Hurricane Hunters to check out remains of Fred; 98L more organized

By: Dr. Jeff Masters , 1:06 PM GMT on September 19, 2009

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A tropical disturbance (98L), is located midway between Africa and the Lesser Antilles Islands. This disturbance has shown a modest increase in heavy thunderstorm activity over the past day. This morning's QuikSCAT pass showed an elongated circulation, with top winds around 30 mph. Wind shear is low, 5 - 10 knots, and Sea Surface Temperatures are 28°C, which is about 2°C above the 26°C threshold needed to support a tropical cyclone. There is a large amount of dry air to the north and west of 98L, and this dry air is interfering with development.

Wind shear over 98L is expected to remain in the low range, 5 - 10 knots, through Sunday evening, according to the SHIPS model. This may allow the storm to organize into a tropical depression, assuming it can fight off the dry air that surrounds it. By Monday, the SHIPS model predicts shear will increase to the high range, 15 - 30 knots, so in is unlikely 98L will become anything stronger thatn a weak tropical storm over the coming 5-day period. The models predict that a strong trough of low pressure will turn 98L to the northwest and then north beginning on Monday, with the result that 98L misses the Lesser Antilles Islands by at least 500 miles. NHC is giving 98L a high (greater than 50%) chance of developing into a tropical depression by Monday. At this time, it does not appear that 98L will ever threaten any land areas.

Fred-ex
The remains of Hurricane Fred are still spinning away about 700 miles east of Florida. There has been a modest increase in heavy thunderstorm activity on the south side of Fred's circulation over the past day, but high wind shear and dry air have kept the thunderstorms from building over Fred's center. Wind shear is moderate, 15 - 20 knots, and there is substantial dry air surrounding ex-Fred on all sides. This morning's QuikSCAT pass showed top winds of 30 mph.

None of the computer models develop ex-Fred, and conditions for development are expected to remain marginal over the next three days, with wind shear of 15 - 20 knots and plenty of dry air around. Most of the models predict ex-Fred should move over Florida on Tuesday, but steering currents may weaken early next week, and ex-Fred could end up slowing down and turning northwest towards South Carolina. A hurricane hunter aircraft this afternoon was cancelled.


Figure 1. Morning visible satellite image of 98L and the remains of Hurricane Fred.

Twenty years ago today
On September 19, 1989, Hurricane Hugo moved away from Puerto Rico, and headed northwest at 15 mph. An upper-level low over Georgia, in combination with the steering currents imparted by the Azores-Bermuda High, were responsible for the northwesterly motion of the storm. Wind shear from strong upper-level winds continued to weaken the hurricane, and Hugo diminished to a Category 2 hurricane with 105 mph winds.


Figure 2. GOES visible satellite image of Hurricane Hugo taken on September 19, 1989. Wind shear had weakened Hugo to a Category 2 storm with 105 mph winds. Image credit: Google Earth rendition of the NOAA HURSAT data base.

I'll have an update this afternoon if there's any major developments to report.

Jeff Masters

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Another victim of the Year of the Sheer/Shear!

I figure if it's like the rest of the storms this year, it'll also be a nakid low level swirl
spinning across the open Atlantic, in the next day or so..LOL
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Here is where Fred should Go in my opinion. He will have to travel around the high to his west as the high moves East.

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1159. Grothar
Quoting zebralove:
ok here is a question.... for the pacific ocean what is the difference between typhoon and hurricane? I always thought it was pretty much the same thing


They are called typhoons west of the International dateline and Hurricanes East of the International Date Line? Same type of storms
Member Since: July 17, 2009 Posts: 71 Comments: 26840
Quoting zebralove:
ok here is a question.... for the pacific ocean what is the difference between typhoon and hurricane? I always thought it was pretty much the same thing
According to the Atlantic Oceanographic and Meteorological Laboratory, a “hurricane” and a “typhoon” are simply different names for a “tropical cyclone.” As a general rule, these cyclones are given the name “hurricane” in the Western hemisphere (the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160E), and the term “typhoon” is applied in the Eastern hemisphere (the Northwest Pacific Ocean west of the dateline).
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1157. will40
1151. jipmg

according to NWS yes

















Member Since: September 19, 2005 Posts: 2 Comments: 4266
ok here is a question.... for the pacific ocean what is the difference between typhoon and hurricane? I always thought it was pretty much the same thing
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Quoting WeatherStudent:


Ohh, pretty plz.
Looks like tonight you are Mr. Johnny Come Lately.
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1153. JLPR
umm
98L not looking so good xD

I'll give it till the blackout to explode, since that's when Erika did her thing =P
if it doesn't explode then, it looks like it could weaken and maybe come back in a few days
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Quoting stormwatcherCI:
Polls are closed.


Ohh, pretty plz.
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1151. jipmg
Quoting will40:
Area Forecast Discussion
Issued by NWS Newport/Morehead, NC

.MARINE...
AS OF 8 PM...A NE SURGE OF 15 TO 20 KT WILL CONTINUE OVERNIGHT AND
FOR THE BETTER PART OF SUN. SEAS ALREADY NEAR 5 FT WILL BUILD
OVERNIGHT...SO BY SUN MORNING EXP 4-6FT SEAS THROUGH ALL COASTAL
WATERS. FOR S WATERS...THE 6 FT SEAS WILL BE ON THE OUTER FRINGE OF
THE 20 NM FORECAST AREA. THE HIGH WILL SLIDE OFFSHORE MON AND SE
FLOW WITH LESS SPEED WILL ALLOW SEAS TO COME DOWN A FOOT OR TWO.
THERE WILL BE SOME SE SWELL FROM THE REMNANTS OF FRED IMPACT THE
BEACHES...THOUGH THIS SWELL IS UNDER 2 FT SO LIKELY NOT ENOUGH TO
CONTINUE SCA. THE WEAK WAVE LEFT FROM FRED WILL MOVE INTO SC
TUE...BRINGING RAIN AND A BRIEF WIND SHIFT POSSIBLE
...THOUGH NOT
MORE THAN 10 KT. THE PATTERN BECOMES DISORGANIZED AS THE UPPER RIDGE
WEAKENS MID WEEK. THIS WILL KEEP WINDS 15KT OR LESS AND ALLOW SEAS
TO FALL TO 4FT OR LESS THROUGH END OF THE FCST.

HIGH ASTRONOMICAL TIDES AND ENE WINDS WILL KEEP A HIGH RISK OF RIP
CURRENTS IN EFFECT FROM CAPE HATTERAS N ON SUN...AND MODERATE TO
CAPE LOOKOUT.


excuse me? Will? So its 100 percent that its going to SC? Not a good forecaster..
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Quoting WeatherStudent:
All, I'll pick B, please.
Polls are closed.
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All, I'll pick B, please.
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1147. will40
Area Forecast Discussion
Issued by NWS Newport/Morehead, NC

.MARINE...
AS OF 8 PM...A NE SURGE OF 15 TO 20 KT WILL CONTINUE OVERNIGHT AND
FOR THE BETTER PART OF SUN. SEAS ALREADY NEAR 5 FT WILL BUILD
OVERNIGHT...SO BY SUN MORNING EXP 4-6FT SEAS THROUGH ALL COASTAL
WATERS. FOR S WATERS...THE 6 FT SEAS WILL BE ON THE OUTER FRINGE OF
THE 20 NM FORECAST AREA. THE HIGH WILL SLIDE OFFSHORE MON AND SE
FLOW WITH LESS SPEED WILL ALLOW SEAS TO COME DOWN A FOOT OR TWO.
THERE WILL BE SOME SE SWELL FROM THE REMNANTS OF FRED IMPACT THE
BEACHES...THOUGH THIS SWELL IS UNDER 2 FT SO LIKELY NOT ENOUGH TO
CONTINUE SCA. THE WEAK WAVE LEFT FROM FRED WILL MOVE INTO SC
TUE...BRINGING RAIN AND A BRIEF WIND SHIFT POSSIBLE
...THOUGH NOT
MORE THAN 10 KT. THE PATTERN BECOMES DISORGANIZED AS THE UPPER RIDGE
WEAKENS MID WEEK. THIS WILL KEEP WINDS 15KT OR LESS AND ALLOW SEAS
TO FALL TO 4FT OR LESS THROUGH END OF THE FCST.

HIGH ASTRONOMICAL TIDES AND ENE WINDS WILL KEEP A HIGH RISK OF RIP
CURRENTS IN EFFECT FROM CAPE HATTERAS N ON SUN...AND MODERATE TO
CAPE LOOKOUT.
Member Since: September 19, 2005 Posts: 2 Comments: 4266
A lotta high pressure for the gulf looks like.

GMZ089-200330-
SYNOPSIS FOR THE GULF OF MEXICO
430 PM CDT SAT SEP 19 2009

.SYNOPSIS...LOW PRESSURE IS OVER THE SOUTHEASTERN U.S. WITH
ASSOCIATED WEAK TROUGH EXTENDING FROM SE LOUISIANA TO 24N97W.
THE TROUGH WILL WEAKEN AND MOVE N AS IT DISSIPATES THROUGH SUN
NIGHT. THIS WILL ALLOW A RIDGE OF HIGH PRES TO BUILD IN FROM THE
E MON AND TUE WITH LIGHT TO MODERATE E TO SE WINDS. ANOTHER
RIDGE OF HIGH PRES WILL BUILD IN FROM THE SRN PLAINS WED AND THU.
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1145. ncstorm
From ILM weather discussion:

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...POSSIBLY THE MOST SIGNIFICANT EVENT OF THE
LONG TERM WILL BE THE FIRST DAY...TUESDAY...AND ALSO CONTAINING
THE MOST UNCERTAINTY. THIS IS IN RELATION TO THE REMNANTS OF
FRED...WHICH SOME GUIDANCE IS TAKING TOWARDS THE SC COAST. AS OF
LATE THE SAT PRESENTATION LOOKS PRETTY POOR...WITH THE LOW LEVEL
CIRCULATION HEADING DUE WEST TOWARDS FL WHILE SOME MID LVL ENERGY IS
TRAVELING NORTHWARD ALONG 70W INTO THE FRONTAL ZONE. HPC/TPC COORD
WILL PUT A TROUGH ALONG 80W ON TUE SO TUE WILL IN FACT HAVE THE
HIGHEST POPS OF THE PD. HOW HIGH TO GO AND QPF PROSPECTS WILL BE
MORE A FUNCTION OF THE SYSTEMS EVENTUAL LATITUDE. TAKE FOR EXAMPLE
THE WRF WHICH BRINGS THE SYSTEM TO THE SPACE COAST...NOT MUCH OF A
RAINMAKER LOCALLY. ADDITIONAL MODEL RUNS AND/OR SOME AIRCRAFT
RECON NEEDED TO MAKE A MORE DEFINITIVE CALL ON HOW TUE PANS OUT.

FLOW WILL BE QUITE WEAK THROUGH THE COLUMN ON WED AS WEAK UPPER
RIDGE AND ILL-DEFINED SFC PATTERN IN PLACE. MOST GUIDANCE SHOWING A
DECENT CONVECTIVE SIGNAL ESP NEAR THE COAST...SEA BREEZE, COASTAL
TROUGH OR POSSIBLY BOTH. THERE`S SOME DISAGREEMENT IN THE N/S
PLACEMENT OF THE MAX PRECIP THOUGH.

WEAK STEERING FLOW CONTINUES FOR THE REMAINDER OF THE WORK WEEK AS
THE SOUTHERN STREAM CUTOFF EITHER STALLS OR CONTINUES TO RETROGRADE
AND THE NORTHERN BRANCH STRENGTHENS ACROSS CANADA. THE LATTER MAY BE
RESPONSIBLE FOR A COLD FROPA NEAR OR JUST BEYOND THE END OF THE LONG
TERM AS A VERY DEEP TROUGH DIGS EITHER INTO THE NORTHEAST OR OFF THE
NEW ENGLAND COAST.
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Quoting AllStar17:
I'll have the answer in a bit....

I'll be lurking until then.
AllStar17. You got mail.
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Quoting AllStar17:
I'll have the answer in a bit....

I'll be lurking until then.


I know it and will post it...but in a little bit.
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I'll have the answer in a bit....

I'll be lurking until then.
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MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
300 PM EDT SAT SEP 19 2009

SW N ATLC...
DISSIPATING TROUGH THROUGH NW BAHAMAS HAS ROTATED CLOCKWISE
TODAY...WITH N PORTION SHIFTING SE...AND SW PORTION MOVING INTO
EXTREME SE FLORIDA...WHERE ACTIVE WEATHER CONTINUES. THIS
FEATURE WILL DISSIPATE DURING THE NEXT 24 HOURS AS HIGH PRESSURE
BUILDS MODESTLY ACROSS THE SUNSHINE STATE AND INTO THE ERN GULF.
THE REMNANTS OF TC FRED...AN ELONGATED SWIRL OF LOW CLOUDS IN
SATELLITE IMAGERY...WAS ALONG 70W...WITH AT LEAST TWO LOW LEVEL
CENTERS DEPICTED...WITH THIS PARENT TROUGH MOVING WNW 10-12 KT.
A MORNING QUIKSCAT PASS STILL SHOWED 20-25 KT WINDS WITH THE
TIGHT LLVL CIRCULATION...BUT THIS HAS SINCE BECOME ELONGATED N
TO S...AND 20 KT WINDS WILL LIKELY BECOME CONFINED TO THE E
PORTIONS OF THE TROUGH WITHIN NEXT 24 HOURS. MAX SEAS STILL
ESTIMATED TO BE NEAR 8 FT IN FORMER NE QUAD OF LOW...AND WILL
SUBSIDE VERY SLOWLY TO LESS THAN 8 FT BY 24 HOURS. THIS TROUGH
IS EXPECTED TO MOVE WNW TO ALONG 73W WITHIN 24 HOURS...77W
WITHIN 48 HOURS...AND ALONG 80W BY 72 HOURS. HIGH PRES WILL
BUILD ACROSS THE AREA FROM THE E BEHIND THIS TROUGH WITH E-SE
WINDS 15 KT AND ISOLATED AREAS OF 20 KT WINDS MON INTO
TUE...WHICH SUBSIDE ON WED.


THERE WAS A LOW LEVEL CONVERGENCE ZONE DURING THE PAST 36 HOURS
BEHIND THIS TROUGH...CURRENTLY EXTENDING FROM ALONG 65W N OF
PUERTO RICO...SE ACROSS THE EXTREME NE CARIBBEAN...TO ALONG 14N
E OF BARBADOS...AND IS DEPICTED BY AN ELONGATED CLOUD BAND IN
SATELLITE IMAGERY. RECENT QUIKSCAT PASSES HAVE SHOWN 20-25 KT
WINDS...SOME LIKELY CONTAMINATED BY SHOWER ACTIVITY...ALONG THE
LEADING EDGE OF THIS LONG BAND...WITH 20 KT ELY FLOW BEHIND IT
FOR SEVERAL DEGREES. SEAS BEHIND THIS BAND WERE BUILDING 7-8 FT
IN NELY WIND SWELL. THIS WILL SHIFT W AND NW NEXT 48 HOURS AND
GRADUALLY DIMINISH.

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Quoting hunkerdown:
can't we extend it for 15 more minutes, pleeeease :)


Ha...ha
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1138. Dakster
Nooooo...
Member Since: March 10, 2006 Posts: 0 Comments: 10567
Quoting hunkerdown:
yes, please...i am dyyyyyying to know


you are lucky to not be banned.
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Quoting AllStar17:
Poll is now closed.
can't we extend it for 15 more minutes, pleeeease :)
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Poll is now closed.
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Quoting Dakster:
Ok. What's the answer?
yes, please...i am dyyyyyying to know
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1132. Dakster
Ok. What's the answer?
Member Since: March 10, 2006 Posts: 0 Comments: 10567
according to the latest QS the LLC of 98L is near 13.3N 43.5W. This is also confirmed by the 850mb vorticity chart. there is little convergence , but quite a bit of divergence with the system. it must be noted there are still a number of vortices within the system. it should be noted that with these facts, 98L is a bit away from development into a cyclone in the near future
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1130. JLPR
Quoting hunkerdown:
knock yourself out...


very well, I gave you the chance
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Quoting gator23:

if there is a high over North Florida how could it head to South Carolina?


I don't think that will happen......Central to South Florida is likely.

This is steerning at the lower levels....it can't go through the High to its NW....it does not appear to be moving toward the weakness to its north. The High to the NW will move off the coast and allow FRed to start moving around the South side and then up the West side....that is why it is bascially stalled....very low steering currents currently.



This is MidLevel Steering...

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1126. JLPR
1114. hunkerdown 10:16 PM AST on September 19, 2009

please modify that before I flag you
that is a personal attack
Member Since: September 4, 2007 Posts: 36 Comments: 5223
1124. viman
Quoting Grothar:
ALLSTAR, Some of us are not that young. I don't even buy green bananas anymore! Know what I mean?


lol
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Is Fred a player or just a remnant low?

Will 98L make something out of herself to become Grade or dissipate?


And what the heck is that coming off of Africa! And look at what's behind it!



Stay tuned to, "As the World Turns."
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A-3
B-5
C-4
D-2
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1120. juslivn
I'll go with 'C' :)
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Quoting hunkerdown:
have you graduated third grade yet ?


?
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Quoting gator23:

if there is a high over North Florida how could it head to South Carolina?


It can't. It's going to pass over south-central Florida and then hit the panhandle.
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A-3
B-5
C-3
D-2
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Quoting AllStar17:
Sorry, hunkerdown.



D
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Quoting TexasHurricane:


Homeless - you got mail....


Hi Tex. You've got mail. :)
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1112. gator23
Quoting TampaSpin:


I have that bookmarked but, thanks as that sure shows how it is seperateing and sure looks like its LLC has reorganzied to the South!

if there is a high over North Florida how could it head to South Carolina?
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Allstar,

I guess B.
Member Since: September 21, 2008 Posts: 9 Comments: 688

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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.