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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Quoting MiamiHurricanes09:
They took off at 6:30PM EDT, however they arrive at 8PM EDT.

I. ATLANTIC REQUIREMENTS
1. TROPICAL STORM COLIN
FLIGHT ONE -- TEAL 71
A. 05/0000, 0600Z
B. AFXXX 0204A COLIN
C. 04/2230Z
D. 18.3N 60.4W
E. 04/2230Z TO 05/0600Z
F. SFC TO 15,000 FT

This is where they expect to find the center?..uh..ok..
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Quoting Tazmanian:



hmm nop read the bold


Quoting Tazmanian:
1236. HarleyStormDude52 3:56 PM PDT on August 04, 2010 Hide this comment.

Quoting Tazmanian:
RIP

invest_DEACTIVATE_ep972010.ren



lets try this... TAZ.. is 92 losing it????




POOF your gone bye




ending this has of now


I know you wanna end this but.. he didn't misread your post, he just wanted to change the subject and ask you for your opinion on 92L instead.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
1260. KEEPEROFTHEGATE (Mod)
04L/XX/XX
MARK
19.93N/62.56W
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Quoting 2010StormNames:


Earl????? WRONG!!!!! Look before you speak next time, please. Also, notice the bridged ridge pattern getting established towards the end of it's run. Additionally, by then, we'll be in both a positive MJO phase and in a negative NAO, which means no troughs and a lot of ridges in its place. The ''fish'' pattern that exists for right now, yes, but that'll be changing soon enough, according to the experts on here, OK?

^_^.

Ciao.


The GFS doesn't even develop Earl...
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Last vis sat pic of the day and man does Colin look good. By the way for anyone who is intrested 7.3M earthquake off Newbritain Local Damaging Tsunami possible.EARTHQUAKES OF THIS SIZE SOMETIMES GENERATE LOCAL
TSUNAMIS THAT CAN BE DESTRUCTIVE ALONG COASTS LOCATED WITHIN
A HUNDRED KILOMETERS OF THE EARTHQUAKE EPICENTER. AUTHORITIES
IN THE REGION OF THE EPICENTER SHOULD BE AWARE OF THIS
POSSIBILITY AND TAKE APPROPRIATE ACTION.



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Quoting stormpetrol:

Kinda a cold Taz, think about it man, maybe he was just asking your opinion on 92L , not 97E "Take it easy man, I've seen tattle talers who can't handle just a touch of authority" I'm I reported "Frankly I dont give a damn", this blog is becoming a real shame lately anyway!


I haven't noticed any mishaps on the blog today whatsoever until this evening.


AOI

AOI

AOI

AOI

AOI

TS BUSTED FORECAST ALIBI
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Quoting BDADUDE:

Keep deaming Reedzone


Not arguing MY PREDICTION.. get it in your head.. It's a free country I can post whatever the heck I want.
Member Since: July 1, 2008 Posts: 13 Comments: 7396
Quoting Snowlover123:


Taz, I think what he's trying to ask, is simply, since 97E has been deactivated, is 92L going to be deactivated? ;)



hmm nop read the bold


Quoting Tazmanian:
1236. HarleyStormDude52 3:56 PM PDT on August 04, 2010 Hide this comment.

Quoting Tazmanian:
RIP

invest_DEACTIVATE_ep972010.ren



lets try this... TAZ.. is 92 losing it????




POOF your gone bye




ending this has of now
Member Since: May 21, 2006 Posts: 5091 Comments: 115241
Wheels up on Recon
Member Since: September 23, 2005 Posts: 14 Comments: 11215
Hope all are having a good evening? I again am trying for the picture...test...guess a hurricane has a better chance than my pic..will see..
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Quoting reedzone:
Colin is actually following the last NHC track, right on the line! Models north of there have it going NNW by now, but is Colin doing that? No.. NW and even some WNW motion as it gets discombobulated by the TUTT should continue for the next 24 hours. Systems or invests interacting with TUTTs can really make the track movements erratic. I'm still not sold yet on Colin sparing the USA.


I'm with you, reedzone! It's a little too far south and west, from my viewpoint for the USA to get spared.
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i think some of you guys need too give it a rest i said 97E was RIP i did not say any thing in the word about 92L


i saying Rip too 97E be come it no longer there

has of this update

invest_DEACTIVATE_ep972010.ren


97E is gone RIP


now do you guys see me any thing about me talking about 92L above


NOP nevere had in the 1st time



done with this moveing on
Member Since: May 21, 2006 Posts: 5091 Comments: 115241
Colin has a nice overshooting top going up right now directly over the center, he certainly looks a lot more intimidating tonight.
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1246. KEEPEROFTHEGATE (Mod)

NMFC Norfolk Tropical Feed
NO Active Tropical Warnings in the Atlantic, Caribbean, or Gulf of Mexico
By Maritime.CDO@navy.mil (NMFC CDO) from Naval Maritime Forecast Center Norfolk Virginia. Published on .

As of Wed 04 Aug 2010 22:45:01Z
2010 Storms
All Active Year

Atlantic
92L.INVEST
04L.COLIN
East Pacific
99E.INVEST
Central Pacific
NONE
West Pacific
97W.INVEST
96W.INVEST
Indian Ocean
90B.INVEST
Southern Hemisphere
NONE
Member Since: Posts: Comments:
Quoting Tazmanian:
1236. HarleyStormDude52 3:56 PM PDT on August 04, 2010 Hide this comment.

Quoting Tazmanian:
RIP

invest_DEACTIVATE_ep972010.ren



lets try this... TAZ.. is 92 losing it????




POOF your gone bye


Taz, I think what he's trying to ask, is simply, since 97E has been deactivated, is 92L going to be deactivated? ;)
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1244. will45
calm down Taz ok?
Member Since: July 18, 2009 Posts: 1 Comments: 994
1243. BDADUDE
Quoting reedzone:
Colin is actually following the last NHC track, right on the line! Models north of there have it going NNW by now, but is Colin doing that? No.. NW and even some WNW motion as it gets discombobulated by the TUTT should continue for the next 24 hours. Systems or invests interacting with TUTTs can really make the track movements erratic. I'm still not sold yet on Colin sparing the USA.

Keep deaming Reedzone
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1242. jeebsa
Im just curious of everyones honest opinion on a grade scale of A,B,C,D,or F on the forecast models for Colin thus far?
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1236. HarleyStormDude52 3:56 PM PDT on August 04, 2010 Hide this comment.

Quoting Tazmanian:
RIP

invest_DEACTIVATE_ep972010.ren



lets try this... TAZ.. is 92 losing it????




POOF your gone bye
Member Since: May 21, 2006 Posts: 5091 Comments: 115241
Quoting Tazmanian:




i said 97E is gone not 92L

97E is RIP

invest_DEACTIVATE_ep972010.ren


plz read my post be for commeting too me back thank you







Kinda a cold Taz, think about it man, maybe he was just asking your opinion on 92L , not 97E "Take it easy man, I've seen tattle talers who can't handle just a touch of authority" I'm I reported "Frankly I dont give a damn", this blog is becoming a real shame lately anyway!
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92l: 14.1/75.9 heading west...<Link
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Quoting KEEPEROFTHEGATE:


You might find this website interesting, I definitely do! It shows most things in real time, except I wouldn't trust the bits like accidents and such. Scroll down on the page too, it has a ton of useful information.

Link

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Quoting TropicalAnalystwx13:


In about an hour I think
They took off at 6:30PM EDT, however they arrive at 8PM EDT.

I. ATLANTIC REQUIREMENTS
1. TROPICAL STORM COLIN
FLIGHT ONE -- TEAL 71
A. 05/0000, 0600Z
B. AFXXX 0204A COLIN
C. 04/2230Z
D. 18.3N 60.4W
E. 04/2230Z TO 05/0600Z
F. SFC TO 15,000 FT
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting Tazmanian:
RIP

invest_DEACTIVATE_ep972010.ren


lets try this... TAZ.. is 92 losing it????
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That would be the best scenario for the GFS to verify....the first five storms do not affect the U.S. or any other land masses with the exception of Alex i can live with that this season has looked good for the U.S. thus far
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Quoting HarleyStormDude52:


Well.. I guess a slip of the mouse... SORRRY!!!!!!!!!


That's okay. We all make mistakes. ;)
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Quoting sammywammybamy:


Dont Forget Charely,Frances, and Jeanne!


Don't forget Andrew!
Member Since: July 7, 2008 Posts: 2 Comments: 3237
Quoting atmosweather:


It's pretty common for La Nina's to extend more than 24 months after switching from El Nino in a 6 month period. 1998-99 is one clear example I remember. I'd not be surprised if we see a strong La Nina (-2.0 or further) persist until next fall.


The cold Pacific Decadal Oscillation would also extend the duration of the La Nina.
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Quoting Snowlover123:


Why are you quoting me when you're asking Taz a question?


Well.. I guess a slip of the mouse... SORRRY!!!!!!!!!
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Quoting Snowlover123:


CybrTeddy, some models show a La Nina to 2012! :o



http://www.jamstec.go.jp/frcgc/research/d1/iod/


It's pretty common for La Nina's to extend more than 24 months after switching from El Nino in a 6 month period. 1998-99 is one clear example I remember. I'd not be surprised if we see a strong La Nina (-2.0 or further) persist until next fall.
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Quoting bballerf50:
HH are going into ex-Colin now right?


In about an hour I think
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1226. Drakoen
Member Since: October 28, 2006 Posts: 57 Comments: 30563
HH are going into ex-Colin now right?
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Quoting HarleyStormDude52:


Taz.. Is 92 losing it?


Why are you quoting me when you're asking Taz a question?
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Quoting KEEPEROFTHEGATE:
A strong earthquake has occurred, but a tsunami IS NOT expected along the California, Oregon, Washington, British Columbia, or Alaska coast. NO tsunami warning, watch or advisory is in effect for these areas.

Based on the earthquake magnitude, location and historic tsunami records, a damaging tsunami IS NOT expected along the California, Oregon, Washington, British Columbia, and Alaska coasts. At coastal locations which have experienced strong ground shaking, local tsunamis are possible due to underwater landslides.

At 3:02 PM Pacific Daylight Time on August 4, an earthquake with preliminary magnitude 7.0 occurred in the New Britain region, PNG . (Refer to the United States Geological Survey for official earthquake parameters.)

Pacific coastal regions outside California, Oregon, Washington, British Columbia, and Alaska should refer to the Pacific Tsunami Warning Center messages for information on the event.

This will be the only statement issued for this event by the West Coast/Alaska Tsunami Warning Center unless conditions warrant. See the WCATWC web site for basic tsunami information, safety rules, and a tsunami travel time map and table. (NOTE: Travel time maps and tables indicate forecasted times only, not that a wave was generated.)


The earthquake occurred on land.
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To think this was the same naming list that once had Allen, Georges and Ivan.

Conversely, the list with the least retired names is in 2012. Might even get a Nino thrown on top if the Pacific had another Nina.
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Quoting HarleyStormDude52:


Taz.. Is 92 losing it?




i said 97E is gone not 92L

97E is RIP

invest_DEACTIVATE_ep972010.ren


plz read my post be for commeting too me back thank you






Member Since: May 21, 2006 Posts: 5091 Comments: 115241
WUblogger LRandyB will be flying into this tonight.

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According to the GFS Collin, Danielle, and Earl would all be fish storms
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Quoting CybrTeddy:


If that happens we'll defiantly be in a La Nina for 2011.


I suppose that means snow in S. Ontario as early as October, then heavy snowstorms in December before a big January thaw, then another series of storms in March.
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Quoting Snowlover123:


???


Taz.. Is 92 losing it?
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At 372 hours we have Gaston in the EATL, but that isn't important. Look at how the 1012mb isobar dominates the tropics, that really would not be good.

Member Since: September 2, 2009 Posts: 130 Comments: 21194
Outflow channel developing on the southern side of the ex-Colin new LLC.
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Quoting TropicalAnalystwx13:


5 named storms in the month of AUG already!!! Lets hope that doesn't happen.




cool whats hop it dos heh
Member Since: May 21, 2006 Posts: 5091 Comments: 115241

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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.

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