ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
 
Tropical Depression Fred Discussion Number  12
NWS National Hurricane Center Miami FL       AL062021
1100 AM EDT Thu Aug 12 2021
 
Fred is poorly organized this morning.  Reports from Air Force 
Reserve and NOAA Hurricane Hunter aircraft, along with 1-minute 
imagery from GOES-16, indicate that the circulation is barely 
closed.  Dropsondes in the area reported surface pressures of 
1013-1014 mb, and the maximum winds of near 30 kt are well to the 
northeast of the center.  In addition, there is currently no 
organized convection anywhere near the center.  Based on the 
evidence of the closed circulation, the system will be maintained as 
tropical depression for this advisory.  However, the structure is 
currently closer to that of an open wave than a normal tropical 
cyclone.

The initial motion is now 300/12.  The subtropical ridge over the 
western Atlantic north of Fred should steer the cyclone 
west-northwestward during the next 36 h or so.  This motion should 
take the depression away from the southeastern Bahamas and 
bring it near the north coast of Cuba.  After that time, Fred 
should approach the western periphery of the ridge, which should 
cause the cyclone to turn northwestward and slow its forward speed. 
There remains some uncertainty as to the when and where of the 
turn, with the track guidance models remaining spread across a 
region from over Florida to the east-central Gulf of Mexico.  The 
new track forecast is little changed from the previous NHC track, 
and it lies a little to the east of the consensus models for the 
first 72 h or so.
 
Fred remains in an environment about 20 kt of westerly vertical
wind shear.  This shear is expected to persist during the next day 
or so, and this combined with the current disorganization should 
prevent significant strengthening during this time.  While 
there is still disagreement between the global models on the 
forecast upper-level winds over the Gulf of Mexico, the shear could 
lessen after 36 h and allow some intensification as the cyclone 
nears south Florida and moves into the eastern Gulf.  The intensity 
guidance has trended weaker since the last advisory, with none of 
the guidance currently calling for Fred to reach hurricane 
strength. The new intensity forecast is similar to the previous 
one while Fred is over water, and it follows the overall trend of 
the intensity guidance.

KEY MESSAGES:
 
1. Heavy rainfall today could lead to flash, urban, and small stream 
flooding, along with possible rapid river rises and the potential 
for mudslides in the Dominican Republic and Haiti. 

2. Tropical storm conditions are possible in the southeastern 
Bahamas and portions of Cuba today.

3. Beginning Friday, heavy rainfall could lead to areal, urban, and 
small stream flooding, along with possible rapid river rises across 
southern Florida. Heavy rainfall associated with Fred will impact 
the remainder of Florida and parts of the Southeast this weekend and 
into next week.

4. There is a risk of tropical storm conditions beginning early 
Saturday in the Florida Keys and south Florida.  This risk will 
spread northward along portions of the Florida west coast and to the 
Florida Panhandle through Monday. A Tropical Storm Watch will likely 
be issued for portions of the Florida Keys and the southern Florida 
Peninsula this afternoon. 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/1500Z 20.9N  74.4W   30 KT  35 MPH
 12H  13/0000Z 21.8N  76.2W   30 KT  35 MPH
 24H  13/1200Z 22.8N  78.3W   30 KT  35 MPH
 36H  14/0000Z 23.8N  79.9W   35 KT  40 MPH
 48H  14/1200Z 24.8N  81.2W   35 KT  40 MPH
 60H  15/0000Z 26.0N  82.4W   40 KT  45 MPH
 72H  15/1200Z 27.5N  83.6W   45 KT  50 MPH
 96H  16/1200Z 30.5N  85.0W   50 KT  60 MPH...INLAND
120H  17/1200Z 33.5N  85.0W   25 KT  30 MPH...INLAND
 
$$
Forecaster Beven
 
NNNN