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 stormpetrol:
wait til 92L explodes later tonight or in the morning hours.


that is what Im thinking..!!!
Member Since: July 8, 2010 Posts: 0 Comments: 345
Quoting stormhank:
If the wave off africa forms would it turn fishy or track toward the lesser antilles ???


most likely it would be a fish
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Quoting stuckinfl:
Test...pic...test


there is a "preview comment" feature, to see what your post will look like after you post it..... perhaps you should try that. Your image also must be hosted somewhere on the net in order for it to be displayed. photobbucket.com is a good place, and its free.......
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wait til 92L explodes later tonight or in the morning hours.
Member Since: Posts: Comments:
1408. HadesGodWyvern (Mod)
National Hurricane Center
Tropical Cyclone Outlook
0:00 AM UTC August 5 2010
=================================

Radar data from Mexico and satellite imagery indicates that the area of low pressure located 85 miles south southwest of Puerto Angel has become better organized this afternoon. Conditions are conducive for additional development and this system could become a tropical depression at any time tonight or Thursday.

Interest along the southern coast of Mexico should monitor the progress of this system.

Tropical Cyclone Formation Potential
=====================================
There is a HIGH chance of this disturbance to form into a significant tropical cyclone within the next 48 hours


---
Taz it was orange at 1800 UTC.
Member Since: May 24, 2006 Posts: 50 Comments: 44911
Quoting jeebsa:
On here tonight is more hostile than the Atlantic. I will try back later!!!


oh cmon!!! its all in fun!!!
Member Since: July 8, 2010 Posts: 0 Comments: 345
Quoting 2010StormNames:
David Thomas, let me ask you a brief question, are you in love with this supposed ''JFV'' fellow? I ask you this, because I've noticed that you are constantly making references to him in here, like 24/7. Why is that, huh? CUT IT OUT, MAN, OK? Enough is enough, my God, geeze, -_-. Anyhow, on that note, back to the tropics. ^_^.




its JFV you been reported
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
Quoting Orcasystems:


Not actually trying to start anything... but you might want to tone down your rhetoric a bit. Thats is basically what you said... and it gets tiresome seeing you say it so often... mellow a bit :)


Sorry if you read it that way, no worries.. I just said I'm not in line with the model consensus. Whatever happens, happens. :)
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1399. Tazmanian
11:49 PM GMT on August 04, 2010
Quoting Ron5244:
The new CV system (if it even develops) would likely follow Colin, anyway. So who really cares?



we do this be come there no land in the way there are a lot of shiping lanes out there for this storm
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
1398. Vero1
11:49 PM GMT on August 04, 2010
Quoting Orcasystems:


If I had to guess... I would say untasked, en route to 92L


It appears to be just Flying in the Gulf.
Member Since: July 21, 2008 Posts: 4 Comments: 2233
1397. nyhurricaneboy
11:48 PM GMT on August 04, 2010
Quoting Cotillion:
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.


Not to mention Andrew.
Member Since: August 19, 2008 Posts: 104 Comments: 503
1396. Orcasystems
11:47 PM GMT on August 04, 2010
Quoting reedzone:


Don't start trouble Orca, I respect you on here and your posts of the models.. It's just my prediction based on what I'm currently seeing on the steering pattern.


Not actually trying to start anything... but you might want to tone down your rhetoric a bit. Thats is basically what you said... and it gets tiresome seeing you say it so often... mellow a bit :)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
1395. CybrTeddy
11:47 PM GMT on August 04, 2010
Surprised they didn't mention PG124L giving its immediacy to develop per the ECMWF and GFS.
Member Since: July 8, 2005 Posts: 259 Comments: 23660
1394. Ron5244
11:47 PM GMT on August 04, 2010
The new CV system (if it even develops) would likely follow Colin, anyway. So who really cares?
Member Since: September 1, 2006 Posts: 7 Comments: 671
1393. alaina1085
11:47 PM GMT on August 04, 2010
Quoting FLdewey:


I still say his name should be on the building.


ROFLMAOOOO!! Best avatar EVER!
Member Since: August 2, 2006 Posts: 0 Comments: 1240
1392. JupiterFL
11:47 PM GMT on August 04, 2010
Quoting dsenecal2009:
JenniferGirl lol this guy just won't quit

JenniFerGirl? JFG... when JFV takes on his female alter egos we should call him JFG


You could also use JFV for a female. Couldn't you?
Member Since: August 10, 2005 Posts: 0 Comments: 2146
1391. xcool
11:46 PM GMT on August 04, 2010
haha
Member Since: September 26, 2009 Posts: 2 Comments: 15626
1390. nrtiwlnvragn
11:46 PM GMT on August 04, 2010
Quoting msgambler:
Why you think training just cause they flew out of Keesler? That is where most HH fly from.


Yes but non-tasked mission. They routinely fly training every few days, by training I also mean they could be testing equipment.
Member Since: September 23, 2005 Posts: 14 Comments: 10961
1389. HarleyStormDude52
11:46 PM GMT on August 04, 2010
Quoting Tazmanian:



its out lool


So...PGI24L (Cape Verde wave) an invest at that point???
Member Since: July 8, 2010 Posts: 0 Comments: 345
1388. reedzone
11:46 PM GMT on August 04, 2010
Quoting FLdewey:


I still say his name should be on the building.



Sure attack me, don't talk about what's going on in the tropics, just attack me, go ahead...
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1386. Tazmanian
11:45 PM GMT on August 04, 2010
LOL from yellow too red 70 ch


000
ABPZ20 KNHC 042340
TWOEP
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
500 PM PDT WED AUG 4 2010

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

RADAR DATA FROM MEXICO AND SATELLITE IMAGERY INDICATE THAT THE AREA
OF LOW PRESSURE LOCATED ABOUT 85 MILES SOUTH-SOUTHWEST OF PUERTO
ANGEL HAS BECOME BETTER ORGANIZED THIS AFTERNOON. CONDITIONS ARE
CONDUCIVE FOR ADDITIONAL DEVELOPMENT AND THIS SYSTEM COULD BECOME A
TROPICAL DEPRESSION AT ANY TIME TONIGHT OR THURSDAY. THERE IS A
HIGH CHANCE...70 PERCENT...OF THIS DISTURBANCE BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD AT ABOUT 15
MPH. INTERESTS ALONG THE SOUTHERN COAST OF MEXICO SHOULD MONITOR
THE PROGRESS OF THIS SYSTEM
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
1384. reedzone
11:44 PM GMT on August 04, 2010
Quoting Orcasystems:


Of course you wouldn't, you have made it quite clear that you know far more then any of those people who work at NHC or the people who make and input model data. I have no idea why they would waste their time when they could have just called you for clarification.


Don't start trouble Orca, I respect you on here and your posts of the models.. It's just my prediction based on what I'm currently seeing on the steering pattern.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1383. psuweathernewbie
11:44 PM GMT on August 04, 2010
The hunters are going into ex-Colin tonight, that is who people are seeing southeast of LA in the GOM. They are heading for Colin.
1382. Tazmanian
11:43 PM GMT on August 04, 2010
Quoting extreme236:


Not according to the TWO. NHC still thinks it could develop in a day or two.



by then it could be on land
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
1381. msgambler
11:43 PM GMT on August 04, 2010
Quoting nrtiwlnvragn:


Most likely training flight, will not go too far from Keesler.
Why you think training just cause they flew out of Keesler? That is where most HH fly from.
Member Since: February 27, 2010 Posts: 0 Comments: 1125
1380. HurricaneSwirl
11:43 PM GMT on August 04, 2010
Quoting MiamiHurricanes09:
Here are my percentages for the 8PM TWO:

92L -- 10%
Ex-Colin -- 30%
PGI24L (Cape Verde wave) -- 30%


It's been out a little bit now :)

20% caribbean wave

40% ex-colin

thats it.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
1379. Tazmanian
11:43 PM GMT on August 04, 2010
Quoting MiamiHurricanes09:
Here are my percentages for the 8PM TWO:

92L -- 10%
Ex-Colin -- 30%
PGI24L (Cape Verde wave) -- 30%



its out lool
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
1378. MiamiHurricanes09
11:42 PM GMT on August 04, 2010

Member Since: September 2, 2009 Posts: 130 Comments: 21091
1377. extreme236
11:42 PM GMT on August 04, 2010
Quoting Tazmanian:
92L may be drop later tonight or thursday


Not according to the TWO. NHC still thinks it could develop in a day or two.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1376. reedzone
11:42 PM GMT on August 04, 2010
Quoting JenniferGirl:


I was on here same time yesterday. Yesterday being my first day. I try to keep the peace, and help people to get along. ;)


Good to have you aboard, i'm Allan btw.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1375. Tazmanian
11:42 PM GMT on August 04, 2010
Quoting HurricaneSwirl:


40%. Was expecting 50 or 60. And still absolutely no mention of the CV disturbance?



i think they want too wait in tell thursday and see how its looking then
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
1374. MiamiHurricanes09
11:42 PM GMT on August 04, 2010
000
ABNT20 KNHC 042338
TWOAT
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...

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.

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
Member Since: September 2, 2009 Posts: 130 Comments: 21091
1373. HurricaneSwirl
11:42 PM GMT on August 04, 2010
Wow no one posted the TWO as it came out.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
1372. HadesGodWyvern (Mod)
11:42 PM GMT on August 04, 2010
Gale Force Winds is being experienced over water well to the northeast of the Leeward Islands. Although upper levels winds are not favorable for significant development, the system does have the potential to regain cyclone status on Thursday as it moves west northwest or northwestward at 20-25 MPH
Member Since: May 24, 2006 Posts: 50 Comments: 44911
1371. Tazmanian
11:41 PM GMT on August 04, 2010
92L may be drop later tonight or thursday
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
1370. BahaHurican
11:41 PM GMT on August 04, 2010
Well, RandyB said he was flying tonight, and he's in St. Croix. That to me suggests they have at least one more tasked mission out of there before the evening is over.

Maybe the other plane we saw is supplementing the guys already there...
Member Since: October 25, 2005 Posts: 19 Comments: 21667
1369. Orcasystems
11:41 PM GMT on August 04, 2010
Quoting reedzone:
Looking at the LATEST steering layers map from CIMMS, trends favor a WNW motion then a NW or NNW motion. We'll see what happens, but I'm not buying the models, nor did I ever for this storm.


Of course you wouldn't, you have made it quite clear that you know far more then any of those people who work at NHC or the people who make and input model data. I have no idea why they would waste their time when they could have just called you for clarification.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
1368. HurricaneSwirl
11:41 PM GMT on August 04, 2010
Quoting StormFreakyisher:
ex Colin is bumped up to code Orange!


40%. Was expecting 50 or 60. And still absolutely no mention of the CV disturbance?
Member Since: July 7, 2008 Posts: 2 Comments: 3237
1367. Tazmanian
11:40 PM GMT on August 04, 2010
hmmm looks like may not see march of any thing out of 92L


92L RIP
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
1366. reedzone
11:40 PM GMT on August 04, 2010
Quoting hurricanejunky:
Hey Reed,
I'm with you as well. Got a new forecast? I didn't see one today...


I got called in to work, just got home not too long ago, I will possibly make one tonight.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1365. nrtiwlnvragn
11:40 PM GMT on August 04, 2010
Quoting Orcasystems:


If I had to guess... I would say untasked, en route to 92L


Most likely training flight, will not go too far from Keesler.
Member Since: September 23, 2005 Posts: 14 Comments: 10961
1364. MiamiHurricanes09
11:39 PM GMT on August 04, 2010
Plenty of overshooting tops associated with PGI24L and 92L (PGI23L)...not so much with ex-Colin (PGI22L).



Member Since: September 2, 2009 Posts: 130 Comments: 21091
1363. HarleyStormDude52
11:39 PM GMT on August 04, 2010
Quoting Orcasystems:


If I had to guess... I would say untasked, en route to 92L


ok.. I give up.. how so I look at this? I have google earth but....
Member Since: July 8, 2010 Posts: 0 Comments: 345
1362. bohonkweatherman
11:39 PM GMT on August 04, 2010
Quoting alaina1085:
My how things have changed with this storm. Havent been on the blog since yesterday morning.
Good Evening to You and to All.
Member Since: July 5, 2009 Posts: 0 Comments: 1348

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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.