CSU leaves their hurricane forecast unchanged; 92L and Colin's remains worth watching

By: Dr. Jeff Masters , 2:38 PM GMT on August 04, 2010

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Tropical Storm Colin was ripped apart by wind shear yesterday, and the storm's remnants are passing just north of the northernmost Lesser Antilles Islands today. Most of the heaviest thunderstorms are passing north of the islands, as seen on Guadeloupe radar. Long range radar out of Puerto Rico also shows this. Colin's remains are in a rather unfavorable environment for re-development, since the disturbance is passing beneath an upper-level low pressure system with dry air and high wind shear. Wind shear is a high 20 - 25 knots over Colin's remains this morning. Recent satellite imagery shows that heavy thunderstorm activity has increased in intensity and areal coverage over the past few hours, though, and Colin's remnants will need to be monitored for re-development.

Forecast for Colin's remains
The latest SHIPS model forecast predicts that wind shear will drop from 15 - 25 knots today to a moderate 15 - 20 knots on Thursday. Wind shear will continue to decline over the weekend, and this relaxation of shear prompts most of the major models to predict re-development of Colin sometime in the next four days. NHC is giving Colin's remain a 20% chance of developing into a tropical depression by Friday morning. A major trough of low pressure is expected to move off the U.S. East Coast on Friday, and this trough will pull Colin to the northwest and cause it to slow down. By Friday, Colin will be moving at half of its current speed. All of the major forecast models are predicting that the trough of low pressure will be strong enough to fully recurve Colin out to sea early next week. Colin's remains may pass close to Bermuda on Saturday, with the latest 06Z (2am EDT) run of the GFDL model predicting that Bermuda will experience tropical storm force winds on Saturday as Colin passes to the west of the island. The Hurricane Hunters are scheduled to investigate Colin's remains at 8pm EDT tonight. It currently appears that Colin will only be a threat to Bermuda and Canada.


Figure 1. Morning satellite image of Colin's remains and Invest 92L.

92L
A tropical wave (Invest 92) in the south-central Caribbean is moving west at 15 - 20 mph. This wave is over warm water and is experiencing low wind shear of 5 - 10 knots, and could show some development over the next two days. However, the wave's rapid westward motion should bring it ashore over Nicaragua and Honduras on Friday, or the Yucatan Peninsula on Saturday, and 92L probably does not have enough time over water to develop into a tropical depression. NHC is giving a 20% chance of this disturbance developing into a tropical depression by Friday morning. This storm was being tagged as 98L yesterday; I'm not sure why it is being called 92L today.

CSU's forecast numbers for the coming hurricane season remain unchanged
A very active Atlantic hurricane season is on tap for 2010, according to the seasonal hurricane forecast issued today, August 4, by Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU). The CSU team continues to call for 18 named storms, 10 hurricanes, 5 intense hurricanes, and an Accumulated Cyclone Energy (ACE) index 185% of average. These are the same numbers as their June 2 forecast. Between 1950 - 2000, the average season had 10 named storms, 6 hurricanes, and 2 intense hurricanes. But since 1995, the beginning of an active hurricane period in the Atlantic, we've averaged 14 named storms, 8 hurricanes, and 4 intense hurricanes per year. The new forecast continues to call for a much above-average chance of a major hurricane hitting the U.S., both along the East Coast (50% chance, 31% chance is average) and the Gulf Coast (49% chance, 30% chance is average). The risk of a major hurricane in the Caribbean is also high, at 64% (42% is average.)

The forecasters cited four main reasons for an active season:

1) Moderate La Niña conditions should be present during the most active portion of this year's hurricane season (August - October). This should lead to reduced levels of vertical wind shear compared with what was witnessed in 2009.

2) Current SST anomalies are running at near-record warm levels. These very warm waters are associated with dynamic and thermodynamic factors that are very conducive for an active Atlantic hurricane season.

3) Very low sea level pressures prevailed during June and July over the tropical Atlantic. Weaker high pressure typically results in weaker trade winds that are commonly associated with more active hurricane seasons.

4) We are in the midst of a multi-decadal era of major hurricane activity, which began in 1995. Major hurricanes cause 80 - 85 percent of normalized hurricane damage.

Analogue years
The CSU team picked four previous years when atmospheric and oceanic conditions were similar to what we are seeing this summer. Those four years were 2005, the worst hurricane season of all time; 1998, which featured 3 major hurricanes, including Category 5 Hurricane Mitch; 1952, a relatively average year that featured just 7 named storms, but 3 major hurricanes; and 1958, a severe season with 5 major hurricanes. The mean activity for these five years was 17 named storms, 11 hurricanes, and 5 intense hurricanes, almost the same as the 2010 CSU forecast.

How accurate are the August forecasts?
The August forecasts by the CSU team over the past 12 years have had a skill 21% - 44% higher than a "no-skill" climatology forecast for number of named storms, hurricanes, intense hurricanes, and the ACE index (Figure 2). This is a good amount of skill for a seasonal forecast, and these August forecasts can be useful to businesses such as the insurance industry and oil and gas industry that need to make bets on how active the coming hurricane season will be. This year's August forecast uses a new formula, so we don't have any history on how the technique has behaved in the past. An Excel spreadsheet of their forecast skill (expressed as a mathematical correlation coefficient) show values from 0.61 to 0.65 for their previous August forecasts using different techniques, which is respectable.


Figure 2. Comparison of the percent improvement over climatology for May and August seasonal hurricane forecasts for the Atlantic from NOAA, CSU and TSR from 1999-2009 (May) and 1998-2009 (August), using the Mean Squared Error. The British firm Tropical Storm Risk (TSR) will issue their outlook for the 2010 Atlantic hurricane season on June 4. Image credit: Verification of 12 years of NOAA seasonal hurricane forecasts, National Hurricane Center.

The British private forecasting firm Tropical Storm Risk, Inc. (TSR) is scheduled to release their August forecast later today. NOAA will also be issuing their August forecast sometime in the next week.

This season has had three named storms so far (Alex, Bonnie, and Colin.) It will be difficult to have a season with 19 or more named storms, since the four seasons that had at least 19 named storms all had at least five named storms by this point (August 4.) These four seasons were 1887, 1933, 1995, and 2005.

Next update
I'll have an update on Thursday morning.

Jeff Masters

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1660. oakland
Quoting flsky:
Off topic - I'm in Daytona Beach Shores facing WSW and I can see lightning associated w/a thunderstorm that is just now entering the Gulf. Amazing! I love Florida!!


If you live in the Daytona area I don't doubt you are seeing lightning but seriously doubt it is associated with a thunderstorm entering the Gulf which is on the opposite side of the state.
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Thanks will, that even is down from where he was....but I think the next fix will be slower

Quoting will45:


not sure 8:00 pm still had him moving between 20/25
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1658. Patrap




Genesis and Rapid Intensification Processes (GRIP)


The Genesis and Rapid Intensification Processes (GRIP) experiment is a NASA Earth science field experiment in 2010 that is being conducted to better understand how tropical storms form and develop into major hurricanes. NASA is using the DC-8 aircraft, the WB-57 aircraft, and the Global Hawk Unmanned Airborne System (UAS) configured with a suite of in situ and remote sensing instruments that are observing and characterizing the lifecycle of hurricanes.

The GRIP deployment is 15 August-30 September 2010 with bases in Ft. Lauderdale, FL for the DC-8, at Houston, TX for the WB-57, and at NASA Dryden Flight Research Facility, CA for the Global Hawk. This campaign is capitalizing on a number of ground networks, airborne science platforms (both manned and unmanned), and space-based assets. The field campaign is being executed according to a prioritized set of scientific objectives. In two separate science solicitations, NASA selected a team of investigators to collect NASA satellite and aircraft field campaign data with the goal of conducting basic research on problems related to the formation and intensification of hurricanes.

The spaceborne and airborne observational capabilities of NASA put it in a unique position to assist the hurricane research community in addressing shortcomings in the current state of the science. The relatively recent launch of several new satellites, the prospect of using a high-altitude UAS for hurricane surveillance, and the emergence of new remote sensing technologies offer new research tools that need to be explored and validated. Of great importance are new remote sensing instruments for wind and temperature that can lead to improved characterization of storm structure and environment.

The GRIP hurricane field campaign and research project are managed by Dr. Ramesh Kakar, Weather Focus Area Leader within the Earth Science Division, NASA Headquarters in Washington, D.C. Dr. Kakar is primarily responsible for assembling the science team and the instrument payload for the NASA aircraft participating in this field experiment.

Track GRIP Flights here
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1656. bappit
Quoting outofdablue:
evening yall!
I have a quick question. Looking at the GOM infared sat. I can see 2 ULL? Does it appear that the big one is moving west and the smaller one moving north? Also, looking at the mslp does it seem that the overall pressures in the GOM are fairly low? One last thing what do the yellow dotted lines represent on the fronts tab? Thanks Kelly

Only see an ULL in the extreme NW Caribbean on this map. Dunno about the pressures. Surface winds look light.
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Some auroras are possible tonight after a series of four coronal mass ejections aimed directly at Earth.



The sun's setting just now, wonder if I'll see any auroras here in Southern Ontario.

Link
Link
Link
Member Since: August 30, 2008 Posts: 8 Comments: 2835
I don't mind some of the younger dudes and lady's that come on here, but I sure wish that school would start again for the ones that come on here and cause trouble.

By the way, it is only Aug. 4th, there is going to be plenty of action within the next 2 - 14 weeks and you can put that in your pipe and smoke it. Although by judging some of the comments in here, it seems as though some may have smoked it all already. LOL
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this commets was made long a go


and i wish they started doing this


Quoting scott39:
Ive had enough of this infintile garbage! Im going to E-Mail Admin and suggest they start charging a mandatory $10.00 every time you sign up under a new user name!That should slow this absurdity down instantly! Anyone else who would like to E-Mail Admin, with the same idea, is welcome to.
Member Since: May 21, 2006 Posts: 5091 Comments: 114701
We need rain...brush fire on I-4 today...near Daytona Beach...
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Quoting IKE:


I forgot about them. Sorry.

Corrected to add #2....

(1)Bermuda.
(2)Canadian Maritime.
(3)This blog.




Mellower crowd in the early am!


At least we're mellow after we've had our coffee! Night all - I hope ex- Colin continues his pattern of dying off during D-Max.
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ok.. Stupid question I suppose (flog me)... But why did the current non tasked recon flight fly a sw track to the coast of LA south of NO then a zig zag back to the SE?? Is it going to recon Colin? It certainly doesnt look like its heading to invest 92.... just an inquiring mind???
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1646. Vero1
Quoting Orcasystems:


Me thinks you spoke to soon.



ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED AUG 4 2010

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

1. SATELLITE IMAGES INDICATE THAT THE CLOUD PATTERN ASSOCIATED WITH THE
REMNANTS OF TROPICAL STORM COLIN IS GRADUALLY BECOMING BETTER
ORGANIZED BUT THE SYSTEM LACKS A WELL-DEFINED CENTER. TROPICAL
STORM FORCE WINDS ARE ALREADY OCCURRING OVER WATER WELL TO THE
NORTHEAST OF THE LEEWARD ISLANDS
AND ALTHOUGH UPPER LEVEL WINDS ARE
NOT FAVORABLE FOR SIGNIFICANT DEVELOPMENT...THE SYSTEM HAS THE
POTENTIAL TO REGAIN TROPICAL STORM STATUS ON THURSDAY AS IT MOVES
TOWARD THE WEST-NORTHWEST OR NORTHWEST AT 20 TO 25 MPH. THERE IS A
MEDIUM CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL

CYCLONE DURING THE NEXT 48 HOURS.

2. A TROPICAL WAVE IS PRODUCING CLOUDINESS AND THUNDERSTORMS BETWEEN
COLOMBIA AND JAMAICA. ALTHOUGH THIS ACTIVITY HAS NOT BECOME ANY
BETTER ORGANIZED DURING THE PAST SEVERAL HOURS...SOME DEVELOPMENT
IS POSSIBLE DURING THE NEXT DAY OR TWO BEFORE THE WAVE BEGINS TO
INTERACT WITH CENTRAL AMERICA. THERE IS A LOW CHANCE...20
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

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

$$
FORECASTER AVILA
NNNN


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1643. flsky
Off topic - I'm in Daytona Beach Shores facing WSW and I can see lightning associated w/a thunderstorm that is just now entering the Gulf. Amazing! I love Florida!!
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Quoting Ossqss:
Anyone find any more info on this?

Huge Hurricane Study Gears Up

NASA Holds Media Teleconference to Preview Major Hurricane Study

"WASHINGTON, Aug. 2 /PRNewswire-USNewswire/ -- NASA will hold a media teleconference on Thursday, Aug. 5, at 3 p.m. EDT to discuss its upcoming airborne research campaign into hurricane behavior."
Interesting. I was just about to ask about the Cape Verde project they were supposed to be running this year.... somebody's post about the different aircraft made me remember it.
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him did they drop 92L?
Member Since: May 21, 2006 Posts: 5091 Comments: 114701
Quoting fallinstorms:
rip colin


Me thinks you spoke to soon.

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Quoting Ossqss:
Anyone find any more info on this?

Huge Hurricane Study Gears Up

NASA Holds Media Teleconference to Preview Major Hurricane Study

"WASHINGTON, Aug. 2 /PRNewswire-USNewswire/ -- NASA will hold a media teleconference on Thursday, Aug. 5, at 3 p.m. EDT to discuss its upcoming airborne research campaign into hurricane behavior."


There is the GRIP website.
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1637. will45
Quoting Goldenblack:
Hey all,

Has Colin slowed his forward progress. He now looks to either be getting badly sheered again or is slowing down quite a bit


not sure 8:00 pm still had him moving between 20/25
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1635. Patrap
Floater - Rainbow Color Infrared Loop
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1634. 1344
We will please be civil, lest n to get people banned. Anyway, I think Colin has a decent change of regeneration, but we will have 99E develop first.
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1633. IKE
Quoting nrtiwlnvragn:


I would not count out the Canadian Maritimes yet.


I forgot about them. Sorry.

Corrected to add #2....

(1)Bermuda.
(2)Canadian Maritime.
(3)This blog.


Quoting CoopsWife:


ROFL, Ike. See you on the blog early in the am - too rough in here for me tonight!


Mellower crowd in the early am!
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1632. bappit
Quoting Drakoen:


Cyclonic curvature along an axis of convergence

Lots of dry air out there.
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1631. BDADUDE
Quoting Hurricanes101:
1568. BDADUDE 12:31 AM GMT on August 05, 2010

last I checked, Bermuda is a landmass


I know that also as i live on this small rock. Colin or remnants wont come within 100nm of here.
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1628. scott39
Quoting Drakoen:
L, 04, 2010080500, , BEST, 0, 202N, 628W, 35, 1009, WV
pressure is dropping- was 1010MB
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Hey all,

Has Colin slowed his forward progress. He now looks to either be getting badly sheered again or is slowing down quite a bit
Member Since: Posts: Comments:
1624. Patrap




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evening yall!
I have a quick question. Looking at the GOM infared sat. I can see 2 ULL? Does it appear that the big one is moving west and the smaller one moving north? Also, looking at the mslp does it seem that the overall pressures in the GOM are fairly low? One last thing what do the yellow dotted lines represent on the fronts tab? Thanks Kelly
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Guys I saw rain today! It rained hard for 5 minutes and now the mosquitoes are out. I was starting to think rain was a mythical once in a lifetime occurrence.
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Jennifer,
The BAMMS I believe is a shallow model, meaning it's a good track for weak storms. I may be wrong, but that's what I've heard.
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Quoting ackee:
so far 2010 seasons to me have all right ingredents for active seasons just seem to me WAVE comeing africa so far as not been that strong enought for devlopment another factor notice Upper level low seem be near by when ever system try to develops
I'm also thinking we've had fewer waves than I would have expected... like they rained themselves out over the Sahel. The TUTT is a normal feature, which is why we usually don't get much activity before mid-Aug. Still, the Twave train seems to be chugging along a bit more slowly than usual.
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1618. Drakoen
L, 04, 2010080500, , BEST, 0, 202N, 628W, 35, 1009, WV
Member Since: October 28, 2006 Posts: 57 Comments: 29883
Quoting IKE:


0%. There's only 2 things Colin will bother anymore...

(1)Bermuda.
(2)This blog.


I would not count out the Canadian Maritimes yet.
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1615. scott39
XCOLIN
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1614. will45
well best thing for you to do is read the header in this blog. Then you wouldnt even think such a thing hopefully
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1612. Ossqss
Anyone find any more info on this?

Huge Hurricane Study Gears Up

NASA Holds Media Teleconference to Preview Major Hurricane Study

"WASHINGTON, Aug. 2 /PRNewswire-USNewswire/ -- NASA will hold a media teleconference on Thursday, Aug. 5, at 3 p.m. EDT to discuss its upcoming airborne research campaign into hurricane behavior."
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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.