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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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: November 8, 2009 Posts: 4 Comments: 13455
New Orleans, Louisiana (Airport)
Updated: 5 min 12 sec ago
66 °F
Clear
Humidity: 60%
Dew Point: 52 °F
Wind: 6 mph from the North

Pressure: 29.96 in (Rising)


Oh Yeah....

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566. IKE
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SAT OCT 2 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A SURFACE TROUGH EXTENDING FROM THE LEEWARD ISLANDS EASTWARD INTO
THE ATLANTIC OCEAN IS PRODUCING DISORGANIZED SHOWERS AND
THUNDERSTORMS. ANY DEVELOPMENT OF THIS SYSTEM SHOULD BE SLOW TO
OCCUR AS IT MOVES WESTWARD OR WEST-NORTHWESTWARD AT ABOUT 15
MPH...AND THERE IS A LOW CHANCE...20 PERCENT...OF THIS SYSTEM
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. REGARDLESS
OF DEVELOPMENT...LOCALLY HEAVY RAINS ARE POSSIBLE DURING THE NEXT
DAY OR TWO OVER THE LEEWARD ISLANDS...THE VIRGIN ISLANDS...AND
PUERTO RICO.

SHOWER AND THUNDERSTORM ACTIVITY HAS DIMINISHED IN ASSOCIATION WITH
A SURFACE TROUGH OVER THE NORTHWESTERN CARIBBEAN SEA. ENVIRONMENTAL
CONDITIONS DO NOT APPEAR FAVORABLE FOR DEVELOPMENT AND THERE IS A
LOW CHANCE...NEAR 0 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY EASTWARD OR
NORTHEASTWARD. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINS ARE
POSSIBLE DURING THE NEXT DAY OR TWO ACROSS THE CAYMAN ISLANDS...
EASTERN CUBA...JAMAICA...AND HISPANIOLA.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BRENNAN
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Hey Storm!! Hopefully there will not be to much damage in eastern NC.
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Morning! A rainy week ahead for us here in the Northeast. Fall has arrived.
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Morning all

Headed towards Eastern NC
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Good Morning all

What a nice surprise here in the Lower Keys

Boca Chica Naval Air Station As Of 6am

73 tmp Dp 68 Pressure 29.78R
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YIKES IKE - 58degrees????? -HUMMMMM, that's a bit COOL for me. In my book - it should never get cooler then 60 : )
Got light, out the door - good day to all
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Wonder if this is the start of the inevitable lull.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Yummm - nice and cool this morning! Good day to clean up the rest of the tree litter!


Norfolk NAS, Virginia (Airport)
Updated: 26 min 15 sec ago

64 °F
Mostly Cloudy
Humidity: 56%
Dew Point: 48 °F
Wind: 14 mph from the ENE

Pressure: 29.97 in (Rising)
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557. ackee
seem there a low pressure in the EAstern carribb
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556. IKE
Quoting surfmom:
Morning IKE - I'm Completely Caffeinated - just waiting for some more light before I hit the road for a run... I'm kinda excited (yes, the best things on life are free) - caused it's cool this morning - first time in a long time - won't feel like I'm on a treadmill inside a sauna.


Morning.

I've got 58.6 right now, outside.
...............................................

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Morning IKE - I'm Completely Caffeinated - just waiting for some more light before I hit the road for a run... I'm kinda excited (yes, the best things on life are free) - caused it's cool this morning - first time in a long time - won't feel like I'm on a treadmill inside a sauna.
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554. IKE
Inland Florida panhandle...

Sunday Night: Mostly clear, with a low around 45. North northwest wind around 5 mph.

Monday: Sunny, with a high near 78. North northwest wind between 5 and 10 mph.

Monday Night: Mostly clear, with a low around 44.

Tuesday: Sunny, with a high near 77.

Tuesday Night: Mostly clear, with a low around 47.
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Big Smile Korithe - I just spied a chance for waves on Sunday - SWFL/Gomex
surf report didn't say why -- so I'm up and poking around looking
AURASURF- M.Weaver
"Our only other shot at waves is a slight chance for a knee to thigh bump at N County late, late Sunday as winds gust from the N for a bit"
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Quoting hydrus:
Here is one for you...Link ......The Great Hurricane of 1780...200 mph winds.!.... Oct-9 thru Oct-20...
great read - specially intersting how weather/the cane affected history
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Quoting surfmom:
GOOD MORNING
RISE AND SHINE
WAKE UP


Oh we will. When there's a tropical threat. :P
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GOOD MORNING
RISE AND SHINE
WAKE UP
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549. HadesGodWyvern (Mod)
Joint Typhoon Warning Center
Tropical Disturbance Summary
06:00 AM UTC October 2 2010
====================================

An area of convection (92W) located at 12.4N 116.8E or 275 NM west southwest of Manila, Philippines. Animated multispectral satellite imagery shows a developing low level circulation center with good low level inflow along the eastern periphery and flaring deep convection. A 0217z ASCAT Pass depicts 10-15 knot winds along the eastern periphery of the low level circulation center. The system is located in an area of upper level divergence with good equatorward outflow and moderate vertical wind shear.

Maximum sustained winds near the center is 10-15 knot with a minimum sea level pressure of 1005 MB. Due to the good outflow aloft and high sea surface temperatures, the potential for this disturbance to form into a significant tropical cyclone within the next 24 hours is UPGRADED TO FAIR.
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Zzzzzzzzzzzzzzzzzz............
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547. JLPR2
Ahh I remembered something I hadnt posted :S had to come back, LOL!

Surface: 925mb vort



Check it out
And now I'm really off...
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546. Relix
ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT SAT OCT 2 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. SHOWERS AND THUNDERSTORMS REMAIN DISORGANIZED IN ASSOCIATION WITH
A SURFACE TROUGH LOCATED FROM THE LEEWARD ISLANDS AND EXTENDING
EASTWARD OVER THE ATLANTIC OCEAN FOR SEVERAL HUNDRED MILES.
DEVELOPMENT...IF ANY...OF THIS SYSTEM SHOULD BE SLOW TO OCCUR...
AND THERE IS A LOW CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD
OR WEST-NORTHWESTWARD AT ABOUT 15 MPH.

2. A SURFACE TROUGH OVER THE NORTHWESTERN CARIBBEAN SEA CONTINUES TO
PRODUCE DISORGANIZED SHOWER AND THUNDERSTORM ACTIVITY. THERE IS A
LOW CHANCE...10 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY EASTWARD OR
NORTHEASTWARD. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINS ARE
POSSIBLE DURING THE NEXT DAY OR TWO ACROSS NORTHERN CENTRAL
AMERICA...THE CAYMAN ISLANDS...EASTERN CUBA...JAMAICA...AND
HISPANIOLA.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER STEWART
NNNN

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545. Relix
Quoting JLPR2:


Here you can see the disturbance to the east of the islands staring to spin, I'm keeping both eyes on it since it is still 1-2 days from me.

And with that, I'm off till tomorrow, night everyone and for the lurkers too! :D


Get your boat ready
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544. JLPR2


Here you can see the disturbance to the east of the islands staring to spin, I'm keeping both eyes on it since it is still 1-2 days from me.

And with that, I'm off till tomorrow, night everyone and for the lurkers too! :D
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wow, global warming??? try global cooling. btw who ever said joe bastardi is full of hype and isnt right most of the time is absolutely crazy... he crafts his ideas and thoughts on past records AND not only that but with what reports show him currently via noaa.the man does his homework and has legit proof that he researches non stop. also he has been pretty accurate as far as this hurricane season is concerned. even go to his blog posts, watch vidoes he posted a few months ago and tell me he isnt right. im not saying hes nostradomus, but hes close...
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542. JLPR2
Not bad at all, but very disorganized.

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then again, i was looking at the model guidences from 6 am yesterday... so either way, reguardless, there will be something that will hang around and get more organized, and if not that, thann maybe the new wave that rolled off of africa. the cape verde season osnt dont yet, so we must keep an eye on that
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Quoting hydrus:
Someone said the Cape Verde season is over..... Are these not waves moving across Africa?...


lol its sort of strange how people attempt to deny global warming, or massive climate changes. Its happening , but maybe just not our fault.. dont want to get into it. But its the second of oct and things like this are really interesting to me atleast.
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Member Since: July 12, 2007 Posts: 0 Comments: 5995
538. JLPR2
Interesting, check out the 00z surface map

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537. Relix
that estimated rotation area is starting to fill a bit in the north. Maybe the beginning?
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Complete Update


AOI
AOI AOI AOI

AOI AOI AOI

TS BUSTED FORECAST ALIBI
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Member Since: July 12, 2007 Posts: 0 Comments: 5995
534. Relix
Man blog is death.

I know there's not much to discuss for now but yeah... darn XD!
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Quoting JLPR2:


ans wet :S


Definitely. We need that rain, but I know that excessive rainfall can be dangerous.
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hi everyone. i have a friend of a friend who is supposed to get married in Jamaica on Oct. 10. How bad do you think the weather will be there then. Hard to say for sure, I know. But most likely, not good. Right? The wedding and reception are planned for the beach. All of the guests are flying down from Indiana. She is wondering if she should move the wedding elsewhere. Poor thing. I don't know what to tell her. The resort did say that they have power.
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531. JLPR2
Quoting CaribBoy:
WELL very strong convection is approaching my area in the Northern Leeward Islands! Thing could finally get interesting.


ans wet :S
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530. JLPR2
Quoting BlizzardBeast99:
actually, quite the contrary, the two areas of disturbed weather are coming together. and models show this to happen and just chill in the carribean for awhile... and with the trough in the north east with the way it is, maybe another nicole like situation. prolly will happen a lot til november. hopefully if the models are correct, the 540 line will start closing in on my area and maybe it will snow instead cause my basement is starting to get flooded and its a little scary lol


I differ since the other area of vorticity started to be apparent just a few images ago.
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WELL very strong convection is approaching my area in the Northern Leeward Islands! Thing could finally get interesting.
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Quoting JLPR2:
97L appears to be splitting in two.

actually, quite the contrary, the two areas of disturbed weather are coming together. and models show this to happen and just chill in the carribean for awhile... and with the trough in the north east with the way it is, maybe another nicole like situation. prolly will happen a lot til november. hopefully if the models are correct, the 540 line will start closing in on my area and maybe it will snow instead cause my basement is starting to get flooded and its a little scary lol
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526. JRRP
,
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Member Since: July 12, 2007 Posts: 0 Comments: 5995
Quoting TropicalMan2010:

lol dont make bring out what koritheman always says :)


In this case, he's right. Odds aren't great for 97L's recovery.
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521. JRRP
Quoting JLPR2:


Or is there?
maybe we are all looking at the screen like...
Hey no one is saying nothin. :P

The blob is starting to look suspicious.


And with that, I'm off till later...

asi es
la conveccion se empeso a incrementar en el momento que dijeron RIP
me voy tengo q trabajar ma%uFFFDana asi que hasta el lunes

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519. JLPR2
I was off for an hour, wow! XD

Quoting Relix:
That's just a convective blob. Nothing else to it. 97L, at least what it was originally designated as, died. NHC may move the circle over there and keep the naming as 97L since it was originally that huge system.


Also to answer this check out the ASCAT pass I posted, there is a very broad and disorganized circulation related to that blob, if the convection manages to expand southward it could tighten up and I agree, the NHC should move the circle or make another one for the Blob to the east of the islands.

I believe our two disturbances never really merged, so we got disturbance #1 just to the east of the islands and the one was that was designated 97L farther to the east.
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518. xcool
Texas season overrrrr
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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.