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Tropical Storm Madeline Discussion Number 3...Corrected
NWS National Hurricane Center Miami FL EP142022
300 AM MDT Sun Sep 18 2022
Corrected numbering of key messages
Early this morning, Madeline still appears to be feeling the effects
of more than 20 kt of easterly shear, with the deepest convective
cloud tops located some 75 to 100 n mi southwest of the center. The
center structure itself is rather broad, and several mesovortices
can be seen rotating around the mean center location. The latest
round of subjective Dvorak intensity estimates were T2.5/35-kt from
SAB and T3.0/45-kt from TAFB. Thus, the initial intensity is being
held at 40 kt for this advisory.
The estimated motion of Madeline has actually been a little bit
right of the previous track, currently estimated a bit east of due
north at 005/7 kt. The track reasoning in the short-term is a bit
complicated. Madeline is currently embedded in large-scale monsoonal
southwesterly flow which appears to be partially responsible for its
short-term rightward deviation from the prior forecast track.
Tropical cyclones (TCs) in this region, including recent TCs Kay
and Lester, have been known to move a bit east of model guidance.
Thus, the initial track forecast has been nudged a bit further east
for the first 12-24 h while the larger-scale low-level flow has a
stronger foothold on Madeline's motion. After that period, a
building mid-level ridge centered over Texas is expected to cause
Madeline to take a rather sharp turn to the northwest, resulting in
Madeline passing south of the Baja California Peninsula. The track
guidance this cycle is notably further north and east early on, but
then shifts back towards the previous track by the end of the
forecast period. Thus, the NHC track forecast was nudged in that
direction, but is not quite as far to the north and east as the
latest HCCA consensus aid. As noted in the previous advisory,
across-track spread at the end of the forecast is rather large, so
this track forecast is of lower confidence.
Intensity-wise, Madeline has only a brief window where the vertical
wind shear is expected to drop below 20 kts, mainly between 12-30 h.
In addition, Madeline is currently a broad tropical cyclone, with a
fairly large radius of maximum wind. Thus, only some modest
additional strengthening is forecast, in line with the upper-end of
the intensity guidance. After 36 h, easterly shear is expected to
increase substantially, and both the GFS and ECMWF simulated IR
brightness show Madeline's convection quickly shearing away as the
storm also crosses the 26 C sea-surface temperature isotherm by 48
h. With the further northward track over cooler waters, the latest
intensity guidance has trended downward, and the NHC intensity
forecast follows suit, weakening Madeline to a depression in 60 h
and making it a remnant low by 72 h. Based on the latest guidance
though, this could occur sooner than forecast.
Madeline is producing a large area of rough surf and high waves,
especially on its south and eastern flank. Given the current large
34-kt radii on the south side of Madeline and the eastward shift in
the forecast track this cycle, the government of Mexico has issued a
Tropical Storm Watch from Manzanillo northward to Cabo Corrientes.
Any further deviation to the right of Madeline's track could require
these watches to be upgraded to a warning later today.
1. Heavy rains from Madeline are expected for portions of coastal
southwestern Mexico into Monday. This rainfall may produce flash and
urban flooding, along with possible mudslides in areas of higher
2. Tropical storm conditions are possible for the southwestern
coast of Mexico from Manzanillo to Cabo Corrientes over the next 24
to 36 hours.
FORECAST POSITIONS AND MAX WINDS
INIT 18/0900Z 17.7N 106.6W 40 KT 45 MPH
12H 18/1800Z 18.8N 107.3W 40 KT 45 MPH
24H 19/0600Z 19.9N 108.4W 45 KT 50 MPH
36H 19/1800Z 20.6N 109.6W 45 KT 50 MPH
48H 20/0600Z 20.9N 110.9W 35 KT 40 MPH
60H 20/1800Z 21.1N 112.2W 30 KT 35 MPH
72H 21/0600Z 21.2N 113.2W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 22/0600Z 21.5N 116.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 23/0600Z 21.0N 118.5W 25 KT 30 MPH...POST-TROP/REMNT LOW