CSU and TSR continue to predict a near-average hurricane season

By: Dr. Jeff Masters , 3:18 PM GMT on August 04, 2009

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A tropical disturbance embedded in the Intertropical Convergence Zone (ITCZ), near 9N 35W, is moving west at about 15 mph. The heavy thunderstorm activity associated with this tropical wave has changed little over the past 24 hours, and remains disorganized. This morning's QuikSCAT pass showed a moderate wind shift, but nothing resembling an organized surface circulation. Top winds were in the 20 - 30 mph range. Strong easterly winds are creating about 20 knots of wind shear over the wave, which is marginally conducive for development. The disturbance is about 300 miles south of the Saharan Air Layer (SAL), so dust and dry air should not hinder development over the next few days.

Given the disturbance's current lack of organization, combined with the presence of 20 knots of wind shear, any development should be slow to occur. The forecast wind shear along the storm's path over the next five days is predicted to remain at or below 20 knots, which should allow some slow development. Sea surface temperatures (SSTs) will warm from about 28°C to 29°C as the storm progresses westward. The GFS model has been indicating some development is possible in several of its runs over the past few days, but has not been consistent with this prediction. None of the other models show any development of the system. NHC is giving the disturbance a low (less than 30% chance) of developing into a tropical depression over the next two days, which is a good forecast. The GFS and ECMWF models predict the system will be approaching the northern Lesser Antilles Islands by Sunday. Both models forecast the development of a band of very high wind shear just to the north of the islands at that time, so the long-range survival of anything that might manage to develop is in doubt.

CSU forecast team continues to predict an average hurricane season
A near-average Atlantic hurricane season is on tap for 2009, according to the seasonal hurricane forecast issued August 4 by Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU). The CSU team is calling for 10 named storms, 4 hurricanes, and 2 intense hurricanes, and an Accumulated Cyclone Energy (ACE) 83% of average. 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 15 named storms, 8 hurricanes, and 4 intense hurricanes per year. The new forecast is a step down from their June forecast, which called for 11 named storms, 5 hurricanes, and 2 intense hurricanes. Their April forecast called for 12 named storms, 6 hurricanes, and 2 intense hurricanes. The new forecast calls for a near-average chance of a major hurricane hitting the U.S., both along the East Coast (27% chance, 31% chance is average) and the Gulf Coast (26% chance, 30% chance is average). The Caribbean is also forecast to have an average risk of a major hurricane (37%; 42% is average).

The forecasters noted that while sea surface temperature anomalies have increased in the tropical Atlantic and surface pressures have fallen in recent weeks, which normally would favor higher hurricane activity, the presence of El Niño conditions in the Eastern Pacific should counteract these influences. They forecast that the current weak El Niño event will strengthen to a moderate event by September:

El Niño events tend to be associated with increased levels of vertical wind shear and decreased levels of Atlantic hurricane activity. Tropical Atlantic sea surface temperatures anomalies have warmed somewhat since our early June prediction and surface pressures have fallen somewhat. But, the negative influences of El Niño-induced strong Caribbean Basin and Main Development Region vertical wind shear typically dominate over surface pressure and sea surface temperature in the tropical Atlantic.



Figure 1. Change in Sea Surface Temperature anomaly (in °C) between July 2009 and May 2009. Most of the tropical Atlantic has warmed, relative to normal, over the past 2 months. Image credit: NOAA/ESRL.

Analogue years
The CSU team picked four previous years when atmospheric and oceanic conditions were similar to what we are seeing this year: weak to moderate El Niño conditions, and average tropical Atlantic and far northern Atlantic SSTs. Those four years were 2002, which featured Hurricane Lili that hit Louisiana as a Category 1 storm; 1965, which had Category 3 Betsy that hit New Orleans; 1963, which had Category 4 Hurricane Flora that devastated Cuba; and 1957, which didn't have any hurricanes that hit hit land during the peak part of hurricane season. The mean activity for these four years was 9 named storms, 4 hurricanes, and 2 intense hurricanes--almost the same as the 2009 CSU forecast.

How accurate are the August forecasts?
The August forecasts by the CSU team have historically offered a skill of 45 -62% higher than a "no-skill" forecast using climatology (Figure 2). However, they are using a new forecast scheme this year, so it is difficult to judge how skillful this year's forecast might be.


Figure 2. Accuracy of long-range forecasts of Atlantic hurricane season activity performed at Colorado State University (CSU) by Dr. Bill Gray's team (colored squares) and Tropical Storm Risk, Inc. (TSR, colored lines). The skill is measured by the Mean Square Skill Score (MSSS), which looks at the error and squares it, then compares the percent improvement the forecast has over a climatological forecast of 10 named storms, 6 hurricanes, and 2 intense hurricanes. TS=Tropical Storms, H=Hurricanes, IH=Intense Hurricanes, ACE=Accumulated Cyclone Energy, NTC=Net Tropical Cyclone Activity. Image credit: TSR.

August 2009 Atlantic hurricane season forecast from Tropical Storm Risk, Inc.
The British private forecasting firm Tropical Storm Risk, Inc. (TSR) also issued a new forecast today, and have increased their numbers by 20% from their June and July forecasts. TSR is also calling for a near-average season, predicting 12.6 named storms, 6.5 hurricanes, 2.8 intense hurricanes, and an Accumulated Cyclone Energy (ACE) 103% of average. Their June forecast called for 10.9 named storms, 5.2 hurricanes, 2.2 intense hurricanes, and an Accumulated Cyclone Energy (ACE) 72% of average. The storm numbers are slightly above the 50-year average of 10 named storms, 6 hurricanes, and 2 intense hurricanes. TSR predicts a 40% chance of an above-average season, 44% chance of a near-average season, and a 19% chance of a below-average season, as defined by ACE index. TSR rates their skill level as 51% above chance at forecasting the number of named storms, 60% skill for hurricanes, and 44% skill for intense hurricanes. These are far higher skill numbers than the June ones: 26% above chance at forecasting the number of named storms, 15% skill for hurricanes, and 19% skill for intense hurricanes.

TSR projects that 3.8 named storms will hit the U.S., with 1.6 of these being hurricanes. The averages from the 1950-2008 climatology are 3.2 named storms and 1.5 hurricanes. Their skill in making these August forecasts for U.S. landfalls is 25% above chance. In the Lesser Antilles Islands of the Caribbean, TSR projects 1.1 named storms, 0.5 of these being hurricanes. Climatology is 1.1 named storms and 0.5 hurricanes.

TSR cites one main factor for their increased forecast: higher sea surface temperatures than expected over the tropical Atlantic, due to the fact that the trade winds over the Atlantic should be slower than originally anticipated. Faster than average trade winds create less spin for developing storms, and allow the oceans to cool down, due to increased mixing of cold water from the depths and enhanced evaporational cooling.

The CSU and TSR groups are done making forecasts for the coming hurricane season, but NOAA is still due to put out an August update.

I'll have an update on Wednesday.
Jeff Masters

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1472. KEEPEROFTHEGATE (Mod)
3:55 PM GMT on August 05, 2009
209

WHXX01 KMIA 051316

CHGE77

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

1316 UTC WED AUG 5 2009



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



EAST PACIFIC OBJECTIVE AIDS FOR



TROPICAL CYCLONE FELICIA (EP082009) 20090805 1200 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

090805 1200 090806 0000 090806 1200 090807 0000



LAT LON LAT LON LAT LON LAT LON

BAMS 13.8N 128.3W 15.1N 130.1W 16.2N 131.7W 17.3N 133.3W

BAMD 13.8N 128.3W 14.9N 130.1W 15.9N 131.8W 16.7N 133.7W

BAMM 13.8N 128.3W 14.9N 130.0W 15.9N 131.6W 16.8N 133.3W

LBAR 13.8N 128.3W 15.0N 129.9W 16.4N 131.6W 17.7N 133.5W

SHIP 100KTS 114KTS 117KTS 112KTS

DSHP 100KTS 114KTS 117KTS 112KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

090807 1200 090808 1200 090809 1200 090810 1200



LAT LON LAT LON LAT LON LAT LON

BAMS 18.2N 135.2W 19.9N 140.1W 21.1N 145.9W 21.6N 151.4W

BAMD 17.2N 135.6W 18.1N 140.1W 19.0N 144.6W 20.2N 148.1W

BAMM 17.5N 135.1W 18.8N 139.6W 20.0N 144.4W 21.1N 148.3W

LBAR 18.6N 135.3W 19.4N 139.3W 19.4N 144.3W 20.1N 148.7W

SHIP 100KTS 77KTS 61KTS 44KTS

DSHP 100KTS 77KTS 61KTS 44KTS



...INITIAL CONDITIONS...

LATCUR = 13.8N LONCUR = 128.3W DIRCUR = 305DEG SPDCUR = 9KT

LATM12 = 12.6N LONM12 = 126.8W DIRM12 = 299DEG SPDM12 = 9KT

LATM24 = 12.0N LONM24 = 124.9W

WNDCUR = 100KT RMAXWD = 25NM WNDM12 = 70KT

CENPRS = 955MB OUTPRS = 1008MB OUTRAD = 200NM SDEPTH = D

RD34NE = 120NM RD34SE = 120NM RD34SW = 90NM RD34NW = 90NM



$$

NNNN


Member Since: July 15, 2006 Posts: 173 Comments: 54344
1471. jeffs713
3:28 PM GMT on August 05, 2009
Quoting stormpetrol:

closed low?

No, there are not any winds out of the south on the eastern side of the circulation near the main convection. If the light circulation around 32W moves west quickly, it can consolidate and become a closed low.
Member Since: August 3, 2008 Posts: 16 Comments: 5883
1470. cg2916
2:52 PM GMT on August 05, 2009
New blog.
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1469. AllStar17
2:51 PM GMT on August 05, 2009
Quoting wunderkidcayman:


Huh....they increased chances for development
Member Since: June 29, 2009 Posts: 13 Comments: 5313
1467. Thundercloud01221991
2:51 PM GMT on August 05, 2009


This is heading right for Hawaii
Member Since: August 1, 2006 Posts: 28 Comments: 3716
1466. wunderkidcayman
2:50 PM GMT on August 05, 2009
don't panic now people the yellow circle will be back at the 2pm outlook
Member Since: June 13, 2009 Posts: 2 Comments: 12147
1465. Claudette1234
2:49 PM GMT on August 05, 2009


Member Since: July 21, 2009 Posts: 0 Comments: 552
1464. cg2916
2:49 PM GMT on August 05, 2009
NEW BLOG
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1463. SQUAWK
2:49 PM GMT on August 05, 2009
NEW BLOG
Member Since: December 9, 2008 Posts: 0 Comments: 2498
1461. kmanislander
2:47 PM GMT on August 05, 2009
Good morning

Only on for a few minutes.

As I surmised yesterday, the upper level circulation outran the developing low and has now dissipated. There is a 1012 mb surface low which is now near 11N 34W but the 850 mb vorticity associated with the feature is somewhat displaced to the East by about 2 to 3 degrees of longitude.

This type of structure would not allow for any quick organization and with very dry air nearby any further move to the NW would likely curtail development.

For the moment it is worth keeping an eye on but that is about all for now.

Member Since: August 19, 2006 Posts: 0 Comments: 15842
1460. MrNatural
2:46 PM GMT on August 05, 2009
Good Morning to all from Austin. Just set the record for all time hottest month in July. Blew the old record away by almost .5 degree. Just hope August, which is traditionally the hottest month is more bearable. On to the tropics, my entry yesterday suggested that the ITCZ wave around 30 deg. was going to be more productive. The satellite imagery suggested that it was developing good out flow at the upper levels. But, as good as it looked, my concern for the dry SAL to the N and NW was spot on. A review of the SAL at http://cimss.ssec.wisc.edu/tropic/real-time/wavetrak/sal.html. shows that at 18:00 UTC on 8/4 the dry air starts to entrain itself within the wave and within 12 hours it was a shell of itself. Pretty graphic. With dry air and plenty of wind shear stretching across the Atlantic basin, it will be difficult for any wave to develop. Maybe next week...
Member Since: July 28, 2009 Posts: 0 Comments: 264
1459. Claudette1234
2:45 PM GMT on August 05, 2009

Hurricane FELICIA Public Advisory
--------------------------------------------------------------------------------
Home Public Adv Fcst/Adv Discussion Wind Probs Maps/Charts Archive
--------------------------------------------------------------------------------



000
WTPZ33 KNHC 051443
TCPEP3
BULLETIN
HURRICANE FELICIA ADVISORY NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082009
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
800 AM PDT WED AUG 05 2009

..FELICIA CONTINUES TO STRENGTHEN...REACHES MAJOR HURRICANE
STATUS...

AT 800 AM PDT...1500 UTC...THE CENTER OF HURRICANE FELICIA WAS
LOCATED NEAR LATITUDE 14.1 NORTH...LONGITUDE 128.7 WEST OR ABOUT
1370 MILES...2210 KM...WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA
CALIFORNIA.

FELICIA IS MOVING TOWARD THE NORTHWEST NEAR 12 MPH...19 KM/HR...AND
THIS MOTION IS EXPECTED TO CONTINUE OVER THE NEXT COUPLE OF DAYS.

SATELLITE IMAGERY INDICATES THAT MAXIMUM SUSTAINED WINDS HAVE
INCREASED TO NEAR 115 MPH...185 KM/HR...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24
HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 35 MILES...55 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 120
MILES...195 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 955 MB...28.20 INCHES.

...SUMMARY OF 800 AM PDT INFORMATION...
LOCATION...14.1N 128.7W
MAXIMUM SUSTAINED WINDS...115 MPH
PRESENT MOVEMENT...NORTHWEST OR 310 DEGREES AT 12 MPH
MINIMUM CENTRAL PRESSURE...955 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
200 PM PDT.

$$
FORECASTER PEREIRA




Member Since: July 21, 2009 Posts: 0 Comments: 552
1458. cg2916
2:45 PM GMT on August 05, 2009
Quoting stormpetrol:

closed low?

No. It's not closed.
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1456. stormpetrol
2:44 PM GMT on August 05, 2009

closed low?
Member Since: April 29, 2007 Posts: 0 Comments: 7930
1455. cg2916
2:43 PM GMT on August 05, 2009
I WAS RIGHT!
000
WTPZ33 KNHC 051443
TCPEP3
BULLETIN
HURRICANE FELICIA ADVISORY NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082009
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
800 AM PDT WED AUG 05 2009

..FELICIA CONTINUES TO STRENGTHEN...REACHES MAJOR HURRICANE
STATUS...

AT 800 AM PDT...1500 UTC...THE CENTER OF HURRICANE FELICIA WAS
LOCATED NEAR LATITUDE 14.1 NORTH...LONGITUDE 128.7 WEST OR ABOUT
1370 MILES...2210 KM...WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA
CALIFORNIA.

FELICIA IS MOVING TOWARD THE NORTHWEST NEAR 12 MPH...19 KM/HR...AND
THIS MOTION IS EXPECTED TO CONTINUE OVER THE NEXT COUPLE OF DAYS.

SATELLITE IMAGERY INDICATES THAT MAXIMUM SUSTAINED WINDS HAVE
INCREASED TO NEAR 115 MPH...185 KM/HR...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24
HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 35 MILES...55 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 120
MILES...195 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 955 MB...28.20 INCHES.

...SUMMARY OF 800 AM PDT INFORMATION...
LOCATION...14.1N 128.7W
MAXIMUM SUSTAINED WINDS...115 MPH
PRESENT MOVEMENT...NORTHWEST OR 310 DEGREES AT 12 MPH
MINIMUM CENTRAL PRESSURE...955 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
200 PM PDT.

$$
FORECASTER PEREIRA
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1454. cg2916
2:43 PM GMT on August 05, 2009
Enrique has all 8's on its Advisories and stuff.
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1453. cg2916
2:41 PM GMT on August 05, 2009
Enrique Advisory...
000
WTPZ32 KNHC 051440
TCPEP2
BULLETIN
TROPICAL STORM ENRIQUE ADVISORY NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP072009
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
800 AM PDT WED AUG 05 2009

AT 800 AM PDT...1500 UTC...THE CENTER OF TROPICAL STORM ENRIQUE WAS
LOCATED NEAR LATITUDE 17.3 NORTH...LONGITUDE 122.1 WEST OR ABOUT 880
MILES...1415 KM...WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA
CALIFORNIA.

ENRIQUE IS MOVING TOWARD THE NORTHWEST NEAR 16 MPH...26 KM/HR. THIS
TRACK WITH A GRADUAL TURN TO THE WEST IS EXPECTED TO CONTINUE.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/HR...WITH HIGHER
GUSTS. ENRIQUE IS EXPECTED TO WEAKEN AND DISSIPATE WITHIN THE NEXT
48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 100 MILES...160 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB...29.53 INCHES.

...SUMMARY OF 800 AM PDT INFORMATION...
LOCATION...17.3N 122.1W
MAXIMUM SUSTAINED WINDS...50 MPH
PRESENT MOVEMENT...NORTHWEST OR 305 DEGREES AT 16 MPH
MINIMUM CENTRAL PRESSURE...1000 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
200 PM PDT.

$$
FORECASTER SOWKO
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1452. cg2916
2:41 PM GMT on August 05, 2009
Enrique Forecast/Advisory out:
000
WTPZ22 KNHC 051439
TCMEP2
TROPICAL STORM ENRIQUE FORECAST/ADVISORY NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP072009
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1500 UTC WED AUG 05 2009

TROPICAL STORM CENTER LOCATED NEAR 17.3N 122.1W AT 05/1500Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 14 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1000 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT....... 80NE 85SE 0SW 30NW.
12 FT SEAS.. 80NE 85SE 30SW 30NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 17.3N 122.1W AT 05/1500Z
AT 05/1200Z CENTER WAS LOCATED NEAR 16.9N 121.5W

FORECAST VALID 06/0000Z 18.4N 124.0W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 70NE 85SE 0SW 30NW.

FORECAST VALID 06/1200Z 19.3N 126.3W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 07/0000Z 19.7N 128.8W
MAX WIND 25 KT...GUSTS 35 KT.

FORECAST VALID 07/1200Z 19.7N 131.4W...REMNANT LOW
MAX WIND 20 KT...GUSTS 25 KT.

FORECAST VALID 08/1200Z...DISSIPATED

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 200 NM
ON DAY 4 AND 250 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 09/1200Z...DISSIPATED

OUTLOOK VALID 10/1200Z...DISSIPATED

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.3N 122.1W

NEXT ADVISORY AT 05/2100Z

$$
FORECASTER SOWKO


Member Since: December 21, 2007 Posts: 13 Comments: 3046
1451. wunderkidcayman
2:40 PM GMT on August 05, 2009
Member Since: June 13, 2009 Posts: 2 Comments: 12147
1450. AllStar17
2:38 PM GMT on August 05, 2009
Quoting wunderkidcayman:
morning guys what is going on with our AOI talk to me people what up no more yellow and the nhc has a low on surface map


I realized they put a surface low on the map, but they took the circle away.
Member Since: June 29, 2009 Posts: 13 Comments: 5313
1449. Thundercloud01221991
2:38 PM GMT on August 05, 2009
The eye is clearing out on nighttime visible too. ADT likely to jump up shortly
Member Since: August 1, 2006 Posts: 28 Comments: 3716
1448. AllStar17
2:38 PM GMT on August 05, 2009
Quoting P451:


Hawaii doesn't get big storms coming in from the East. They come in from the south.

I don't ever recall seeing even the largest of EPAC hurricanes making it to Hawaii as anything more than a minor TS or a depression.

I do recall Hawaii's big storms forming to the south and heading north through the chain as intense systems.



Hurricane Flossie was a tropical storm as it passed (with about 60 mph winds)
Member Since: June 29, 2009 Posts: 13 Comments: 5313
1447. wunderkidcayman
2:37 PM GMT on August 05, 2009
morning guys what is going on with our AOI talk to me people what up no more yellow and the nhc has a low on surface map
Member Since: June 13, 2009 Posts: 2 Comments: 12147
1445. CycloneOz
2:35 PM GMT on August 05, 2009
Quoting presslord:


Oz....you know I am a huge fan of y'alls work....but in this case, I've got your number...this is just a convenient excuse to go spend a few days in Hawaii....I know it's tough duty for you poor souls, but I suppose somebody's gotta do it... ; )


You know...it's been over 22 years since I've been to the Big Island. I was thinking about covering the landfall from the area of the active volcano.

A natural two-fer! :)
Member Since: August 26, 2006 Posts: 10 Comments: 3752
1444. AllStar17
2:35 PM GMT on August 05, 2009
Also looking at Felicia, a clear eye is now visible on infrared images.

Member Since: June 29, 2009 Posts: 13 Comments: 5313
1443. hurricanejunky
2:34 PM GMT on August 05, 2009
I think dry air and wind shear is having an effect. Or as Oz put it, the AWDZ is in full effect. In case you missed, it AWDZ is the African Wave Destroyer Zone.
Member Since: August 28, 2006 Posts: 6 Comments: 2899
1442. CycloneOz
2:34 PM GMT on August 05, 2009
Yeah, Patrap...read all that earlier.

Not booking flight yet, no hurry. Can wait for the 36 hour update to see if the intensity does indeed fall off as forecasted.

50 knot winds at landfall or at 24 hours out from landfall will not be significant enough to justify travel, so it will be important in the coming 36 hours for you folks who are in the know to advise us.

Standing by...
Member Since: August 26, 2006 Posts: 10 Comments: 3752
1441. AllStar17
2:34 PM GMT on August 05, 2009
Convection expanding a bit......this still deserves some watching

Member Since: June 29, 2009 Posts: 13 Comments: 5313
1440. cyclonekid
2:32 PM GMT on August 05, 2009
What happened to our yellow circle...wait a second....what happened to the CONVECTION!!!???
Member Since: July 14, 2009 Posts: 51 Comments: 1731
1438. presslord
2:32 PM GMT on August 05, 2009
Quoting CycloneOz:
Update from XtremeHurricanes.com

The Extreme Hurricanes Team is considering travel to the Big Island of Hawaii on Saturday for a Monday / Tuesday intercept of Hurricane Felicia.

Final decision still 72 hours away...


Oz....you know I am a huge fan of y'alls work....but in this case, I've got your number...this is just a convenient excuse to go spend a few days in Hawaii....I know it's tough duty for you poor souls, but I suppose somebody's gotta do it... ; )
Member Since: August 13, 2007 Posts: 0 Comments: 10492
1437. Claudette1234
2:30 PM GMT on August 05, 2009
Hello Patrap

i think new NHC forecast will be in one hour.
Anyway Felicia looks impresive at the SAT pictures.
Member Since: July 21, 2009 Posts: 0 Comments: 552
1436. Patrap
2:27 PM GMT on August 05, 2009
Quoting CycloneOz:
Update from XtremeHurricanes.com

The Extreme Hurricanes Team is considering travel to the Big Island of Hawaii on Saturday for a Monday / Tuesday intercept of Hurricane Felicia.

Final decision still 72 hours away...


Id read the discussion b-4 Id book a flight OZ


Hurricane Felicia Discussion Number 7



Statement as of 2:00 am PDT on August 05, 2009

satellite intensity estimates at 0600 UTC from TAFB and SAB were
t4.5 and t4.0...respectively...but since that time the satellite
presentation has continued to improve. The eye has now persisted
for several hours and continues to warm with the deepest convection
located in the eastern and southeastern semicircles. An analysis
would now yield a average data T-number of 5.0 on the Dvorak
scale...and the initial intensity is being raised to 90 kt.

Now that Felicia is a deeper system...it is being pulled a little
more to the north by a large mid- to upper-level trough located off
the U.S. West Coast. The initial motion is 300/10...and little
change to this heading is expected over the next 48 hours while the
mid-latitude trough remains nearly stationary. By days 4 and 5...
two factors will cause Felicia to turn to the west. First...the
trough will move eastward over western North America and will be
replaced by a mid-level high currently located north of Hawaii.
Second...Felicia will likely be weakening by that time and will be
influenced more strongly by the lower-level trade wind flow. There
has been a noticeable northward shift in the tightly-clustered
guidance envelope for this package...and the official forecast is
shifted northward towards the model consensus.

The environment around Felicia remains conducive for further
strengthening. The mid-level cut-off low near California is
inducing diffluence aloft to the north of Felicia...and it appears
that an outflow jet may be forming. Vertical shear is expected to
remain light over the next five days...and oceanic heat content
should remain sufficient for at least the next 36 hours. The
northward shift in the track forecast puts Felicia over 24-25
degrees celsius water after 48 hours...and the new official
intensity forecast accounts for this by showing faster weakening
than was indicated in the previous forecast. If Felicia stays a
little farther south...it might be able to maintain its intensity
for a longer period of time.

Forecast positions and Max winds

initial 05/0900z 13.4n 128.2w 90 kt
12hr VT 05/1800z 14.1n 129.5w 100 kt
24hr VT 06/0600z 15.1n 131.2w 105 kt
36hr VT 06/1800z 16.1n 132.8w 100 kt
48hr VT 07/0600z 17.1n 134.6w 90 kt
72hr VT 08/0600z 18.5n 139.0w 75 kt
96hr VT 09/0600z 19.0n 144.5w 65 kt
120hr VT 10/0600z 19.0n 150.0w 50 kt

$$
forecaster Berg
Member Since: July 3, 2005 Posts: 426 Comments: 128639
1435. cg2916
2:26 PM GMT on August 05, 2009
Quoting Claudette1234:
Allstar17

NAVY page gives felicia this position and forced

FELICIA.100kts-955mb-138N-1283W


wow 955mb

i seriously think about CAT4 hurricane tomorrow

Link

In that case, change my forecast to 955 instead of 960 MB.
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1434. Claudette1234
2:26 PM GMT on August 05, 2009
Like to see the new track at NHC for Felicia
and if posible to land in Hawai as TS of CAT1 hurricane
Member Since: July 21, 2009 Posts: 0 Comments: 552
1433. CycloneOz
2:24 PM GMT on August 05, 2009
Update from XtremeHurricanes.com

The Extreme Hurricanes Team is considering travel to the Big Island of Hawaii on Saturday for a Monday / Tuesday intercept of Hurricane Felicia.

Final decision still 72 hours away...
Member Since: August 26, 2006 Posts: 10 Comments: 3752
1431. Claudette1234
2:20 PM GMT on August 05, 2009
Allstar17

NAVY page gives felicia this position and forced

FELICIA.100kts-955mb-138N-1283W


wow 955mb

i seriously think about CAT4 hurricane tomorrow

Link
Member Since: July 21, 2009 Posts: 0 Comments: 552
1430. hurricanejunky
2:15 PM GMT on August 05, 2009
Looking at the water vapor it looks like the dry air is truncating the westernmost part of the ITCZ and putting up a roadblock for the AOI's. I'm not an expert but that's what it looks like to me.
Member Since: August 28, 2006 Posts: 6 Comments: 2899
1429. AllStar17
2:12 PM GMT on August 05, 2009
Quoting hurricanejunky:
Is it me or is the dry air wreaking havoc on the ITCZ?


The AOI is within a moist environment with dry air off to the NW.

Member Since: June 29, 2009 Posts: 13 Comments: 5313
1428. AllStar17
2:11 PM GMT on August 05, 2009
Quoting cg2916:
I think that Felicia will be 115 MPH with 960 MB at the next advisory, and if I'm worng, then I'll eat crow.


I would agree with you...she is looking very good.

Member Since: June 29, 2009 Posts: 13 Comments: 5313
1427. hurricanejunky
2:10 PM GMT on August 05, 2009
Is it just me or is the dry air wreaking havoc on the ITCZ?
Member Since: August 28, 2006 Posts: 6 Comments: 2899
1426. jeffs713
2:10 PM GMT on August 05, 2009
I just had a great idea for a new company.... I could start a company that sells prepackaged crow! It would be great for internet bloggers, weather freaks, and people who just like the other, OTHER white meat.
Member Since: August 3, 2008 Posts: 16 Comments: 5883
1425. AllStar17
2:10 PM GMT on August 05, 2009
Quoting stoormfury:
yes the low of 1012 mb is located to the ogof the convection moving west. looks to be the stongest 850 mb vorticity in the catl all season. moving into low shear and warmer sst soon


Lets not go that far....the vorticity is NOT the strongest we have seen all year. It is moving into warmer sst's......but right now it is only an AOI with a shot at development.
Member Since: June 29, 2009 Posts: 13 Comments: 5313
1424. stoormfury
2:10 PM GMT on August 05, 2009
yes the low of 1012 mb is located to the south of the convection moving west. looks to be the strongest 850 mb vorticity in the catl all season. moving into low shear and warmer sst soon
Member Since: August 22, 2006 Posts: 0 Comments: 2713
1423. cg2916
2:08 PM GMT on August 05, 2009
I think that Felicia will be 115 MPH with 960 MB at the next advisory, and if I'm worng, then I'll eat crow.
Member Since: December 21, 2007 Posts: 13 Comments: 3046
1422. AllStar17
2:07 PM GMT on August 05, 2009
Quoting AllStar17:


IKE, what area are you taking about? The area with high vorticity near 30W?


The more I look at it Ike.....the thunderstorms and the highest vorticity are fairly close to each other. This might night be done yet. The easterly shear must be lessening.....this may stand a chance after all.
Member Since: June 29, 2009 Posts: 13 Comments: 5313

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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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