92L still a threat to develop; Igor a hurricane; TD 12 forming near Africa

By: Dr. Jeff Masters , 2:18 PM GMT on September 12, 2010

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Tropical disturbance (92L) over the Central Caribbean, a few hundred miles south of the Dominican Republic, remains a threat to develop into a tropical depression. Satellite loops this morning show 92L may be starting to form a surface circulation, and an Air Force Hurricane Hunter aircraft will investigate 92L this afternoon to see if a tropical depression is forming.

The storm has only a modest area of heavy thunderstorm with limited low-level spiral banding and upper-level outflow, thanks to an infusion of dry air last night that disrupted the storm. Long range radar out of Puerto Rico shows that heavy rains are affecting that island, but there is no rotation to the radar echoes evident. Wind shear over 92L is low, 5 - 10 knots. The waters beneath are hot, 29.5°C, and these warm waters extend to great depth. Water vapor satellite loops show a large area of dry air lies to the north and west of 92L, and this dry air could interfere with development at times over the next few days.


Figure 1. Morning satellite image of 92L.

Track forecast for 92L
The disturbance is moving west to west-northwest at 15 mph, and steering currents favor a continuation of this motion for the next three days. Model support for development is scattered. The GFS and NOGAPS models do not develop 92L. The GFDL and ECMWF models predict development, with a track taking 92L into Belize or Mexico's Yucatan Peninsula on Wednesday. On this track, the southern Dominican Republic can expect heavy rains of 3 - 6 inches today through Monday morning; southern Haiti can expect similar rains tonight through Monday night, and Jamaica and the Cayman Islands can expect heavier rains of 4 - 8 inches Monday and Tuesday. Eastern Cuba can expect rains in the 2 - 4 inch range. Once 92L crosses the Yucatan, the ridge of high pressure steering it is expected to remain in place, forcing 92L to a second landfall in Mexico south of the Texas border.

Intensity forecast for 92L
NHC is putting the odds of 92L developing into a tropical depression by Tuesday at 50%; I'd put them higher, at 70%. However, time is running out for 92L to become a hurricane before hitting the Yucatan Peninsula on Wednesday. Given the current disorganized state of 92L, it would be difficult for it to intensify quickly enough to become a hurricane by then. The storm may also suffer another of its mysterious evening collapses, where it loses most of its heavy thunderstorm activity. However, the SHIPS model predicts wind shear will remain low, 5 - 10 knots, through the period, and water temperatures are certainly warm enough to support development. The main detriment to intensification is likely to be dry air, and 92L could wrap in some of the dry air to its northwest at times, slowing down development. There are a number of research flights being made into 92L this afternoon that should help long-term efforts to make better predictions in the future on whether or not disturbances like this will develop or not.


Figure 2. Morning satellite image of Igor.

Igor
Hurricane Igor appears destined to become a large and powerful major hurricane over the Central Atlantic in the days to come. Wind shear is low, 5 - 10 knots, and is expected to drop below 5 knots for the next five days. Waters are warm, 28°C, and will warm to 29°C by Wednesday. Igor has moistened its environment enough to keep the dry air of the Saharan Air Layer (SAL) at bay. Igor is undergoing a period of rapid intensification today, and will probably be a Category 3 or 4 hurricane by Monday.

The track forecast for Igor remains unchanged. Igor will move west under the influence of a strong ridge of high pressure for the next 2 - 3 days, then turn more to the west-northwest then northwest in response to the steering influence of a broad trough of low pressure moving across the Western Atlantic on Tuesday and Wednesday. This should allow Igor to pass several hundred miles to the northeast of the Lesser Antilles. In the longer range, Igor may be a threat to Bermuda, and does have a small chance of making landfall on the U.S. East Coast or Canada. Climatology shows that about 15% of all tropical cyclones that have existed at Igor's current position have gone on to hit the U.S. East Coast; these odds are about 10% for Bermuda and 10% for Canada. The forecast steering pattern for the period 5 - 12 days from now from the ECMWF and GFS models shows a continuation of the pattern we've seen all hurricane season, with regular strong troughs of low pressure moving off the U.S. East Coast. This pattern favors Igor eventually recurving out to sea without affecting any land areas. Recent runs of the ECMWF model indicate that these troughs may not be as intense as previously thought, so it is possible Igor has a higher chance than usual to hit land than climatology suggests. One wild card may be the possible development of TD 12 behind Igor. If TD 12 develops into a hurricane, and moves close to Igor, as some of the models are suggesting, the two hurricanes could rotate around a common center, forcing Igor more towards the coast of the U.S. The long term fate of Igor is difficult to predict at this point.

Tropical Depression Twelve forms
Tropical Depression Twelve formed between the Cape Verdes Islands and coast of Africa this morning, and is already affecting the Cape Verdes with winds near tropical storm strength; sustained winds of 35 mph were recorded in the northwest Cape Verdes this morning. You can follow the progress of TD 12 through the Cape Verdes today using our wundermap.

Next post
I'll have a new post Monday morning, and perhaps late this afternoon if events warrant.

Jeff Masters

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3196. wjdow
Quoting joetuttledays:
they still saying Igor is gonna recurve?


read dr. masters latest. hasn't been wrong yet.
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3195. angiest
Quoting weatherwart:
Moving west at 13 mph. There you go. Igor wobbles but he doesn't go south.


The discussion says he was going a little south.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
I agree my eyes see a sw movement. And I tried the line up the southern edge of the eye, tried putting my mouse in the center at the start of the loop and just tried eyeballing it with the L/L on. And all I see is a slight movement to the sw.

And unless it starts back nw I think it is significant and will not make the next forecast point (unless of course that point is moved).

But then again my eyes are failing due to advanced age! And I know nothing about nautical bearings. So I guess it all means nothing.
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Exactly! Thanks for the info!
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Beautiful Africa...

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3190. Ldog74
Quoting hunkerdown:
as I stated above, contracting diameter has no bearing on path of the center point of the eye, no matter what the size of the eye. The center point of the eye has definitely moved slightly south of due west over the last few frames.


Both arguments are valid. Here's why: John is in Seattle. Sue is in St. Louis. Bill is in Miami. John finds the halfway point between him and Bill. Sue finds the halfway point between her and Bill. In both cases, Bill is in the same place. However, the center between John and Bill is more to the Northwest than the center between Sue and Bill.

As the northern part of the eyewall contracts, the center of the eye effectively moves WSW, even though the system as a whole is still moving west.
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11pm cone shifted significantly to a northerly bias...
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3188. sopla2o
Quoting bluenosedave:


What would you anchor a buoy to? The Mid-Atlantic Ridge? ;-)


Actually did some research on it and they have one at 19/38 and another at 21/58 ... But nothing in between... So I guess they do have bouys in the area...
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.
Member Since: September 2, 2009 Posts: 130 Comments: 21193


It has moved ever so slightly WSW
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Moving west at 13 mph. There you go. Igor wobbles but he doesn't go south.
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Quoting DestinJeff:


Space bags.
I tried that but they got really wrinkled!
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000
WTNT41 KNHC 130248
TCDAT1
HURRICANE IGOR DISCUSSION NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010
1100 PM AST SUN SEP 12 2010

IGOR HAS CONTINUED TO INTENSIFY WITH VERY COLD CLOUD TOPS...LOWER
THAN -70C...WRAPPING AROUND THE SLOWLY-SHRINKING EYE DURING THE
PAST SEVERAL HOURS. ALTHOUGH THE TOPS HAVE RECENTLY WARMED A
LITTLE OVER THE SOUTHWEST QUADRANT...SUBJECTIVE DVORAK ESTIMATES
FROM TAFB AND SAB ARE T6.5/127 KT AND OBJECTIVE ESTIMATES FROM THE
ADT AND HIE ALGORITHMS ARE T6.6/130 KT AND T6.9/137 KT...
RESPECTIVELY. AS A COMPROMISE...THE INITIAL INTENSITY IS SET AT
130 KT. AN EXPERIMENTAL PRODUCT FROM UW-CIMSS RUN AT NHC INDICATES
THAT THERE IS A 42 PERCENT CHANCE OF SECONDARY EYEWALL FORMATION
WITHIN THE NEXT 12 HOURS...AND A 90 PERCENT CHANCE WITHIN 24 HOURS.
THE PERIOD OF RAPID INTENSIFICATION IS LIKELY TO END SOON...BUT THE
OFFICIAL FORECAST FOLLOWS THE SHIPS/LGEM MODELS BY SHOWING IGOR
REACHING THE THRESHOLD OF CATEGORY 5 STRENGTH BEFORE THAT HAPPENS.
SOME WEAKENING IS THEN INDICATED AFTER EYEWALL REPLACEMENT
OCCURS...BUT IGOR IS EXPECTED TO REMAIN A POWERFUL HURRICANE FOR
SEVERAL DAYS. AS IS ALWAYS THE CASE WITH STRONG HURRICANES LIKE
IGOR...FLUCTUATIONS IN INTENSITY ARE LIKELY BUT ARE ALSO DIFFICULT
TO FORECAST.

THE MEAN MOTION IS 270/11...BUT IGOR HAS BEEN WOBBLING A LITTLE TO
THE SOUTH OF THAT VECTOR. IGOR IS MOVING INTO AN ENVIRONMENT WHERE
THE STEERING FLOW IS BECOMING INCREASINGLY DICTATED BY A LARGE
LONGWAVE TROUGH OVER THE WESTERN ATLANTIC...AND THE HURRICANE IS
EXPECTED TO RESPOND BY TURNING TOWARD THE WEST-NORTHWEST WITHIN THE
NEXT 24-48 HOURS. SOME OF THE GLOBAL MODELS INDICATE THAT THE
TROUGH COULD FLATTEN A LITTLE BY DAY 3 AND ALLOW THE SUBTROPICAL
RIDGE TO BUILD WESTWARD...BUT AT THIS TIME THERE IS TOO MUCH
DISAGREEMENT TO INDICATE A WESTWARD TURN IN THE FORECAST. THE
TRACK GUIDANCE HAS SHIFTED A LITTLE TO THE NORTH...BUT THE NEW
OFFICIAL FORECAST STILL LIES ON THE SOUTHERN SIDE OF THE GUIDANCE
ENVELOPE UNTIL IT BECOMES CLEAR THAT IGOR IS READY TO TURN. THIS
SOLUTION ALSO GIVES CREDENCE TO THE MORE SOUTHERN ECMWF AND UKMET
MODELS.
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Stored energy that depends upon the relative position of various parts of a system. A train of cars on a gravity-powered roller coaster has more potential energy raised above the ground at the top of a hill than it has after falling to the earth along the hill's inclined track. In the elevated position it is capable of doing more work. By extension, the higher the lift hill, the greater the potential energy.

Potential energy is a property of a system and not of an individual body or particle. It depends only on its initial and final configurations; it is independent of the path the object travels. The value of potential energy is arbitrary and relative to the choice of reference point. Gravitational potential energy near the Earth's surface may be computed by multiplying the weight of an object by its distance above the reference point.

Potential energy may be converted into energy of motion, called kinetic energy. Traditionally potential energy is included with kinetic energy as a form of mechanical energy so that the total energy in gravitational systems can be calculated as a constant.

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000
WTNT41 KNHC 130248
TCDAT1
HURRICANE IGOR DISCUSSION NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010
1100 PM AST SUN SEP 12 2010

IGOR HAS CONTINUED TO INTENSIFY WITH VERY COLD CLOUD TOPS...LOWER
THAN -70C...WRAPPING AROUND THE SLOWLY-SHRINKING EYE DURING THE
PAST SEVERAL HOURS. ALTHOUGH THE TOPS HAVE RECENTLY WARMED A
LITTLE OVER THE SOUTHWEST QUADRANT...SUBJECTIVE DVORAK ESTIMATES
FROM TAFB AND SAB ARE T6.5/127 KT AND OBJECTIVE ESTIMATES FROM THE
ADT AND HIE ALGORITHMS ARE T6.6/130 KT AND T6.9/137 KT...
RESPECTIVELY. AS A COMPROMISE...THE INITIAL INTENSITY IS SET AT
130 KT. AN EXPERIMENTAL PRODUCT FROM UW-CIMSS RUN AT NHC INDICATES
THAT THERE IS A 42 PERCENT CHANCE OF SECONDARY EYEWALL FORMATION
WITHIN THE NEXT 12 HOURS...AND A 90 PERCENT CHANCE WITHIN 24 HOURS.
THE PERIOD OF RAPID INTENSIFICATION IS LIKELY TO END SOON...BUT THE
OFFICIAL FORECAST FOLLOWS THE SHIPS/LGEM MODELS BY SHOWING IGOR
REACHING THE THRESHOLD OF CATEGORY 5 STRENGTH BEFORE THAT HAPPENS.
SOME WEAKENING IS THEN INDICATED AFTER EYEWALL REPLACEMENT
OCCURS...BUT IGOR IS EXPECTED TO REMAIN A POWERFUL HURRICANE FOR
SEVERAL DAYS. AS IS ALWAYS THE CASE WITH STRONG HURRICANES LIKE
IGOR...FLUCTUATIONS IN INTENSITY ARE LIKELY BUT ARE ALSO DIFFICULT
TO FORECAST.

THE MEAN MOTION IS 270/11...BUT IGOR HAS BEEN WOBBLING A LITTLE TO
THE SOUTH OF THAT VECTOR. IGOR IS MOVING INTO AN ENVIRONMENT WHERE
THE STEERING FLOW IS BECOMING INCREASINGLY DICTATED BY A LARGE
LONGWAVE TROUGH OVER THE WESTERN ATLANTIC...AND THE HURRICANE IS
EXPECTED TO RESPOND BY TURNING TOWARD THE WEST-NORTHWEST WITHIN THE
NEXT 24-48 HOURS. SOME OF THE GLOBAL MODELS INDICATE THAT THE
TROUGH COULD FLATTEN A LITTLE BY DAY 3 AND ALLOW THE SUBTROPICAL
RIDGE TO BUILD WESTWARD...BUT AT THIS TIME THERE IS TOO MUCH
DISAGREEMENT TO INDICATE A WESTWARD TURN IN THE FORECAST. THE
TRACK GUIDANCE HAS SHIFTED A LITTLE TO THE NORTH...BUT THE NEW
OFFICIAL FORECAST STILL LIES ON THE SOUTHERN SIDE OF THE GUIDANCE
ENVELOPE UNTIL IT BECOMES CLEAR THAT IGOR IS READY TO TURN. THIS
SOLUTION ALSO GIVES CREDENCE TO THE MORE SOUTHERN ECMWF AND UKMET
MODELS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 13/0300Z 17.6N 47.8W 130 KT
12HR VT 13/1200Z 17.8N 49.5W 140 KT
24HR VT 14/0000Z 18.2N 51.3W 135 KT
36HR VT 14/1200Z 18.9N 53.0W 130 KT
48HR VT 15/0000Z 19.8N 54.6W 125 KT
72HR VT 16/0000Z 22.0N 57.5W 125 KT
96HR VT 17/0000Z 24.0N 60.0W 120 KT
120HR VT 18/0000Z 27.0N 63.0W 110 KT

$$
FORECASTER BERG

Member Since: September 2, 2009 Posts: 130 Comments: 21193
Im not sure if Igor will make it to 140kt before an EWRC. We'll see.
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I haven't seen that color in the Atlantic being predicted since August 2008.

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HURRICANE IGOR DISCUSSION NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010
1100 PM AST SUN SEP 12 2010

IGOR HAS CONTINUED TO INTENSIFY WITH VERY COLD CLOUD TOPS...LOWER
THAN -70C...WRAPPING AROUND THE SLOWLY-SHRINKING EYE DURING THE
PAST SEVERAL HOURS. ALTHOUGH THE TOPS HAVE RECENTLY WARMED A
LITTLE OVER THE SOUTHWEST QUADRANT...SUBJECTIVE DVORAK ESTIMATES
FROM TAFB AND SAB ARE T6.5/127 KT AND OBJECTIVE ESTIMATES FROM THE
ADT AND HIE ALGORITHMS ARE T6.6/130 KT AND T6.9/137 KT...
RESPECTIVELY. AS A COMPROMISE...THE INITIAL INTENSITY IS SET AT
130 KT. AN EXPERIMENTAL PRODUCT FROM UW-CIMSS RUN AT NHC INDICATES
THAT THERE IS A 42 PERCENT CHANCE OF SECONDARY EYEWALL FORMATION
WITHIN THE NEXT 12 HOURS...AND A 90 PERCENT CHANCE WITHIN 24 HOURS.
THE PERIOD OF RAPID INTENSIFICATION IS LIKELY TO END SOON...BUT THE
OFFICIAL FORECAST FOLLOWS THE SHIPS/LGEM MODELS BY SHOWING IGOR
REACHING THE THRESHOLD OF CATEGORY 5 STRENGTH BEFORE THAT HAPPENS.
SOME WEAKENING IS THEN INDICATED AFTER EYEWALL REPLACEMENT
OCCURS...BUT IGOR IS EXPECTED TO REMAIN A POWERFUL HURRICANE FOR
SEVERAL DAYS. AS IS ALWAYS THE CASE WITH STRONG HURRICANES LIKE
IGOR...FLUCTUATIONS IN INTENSITY ARE LIKELY BUT ARE ALSO DIFFICULT
TO FORECAST.

THE MEAN MOTION IS 270/11...BUT IGOR HAS BEEN WOBBLING A LITTLE TO
THE SOUTH OF THAT VECTOR. IGOR IS MOVING INTO AN ENVIRONMENT WHERE
THE STEERING FLOW IS BECOMING INCREASINGLY DICTATED BY A LARGE
LONGWAVE TROUGH OVER THE WESTERN ATLANTIC...AND THE HURRICANE IS
EXPECTED TO RESPOND BY TURNING TOWARD THE WEST-NORTHWEST WITHIN THE
NEXT 24-48 HOURS. SOME OF THE GLOBAL MODELS INDICATE THAT THE
TROUGH COULD FLATTEN A LITTLE BY DAY 3 AND ALLOW THE SUBTROPICAL
RIDGE TO BUILD WESTWARD...BUT AT THIS TIME THERE IS TOO MUCH
DISAGREEMENT TO INDICATE A WESTWARD TURN IN THE FORECAST. THE
TRACK GUIDANCE HAS SHIFTED A LITTLE TO THE NORTH...BUT THE NEW
OFFICIAL FORECAST STILL LIES ON THE SOUTHERN SIDE OF THE GUIDANCE
ENVELOPE UNTIL IT BECOMES CLEAR THAT IGOR IS READY TO TURN. THIS
SOLUTION ALSO GIVES CREDENCE TO THE MORE SOUTHERN ECMWF AND UKMET
MODELS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 13/0300Z 17.6N 47.8W 130 KT
12HR VT 13/1200Z 17.8N 49.5W 140 KT
24HR VT 14/0000Z 18.2N 51.3W 135 KT
36HR VT 14/1200Z 18.9N 53.0W 130 KT
48HR VT 15/0000Z 19.8N 54.6W 125 KT
72HR VT 16/0000Z 22.0N 57.5W 125 KT
96HR VT 17/0000Z 24.0N 60.0W 120 KT
120HR VT 18/0000Z 27.0N 63.0W 110 KT

$$
FORECASTER BERG

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Quoting weatherxtreme:
Is Igor moving more south now of west? or just my untrained eyes playing tricks? probably just a wobble though.


According to RGB LOOP, yes. May only be a jog though and we'd need to see if that motion maintains. It could, however, be instrumental movement, delaying the turn or making the turn less pronounced.

Keep watching! ;)
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Quoting DestinJeff:
NEW!



I literally gasped in real life when I saw that.
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3174. djdanik
ok a lot of asking if he is annular or no. i believe some people dont know what is a annular hurricane and how rare this things are, how many criteria have to be met etc etc. not to metntion the fact annular hurricanes were just "discovered" since 2002, not that there werent any before that, but just saying. an annular hurricane cares very little about its surroundings, even in terrible conditions they endure, and after getting to peak intensity they decay slower than normal hurricanes.

theres a complete article about it in wikipedia: here is the link if u wish to know more about them.
http://en.wikipedia.org/wiki/Annular_hurricane
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Quoting pottery:

Heh!
That's FAR simpler than my explanation....
Yours was a slightly more technical answer. Kind of like graduating fom primary to secondary school. Both are apt, but the "Washing Machine Theory", has now been officially christened in my book. Kudos, MZT.
Member Since: Posts: Comments:
3170. Grothar
Igor now up to 150mph
Member Since: Posts: Comments:
TNT42 KNHC 130248
TCDAT2
TROPICAL STORM JULIA DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010
1100 PM AST SUN SEP 12 2010

INFRARED AND MICROWAVE SATELLITE IMAGERY SHOW THAT THE CENTER OF
THE CYCLONE IS LOCATED NEAR THE EASTERN EDGE OF A CURVED BAND OF
CONVECTION THAT WRAPS AROUND THE WESTERN SEMICIRCLE OF THE SYSTEM.
SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE 35 KT FROM TAFB AND 30 KT
FROM SAB. OBJECTIVE DVORAK ESTIMATES FROM UW/CIMMS ARE SLIGHTLY
HIGHER. A BLEND OF THESE ESTIMATES SUPPORT AN UPGRADE OF THE
DEPRESSION TO A 35-KT TROPICAL STORM...THE TENTH OF THE 2010
ATLANTIC HURRICANE SEASON.

THE EASTERLY SHEAR IS EXPECTED TO WEAKEN DURING THE NEXT 12 HOURS
AND IS FORECAST TO REMAIN LIGHT OVER THE NEXT COUPLE OF DAYS.
DURING THAT TIME JULIA WILL BE TRAVERSING WARM WATER AND AS A
RESULT...STEADY STRENGTHENING IS ANTICIPATED. THE SHIPS...LGEM...
AND GFDL MODELS ALL BRING JULIA TO HURRICANE STATUS WITHIN TWO DAYS
AND THE NHC FORECAST IS IN GOOD AGREEMENT. THEREAFTER...JULIA WILL
BE MOVING OVER SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND INTO AN
AREA OF INCREASING SOUTHWESTERLY SHEAR TO THE EAST OF AN
UPPER-LEVEL LOW/TROUGH BETWEEN 30W AND 40W. IT IS A BIT SURPRISING
GIVEN THESE NEGATIVE FACTORS THAT THE INTENSITY GUIDANCE SHOWS
LITTLE...IF ANY...WEAKENING. BECAUSE OF THAT...THE OFFICIAL
FORECAST WILL KEEP JULIA AT 65 KT AT DAYS 3-5 FOR NOW.

THE CENTER OF JULIA WAS RELOCATED A LITTLE EAST OF THE PREVIOUS
ADVISORY POSITION BASED ON THE EARLIER MICROWAVE DATA. THE INITIAL
MOTION ESTIMATE IS 285/10. THE TRACK FORECAST REASONING REMAINS
THE SAME AS THE PREVIOUS ADVISORY. JULIA IS FORECAST TO MOVE
WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A MID-LEVEL
RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN ATLANTIC.
IN A COUPLE OF DAYS...THE CYCLONE IS FORECAST TO TURN NORTHWESTWARD
TOWARD A WEAKNESS IN THE RIDGE. MOST OF THE GUIDANCE INDICATES A
TURN BACK TOWARD THE WEST-NORTHWEST LATE IN THE PERIOD AS JULIA
MOVES AROUND THE NORTH SIDE OF AN UPPER-LEVEL LOW THAT CUTS OFF
NEAR 40W. THE OFFICIAL FORECAST TRACK IS GOOD AGREEMENT WITH THE
PREVIOUS ADVISORY AND A BLEND OF THE LATEST RUNS OF THE GFS...
UKMET...GFDL...HWRF...AND ECMWF MODELS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 13/0300Z 13.5N 23.5W 35 KT
12HR VT 13/1200Z 14.0N 25.3W 45 KT
24HR VT 14/0000Z 14.9N 27.6W 50 KT
36HR VT 14/1200Z 15.9N 29.5W 55 KT
48HR VT 15/0000Z 17.1N 31.1W 65 KT
72HR VT 16/0000Z 20.9N 35.1W 65 KT
96HR VT 17/0000Z 24.5N 41.0W 65 KT
120HR VT 18/0000Z 27.5N 46.5W 65 KT

$$
FORECASTER BROWN
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Igor now predicted to become a Category 5.
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Wide view
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they still saying Igor is gonna recurve?
Member Since: Posts: Comments:
3165. aimetti
so correct me if im wrong but igor has gone from 75 mph to 150 mph in 24 hours?

Member Since: Posts: Comments:
Ach! not as yet any discussion!!!

But Here's Julia!... and Igor at 150mph...
Member Since: October 25, 2005 Posts: 19 Comments: 22081
Quoting DestinJeff:


I like to keep my references fresh.
I keep mine in the crisper
Member Since: Posts: Comments:
3161. MZT
Quoting DestinJeff:


I like to keep my references fresh.
Where's the beef?
Member Since: September 24, 2005 Posts: 0 Comments: 793
3160. angiest
Quoting DestinJeff:
NEW!



Forecast to be cat 5.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM JULIA DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010
1100 PM AST SUN SEP 12 2010

INFRARED AND MICROWAVE SATELLITE IMAGERY SHOW THAT THE CENTER OF
THE CYCLONE IS LOCATED NEAR THE EASTERN EDGE OF A CURVED BAND OF
CONVECTION THAT WRAPS AROUND THE WESTERN SEMICIRCLE OF THE SYSTEM.
SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE 35 KT FROM TAFB AND 30 KT
FROM SAB. OBJECTIVE DVORAK ESTIMATES FROM UW/CIMMS ARE SLIGHTLY
HIGHER. A BLEND OF THESE ESTIMATES SUPPORT AN UPGRADE OF THE
DEPRESSION TO A 35-KT TROPICAL STORM...THE TENTH OF THE 2010
ATLANTIC HURRICANE SEASON.

THE EASTERLY SHEAR IS EXPECTED TO WEAKEN DURING THE NEXT 12 HOURS
AND IS FORECAST TO REMAIN LIGHT OVER THE NEXT COUPLE OF DAYS.
DURING THAT TIME JULIA WILL BE TRAVERSING WARM WATER AND AS A
RESULT...STEADY STRENGTHENING IS ANTICIPATED. THE SHIPS...LGEM...
AND GFDL MODELS ALL BRING JULIA TO HURRICANE STATUS WITHIN TWO DAYS
AND THE NHC FORECAST IS IN GOOD AGREEMENT. THEREAFTER...JULIA WILL
BE MOVING OVER SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND INTO AN
AREA OF INCREASING SOUTHWESTERLY SHEAR TO THE EAST OF AN
UPPER-LEVEL LOW/TROUGH BETWEEN 30W AND 40W. IT IS A BIT SURPRISING
GIVEN THESE NEGATIVE FACTORS THAT THE INTENSITY GUIDANCE SHOWS
LITTLE...IF ANY...WEAKENING. BECAUSE OF THAT...THE OFFICIAL
FORECAST WILL KEEP JULIA AT 65 KT AT DAYS 3-5 FOR NOW.

THE CENTER OF JULIA WAS RELOCATED A LITTLE EAST OF THE PREVIOUS
ADVISORY POSITION BASED ON THE EARLIER MICROWAVE DATA. THE INITIAL
MOTION ESTIMATE IS 285/10. THE TRACK FORECAST REASONING REMAINS
THE SAME AS THE PREVIOUS ADVISORY. JULIA IS FORECAST TO MOVE
WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A MID-LEVEL
RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN ATLANTIC.
IN A COUPLE OF DAYS...THE CYCLONE IS FORECAST TO TURN NORTHWESTWARD
TOWARD A WEAKNESS IN THE RIDGE. MOST OF THE GUIDANCE INDICATES A
TURN BACK TOWARD THE WEST-NORTHWEST LATE IN THE PERIOD AS JULIA
MOVES AROUND THE NORTH SIDE OF AN UPPER-LEVEL LOW THAT CUTS OFF
NEAR 40W. THE OFFICIAL FORECAST TRACK IS GOOD AGREEMENT WITH THE
PREVIOUS ADVISORY AND A BLEND OF THE LATEST RUNS OF THE GFS...
UKMET...GFDL...HWRF...AND ECMWF MODELS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 13/0300Z 13.5N 23.5W 35 KT
12HR VT 13/1200Z 14.0N 25.3W 45 KT
24HR VT 14/0000Z 14.9N 27.6W 50 KT
36HR VT 14/1200Z 15.9N 29.5W 55 KT
48HR VT 15/0000Z 17.1N 31.1W 65 KT
72HR VT 16/0000Z 20.9N 35.1W 65 KT
96HR VT 17/0000Z 24.5N 41.0W 65 KT
120HR VT 18/0000Z 27.5N 46.5W 65 KT

$$
FORECASTER BROWN

NNNN
Member Since: September 2, 2009 Posts: 130 Comments: 21193
3158. wjdow
Quoting bluenosedave:


What would you anchor a buoy to? The Mid-Atlantic Ridge? ;-)


no, but satellites can measure wave height, at least i think they can (:
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92L will soon make its WilmaShow.....
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Hmm. NCEP has a HURRICANE striking the YUCATAN on 9/18

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000
WTNT31 KNHC 130246
TCPAT1
BULLETIN
HURRICANE IGOR ADVISORY NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010
1100 PM AST SUN SEP 12 2010

...IGOR STILL INTENSIFYING...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.6N 47.8W
ABOUT 1005 MI...1620 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/HR
PRESENT MOVEMENT...W OR 270 DEGREES AT 13 MPH...20 KM/HR
MINIMUM CENTRAL PRESSURE...935 MB...27.61 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 PM AST...0300 UTC...THE EYE OF HURRICANE IGOR WAS LOCATED
NEAR LATITUDE 17.6 NORTH...LONGITUDE 47.8 WEST. IGOR IS MOVING
TOWARD THE WEST NEAR 13 MPH...20 KM/HR. A TURN TOWARD THE
WEST-NORTHWEST WITH SOME DECREASE IN FORWARD SPEED IS EXPECTED TO
BEGIN LATE MONDAY AND TUESDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 150 MPH...240
KM/HR...WITH HIGHER GUSTS. IGOR IS A CATEGORY FOUR HURRICANE ON
THE SAFFIR-SIMPSON HURRICANE WIND SCALE. SOME FLUCTUATION IN
INTENSITY IS LIKELY DURING THE NEXT 48 HOURS...AND IGOR COULD
BECOME A CATEGORY FIVE HURRICANE ON MONDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES...65 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 160
MILES...260 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 935 MB...27.61 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 AM AST.

$$
FORECASTER BERG
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3152. angiest
Quoting KanKunKid:


What is the scale? 1 to 10?


1 to 100. Igor is the most annular storm since Danielle, which also rated a 1 at one time.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
...IGOR STILL INTENSIFYING...

SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.6N 47.8W
ABOUT 1005 MI...1620 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/HR
PRESENT MOVEMENT...W OR 270 DEGREES AT 13 MPH...20 KM/HR
MINIMUM CENTRAL PRESSURE...935 MB...27.61 INCHES
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Well, it will be interesting to see if 92L behaves according to the John Hope rule after it passes 75W tonight. You'd have thought that by now, with all that heat energy in the water, we would have had our other major hurricane. Hopefully it stays disorganized and dies like Gaston did.
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TROPICAL STORM JULIA ADVISORY NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122010
1100 PM AST SUN SEP 12 2010

...DEPRESSION BECOMES A TROPICAL STORM...TENTH OF THE ATLANTIC
HURRICANE SEASON...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...13.5N 23.5W
ABOUT 110 MI...175 KM SE OF THE SOUTHERNMOST CAPE VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/HR
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 12 MPH...19 KM/HR
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE SOUTHERN CAPE VERDE ISLANDS...INCLUDING MAIO...SAO TIAGO...
FOGO...AND BRAVA

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 PM AST...0300 UTC...THE CENTER OF TROPICAL STORM JULIA WAS
LOCATED NEAR LATITUDE 13.5 NORTH...LONGITUDE 23.5 WEST. JULIA IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 12 MPH...19 KM/HR. THIS
GENERAL MOTION IS EXPECTED TO CONTINUE THROUGH MONDAY...FOLLOWED BY
A TURN TOWARD THE NORTHWEST WITH A DECREASE IN FORWARD SPEED ON
TUESDAY. ON THE FORECAST TRACK...THE CENTER OF JULIA IS EXPECTED
TO PASS NEAR THE SOUTHERNMOST CAPE VERDE ISLANDS OVERNIGHT AND
MONDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 40 MPH...65
KM/HR...WITH HIGHER GUSTS. STRENGTHENING IS FORECAST DURING THE
NEXT COUPLE OF DAYS AND JULIA COULD BECOME A HURRICANE ON TUESDAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB...29.65 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED TO SPREAD OVER THE
WARNING AREA OVERNIGHT AND EARLY MONDAY.

RAINFALL...JULIA IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF
2 TO 4 INCHES OVER MUCH OF THE CAPE VERDE ISLANDS ...WITH POSSIBLE
ISOLATED MAXIMUM AMOUNTS OF 8 INCHES. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUDSLIDES.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 AM AST.
NEXT COMPLETE ADVISORY...500 AM AST.

$$
FORECASTER BROWN
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NASA missions collect data that tells us more about the composition, behavior, and quality of our air. Using that data, scientists develop or refine their theories about climate and its effects. They try to determine which long-term variations in climate result from natural causes and which are caused by people.

They monitor the ozone layer to detect changes, and they try to determine the causes and their impact on the planet. To test their theories, they send up new missions. They share what they learn, so we can benefit from weather prediction and understand how we affect the air quality and how it affects us.

Over the next 15 years, an international program called EOS will monitor climate and environmental change on Earth. The leading satellite in this program is called Terra. From Terra will come data for new research about how Earth's lands, oceans, air, ice, and life function as a total environmental
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Quoting CosmicEvents:
94% of the blog have never seen the commercial. 5% have seen it but forgotten it. That leaves you, me, and a handful of others. And it won't be long before you can put me in the "forgot it" pile.
"But of course"
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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.