97L a major rainfall threat; October hurricane outlook; NC rains finally end
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
Shannon Hills, Ridgeway, VA
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 — Blog Index
Oh we will. When there's a tropical threat. :P
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"
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.
Morning.
I've got 58.6 right now, outside.
...............................................
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)
Got light, out the door - good day to 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
Headed towards Eastern NC
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
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....
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...
Hope youe stay at bed for the rest of the season.
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."
Dynamic models:
Intesity models:
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!
Hey Grothar how are you. Oh, I'm fine. Everything OK.
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.
Nice models!
Gee, thanks! Glad someone appreciated them. Seen anyone else on the blog today?
Not really, just a few .
OH.
Yo, Teddy!
Having a conversation with yourself eh? :)
'Cant Model Crap'
But having the CMC/GGEM on board certainly adds to the credibility that this system might form.
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.
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.
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
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.
Link
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!
Jejejejeej AGREE 100%
CyberTeddy said "Can't Model Crap" It could also stand for "Creating Major Catastophes"
Viewing: 551 - 601
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 — Blog Index