Atlantic Hurricane Feed

Tropical Storm Wanda Forecast Discussion



020 
WTNT41 KNHC 051445
TCDAT1

Tropical Storm Wanda Discussion Number  23
NWS National Hurricane Center Miami FL       AL212021
300 PM GMT Fri Nov 05 2021

Wanda's cloud pattern has again changed little since the last
advisory, with bands of moderately deep convection currently
located mainly in the southern semicircle.  Just-received ASCAT
data indicates an area of 40-45 kt winds mainly west of the center,
and based on this the initial intensity is a possibly conservative
45 kt.  The ASCAT data also show that the wind field has expanded
on the west side, and the initial and forecast wind radii have thus
been modified.

The initial motion is now south-southeastward or 160/7 kt.  A
southward motion is forecast during the next 24 h as a mid-level
ridge builds to the north and west of the cyclone.  After that time,
a developing mid-latitude cyclone currently south of eastern Canada
will move close enough to break down the ridge and produce
southwesterly deep-layer flow around Wanda.  This should cause the
tropical cyclone to turn northeastward and accelerate, with a quick
northeastward motion continuing until Wanda dissipates.  The latest
track guidance is in good agreement, and the new forecast track lies
close to the various consensus models.

The southward motion should bring the center over slightly warmer 
water during the next 24-36 h, and during this time Wanda should be 
in an area of light to moderate shear inside of the circulation of a 
nearby upper-level low.  This environment should allow Wanda to 
maintain its strength and perhaps strengthen a little.  By 48 h, the 
mid- latitude system approaching from the west should cause 
increased shear, although the associated increased upper-level 
divergence may offset any weakening caused by the shear.  Wanda is 
forecast to merge with a frontal zone by 72 h, and by 120 h the 
system is forecast to weaken to a tough to the south of a large 
mid-latitude low over the northeastern Atlantic.  The new intensity 
forecast has only minor adjustments from the previous forecast.


FORECAST POSITIONS AND MAX WINDS

INIT  05/1500Z 40.6N  37.8W   45 KT  50 MPH
 12H  06/0000Z 39.1N  37.7W   45 KT  50 MPH
 24H  06/1200Z 37.9N  37.7W   45 KT  50 MPH
 36H  07/0000Z 38.2N  36.5W   45 KT  50 MPH
 48H  07/1200Z 41.0N  33.1W   50 KT  60 MPH
 60H  08/0000Z 45.4N  28.2W   50 KT  60 MPH
 72H  08/1200Z 50.0N  22.6W   45 KT  50 MPH...POST-TROP/EXTRATROP
 96H  09/1200Z 57.5N  12.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  10/1200Z...DISSIPATED

$$
Forecaster Beven




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