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Somerset Squall

Major Hurricane Fred

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Invest 96L has become organised enough to classify a tropical depression:

TROPICAL DEPRESSION SEVEN ADVISORY NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009

500 PM AST MON SEP 07 2009

...NEW TROPICAL DEPRESSION FORMS IN THE FAR EASTERN ATLANTIC...

AT 500 PM AST...2100 UTC...THE CENTER OF TROPICAL DEPRESSION SEVEN

WAS LOCATED NEAR LATITUDE 12.5 NORTH...LONGITUDE 24.5 WEST OR ABOUT

160 MILES...255 KM...SOUTH OF THE SOUTHERNMOST CAPE VERDE ISLANDS.

THE DEPRESSION IS MOVING TOWARD THE WEST NEAR 16 MPH...26 KM/HR. A

TURN TOWARD THE WEST-NORTHWEST AND A SLIGHT DECREASE IN FORWARD

SPEED IS FORECAST DURING THE NEXT DAY OR TWO.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER

GUSTS. STRENGTHENING IS FORECAST OVER THE NEXT COUPLE OF DAYS...AND

THE DEPRESSION IS EXPECTED TO BECOME A TROPICAL STORM TONIGHT OR

TUESDAY.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB...29.68 INCHES.

OUTER RAIN BANDS FROM THE DEPRESSION ARE EXPECTED TO CONTINUE TO

SPREAD ACROSS THE SOUTHERN CAPE VERDE ISLANDS TONIGHT...PRODUCING

LOCALLY HEAVY RAINFALL AND GUSTY WINDS.

...SUMMARY OF 500 PM AST INFORMATION...

LOCATION...12.5N 24.5W

MAXIMUM SUSTAINED WINDS...35 MPH

PRESENT MOVEMENT...WEST OR 280 DEGREES AT 16 MPH

MINIMUM CENTRAL PRESSURE...1005 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT

1100 PM AST.

$$

FORECASTER BROWN

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at200907.gif

models have this going in a strange direction

at200907_model.gif

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07L was upgraded to Tropical Storm Fred in the early hours, and the storm is continuing to intensify in low shear and warm waters. Fred has a nice, curved band wrapping from the south into a well defined LLC which is also building some deep, centralised convection. Based on current trends, Fred could well become a hurricane over the next day or so.

Fred is moving westwards along the southern periphery of a ridge to the north. This motion is not expected to last as the ridge erodes allowing Fred to turn to the north into a weakness. This motion will eventually take Fred over cooler waters and increasing shear which should induce weakening beyond 48hrs.

This CIMSS satellite image shows the increased organisation of Fred and also how far east he is, very, very unlikely to be a threat to America. The image also shows another wave soon to emerge over water behind Fred, it is unclear whether the two systems will have any effect on each other:

xxirnm7.GIF

models have this going in a strange direction

Indeed Cookie, not all that common for a storm to turn directly north this far east!

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Indeed LS, the only land Fred has modestly affected is the Cape Verde Islands, and that is only with the outer bands.

Fred has intensified further and is now a 55kt tropical storm. A banding eye has developed with good convection banding spiralling around the defined LLC. Shear is low and waters warm, and good outflow is aiding spin up of the storm. Fred could become a hurricane as early as tonight. Fred has about 36hrs in which to intensify further, could reach cat 2 before weakening occurs as an approaching trough causes an increase in shear. This same trough will pull Fred towards the north. Likely to be a fish storm this one, can't see it crossing the Atlantic from here.

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The model runs have him stalled just north of his present location for a couple of days and I'm wondering how that will impact on our current 5 day forecast ?

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Latest from NHC

...FRED ALMOST A HURRICANE...

AT 500 PM AST...2100 UTC...THE CENTER OF TROPICAL STORM FRED WAS

LOCATED NEAR LATITUDE 12.1 NORTH...LONGITUDE 29.8 WEST OR ABOUT 410

MILES...655 KM...WEST-SOUTHWEST OF THE SOUTHERNMOST CAPE VERDE

ISLANDS.

FRED IS MOVING TOWARD THE WEST NEAR 14 MPH...22 KM/HR. A GRADUAL

TURN TOWARD THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN

FORWARD SPEED IS EXPECTED OVER THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 70 MPH...110 KM/HR...

WITH HIGHER GUSTS. ADDITIONAL STRENGTHENING IS LIKELY AND FRED IS

EXPECTED TO BECOME A HURRICANE LATER TONIGHT OR EARLY TOMORROW.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 105 MILES...165 KM

FROM THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB...29.23 INCHES.

...SUMMARY OF 500 PM AST INFORMATION...

LOCATION...12.1N 29.8W

MAXIMUM SUSTAINED WINDS...70 MPH

PRESENT MOVEMENT...WEST OR 280 DEGREES AT 14 MPH

MINIMUM CENTRAL PRESSURE...990 MB

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Yep Fred is a good looking Hurricane now, shame there he's too far away to get any recon so we can only guestimate how strong he is.

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There is a small bit on confusion wrt Fred's track. As shown below.

Tbh he could end anywhere, ECM still has Fred out in the Atlantic in 10 days time. Needless to say the models struggle with ridges etc 5 days down the line, and 5 days down the line, he's likely not to have moved too much.

Nice eye this morning, looking very strong now.

Nice eye this morning, looking very strong now.

post-6326-1252484858192_thumb.png

post-6326-12524850407535_thumb.jpg

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Taken from the latest NHC update.

At least 90Kts and likely to be a CAT 3 by the end of today easily.

ENHANCED INFRARED SATELLITE IMAGES INDICATE THAT FRED HAS UNDERGONE

RAPID INTENSIFICATION. THE EYE IS NOW EMBEDDED WITHIN CLOUD TOPS

OF -55 DEG C OR COLDER...AND THE DATA T-NUMBER IS AT LEAST 5.0.

THIS CORRESPONDS TO A CONSERVATIVE CURRENT INTENSITY ESTIMATE OF 90

KT.

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A nice Hurricane now, the eye is slowly clearing on visual, which is usually a sign of intensification. Although on IR it's still a very small eye.

A good chance of being between 95Kts and 100Kts at the next advisory.

post-6326-12524988294905_thumb.png

post-6326-12524988454631_thumb.jpg

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Latest update concurs. Quite an unusual beasty as well

FRED HAS CONTINUED TO RAPIDLY INTENSIFY THIS MORNING AND IS NOW A

MAJOR HURRICANE. SATELLITE IMAGES SHOW THAT THE EYE HAS BECOME

DISTINCT ON BOTH VISIBLE AND INFRARED CHANNELS AND REMAINS

EMBEDDED WITHIN A COLD CENTRAL DENSE OVERCAST. THE LATEST DVORAK

ESTIMATES FROM TAFB/SAB ARE 102 KT...WITH OBJECTIVE T-NUMBERS NEAR

115 KT. THE INITIAL INTENSITY IS RAISED TO 105 KT...MAKING FRED

THE SECOND MAJOR HURRICANE OF THE SEASON.

ADDITIONAL STRENGTHENING IS POSSIBLE TODAY BEFORE INCREASING SHEAR

AND SLIGHTLY COOLER WATERS CAUSE FRED TO WEAKEN TOMORROW.

THEREAFTER...THE HURRICANE WILL BE MOVING OVER MARGINAL SSTS COOLER

AND INTO A DRIER MID-LEVEL AIRMASS...WHICH SHOULD ENHANCE THE

WEAKENING EFFECTS OF THE EXPECTED STRONG SHEAR. THE LATEST NHC

FORECAST IS CLOSE TO A BLEND OF THE SHIPS MODEL AND THE PREVIOUS

FORECAST. THE GFDL AND HWRF MODELS...WHICH APPEAR TO BE LESS

SENSITIVE TO INCREASED SHEAR...DO NOT WEAKEN FRED NEARLY AS MUCH AS

THE OFFICIAL FORECAST AT DAYS 4 AND 5.

THE MOTION CONTINUES TO BEND GRADUALLY TO THE RIGHT AND IS NOW ABOUT

305/11. THERE IS NO CHANGE TO THE FORECAST REASONING AS MOST

GUIDANCE IS WELL-CLUSTERED ON A GRADUAL TURN TOWARD THE NORTH AND

NORTHEAST DUE TO A MID- TO UPPER-LEVEL TROUGH OVER THE CENTRAL

ATLANTIC. IN ABOUT 48 HOURS...ALL GUIDANCE SIGNIFICANTLY

DECELERATES FRED AS THE HURRICANE BECOMES CAUGHT IN LIGHT STEERING

CURRENTS. MOST OF THE GLOBAL MODELS REBUILD THE RIDGE TO THE NORTH

OF FRED BY THE END OF FORECAST PERIOD...WHICH WOULD CAUSE THE

CYCLONE TO MOVE MORE TO THE NORTHWEST. THE OFFICIAL FORECAST IS

SLIGHTLY EAST OF THE MODEL CONSENSUS INITIALLY...THEN ENDS UP

SOMEWHAT TO THE WEST IN THE ANTICIPATION THAT A WEAKER SYSTEM WOULD

TAKE A MORE WESTWARD PATH. THE TWO BIGGEST OUTLIERS TO THIS

FORECAST ARE THE GFDL AND HWRF...WHICH TAKE FRED FARTHER NORTH THAN

MOST OF THE OTHER MODELS...PROBABLY BECAUSE THEY KEEP IT AS A DEEP

CYCLONE FOR TOO LONG.

IT IS QUITE UNUSUAL TO HAVE SUCH A POWERFUL SYSTEM SO FAR EAST IN

THE BASIN AND FRED IS ONLY THE THIRD MAJOR HURRICANE NOTED EAST OF

35W IN THE TROPICAL ATLANTIC OCEAN...AND THE STRONGEST HURRICANE SO

FAR SOUTH AND EAST IN OUR DATA RECORD. THIS TYPE OF SYSTEM...

HOWEVER...WOULD HAVE BEEN VERY DIFFICULT TO ACCURATELY OBSERVE

BEFORE SATELLITE PICTURES BEGAN IN THE 1960S.

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Will soon meet its death as shear gets to grips and the cool Atlantic takes it toll.

MOV8-4.07L.GIF

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wow, this went from nothing to a major very fast

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Strong shear and cooler waters continue to weaken Fred, and the cyclone is barely a hurricane. Steering currents have completely collapsed and as a result Fred is pretty much stationary. Fred has been heading northwards over the last day. As Fred continues to weaken in the hostile environment, he will feel the effects of low level steering and be forced west-northwestwards, weakening to a remnant low by this point. There is a large swathe of even stronger shear in this direction which will probably then destroy the remnant circulation. If this doesn't happen however, there may be a chance of redevlopment later down the line as Fred is still very much in the tropics and out to sea. At this time, this appears very unlikely.

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This has got to be the weirdest storm I have ever tracked. Firstly, Fred was the strongest documented storm this far south and east. Now, all remains is an exposed but well defined LLC, right in the deep tropics, which is an unusual sight. The fact that this system has gone to cat 3 and then turned around and weakened just as fast, all so far east, is very odd. Net motion for Fred has been very slow- but get this- he has been drifting east-southeastwards back TOWARDS the Cape Verde Islands. I have never seen or can see a track back on archives that even remotely resembles this one! Very interesting indeed.

Fred has no convection left realted to the LLC. He has just this second been declared a remnant low. Redevelopment is unlikely due to persistant shear over the next 3 days at least which could destroy the low.

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this sort of shows your point

at200907.gif

it went up and down very fast from a major to a tropical low

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In the face of strong shear, convection is increasing near the remnant low of Fred this evening, making regeneration possible:

SHOWER AND THUNDERSTORM ACTIVITY HAS INCREASED TO THE

NORTH OF THE CENTER OF THE REMNANT CIRCULATION OF FRED...WHICH IS

LOCATED ABOUT 700 MILES WEST-NORTHWEST OF THE NORTHERNMOST CAPE

VERDE ISLANDS. WHILE UPPER-LEVEL WINDS ARE EXPECTED TO REMAIN

UNFAVORABLE FOR RE-DEVELOPMENT AS THIS SYSTEM MOVES SLOWLY WESTWARD

OVER THE NEXT COUPLE OF DAYS...REGENERATION INTO A TROPICAL CYCLONE

IS POSSIBLE IF SHOWER AND THUNDERSTORM ACTIVITY CONTINUES TO BECOME

BETTER ORGANIZED. THERE IS A MEDIUM CHANCE...30 TO 50 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.

post-1820-12528828530215_thumb.jpg

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Just out of interest if it does pick up enough strength would it still be fred as it is the same storm system

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