Hurricane Analytics

Just returned home from the Gulf Coast (with @hurricanetrack) from our field research mission for tropical storm Karen. Because it dissipated, I could not add it to the tracking map of other field missions I have completed, studying landfalling storms, with Mark Sudduth at HurricaneTrack.com. Here's that map (since I joined him in 2005):

Projected model tracks for tropical storm Karen - still a lot of uncertainty. If Karen is stronger it will move to the east side of the guidance (FL), if weaker possibly to the left (LA). 

Very latest official forecast track and reliable track/global models for tropical storm Karen.  Forecast is right in the middle of the track guidance, with the GFS to the east (central FL panhandle) and GFDL to the west (eastern LA/MS).  Karen is expected to become a hurricane, and hurricane watches are up for the northern Gulf coast.  However, it is expected to weaken slightly to a tropical storm before landfall, but there is still some uncertainty in the forecast so residents should watch this system carefully.

Graphic: Reliable track and global models for 97L (Caribbean system) as of 9:00PM EDT - the track envelope spans from eastern LA to the FL big bend. All interests the northern Gulf should watch this system carefully as we move toward the weekend.

Invest 97L continues to produce a concentrated area of convection and an impressive upper outflow pattern. The circulation around an upper-low east of Florida (yellow arrows) may be helping to establish the favorable upper environment, venting the rain-cooled air away from the tropical system.  This anti-cyclonic (clockwise) flow is generally conducive for developing tropical cyclones.

Invest 97L, the tropical system in the Caribbean, is expected to track into the Gulf of Mexico in the next 2-3 days.  Here is a look at the upper level wind forecast from the GFS model showing expected wind flow...if the system tracks on the east side of the Gulf of Mexico (under red circle), or if the upper trough sets up slightly further west than currently forecast, 97L could find an upper-wind profile favorable for development.  Worth watching developments with this system very closely today.

Invest 95L: Comparison of the forecast tracks from the HWRF model over the last day. Latest model run (dark red) is drastically different from the previous three, showing a position 10 degrees north and 7 degrees east of the run from just six hours before.  Note: Model runs from 12Z on 9/17 to 06Z on 9/18 (interpolated ahead 6 hours to 18Z 9/17 to 12Z on 9/18)

Morning models for Invest 95L.  Center has almost emerged from the Yucatan.  Tight model agreement through 72 hours, then a large spread...spanning from the Bay of Campeche to South Carolina.  HWRF solution continues to be puzzling and inconsistent with other models (and other runs of the HWRF).  Synoptic pattern does not appear to be very favorable today, but this can change quickly, so still worth watching this system closely.  

Updated model plots for Invest 95L - looking at the global and hurricane specific models with intensity at the point labels (in knots).  HWRF ramps up the system to 84 knots in the central Gulf on day 5, but there is a large amount of uncertainty in track and intensity at this point.  Still, this system bears watching, and has a high chance of becoming a tropical cyclone within the next two days.  

Invest 95L model map excluding the BAM (Beta and Advection Models). Note other guidance, including the GFS, GFS Ensembles and consensus models, forecast a stall or slight move back to the east in 4-5 days as the steering currents break down to the north of the system.  Also worth noting the GFS loses the system after 4 days.

nitial model map for new Invest 95L, over the eastern Yucatan peninsula. While the BAM models show it following a similar course to many other systems this season, the long range solution may not be as straight-forward.  Steering currents may weaken as the ridge over the Midwest is forecast to break down over the next five days, which could lead to this system stalling over the southwestern Gulf instead of moving directly into Mexico. 

Tropical Storm Ingrid models have nudged a little to the left (west) today, with most bringing the center inland over eastern Mexico in less than three days. With the Euro and GFS model in fairly good agreement, expecting few changes to the next NHC forecast track later today. 

Tropical Depression Ten has formed in the southwest Gulf of Mexico/Bay of Campeche. Dynamical computer models have it moving very slowly over the next few days, which at a minimum will bring significant flooding to the Gulf coast of Mexico.

Monitoring an area of disturbed weather (Invest 93L) expected to emerge into the Bay of Campeche by Thursday.  This system has a high chance, 70%, of developing into a tropical cyclone by the weekend.  Model guidance shows the pattern may evolve to allow this system to move further north than other systems developing in this area earlier this season.

1. The center position estimate has improved due to visible imagery being available 2. A slight wobble to the left  3. A reformation of the tracked center  Either way the large scale environment still supports a track along/within the cone after what is likely a temporary blip to the west.