Sunday, June 24, 2012

Tropical Storm Debby following a Hybrid Playbook

Tropical Storm Debby has surprised forecasters by moving toward the FL Panhandle and following more closely with the GFS Model solution than the usually more dependable ECMWF and HWRF.  While I am late to the Debby forecast track derby, it seems like my own philosophy regarding types of tropical storms may bear fruit in determining the ultimate outcome. Here are 3 observations that may explain the reason why the GFS has been more helpful.

  • Debby is a hybrid storm containing a tropical warm core and a baroclinic frontal structure.  The two structures do not appear very united which is good news.  The GFS manages baroclinic features in a more helpful manner than tropical.
  • Heat ridge centered over TX and AK might have been underestimated as an influence.
  • Disturbances that are diving into the Eastern Trough are stronger than I expect at this time of year.  A stronger trough pulls the tropical storm north into it.
This water vapor image  shows the poorly organized center of Debby and the expansive area of convection that is dousing Florida.  The hybrid structure is connected to a stream of moisture originating from the Pacific.   Take note that the energy is not building the center of Debby,
Image Source: Univ of Wisc SSEC
National Weather Service Radar shows rain bands moving inland over FL.  The question is whether the  stormy weather's destiny is different than the tropical storm center known as Debby.  Another issue is whether the non-tropical piece of the storm system affects Florida more greatly than the Debby storm center's destination.

My suspicion is that the hybrid structure will follow the GFS idea of the storm moving through Florida.The Debby storm center will most likely decouple completely from the baroclinic structure and drift west.   Whether the storm generates into a formidable system and impacts LA or TX, dies out, or spins down over land is the next question.

No comments:

Post a Comment