked like most of TX wasn't getting much from him other than a reprieve for some of the heat. He's begun to meander with a slight eastward intent for the last 4 hrs. I'm thinking it's been about as far west as it ever will be... Ironic, it may hit both the family farm in Southern MS & my other farm in WNC, while I watch from FL. Slow moving soaking storm. The remnants may merge with Katia at some point like over the NE. Could be really bad for the NE, but that's 6 days out..so little early to say.
Member Since: 10.08.2005 Posts: 156 Comments: 36173
2106. 5Rockets
4. syyskuuta 2011 klo 01:35 (GMT)
So if you don't believe me, then say it. And say whatever you've been struggling to scream at me about.
Member Since: 30.08.2011 Posts: 0 Comments: 60
2105. 5Rockets
4. syyskuuta 2011 klo 01:29 (GMT)
Quoting luvhurricanes:
Katia is out there and who knows she could hit Florida just as easy as New England. U just dont know about these storms.


I'm sorry, then you're telling so many other sources that they don't know either. Because that's where my estimations come from.
Member Since: 30.08.2011 Posts: 0 Comments: 60
2104. 5Rockets
4. syyskuuta 2011 klo 01:28 (GMT)
Well, who has the bravery to shoot out trash at me?
Member Since: 30.08.2011 Posts: 0 Comments: 60
2103. luvhurricanes
4. syyskuuta 2011 klo 01:26 (GMT)
Katia is out there and who knows she could hit Florida just as easy as New England. U just dont know about these storms.
Member Since: 23.08.2011 Posts: 0 Comments: 6
2102. 5Rockets
4. syyskuuta 2011 klo 01:25 (GMT)
If anyone objects to what I'm saying, fire away at me.
Member Since: 30.08.2011 Posts: 0 Comments: 60
2101. franck
4. syyskuuta 2011 klo 01:25 (GMT)
Quoting HoustonTxGal:



Heck, many of us down in here in Texas have our CHL..Perry is just more in the spotlight about it. Heck, I have a CHL :o)


Oh, you're not telling me..I'm from Alabama. Sold my guns years ago. You know the saying, live by the sword....
Member Since: 30.08.2005 Posts: 0 Comments: 1150
2100. Tazmanian
4. syyskuuta 2011 klo 01:23 (GMT)
little too no dust in the way




wind shear seems low for PG23L and PG24L

Member Since: 21.05.2006 Posts: 5089 Comments: 114074
2098. 5Rockets
4. syyskuuta 2011 klo 01:23 (GMT)
Quoting twincomanche:
5Rockets=Troll??


Nope. Not a troll.
Member Since: 30.08.2011 Posts: 0 Comments: 60
2097. JLPR2
4. syyskuuta 2011 klo 01:22 (GMT)
Seems like the only way for Katia to bring at least a band of rain to my area is to move due west for at least a day and that is highly unlikely.

I bed adieu to Katia and wish the Bahamas, Bermuda, East Coast and Canada good luck.

Member Since: 4.09.2007 Posts: 7 Comments: 8459
2096. mamabeth
4. syyskuuta 2011 klo 01:22 (GMT)
Quoting PcolaDan:

Must be just your area. See my post 2024 for numbers.



May very well be. Just looked like it on radar. Know its gonna change.
Member Since: 11.09.2008 Posts: 0 Comments: 9
2095. EastTexasWxGal
4. syyskuuta 2011 klo 01:22 (GMT)
In East Texas, it has been RAINING steadily for about 4 hours now. Very gentle, soaking rain. This is the most rain we have had in months! Who else in Texas is getting this? This beautiful rain is due to Lee. It looks like it will last another 4 hours or more, but the official forecast says only 30% rain.
Member Since: 28.07.2011 Posts: 0 Comments: 3
2094. 5Rockets
4. syyskuuta 2011 klo 01:22 (GMT)
Quoting 5Rockets:


Yes. And a good one, too. I mean, not everyone's predictions are perfecto. I'm saying mine's pretty good estimation.


Does anybody object to that?
Member Since: 30.08.2011 Posts: 0 Comments: 60
2093. A4Guy
4. syyskuuta 2011 klo 01:22 (GMT)
NEW BLOG from ANGELA
Member Since: 23.06.2006 Posts: 0 Comments: 655
2092. 5Rockets
4. syyskuuta 2011 klo 01:21 (GMT)
Quoting will40:



lmao so it is a prediction from you


Yes. And a good one, too. I mean, not everyone's predictions are perfecto. I'm saying mine's pretty good estimation.
Member Since: 30.08.2011 Posts: 0 Comments: 60
2090. PcolaDan
4. syyskuuta 2011 klo 01:20 (GMT)
Quoting mamabeth:
Looks like Mississippi threw up a shield. All the bands parting and going around it.

Must be just your area. See my post 2024 for numbers.
Member Since: 22.08.2008 Posts: 12 Comments: 6010
2089. blsealevel
4. syyskuuta 2011 klo 01:20 (GMT)
These models all showing lee heading NE and being absorbed by the Atlantic storm
But all models also are showing something else starting in the S GOMEX in 3 or 4 days days

Member Since: 23.08.2008 Posts: 0 Comments: 1918
2088. splash3392
4. syyskuuta 2011 klo 01:20 (GMT)
Hi Dewey and 5rockets had this same conversation this morning. Nothing significant has changed. Dewey is/was correct!
Member Since: 24.01.2007 Posts: 1 Comments: 641
2087. NEFLWATCHING
4. syyskuuta 2011 klo 01:20 (GMT)
"mamabeth: Looks like Mississippi threw up a shield. All the bands parting and going around it."

Well, that pinpoints Cantore.
Member Since: 16.09.2008 Posts: 0 Comments: 192
2086. xtremeweathertracker
4. syyskuuta 2011 klo 01:19 (GMT)
New Blog!!
Member Since: 31.05.2011 Posts: 57 Comments: 566
2085. ConnecticutWXGuy
4. syyskuuta 2011 klo 01:19 (GMT)
Quoting HuracanTaino:

also moving west, west north west, all day, why they say NW?


because it's actually been moving Northwest. It's just hard to tell on satellite... there's been a lot of wobbles, but when all averaged out the motion is 305 degrees/NW.
Member Since: 17.11.2010 Posts: 11 Comments: 527
2083. brazocane
4. syyskuuta 2011 klo 01:18 (GMT)
Couple more Lee Sunset pics:



Member Since: 23.08.2006 Posts: 0 Comments: 678
2081. will40
4. syyskuuta 2011 klo 01:18 (GMT)
Quoting 5Rockets:


Well, I look at their charts, then I predict where.
But I checked yesterday, and there was a chart I just happened to find on NHC.



lmao so it is a prediction from you
Member Since: 19.09.2005 Posts: 2 Comments: 4066
2080. nofailsafe
4. syyskuuta 2011 klo 01:17 (GMT)
Went to the store, saw people buying water. I did too, and a case of guinness. For, you know, happy fun rainy time.
Member Since: 18.06.2010 Posts: 3 Comments: 928
2079. HuracanTaino
4. syyskuuta 2011 klo 01:17 (GMT)
Quoting hurricanehunter27:
Eye should pop up tonight or morning but def cat 1.

also moving west, west north west, all day, why they say NW?
Member Since: 31.05.2011 Posts: 0 Comments: 769
2077. mamabeth
4. syyskuuta 2011 klo 01:17 (GMT)
Looks like Mississippi threw up a shield. All the bands parting and going around it.
Member Since: 11.09.2008 Posts: 0 Comments: 9
2076. HoustonTxGal
4. syyskuuta 2011 klo 01:17 (GMT)
Quoting beell:


30% is twice as big, isn't it?

To prove that his land is bigger than a Tennessee farm, the Texas rancher bragged, "My ranch is so big that I can get in my pickup and drive all day and all night, and still not leave it!" The Tennessee farmer responded, "I know what you mean. I have an old broke-down truck, too."


The drive from the east side of Texas to the west side of Texas is about the same distance as driving from Dallas to Chicago.
Member Since: 18.09.2007 Posts: 0 Comments: 1073
2072. Tazmanian
4. syyskuuta 2011 klo 01:15 (GMT)
Quoting stormpetrol:


Taz, be careful how you say that , you might get labelled a westcaster J/K , how r ya Taz?




doing well
Member Since: 21.05.2006 Posts: 5089 Comments: 114074

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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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