AXNT20 KNHC 171030 
TWDAT 
 
Tropical Weather Discussion 
NWS National Hurricane Center Miami FL 
630 AM EDT Mon Jul 17 2017 
 
Tropical Weather Discussion for North America, Central America 
Gulf of Mexico, Caribbean Sea, northern sections of South 
America, and Atlantic Ocean to the African coast from the 
Equator to 32N. The following information is based on satellite 
imagery, weather observations, radar and meteorological analysis. 
 
Based on 0600 UTC surface analysis and satellite imagery through 
1030 UTC. 
 
...SPECIAL FEATURES... 
Low pressure is centered near 10.5N49W. Scattered moderate 
isolated strong convection is noted within 120 nm northwest 
semicircle of the low. Environmental conditions are marginally 
conducive for further development of this system and there is a 
medium chance that the low will develop into a tropical cyclone in 
the next 48 hours. Please refer to the latest Tropical Weather 
Outlook for more information on this low. 
 
...TROPICAL WAVES... 
 
The axis of a tropical wave is near 20N32W to 03N33W. The wave is 
moving westward about 10-15 kt. 
 
The axis of a tropical wave is near 19N53W to 04N54W. The wave is 
moving westward near 15 kt. 
 
The axis of a tropical wave is near 24N81W to 06N81W. The wave is 
moving westward near 15 kt. 
 
...ITCZ/MONSOON TROUGH... 
 
The monsoon trough extends from 19N16W to 09N37W to low pres near 
10.5N49W. The ITCZ extends from 10.5N49W to 09N60W. Scattered 
moderate isolated strong convection was noted within 30 nm north 
and 120 nm south of the monsoon trough between 35W and 45W. 
Scattered moderate isolated strong convection was noted within 120 
nm northwest semicircle of the low. 
 
...DISCUSSION... 
 
GULF OF MEXICO... 
 
A weak pressure pattern prevails over the Gulf of Mexico. As a 
result benign marine conditions prevail over the area. Winds are 
generally in the light to gentle range with seas of 1-2 ft. High 
pressure will build across the region early this week and prevail 
through the remainder of the week. 
 
CARIBBEAN SEA... 
 
A tropical wave is moving through the western Caribbean, helping 
enhance convection over this area. A weak pressure pattern 
prevails over the forecast area producing moderate to fresh winds 
prevail over the eastern and central Caribbean, and light to 
gentle winds over the western Caribbean. High pressure will build 
north of the area early this week, which will tighten the pressure 
gradient and bring an increase to the tradewinds across the area. 
 
...HISPANIOLA... 
 
Active diurnal convection has dissipated over the island. Expect 
another round of afternoon thunderstorms to develop and last into 
the early evening hours today. 
 
ATLANTIC OCEAN... 
 
Central Atlantic high pressure centered near 35N39W extends a 
ridge westward to the southeast United States. As typical for this 
time of year, tropical waves are moving through the tropical 
Atlantic waters. Low pressure has developed within the monsoon 
trough near 10.5N48W. Active convection associated to this low is 
noted within 90 nm northwest semicircle of the low as noted in the 
ITCZ/ monsoon trough section. 
 
For additional information please visit 
http://www.hurricanes.gov/marine