97L a major rainfall threat; October hurricane outlook; NC rains finally end

By: Dr. Jeff Masters , 2:08 PM GMT on October 01, 2010

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A large and complex region of disturbed weather (Invest 97L), centered about 800 miles east of the Lesser Antilles Islands, is headed west-northwest at 15 - 20 mph and will bring heavy rain showers and gusty winds to the northern Lesser Antilles Islands on Saturday and Sunday. Wind shear is a moderate 5 - 15 knots over 97L, and the waters beneath are very warm, 29°C. However, recent satellite imagery shows that the intensity and areal coverage of 97L's heavy thunderstorms have decreased this morning, thanks to some dry air being ingested into the storm. The SHIPS model predicts that wind shear over 97L will rise to the high range, 20 - 30 knots, Saturday through Tuesday, but some of the global computer models depict only moderate amounts of shear for 97L during this period. The NOGAPS model is the only model currently showing significant development 97L, and that model predicts 97L will be near Puerto Rico on Monday, the Dominican Republic on Tuesday, Haiti on Wednesday, and Eastern Cuba and the southeast Bahamas on Thursday. NHC is giving 97L a 40% chance of developing into a tropical depression by Sunday, but as of this morning, had not tasked the Hurricane Hunters to fly into the storm over the next two days. 97L will slow down to 5 - 10 mph on Sunday, bringing the potential for an extended 3 - 4 day period of heavy rains for the islands in its path. Even if 97L does not develop into a tropical depression, its slow motion may result in life-threatening flash flooding and mudslides in Puerto Rico, the Dominican Republic, Haiti, and eastern Cuba next week.


Figure 1. Morning satellite image of Invest 97L.

October hurricane outlook
October is here, and it is time to take stock of where we stand and how far we have to go before hurricane season is over. The beginning of October traditionally marks the two-thirds point of hurricane season; approximately one-third of all hurricanes and 28% of named storms occur after October 1. Tropical Storm Nicole brought us up to fourteen named storms for the year, and I expect about 4 - 5 more named storms this year with 2 - 3 of these being hurricanes. That would add up to 18 - 19 named storms for the season, putting 2010 in 3rd - 5th place all-time for most named storms. Since record keeping began in 1851, only four seasons have finished with more than eighteen named storms. These seasons were 2005 (28 named storms, with the 17th named storm, Rita, occurring by October 1); 1933 (21 named storms, with the 18th named storm occurring by October 1;) 1995 (19 named storms, with the 15th named storm, Opal, occurring by October 1;) and 1887 (19 named storms, with the 10th named storm occurring by October 1.) The most likely time to get activity is during the first two weeks of October. There are still two weeks of peak hurricane season left before the activity traditionally begins to decline steeply (Figure 2.) Given the record warm sea surface temperatures in the Atlantic this fall, the presence of La Niña in the Eastern Pacific keeping wind shear lower than average, and the observed increase in late-season activity in recent decades, I expect this year's peak portion of hurricane season will last until the end of October. I predict three named storms, two hurricanes, and one intense hurricane will form in the Atlantic this month, with two named storms and one hurricane occurring in November - December, making 2010 as the third busiest Atlantic hurricane season of all-time.


Figure 2. Climatological frequency of Atlantic named storms and hurricanes.

Jamaica cleans up after Nicole
Tropical Storm Nicole lasted only six hours as a tropical storm, but the storm's torrential rains hit Jamaica hard. Nicole's rains killed at least six people on the island, and at least thirteens others are missing and feared dead. The storm cut power to 170,000 island residents, and caused millions of dollars in damages. Wunderground member JamaicaZed wrote me to say his rain gauge in the Kingston suburb of Norbrook caught 17.39" of rain Monday through Thursday, with 11.10" coming on Wednesday.

Historic rainfall event for eastern North Carolina ends
The rains have finally ended In North Carolina, where tropical moisture streaming northward in advance of Nicole generated a historic rainfall event this week. Wilmington, NC set records this week for the heaviest 3-day, 4-day, and 5-day rainfall events in city history, and the month of September ended up as the second rainiest month ever recorded in the city. A remarkable 22.54" of rain fell on Wilmington during the 5-day period Sunday through Thursday. The previous record was 19.06", set in September 1999 during Hurricane Floyd. Fortunately, eastern North Carolina was under moderate drought conditions prior to this week's rainfall onslaught, with just 0.18" of rain falling during the first 25 days of September. Only minor to moderate flooding is occurring on North Carolina rivers, with just one river, the Northeast Cape Fear River near Chinquapin, expected to experience major flooding. Portlight.org is beginning to identify needs in Eastern North Carolina in the wake of the flooding, and expects to perform the first deployment of their new relief trailer within the next few days and send a truck loaded with water, food and personal hygiene supplies.

The most remarkable thing about Wilmington's second-wettest month in history is that it came without a hurricane affecting North Carolina. All four of the other top-five wettest Septembers in history were due, in large part, to hurricanes:

#1 23.41 inches 1999 (Hurricanes Dennis and Floyd)
#2 22.72 inches 2010 (plume of tropical moisture in advance of TS Nicole)
#3 20.10 inches 1877 (Hurricane Four)
#4 18.94 inches 1984 (Hurricane Diana)
#5 16.93 inches 1924 (Hurricane Five and Tropical Storm Eight)


Figure 3. Radar-estimated precipitation for North Carolina since Sunday shows that the precursor moisture from Nicole has brought widespread rain amounts of fifteen inches (white colors.)

Heavy rains and flooding for New England
The plume of tropical moisture that affected North Carolina is now triggering heavy rains in New England, and flood warnings are posted throughout most of New Jersey, eastern Pennsylvania, eastern New York, Delaware, and Vermont this morning. In New York City, heavy rains this morning have overwhelmed one section of the city's subway system, and flooding closed several key road arteries in the city, snarling the morning commute. About two inches of rain have fallen so far this morning in the city. Severe weather is not expected, and no tornadoes were reported yesterday in association with this weather system.

Elsewhere in the tropics
Disturbed weather continues in the Central Caribbean, where the remnants of Tropical Storm Nicole will bring isolated heavy rain showers today to Hispaniola, Jamaica, Cuba, the Cayman Islands, and northern Honduras. The GFS model predicts this activity will concentrate near Hispaniola over the weekend, then push northwards into the Bahamas, with a subtropical or extratropical storm forming over the Bahamas on Sunday or Monday. This storm could bring 2 - 4 inches of rain to the Bahamas Sunday and Monday. The storm will then move north-northeastwards, parallel to the U.S. East Coast, and not affect any other land areas. Several of the models are predicting the formation of a tropical depression in the Mid-Atlantic 5 - 7 days from now, in a location that would not be of any danger to land areas.

Next update
I'll have an update Saturday morning.

Jeff Masters

Flooding (jdwagon)
Shannon Hills, Ridgeway, VA
Flooding
()

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768. KBH
Does any one have any data on flood damage cause by weather systems (not hurricanes/ storms)in the C'bean region?
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pretty sure nikki's old llc is spinning off jax,it dove ssw yesterday from offshore nc!!!!,check it out rather obvious on radar loops...
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The NationalSnow&IceDataCenter called the melt season 9days too early.
JAXA sea ice area (daily chart)

DMI sea ice extent (daily chart)
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - NSIDC sea ice extent (monthly chart)
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JAXA sea ice extent chart

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - NSIDC daily sea ice extent chart
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(Sorry about distortion on the NSIDC charts, hadda squeeze 'em to make the charts easily comparable)

2010 came so close to becoming 2nd lowest with its minimum sea-ice extent that 2008 and 2010 will be inextricably intertwined : ie they'll move as a pair in the record books.
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Quoting cat5hurricane:

Ya know, I miss the really cold weather too, & enjoy the occasional white Christmas (as long as it doesn't screw up traffic really bad!!).

But usually after January, I'd had enough already. It's nice this time of year, but come March I'm just so ready to come out of the cocoon!
well yea i guess your right but i just love the trees changing colors and picking a pumpkin from a real pumkin patch and hay rides... I love florida dont get me wrong it is 83 today and gorgeous kids at the beach as they live on the sand i think..lol but i miss snow and christmas is just not the same u have to inundate your house with lights just for it to feel like it is that time of the year!!
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(Moved to new blog)
Member Since: November 8, 2009 Posts: 4 Comments: 13529
Quoting cat5hurricane:
And frost advisories up over much of the upper Midwest tonight: MO, NE, IA, MN, KS, WI, & IL
i miss the cold weather .....living in florida i sooo mich the fall season and christmas with snow i envy you!!!
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If they didn't kill that most be one hell of a tranquillizer.
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Quoting PanhandleChuck:
On a more serious note, This beast was caught just about 5 miles to south of my house. A mere 19 inches off of the state record.

Beautiful animal,he shold be kept in its habitat, hope they didn't kill him!
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Quoting PanhandleChuck:
On a more serious note, This beast was caught just about 5 miles to south of my house. A mere 19 inches off of the state record.



man thats a big gator. and speaking of gators, Go Gators!
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752. srada
Quoting PanhandleChuck:


He's sleeping permanently! The kid who bagged him was 19 yrs old. It was 12' 9". He and his two friends were in a 13' boat in the Yellow River Wednesday morning at 03:30 when they came across him. From the articles in the paper, it was quite a fight.


So did they say what they were going to do with him?
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751. Relix
Some banding is noted on 97L. Finally. =O
Member Since: August 3, 2006 Posts: 0 Comments: 2722
Quoting hurricane23:


Starting to fell pretty confident we will make it a second season in a row without a US landfalling hurricane and the fifth in a row (first time since 1909-1915) without a major hurricane landfall.


Time to break out the X-Mas music? :)
Member Since: September 10, 2007 Posts: 0 Comments: 11151
Quoting cat5hurricane:

Sure...this season may have been unusually active for August & Sept. However, just because a season may start out active or have an active period in there does not necessarily mean that the ENTIRE season (June 1st - Nov 30th) will mirror that. Take 2004 for example. 2004 had 7 named storms in Aug, 4 in Sept, but only 2 in October & only 1 in November.

One can argue that August & Sept in 2004 were very active, but then not so much in October & November.


El Nino!

La Nina years cause more mischief in the later part of the season. 2004 was an El Nino year
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yup the gulf season is done now nicole couldnt even make it in the gulf and poofed quick. 97l poof too in atlantic. Its getting harder now for systems to develop!:)
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Quoting reedzone:
You all seem to forget that we still have 2 months of the season left. Look at Wilma, Mitch, and Opal. They formed late and hit the USA, though Mitch was a Tropical Storm due to land interaction with CA. Sorry, but the Eastern Gulf Coast is at high risk for a landfalling Tropical System. It's not wise to let your guards down this early, we still have more to go.



I will not put my stock pile of gas into the vehicles until mid December. There is still a lot of energy and potential out there.

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Lastly if that trough hangs out were it's been all summer, may be a long winter for the eastern US. Which means low electric bills for S. Fl praise the Lord.
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You all seem to forget that we still have 2 months of the season left. Look at Wilma, Mitch, and Opal. They formed late and hit the USA, though Mitch was a Tropical Storm due to land interaction with CA. Sorry, but the Eastern Gulf Coast is at high risk for a landfalling Tropical System. It's not wise to let your guards down this early, we still have more to go.

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Quoting cat5hurricane:
Wow!

That'll really get that Sugar Maple to shed it's leaves.
lol, yeah. Half-bare now.
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Post 715 Atmo post of the day. Can't top that so I am off to football land 12 o'clock canes first. Remember panhandle no guns allowed at football games.
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Quoting atmoaggie:
We're getting upper 40s here, too. (40 miles north of NOLA)

Ahh, the joys of a big trough in the upper atmosphere over the Eastern CONUS :O)
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting Bordonaro:

Upper 40's on Monday night :O)!!
We're getting upper 40s here, too. (40 miles north of NOLA)
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Quoting TropicalAnalystwx13:
And now, a look at Levi's local weather

Today...Rain. Highs in the upper 40s to upper 50s. Northeast wind 15 to 25 mph becoming southwest to 15 mph in the afternoon.

Tonight...Rain. Lows in the mid 30s to lower 40s. South wind 10 to 20 mph.

Sunday...A chance of rain in the morning...then rain in the afternoon. Highs in the lower 40s to lower 50s. Variable wind 10 mph.

Sunday Night...Rain in the evening. Lows in the mid 30s to lower 40s. Southeast wind 10 to 20 mph.

Monday...Mostly cloudy. Isolated rain showers in the afternoon. Highs in the lower to mid 40s. Southeast wind 10 to 15 mph.

Monday Night...Cloudy with isolated rain showers. Lows 35 to 45.

Tuesday Through Friday...Mostly cloudy with a chance of rain. Highs in the 40s. Lows 35 to 45.


Please pass the hot chocolate and my parka, thanks you :O)!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting srada:


Please tell me he is not sleeping?


He's sleeping permanently! The kid who bagged him was 19 yrs old. It was 12' 9". He and his two friends were in a 13' boat in the Yellow River Wednesday morning at 03:30 when they came across him. From the articles in the paper, it was quite a fight.
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Quoting srada:


I personally dont measure a storm on how many people died..if one person loses their life, then to me its a catastrophe..I think we need to stop measuring the season on body count and just concentrate on the fact if anyone dies..You're right Katrina was a terrible tragedy but Im sure the families of the people who lost their lives in NC earlier this week arent going to be "measuring" the differences between the two storms..Any Loss of life period is a catastrophe..
While, in principle, I do agree that any loss of life is not good, this is simply one way we compare storms, whole seasons, and other natural disasters.

Ida killing one man in a boat is no comparison to Katrina, but both took lives here. To say this season has met the doom expectations is a reach, IMHO, from a forest, not trees, perspective.

In modern times, has any hurricane season not resulted in at least a single death?
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Quoting cat5hurricane:
Gonna be a big rain event for those aforementioned indeed.

I really don't think we'll even see a minimal hurricane hitting the CONUS the rate it's going. 97L will re-curve eventually.


Starting to fell pretty confident we will make it a second season in a row without a US landfalling hurricane and the fifth in a row (first time since 1909-1915) without a major hurricane landfall.
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And now, a look at Levi's local weather

Today...Rain. Highs in the upper 40s to upper 50s. Northeast wind 15 to 25 mph becoming southwest to 15 mph in the afternoon.

Tonight...Rain. Lows in the mid 30s to lower 40s. South wind 10 to 20 mph.

Sunday...A chance of rain in the morning...then rain in the afternoon. Highs in the lower 40s to lower 50s. Variable wind 10 mph.

Sunday Night...Rain in the evening. Lows in the mid 30s to lower 40s. Southeast wind 10 to 20 mph.

Monday...Mostly cloudy. Isolated rain showers in the afternoon. Highs in the lower to mid 40s. Southeast wind 10 to 15 mph.

Monday Night...Cloudy with isolated rain showers. Lows 35 to 45.

Tuesday Through Friday...Mostly cloudy with a chance of rain. Highs in the 40s. Lows 35 to 45.

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Quoting TropicalAnalystwx13:


Oh...

Its not dropping down to the 30s there, though.

Upper 40's on Sunday night/ D-FW, TX short term forecast, we LOVE troughs on the E Coast :O)!!

Today: Sunny, with a high near 84. North wind around 10 mph.

Tonight: Mostly clear, with a low around 55. North wind between 5 and 10 mph.

Sunday: Mostly sunny, with a high near 75. North northeast wind between 5 and 10 mph.

Sunday Night: Partly cloudy, with a low around 49. East northeast wind around 5 mph.

Monday: Mostly sunny, with a high near 78. East southeast wind between 5 and 10 mph.

Monday Night: Partly cloudy, with a low around 53. Southeast wind around 5 mph.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting Bordonaro:

New Haven, CT


Oh...

Its not dropping down to the 30s there, though.
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Quoting TropicalAnalystwx13:


You live in ______?

New Haven, CT
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting pottery:

I am seriously considering finding a new place to hang-out.
Everyone here is so dam old, man.
The Pretenders??? WOW!
Going to be singing that number all day long now.

Here this is for you, if you try to leave:
Link
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Alligators are so cuddly.

Try sleeping with one :)

It'll keep you warm.

I think they'll bite if you make them mad though, so be sure to run to McDonalds often to avoid getting eaten.
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Quoting jasoniscoolman2010xo:
its 11am in the morning here its only 52F RIGHT NOW in new haven..and colder weather tonight maybe in the 30s tonight.


You live in ______?
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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.