Eastern Pacific Basin Tropical Cyclones

Tropical Depression Nineteen-E Forecast Discussion


000
WTPZ44 KNHC 071459
TCDEP4

Tropical Depression Nineteen-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP192021
800 AM MST Sun Nov 07 2021

The broad area of low pressure we have been monitoring for the last 
several days well south of the Baja California Peninsula has 
improved in organization this morning. Overnight scatterometer 
data suggested that a better defined center was trying to develop 
close to the deep convection. Microwave data from an 0857 UTC AMSR2 
pass also indicated low-level cloud curvature on the 37-GHz 
channel, suggesting a well-defined center had formed. Indeed, first 
light 1-min visible imagery from a GOES-17 mesoscale domain now 
shows a tight low-level swirl located just to the west of a new 
burst of deep convection. All these data suggest the system's 
circulation is now well-defined. Therefore, advisories are being 
initiated on Tropical Depression Nineteen-E. Subjective Dvorak 
estimates from both TAFB and SAB are both at CI 2.5/35 kt,  
suggesting the depression may already be close to tropical storm 
intensity.  

The initial motion of the depression is estimated to be 290/7 kt, 
though uncertainty exists since the center only recently became 
well-defined. The system currently lies along the southwestern 
periphery of a mid-level ridge centered over Mexico. This synoptic 
pattern should allow the depression to maintain a west-northwest 
motion over the next 12-24 hours while it remains vertically coupled 
to the deep-convection. Afterwards, the remaining deep convection 
is expected to dissipate and the leftover shallow vortex is 
expected to be increasingly steered around a low-level ridge 
offshore of the west coast of Mexico. This pattern should cause the 
cyclone to turn westward and then west-southwestward over the 
remainder of its lifespan. The track guidance is in fairly good 
agreement on this general solution, and the NHC official track lies 
close to the consensus aids TVCN and HCCA.

As mentioned above, the subjective satellite estimates already 
suggest that this system could be near tropical storm intensity and 
the peak wind from the overnight scatterometer data was 31 kt. 
While the system is currently battling about 20-25 kt of 
south-southwesterly vertical wind shear, this magnitude is not 
expected to change much during the next 12-24 hours. Thus, there is 
an opportunity for some slight intensification, which is reflected 
in the NHC intensity forecast which takes the system up to a 
35-kt tropical storm by tonight. However, increasing shear and a 
drying mid-level environment should result in weakening beginning by 
36 hours with the storm forecast to become a remnant low by 
Tuesday. The NHC intensity forecast is a bit above the consensus 
aids, but a bit below the latest HWRF/HMON runs which suggests a 
slightly higher 40-45 kt peak intensity.  


FORECAST POSITIONS AND MAX WINDS

INIT  07/1500Z 13.7N 113.7W   30 KT  35 MPH
 12H  08/0000Z 14.3N 114.7W   35 KT  40 MPH
 24H  08/1200Z 15.1N 115.8W   35 KT  40 MPH
 36H  09/0000Z 15.6N 117.3W   30 KT  35 MPH
 48H  09/1200Z 15.6N 119.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  10/0000Z 15.3N 121.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  10/1200Z...DISSIPATED

$$
Forecaster Papin



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