Tropical Storm HERNAN
ZCZC MIATCDEP3 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM HERNAN DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082014
200 AM PDT MON JUL 28 2014
Hernan is now on a weakening trend. The coverage of deep convection
has decreased markedly over the past several hours, and the cloud
pattern has a more elongated appearance than it did earlier.
Microwave images also show a pronounced vertical tilt of the vortex
due to about 15 kt of westerly shear. Dvorak and ADT intensity
estimates have decreased from all agencies, and using a blend of the
CI- and T-numbers yields an initial intensity of 60 kt. A
combination of moderate shear, a dry stable air mass, and decreasing
sea surface temperatures should cause Hernan to continue weakening
during the next few days. The system is expected to become a
remnant low in about 2 days when it is forecast to be over waters
cooler than 23 C.
The storm has turned slightly to the left, and the latest initial
motion estimate is 300/13 kt. This general motion should continue
for the next 24 hours while Hernan remains steered by a strong
mid-level high over the southwestern United States. After that
time, a gradual turn to the west with a decrease in forward speed
is predicted when the shallow system becomes more influenced by the
lighter low-level flow. The official track forecast is just a
little to the left of the previous one, and near the multi-model
consensus TVCE.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0900Z 19.9N 114.5W 60 KT 70 MPH
12H 28/1800Z 20.9N 116.4W 50 KT 60 MPH
24H 29/0600Z 22.3N 118.8W 45 KT 50 MPH
36H 29/1800Z 23.4N 120.6W 35 KT 40 MPH
48H 30/0600Z 24.1N 122.2W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 31/0600Z 24.5N 124.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 01/0600Z 24.5N 126.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 02/0600Z...DISSIPATED
$$
Forecaster Cangialosi
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