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

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

Share this Blog
3
+

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
()

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: 618 - 568

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16Blog Index

Quoting Eugeniopr:


No doubt about it. Did you check this site http://weather.rabirubia.com/ ?


It won't open. Do you know how to post a link on it? If not, I'll tell you how.
Member Since: Posts: Comments:
IMO, that rabbit is smart. Look at all the greenery (food),a space underneath to get out of winds and not likely that other predators will swim out to kill it.

Perhaps all of us should be as well-prepared as that rabbit.
Member Since: Posts: Comments:
Quoting Orcasystems:

Complete Update


AOI
AOI AOI AOI

AOI AOI AOI

TS BUSTED FORECAST ALIBI


Hey, Orca, how come you never have my name on your map? I'm one of the few people who are nice to you. LOL.
Member Since: Posts: Comments:
GM, 17.3 55.1W according to NRL
Member Since: October 6, 2007 Posts: 0 Comments: 6028
Looking at the models a little closer, I think what all the models are showing are indeed 97L but on a different path. ECMWF takes the energy that is 97L WSW into the Caribbean THEN it begins to form as it nears Hispaniola. This is also the case with the CMC, GFS, UKMET. Development begins as early as Tuesday.
Member Since: Posts: Comments:
Quoting cat5hurricane:
I like this. Thnx for posting


Thought it was interesting. Too many people discount October, but they have had some strong ones in October. And those were only majors, there have been many others not on there.
Member Since: Posts: Comments:
Quoting Grothar:


October can stir up some mean storms.


No doubt about it. Did you check this site http://weather.rabirubia.com/ ?
Member Since: Posts: Comments:
Quoting Eugeniopr:


Still sunny in San Juan, let's see what happens later. Take a look to the web cams http://weather.rabirubia.com/ . They should change the name oc the CMC to HMC, Hopping for major Cat.


October can stir up some mean storms.
Member Since: Posts: Comments:

Complete Update


AOI
AOI AOI AOI

AOI AOI AOI

TS BUSTED FORECAST ALIBI
Member Since: Posts: Comments:
Link
Member Since: Posts: Comments:
606. DDR
Morning
wish we had an Autumn here(Trinidad),its either hot,humid and rainy or dry and hot.We got 3 more months of rainy season offically,4-5 more if you ask me(this being a la nina yr)
Member Since: Posts: Comments:
Quoting Grothar:


CyberTeddy said "Can't Model Crap" It could also stand for "Creating Major Catastophes"


Still sunny in San Juan, let's see what happens later. Take a look to the web cams http://weather.rabirubia.com/ . They should change the name oc the CMC to HMC, Hopping for major Cat.
Member Since: Posts: Comments:

18n 55w
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Actually according to the Cimss predict page there have been 3 pgl's areas very close to each other the one Kman is referring to is pg151L which is forecast to be pretty much stationary next day or so. I think this is the area besides the one at 18n 55w that will be worth watching.All though 18 north looks to be in a hurry this morning.
Member Since: Posts: Comments:
Quoting Eugeniopr:


Jejejejeej AGREE 100%


CyberTeddy said "Can't Model Crap" It could also stand for "Creating Major Catastophes"
Member Since: Posts: Comments:
Quoting Grothar:
Hey Teddy, gotta love the CMC. They always turn everything into a major. What does CMC stand for? Creating Mass Confusion. LOL



Jejejejeej AGREE 100%
Member Since: Posts: Comments:
Quoting kmanislander:
Good morning folks.

Semi quiet out there today. The one area of particular interest to me is in the SE Caribbean. This feature was the "original" 97L before the NHC started tracking what is now known by that designation.

The 850 vort has been consistent over the past 24 hours and there is a decent amount of convection associated with it. Something to watch for 75 West and beyond.


I think the blog might hit 600 posts by noon!
Member Since: Posts: Comments:
there is a weak system about 300 miles east of florida. is that the leftovers of nicol?
Member Since: Posts: Comments:
Good morning folks.

Semi quiet out there today. The one area of particular interest to me is in the SE Caribbean. This feature was the "original" 97L before the NHC started tracking what is now known by that designation.

The 850 vort has been consistent over the past 24 hours and there is a decent amount of convection associated with it. Something to watch for 75 West and beyond.
Member Since: Posts: Comments:
Stormjunkie enroute to Eastern North Carolina live video and chat
Link
Member Since: Posts: Comments:
Quoting gordydunnot:
Think they jumped the gun on lowering to yellow. That's some heavy convection.Look out northern Antilles someone going to get wet and windy.


They might as well as gone ahead, looking a the models only the CMC might be showing 97L. The ECMWF, GFS, and UKMET are showing a system somewhat similar track wise to Hurricane Omar in 2008.
Member Since: Posts: Comments:
Quoting Neapolitan:


Sure seems that way, at least today. The question is, then, what kind of a lull will it be? 2005 was just finishing a two-week long lull about now, while 1995 had finished one a bit earlier. And 1933 was just starting on a 3.5 week-long lull. Even 2009 was finishing a one-month dry spell before quickly popping out two more storms then entering another one-month lull.

At any rate, it will be interesting to watch...


Good Morning Neo.,
A link for all during the lull.
It's RSOE EDIS worldwide.Coffee tastes good this AM.59 Degrees here in P'cola with 63% RH.I'll take it.(Streches and posts).
v/r
Moe
Link
Member Since: Posts: Comments:
Quoting CybrTeddy:


'Cant Model Crap'

But having the CMC/GGEM on board certainly adds to the credibility that this system might form.


Ha, another one! But, yes, a few of the other early models are still predicting some formation. All have a low intensity, though. Wouldn't be surprised if they relocate the center again.
Member Since: Posts: Comments:
Quoting Grothar:


You know what they say? When no one else is around, you might as well.


I must say I can't argue with that logic.
Member Since: Posts: Comments:
Quoting CybrTeddy:


Having a conversation with yourself eh? :)


You know what they say? When no one else is around, you might as well.
Member Since: Posts: Comments:
Quoting Grothar:
Hey Teddy, gotta love the CMC. They always turn everything into a major. What does CMC stand for? Creating Mass Confusion. LOL



'Cant Model Crap'

But having the CMC/GGEM on board certainly adds to the credibility that this system might form.
Member Since: Posts: Comments:
Think they jumped the gun on lowering to yellow. That's some heavy convection.Look out northern Antilles someone going to get wet and windy.
Member Since: Posts: Comments:
Hey Teddy, gotta love the CMC. They always turn everything into a major. What does CMC stand for? Creating Mass Confusion. LOL

Member Since: Posts: Comments:
Quoting Grothar:


Nice models!

Gee, thanks! Glad someone appreciated them. Seen anyone else on the blog today?

Not really, just a few .

OH.


Having a conversation with yourself eh? :)
Member Since: Posts: Comments:
Quoting CybrTeddy:
ECMWF 00z 144 hours.


Storm forms in Caribbean, hits Hispaniola, emerges then turns out to sea.

GFS 06z shows it but weaker.


00z GGEM (extension of CMC) shows a hurricane in that timeframe as well, but doesn't come from the Caribbean.


00z UKMET has a weaker system similar to the GFS.


00z ECMWF ensembles have it too.


We need to watch the Eastern Caribbean next week.



Yo, Teddy!
Member Since: Posts: Comments:
Quoting Grothar:


Hey Grothar how are you. Oh, I'm fine. Everything OK.


Nice models!

Gee, thanks! Glad someone appreciated them. Seen anyone else on the blog today?

Not really, just a few .

OH.
Member Since: Posts: Comments:
ECMWF 00z 144 hours.


Storm forms in Caribbean, hits Hispaniola, emerges then turns out to sea.

GFS 06z shows it but weaker.


00z GGEM (extension of CMC) shows a hurricane in that timeframe as well, but doesn't come from the Caribbean.


00z UKMET has a weaker system similar to the GFS.


00z ECMWF ensembles have it too.


We need to watch the Eastern Caribbean next week.

Member Since: Posts: Comments:
Quoting Grothar:


Intesity models:



Hey Grothar how are you. Oh, I'm fine. Everything OK.
Member Since: Posts: Comments:
575. unf97
Good morning everyone

Fall has arrived! What a great morning. I registered a low temp of 61.2 degrees this morning. Very nice. It is going to get even better this week as a surge of cooler air will embark on the Eastern CONUS. We are going to have lows dip to around 50 by Tuesday morning of next week and highs in the mid 70s by mid week.


Loving this! After such a ridiculously hot summer, I am really looking forward to this treat of wonderful weather the next few days!
Member Since: Posts: Comments:


Intesity models:

Member Since: Posts: Comments:
Early models:



Dynamic models:

Member Since: Posts: Comments:
Quoting islander101010:
wet time in the carib. acc/ to the models looks like more heavy rain ahead
carib. prime for another development in a wk or two
Member Since: Posts: Comments:
Season 2010 - GOES East Animation: June - July

This GOES East Infrared Hurricane Sector animation is a long loop that shows all of June and July 2010. This video features Hurricane Alex, which blew up quickly and torched the Mexico Gulf coast and well inland! Also shown is Tropical Storm Bonnie, which could not quite get it together. This video features the music of Gustav Holtz's symphony - "The Planets."



Season 2010 - GOES East Animation: August - September

This GOES East Infrared Hurricane Sector animation is a long loop that shows all of August and September 2010. This video features a slew of tropical storms and hurricanes, none of which made official landfall along the U.S. coastline. How many can you correctly identify? This is one killer video you will want to see again and again. This video features the music of Gustav Holtz's symphony - "The Planets."

Member Since: Posts: Comments:
Quoting KoritheMan:


Oh we will. When there's a tropical threat. :P


Hope youe stay at bed for the rest of the season.
Member Since: Posts: Comments:
wet time in the carib. acc/ to the models looks like more heavy rain ahead
Member Since: Posts: Comments:
Quoting Cotillion:
Wonder if this is the start of the inevitable lull.


Sure seems that way, at least today. The question is, then, what kind of a lull will it be? 2005 was just finishing a two-week long lull about now, while 1995 had finished one a bit earlier. And 1933 was just starting on a 3.5 week-long lull. Even 2009 was finishing a one-month dry spell before quickly popping out two more storms then entering another one-month lull.

At any rate, it will be interesting to watch...
Member Since: Posts: Comments:

Viewing: 618 - 568

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16Blog 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.