000
WTPZ44 KNHC 172032
TCDEP4
 
Tropical Storm Madeline Discussion Number   1
NWS National Hurricane Center Miami FL       EP142022
300 PM MDT Sat Sep 17 2022

A low pressure system located several hundred miles southwest of the 
southwest coast of Mexico has very slowly become better organized 
during the past several days. This system has developed and 
maintained a well-defined center today, and while it is still 
strongly sheared, the convective organization now appears to be 
sufficient to classify it as a tropical cyclone. This is supported 
in part by Dvorak classifications of 2.0 and 2.5 from TAFB and SAB, 
respectively. The initial intensity is based primarily on 
scatterometer data from around 18Z that showed peak winds near 40 kt 
to the southeast of the cyclone's center.

Madeline is currently drifting slowly northward, but a faster 
northward motion is forecast to begin this evening. A broad 
mid-level ridge extending from over the Atlantic should be the 
primary steering feature for the next 24 h or so, until another 
ridge centered over Texas begins to build on Sunday. That should 
cause Madeline to turn westward and remain on a westward heading 
through at least the middle of next week. All of the 
normally-reliable track guidance agrees with this general scenario, 
but there is a large amount of uncertainty regarding exactly how 
fast Madeline will make its turn.

While all of the track guidance keeps the tropical storm well 
offshore of Mexico, this uncertainty will have a big impact on the 
intensity forecast since Madeline is forecast to turn westward very 
near the 26 degree isotherm. A relatively southerly track will allow 
Madeline to strengthen, particularly in the 72-120 h portion of the 
forecast period when the wind shear may lessen substantially. On the 
other hand, a northern track could cause Madeline to become a 
remnant low within the next few days. The NHC intensity forecast is 
near the multi-model consensus and shows a middle ground scenario 
where Madeline moves through an environment that would allow it to 
remain a tropical cyclone but not substantially strengthen. Given 
the uncertainty in the track guidance and the sensitivity of the 
intensity to the exact track, the NHC forecast is not very high 
confidence at this time.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  17/2100Z 15.9N 106.9W   40 KT  45 MPH
 12H  18/0600Z 17.0N 107.0W   45 KT  50 MPH
 24H  18/1800Z 18.4N 107.8W   45 KT  50 MPH
 36H  19/0600Z 19.5N 108.9W   50 KT  60 MPH
 48H  19/1800Z 20.2N 110.2W   50 KT  60 MPH
 60H  20/0600Z 20.4N 111.3W   45 KT  50 MPH
 72H  20/1800Z 20.5N 112.6W   40 KT  45 MPH
 96H  21/1800Z 20.5N 115.0W   40 KT  45 MPH
120H  22/1800Z 20.5N 118.0W   45 KT  50 MPH
 
$$
Forecaster D. Zelinsky