Hurricane Hunters find 50 - 60 mph winds in disturbance 92L north of Puerto Rico

By: Dr. Jeff Masters , 8:54 PM GMT on August 25, 2009

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The tropical wave (92L) a few hundred miles north of Puerto Rico is generating a large area of surface winds of 50 - 60 mph, according to the latest information from the Hurricane Hunters. Top winds seen so far at their flight level of 1,000 feet were 69 mph, which would make 92L a strong tropical storm if it had a surface circulation.
However, the aircraft has not found a surface circulation, and the satellite appearance shows virtually no change in the amount, intensity, or organization of the storm's thunderstorm activity. Wind shear has dropped to the moderate range, 15 - 20 knots this afternoon, but the upper low 92L is moving underneath is dumping cold, dry air into the region. Dry air continues to get ingested into 92L's thunderstorms, creating strong downdrafts that are robbing 92L of heat and moisture. These downdrafts are creating surface arc clouds that spread out from where the downdraft hits the ocean surface. NHC continues to give 92L a high (greater than 50% chance) of developing into a tropical depression by Thursday afternoon.

The forecast for 92L
As 92L moves underneath the center of the upper low on Wednesday morning, the upper low is expected to weaken, and wind shear is expected to decline to the low range, 5 - 10 knots. However, the upper-level low will continue to dump dry, cold air into 92L through Thursday afternoon, slowing down development. By Thursday night, when 92L should be several hundred miles off the coast of northern Florida, the upper-level low may be weak enough and far enough away that 92L will find itself in a region with light upper level anticyclonic winds, which would favor more rapid development. However, this favorable environment will not last long, since a strong trough of low pressure will be approaching the U.S. East Coast on Friday. This trough will bring high wind shear of 20 - 30 knots by Friday night. This trough should be strong enough to turn 92L to the north. The models disagree substantially on how close 92L will be to the coast at that time. One camp of models, including the NOGAPS, Canadian, UKMET, and ECMWF models, predict 92L will pass very close to the Outer Banks of North Carolina on Friday night or Saturday morning. The GFS, GFDL, and HWRF models keep 92L several hundred miles out to sea. Both sets of models bring 92L north-northeastwards on Saturday, with a track over Massachusetts or Nova Scotia. The intensity forecast for 92L is problematic, since it's eventual strength depends upon how quickly it manages to become a tropical depression. Given that 92L will find itself in a favorable environment for strengthening for about 36 hours this week, and marginal for the remainder of the week, I give the system these odds:

10% chance of never getting a name.
20% chance of becoming a weak tropical storm (40 - 50 mph winds).
40% chance of becoming a strong tropical storm (55 - 70 mph winds).
30% chance of attaining hurricane strength.

Elsewhere in the Atlantic
The ECMWF and UKMET models predict the development of a tropical wave coming off the coast of Africa late this week. The GFS model no longer shows this.

I'll have an update Wednesday morning.

Jeff Masters

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thanks SJ =)
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Quoting StormJunkie:
Funny Bonedog & HK :~)


Is the SWFWM site usually the first to update with the Xtrap, and the BAM models?


Morning SJ, they have been slow lately not sure why. You can also try Raleigh Weather
Member Since: September 23, 2005 Posts: 14 Comments: 11215
Ana
Bill
Claudette
Danny
Erika
Fred
Grace
Henri
Ida
Joaquin
Kate
Larry
Mindy
Nicholas
Odette
Peter
Rose
Sam
Teresa
Victor
Wanda
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Quoting mikatnight:


Thought it was Dean, not Danny, for the next named storm...


Nope, it's Danny. Hmmm. Sorry about that chief...
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885. 7544
whats the speacial feature thats moving due west is it 92l im confused lol

also 10 day gfsx more a coming

Link
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As Press says, it is not the Carolinas, it is either North Carolina or South Carolina. Our neighbors to the North, stick out like a sore thumb. I have always thought of Wilmington as the magnetic north for east coast storms. Folks from OBX, Wilmington know the drill. IF 92L/Danny runs a bit more west up the coast, I would be surprised if they get caught unprepared.

NWS for Charleston:
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THERE IS CONSIDERABLE UNCERTAINTY IN THE FORECAST OVER THE FRIDAY
AND SATURDAY TIME FRAME GIVEN THE POTENTIAL FOR A TROPICAL SYSTEM
TO HAVE AN INFLUENCE ON LOCAL WEATHER CONDITIONS AS IT PASSES WELL
EAST OF THE AREA. THE DISTURBANCE WELL NORTH OF HISPANIOLA IS
EXPECTED TO PASS WELL OFF THE GEORGIA AND SOUTH CAROLINA COASTS
FRIDAY INTO FRIDAY NIGHT...BEFORE LIFTING NORTHEAST TOWARD THE
VICINITY OF THE OUTER BANKS OF NORTH CAROLINA ON SATURDAY.
THE
NAM...CANADIAN AND ECMWF ALL APPEAR TO BE SIMILARLY CLUSTERED WITH
REGARDS TO THE TRACK OF THIS SYSTEM...WITH THE GFS APPEARING TO BE
A BIT OF AN EASTERN OUTLIER. THE ULTIMATE TRACK OF THE SYSTEM WILL
BE DEPENDENT ON HOW DEEP AN UPPER LEVEL TROUGH BECOMES OVER THE
SOUTHEASTERN U.S. AND HOW QUICKLY IT LIFTS NORTHEAST THROUGH THE
FIRST PART OF THE WEEKEND. WHILE THE TROUGH COULD BRING UNSETTLED
WEATHER TO THE REGION FRIDAY INTO SATURDAY...LARGE SCALE
SUBSIDENCE AND DRIER AIR ALONG THE WESTERN PERIPHERY OF THE
TROPICAL SYSTEM COULD HAVE AN EFFECT BY LIMITING THE EXTENT OF
PRECIPITATION ACROSS THE AREA. UNTIL CONFIDENCE IN HOW THE SYSTEM
EVOLVES AND TRACKS INCREASES... WILL LIMIT THE PROBABILITY OF
PRECIPITATION TO A CHANCE BOTH FRIDAY AND SATURDAY. TEMPERATURES
SHOULD ALSO REMAIN NEAR TO SLIGHTLY BELOW NORMAL DURING THIS TIME
PERIOD.
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06 gfdl starting to track west now =(

Link

wonder what the other models will start doing? east coast better keep a weather eye out for 92L/Danny might be our turn to finally get hit =(
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Funny Bonedog & HK :~)


Is the SFWM site usually the first to update with the Xtrap, and the BAM models?
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Thats the same image, Jeff.
EDIT...
OK, you edited it.
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Quoting willdunc79:
Our local mets are sure that 92L/Danny will stay offshore of N. Carolina and will give us some breezy conditions if that.


Thought it was Dean, not Danny, for the next named storm...
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re 875 yup check 874 LOL

my bad, still on the first cup
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Morning SJ... Love the pic of you and little man.
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Quoting Bonedog:
exposed coc now 24.78 70.18



finally a good spot

Convection displaced to the W and NW


Uhh you mean east and northeast right? LOL
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LOL oops I mean East and Northeast

sorry direction diareha this morning
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Quoting IKE:
Looks like it's moving almost due west.


Be interesting to see the 12z xtrap and BAM models when they come out shortly.

Morning all,

Good to see ya press and Dart.
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Shear has subsided we should soon see some convection wrapping in
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exposed coc now 24.78 70.18



finally a good spot

Convection displaced to the W and NW
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Good Morning Press...
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I'm just a novice but if 92L gets its act together that thing could be scary. It appears to be a pretty decent size storm.
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Quoting DaytonaBeachWatcher:


You're gonna get in trouble for that, lol


IKE...
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when can we see NHC put up a T.S. warning for bahamas? do you think tomorrow or later tonight?
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92L still looks like crap. I'm not sure why the NHC says this can become a Tropical Storm at any time. No TS until late Thursday at the earliest.
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865. IKE
Tell 92L to put some clothes on...

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting eddye:
im at school
turn off computer and learn something
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Hurricane Bill's remnants currently bringing warm, horizontal drizzle to sw Scotland as I look out of the window.
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Same Buoy
Station 41046 (Requested) - E Bahamas 23.867 N 70.870 W

Wind Direction
08 26 5:50 am NNE
08 26 4:50 am NNE
08 26 3:50 am NE
08 26 2:50 am NE
08 26 1:50 am ENE
08 26 12:50 am NE
08 25 11:50 pm ENE
08 25 10:50 pm NE
08 25 9:50 pm ENE
08 25 8:50 pm NE
08 25 7:50 pm ENE
08 25 6:50 pm E
08 25 5:50 pm ENE
08 25 4:50 pm ENE
08 25 3:50 pm E
08 25 2:50 pm E
08 25 1:50 pm E
08 25 12:50 pm E
08 25 11:50 am E
08 25 10:50 am E
08 25 9:50 am E
08 25 8:50 am NE
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Quoting IKE:


To me, the ECMWF.


I agree.
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NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
300 AM EDT WED AUG 26 2009

THERE IS LOW CONFIDENCE IN THE LATER PART OF THE WEEK AS THE MODEL
UNCERTAINTY IN THE DEVELOPMENT AND TRACK OF AN AREA OF DISTURBED
WX NEARING THE BAHAMAS COULD RESULT IN VERY DIFFERENT MARINE OUTCOMES
FOR THE NC COASTAL WATERS. THE SWELL FROM THIS SYSTEM IS
ANTICIPATED TO MOVE INTO THE AREA ON THU...GRADUALLY PUSHING SEAS
BACK UP TO NEAR SCA. THE SWELL WILL KEEP SEAS UP INTO THU NT...WITH
WINDS UNDER 15KT. USING HPC FRONT/PRESSURE PATTERN AS A GUIDE SHOW
A WEAK LOW MOVING OUT OF THE S AND PASSING THROUGH THE PAM SOUND
BY SAT.
HAVE BUMPED UP THE WINDS MARGINALLY TO 15 TO 20 KT FRI
NT/SAT GIVEN UNCERTAINTY IN STRENGTH. GFS CONTINUE TO BE THE
UNFAVORED MODEL GIVEN FAR E OUTLIER...SO DON`T TRUST WAVEWATCH SEA
HEIGHTS AT THIS TIME. WILL CONTINUE WITH MARGINAL SCA BUT BUMPED
SEAS UP ABOUT A FOOT TO BETTER MATCH OUR OPC OFFSHORE FCST. AT
THIS TIME FCST HIGHLY DEPENDANT ON SYSTEM POTENTIAL DEVELOPMENT
WHICH IS BEING MONITORED BY NHC. WILL HOLD OFF ON ANY HEADLINES
GIVEN UNCERTAINTY WITH DEVELOPING LOW.

This was in the marine section. Well they believe a landfall should occur and the gfs is to far east since there has to be a landfall for it to get in the sound.
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858. IKE
Quoting claimsadjuster:


Which of these have been the best so far this season Ike?


To me, the ECMWF.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting P451:
QSCAT also appears to give this invest frontal features in addition to the elongated center.

Just not all that tropical looking to me.

Looks like something you'd find off the North Carolina coast in October.



Nice illustration. The combination of the track, winds and proximity to land will probably spur the NHC into classifying it. If the low tightens up later it should look more tropical in nature.
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Quoting IKE:


ECMWF and CMC and NAM have it making landfall on the Carolina coast.

Other models like the GFS, GFDL, HWRF and NOGAPS keep it offshore.


Which of these have been the best so far this season Ike?
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Our local mets are sure that 92L/Danny will stay offshore of N. Carolina and will give us some breezy conditions if that.
Member Since: June 27, 2009 Posts: 0 Comments: 152
Quoting IKE:


ECMWF and CMC and NAM have it making landfall on the Carolina coast.

Other models like the GFS, GFDL, HWRF and NOGAPS keep it offshore.


You're gonna get in trouble for that, lol
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Quoting kmanislander:
Anyway time to get ready for the day. Will check in later


Have to do the same... l8r Kman... and everyone... checking back in 1 to 2 hours.
Member Since: August 14, 2008 Posts: 4 Comments: 4977
851. eddye
im at school
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850. IKE
Quoting K8eCane:


hey IKE
saved ya some pancakes and sausage LOL
Ok bout how close mile wise are the models bringin this thingy to you know where?


ECMWF and CMC and NAM have it making landfall on the Carolina coast.

Other models like the GFS, GFDL, HWRF and NOGAPS keep it offshore.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting eddye:
due west towards the bahamas then florida



I doubt it will make it that far west but, ya never know.
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Quoting TheCaneWhisperer:



No the Bahama's


LOL... I though he went to school already. I guess he might skip it today.
Member Since: August 14, 2008 Posts: 4 Comments: 4977
Anyway time to get ready for the day. Will check in later
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Quoting KEHCharleston:
813. kmanislander : 24N 70W

Station 41046 (Requested) - E Bahamas Image 23.867 N 70.870 W (23°52'1" N 70°52'12" W)



Pressure not very low though. Only 1010.5 mb
but I would expect that as small as the apparent center is the area of lowest pressure was away somewhat from the location of the buoy.
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843. eddye
due west towards the bahamas then florida
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Quoting kmanislander:


I was " rounding up " LOL


LOL
Member Since: August 14, 2008 Posts: 4 Comments: 4977
Quoting eddye:
due west towards florida


then heading to the GOM..right? no chance on hitting florida! j/k..
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Quoting IKE:
Looks like it's moving almost due west.


Well... based on the 09Z currrents... during the last 6HR the Bermuda High has strengthen a bit and adding the fact that the system remains shallow... it should explain the more westward movement.

Member Since: August 14, 2008 Posts: 4 Comments: 4977
Quoting eddye:
due west towards florida



No the Bahama's
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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.