98L may develop into a tropical depression near Florida; Ma-on a threat to Japan

By: Dr. Jeff Masters , 3:09 PM GMT on July 17, 2011

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A tropical disturbance (Invest 98L) has formed off the east coast of Florida, along the tail end of a cold front that pushed off the coast late last week. This disturbance has the potential to develop into a tropical depression that will bring heavy rains to the northern Bahamas and east coast of Florida today through Tuesday. Satellite imagery shows that the disturbance has become more organized this morning, with an expanding area of intense thunderstorms, the beginnings of a surface circulation, and upper-level outflow on the east and north sides of the storm. Some rotation of 98L is also evident on long-range radar out of Melbourne, Florida, but the rain showers are poorly organized and there is little evidence of low-level spiral banding. Wind shear is a moderate 10 - 20 knots, and sea surface temperatures are 27 - 28°C, which is plenty warm enough to support a tropical storm. There is dry, continental air over North Florida, and upper level winds out of the northwest are driving this dry air into the center of 98L, retarding development.


Figure 1. Morning satellite image of Invest 98L.

Forecast for 98L
The models are shy about developing 98L; only the HWRF model shows a tropical depression developing. The SHIPS model predicts that wind shear will be in the low to moderate range, 5 - 15 knots, over the next five days. NHC is giving 98L a 30% chance of developing into a tropical depression by Wednesday. Given the recent satellite and radar presentation of the storm, I'd put those odds higher, at 50%. A hurricane hunter aircraft is scheduled to investigate 98L this afternoon.

Steering currents are weak off the coast of Florida, and 98L can be expected to move slowly at less than 5 mph over the next two days. The HWRF and GFDL models predict 98L will execute a clockwise loop, heading towards the coast of Florida on Monday, then looping northeastwards towards South Carolina later in the week. The track of 98L will depend strongly on how intense the storm gets; a weak system is likely to stay farther to the south, while a stronger system will "feel" upper level winds with a west-to-east component, and tend to move to the northeast, parallel to the coast.

None of the reliable models predict tropical cyclone development over the remainder of the Atlantic through July 23.

U.S. heat wave to last at least another week
An unusually intense, widespread, and long-lasting heat wave over the majority of the U.S. continues to set numerous daily record highs. The latest long-range forecasts from the GFS and ECMWF models predict that the ridge of high pressure responsible for the heat wave will remain entrenched over the center or eastern portion of the country during the coming week, so the heat wave should continue for all but the Pacific Northwest through July 23. The GFS model does show that the ridge will break down some during the period 10 - 16 days from now, but such long range forecasts have low skill, and the heat wave could easily continue through the remainder of July. I'll present a more detailed look at the heat wave later this week.


Figure 2. Microwave satellite image of Typhoon Ma-on at 08:26 UTC July 17, 2011, over the West Pacific Ocean. The typhoon was undergoing an eyewall replacement cycle, with the inner eyewall collapsing and a new, larger eyewall forming from an outer spiral band. Image credit: Navy Research Lab, Monterey.

Typhoon Ma-on headed towards Japan
Powerful Category 3 Typhoon Ma-on is headed northwestward towards Japan, and is expected to brush the east coast of the main island of Honshu on Tuesday. The typhoon has weakened some over the past day, thanks to an eyewall replacement cycle where the inner eyewall collapsed, and a new, larger eyewall formed from an outer spiral band. Once this process completes, Ma-on is expected to intensify into a Category 4 storm. With water temperatures along the path of the typhoon ranging from 29 - 30°C, and wind shear expected to remain in the low to moderate range of 5 - 15 knots, Ma-on has the potential to hit Japan as a major Category 3 storm. The typhoon is unusually large, with winds of tropical storm force (39+ mph) extending out almost 350 miles to the north of the storm. A large portion of the south coast of Japan will receive tropical storm-force winds and large battering waves from Ma-on. Although the typhoon is currently a minimal Category 3 storm, its large size means that Ma-on has a tremendous amount of total kinetic energy, characteristic of a Category 5 storm. This means that Ma-on has the potential to bring a large and highly destructive storm to the coast on the right front side of where the eye makes landfall. If the eye remains just offshore, as some models are predicting, this storm surge will largely miss Japan, though.

Jeff Masters

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the stronger the storm is, the more it will feel the effects of that northward pull..remember, we have another DMAX..might be waking up to a TS in the morning..
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Quoting cchsweatherman:


That goes against what the NWS offices across Florida are suggesting.

Which one?? NWS Miami agrees w E movement as of 2pm discussion, and Melbourne says nothing about it moving over the state. Sorry.
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What was I saying yesterday...

They can spin up out of NOWHERE.
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There it is!
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having the 18z pkg here will give a good baseline for the next one later


18z Early Cycle NHC model tracks
Invest98
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)




Early Model Wind Forecasts

Member Since: July 3, 2005 Posts: 423 Comments: 127932
697. 7544
these models posted do not have the new data from the recon correct ?
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invest_RENUMBER_al982011_al022011
Member Since: June 9, 2007 Posts: 4 Comments: 15884
Quoting nrtiwlnvragn:
invest_RENUMBER_al982011_al022011.ren 17-Jul-2011 19:55 1.3K


We now have at least Tropical Depression 2.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
Quoting CybrTeddy:
BINGO!!
TD2!
invest_RENUMBER_al982011_al022011



but how we no its TD 2 or TS
Member Since: May 21, 2006 Posts: 5091 Comments: 114973
And we have TD 2!
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cybrted can you rephrase what you told me... my brains fried from watching the blog speed by...
Member Since: October 3, 2010 Posts: 40 Comments: 4129
BINGO!!
TD2!
invest_RENUMBER_al982011_al022011
Member Since: July 8, 2005 Posts: 259 Comments: 23935
Looking at WV across the SE US, you can clearly see the high to the NW of the system, it's just about underneath the SE edge. Definitely think it's a toss up, depends how strong that shortwave is. Really not seeing it right at the moment. Doesn't mean it won't pull NE tho.
Member Since: December 18, 2006 Posts: 7 Comments: 2686


Takes it out to sea
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Strong west winds found south of the system. Could see a vortex message out of this.
Member Since: October 28, 2006 Posts: 57 Comments: 30355
invest_RENUMBER_al982011_al022011.ren 17-Jul-2011 19:55 1.3K
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Quoting AllStar17:
Not looking particularly healthy right now. Hopefully it stays that way.
I hope it keeps it's ragged ways as well.Looks like Ma-on got affended when I told him to go to hell.Looks like it's working...
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Member Since: July 3, 2005 Posts: 423 Comments: 127932
Member Since: August 22, 2008 Posts: 12 Comments: 6010
Quoting aquak9:
Quoting VirgilSolozzo:
C'mon...it looks like a duck, smells like a duck.....throw some orange sauce on it and serve it already. And bring out those 20 plates of crow.


I thought I was in charge of the duck-calling around here.
Just filling in in your absence ma'am.
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679. 7544
Quoting cchsweatherman:


Hard to say, but I tend to believe that this will move southwest to west and possibly into Florida. Reason being is that the system currently is in a weak steering environment, but all forecasts across Florida from all the NWS offices suggest ridging building in over the area which would force the system more to the west. I'm not buying the northern model solutions.


thanks we just have to wait watch and see but the more se it goes then the high pushing it west where about you think this will take place aroun 26 0r 25 n tia
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Quoting VirgilSolozzo:
C'mon...it looks like a duck, smells like a duck.....throw some orange sauce on it and serve it already. And bring out those 20 plates of crow.


I thought I was in charge of the duck-calling around here.
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.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
Quoting HurricaneDean07:
No TD yet, Recon has to investigate the SE side to determine if we have a closed low or not.


Man this blog is going 100 mph


Not quite, as they found west winds right as they entered the lowest pressure.
Member Since: July 8, 2005 Posts: 259 Comments: 23935
Quoting KEEPEROFTHEGATE:
SOMETHING HAS LEFT AFRICA OVER WATER NOW KEEP WATCH

We were looking at this earlier.... looked almost as good on sat as 98L did at the time... lol

Quoting CaneHunter031472:


I don't know, but if it was me, I better eat a crow at the NHC than having to surprise people with a sudden tropical storm. This close to land and whith these conditions, I would not dare being conservative. Dang at least give it a higher perentage so we know they are not sleeping or on lunch break.
I dunno, 40% to me means "keep an eye out"....70% would be more like "recheck supplies"... lol
Member Since: October 25, 2005 Posts: 19 Comments: 21947
Not looking particularly healthy right now. Hopefully it stays that way.
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Product: Air Force Tropical RECCO Message (URNT11 KNHC)
Transmitted: 17th day of the month at 19:50Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Mission Purpose: Investigate second suspect area (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 11

Mandatory Data...

Observation Time: Sunday, 19:48Z
Radar Capability: Yes
Aircraft Altitude: Below 10,000 meters
Coordinates: 27.3N 78.0W
Location: 134 miles (215 km) to the ENE (72°) from West Palm Beach, FL, USA.
Turbulence: Light
Conditions Along Flight Route: In the clear
Pressure Altitude: 190 meters
Flight Level Wind: From 230° at 17 knots (From the SW at ~ 19.5 mph)
- The above is a spot wind.
- Winds were obtained using doppler radar or inertial systems.
Flight Level Temperature: 25°C
Flight Level Dew Point: 23°C
Weather (within 30 nautical miles): Thunderstorm(s)
Mean Sea Level Pressure (MSLP): 1014 mb (extrapolated)

Optional Data...

Estimated Surface Wind: From 230° at 25 knots (From the SW at ~ 28.7 mph)
Member Since: April 29, 2007 Posts: 0 Comments: 7862
i can't believe Ma-On has stayed as strong as it is with all that dry air it's been sucking in it's entire life.
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Quoting cchsweatherman:


Hard to say, but I tend to believe that this will move southwest to west and possibly into Florida. Reason being is that the system currently is in a weak steering environment, but all forecasts across Florida from all the NWS offices suggest ridging building in over the area which would force the system more to the west. I'm not buying the northern model solutions.


A new shortwave cuts across the Atlantic in 48 hours or so, renewing the northeastward pull on the system, which should take it slowly on out. The models are in just about unanimous agreement on this now.
Member Since: November 24, 2005 Posts: 635 Comments: 26614
Interesting

27.500N 78.333W
1012.5 mb(~ 29.90 inHg)
From 304° at 31 knots
(From between the WNW and NW at ~ 35.6 mph)
33 knots
(~ 37.9 mph)
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Quoting AllStar17:
Now the major question becomes where will it go?


Out to sea hopefully.
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Like really, can these NHC people do something?
I don't think there is a 40% chance.
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Quoting VirgilSolozzo:
C'mon...it looks like a duck, smells like a duck.....throw some orange sauce on it and serve it already. And bring out those 20 plates of crow.


OMG "Now Thats Funny"

Still Laughing at you.... Well Said.....

Taco :o)
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No TD yet, Recon has to investigate the SE side to determine if we have a closed low or not.


Man this blog is going 100 mph
Member Since: October 3, 2010 Posts: 40 Comments: 4129
Quoting cchsweatherman:


Hard to say, but I tend to believe that this will move southwest to west and possibly into Florida. Reason being is that the system currently is in a weak steering environment, but all forecasts across Florida from all the NWS offices suggest ridging building in over the area which would force the system more to the west. I'm not buying the northern model solutions.

Agreed
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Quoting HurricaneDean07:
Tropical Depression Two on the way...
Status:
35 Mph
1010 MB
Moving SSE at 5
77.4 W ; 27.6 N
I'd say sometime late tonight into early tomorrow morning.
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98L Floater - RGB Color Infrared Loop
Member Since: July 3, 2005 Posts: 423 Comments: 127932
Quoting Hurrykane:
Subtropical?


Well that is possible too. According to RUC analysis, an 850mb isotherm still slices right through 98L's center, and it is still attached to a front. As long as it has the front, they won't upgrade it.

Member Since: November 24, 2005 Posts: 635 Comments: 26614
Quoting 7544:


agree agree but where you think it might track thanks


Hard to say, but I tend to believe that this will move southwest to west and possibly into Florida. Reason being is that the system currently is in a weak steering environment, but all forecasts across Florida from all the NWS offices suggest ridging building in over the area which would force the system more to the west. I'm not buying the northern model solutions.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
I'll guess we'll have Bret by tomorrow morning.
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So much for a nice rain maker for Florida :(
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Tropical Depression Two on the way...
Status:
35 Mph
1010 MB
Moving SSE at 5
77.4 W ; 27.6 N
Member Since: October 3, 2010 Posts: 40 Comments: 4129
Now the major question becomes where will it go?
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655. 7544
looks like its atd now and bret will be born on a speacial update imo being its close to land
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Quoting cabice:
The circulation looks to be moving east, being pushed by the dry airmass to the NW

iv noticed that also
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Afternoon All.

Just got back from the beach, Jupiter, FL. Stiff N wind creating rather large surfable breakers. A lot of people out there today.
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652. ackee
INTRESTING times ahead what will the NHC do according to recon we have a TD but 98L still look poorly organize to me what will the NHC do at 5pm only time will tell
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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.