Tropical Cyclone Discussion

153
WTNT44 KNHC 271449
TCDAT4
 
Tropical Storm Dolly Discussion Number   1
NWS National Hurricane Center Miami FL       AL042026
1100 AM AST Thu Aug 27 2026
 
Satellite images indicate that the area of low pressure (Invest
AL96) has developed a well-defined center this morning along with
organized deep convection.  There is a bit of northwesterly shear, 
causing most of the thunderstorm activity to be located on the 
southern side of the circulation largely away from the center. 
Scatterometer data shows that the maximum winds are near 35 kt in
the northeastern quadrant, along with a Dvorak T2.5/35 kt
classification from TAFB, so advisories are initiated on Tropical
Storm Dolly.  
 
The initial motion estimate is 275/21 kt.  Dolly should continue
moving quickly westward for the next couple of days under a strong
ridge of high pressure over the central Atlantic.  Model guidance
is tightly packed on a track towards the Leeward Islands, and 
the NHC forecast is on the faster and southward side of the 
guidance envelope.  This forecast is consistent with the NOAA HCCA 
model and the well-known bias for models to be too slow and 
poleward in the tropical Atlantic.

The environment around Dolly should become unfavorable for 
strengthening by tomorrow with increasing southwesterly shear due 
to a central Atlantic upper-level trough, fast forward motion and 
dry air aloft.  Until then, some slight intensification is 
possible, consistent with the model consensus.  All of our guidance 
is showing Dolly opening up into a strong tropical wave before it 
reaches the Leeward Islands, which is our expectation as well, and 
post-tropical positions are provided given the risk of gusty winds 
and heavy rainfall.  

The timing of the use of the name Dolly for this storm is purely 
coincidental.  Tropical storm and hurricane names for the North 
Atlantic Basin originate from six pre-determined rotating lists 
established by the World Meteorological Organization Region IV 
Hurricane Committee.  The name Dolly replaced Diana after the 
1990 hurricane season and was first used in 1996.

KEY MESSAGES:

1. Although Dolly is forecast to no longer be a tropical cyclone 
when it passes near the Leeward Islands, heavy rainfall could begin 
to affect the Leeward Islands late Saturday into Sunday and the 
Virgin Islands, Puerto Rico and Hispaniola Sunday and Monday.  This 
heavy rain may produce flash flooding, especially in areas of 
higher terrain.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  27/1500Z 13.6N  38.7W   35 KT  40 MPH
 12H  28/0000Z 13.7N  42.0W   40 KT  45 MPH
 24H  28/1200Z 14.4N  46.4W   40 KT  45 MPH
 36H  29/0000Z 15.1N  51.1W   40 KT  45 MPH
 48H  29/1200Z 15.9N  55.6W   40 KT  45 MPH
 60H  30/0000Z 16.7N  59.5W   35 KT  40 MPH...POST-TROPICAL
 72H  30/1200Z 17.7N  63.2W   35 KT  40 MPH...POST-TROPICAL
 96H  31/1200Z...DISSIPATED