Tropical Weather Discussion

axnt20 knhc 090604

Tropical weather discussion
NWS National Hurricane Center Miami FL
205 am EDT Fri Oct 09 2015

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 observations...radar...and meteorological 

Based on 0000 UTC surface analysis and satellite imagery through 
0515 UTC.

...Tropical waves...    

an Atlantic Ocean tropical wave is along 12n32w 07n34w 03n35w... 
moving westward 10 to 15 knots. Convective precipitation... 
widely scattered moderate to scattered moderate and isolated 
strong within 90 nm on either side of 15n27w 10n31w 07n36w. 

A Caribbean Sea tropical wave is along 15n61w 12n62w 07n63w... 
moving westward 20 to 25 knots during the last 24 hours.   
Convective precipitation...scattered moderate to isolated strong 
from 10n to 12n between 57w and 61w. 

A Caribbean Sea tropical wave extends from eastern Puerto Rico 
to 14n66w to 10n66w at the coast of Venezuela...moving westward 
15 knots during the last 24 hours. The wave is moving through an 
area of middle level to upper level southeasterly wind flow. The 
southeasterly wind flow is part of a larger-scale area of a 
32n54w 24n59w 16n60w ridge. Convective precipitation...isolated 
moderate to locally strong from 16n to 20n between 60w and 67w. 

...ITCZ/monsoon trough...                                     

The monsoon trough passes coastal sections of senegal near 
15n17w to 13n24w and 09n32w. The ITCZ starts near 08n36w...and 
it continues to 07n49w and 09n55w. Convective precipitation... 
widely scattered to scattered moderate and isolated strong from 
08n to 10n between 11w and 16w. Isolated moderate elsewhere from 
03n to 12n between 08w and 23w. Isolated moderate within 90 nm 
on either side of 07n36w 08n40w 09n44w 11n50w. Rainshowers also 
are possible elsewhere from 11n southward between 50w and 57w.


The Gulf of Mexico... 

Upper level anticyclonic wind flow covers the Gulf of Mexico. 
The anticyclonic wind flow is moving around a ridge that extends 
from the southwestern corner of the Gulf of Mexico...through the 
central Gulf waters...beyond the coastal plains of the 
U.S.A. Between the Florida Panhandle and southeastern Louisiana. 
Comparatively drier air in subsidence is apparent in water vapor 
imagery within 180 nm of the U.S.A. Coast between 83w for 
Florida and 97w for Mexico.

A surface ridge extends from the northern coastal waters of the 
Gulf of a 1020 mb northwestern South 
Carolina high pressure center. One surface trough is along 
26n83w 23n86w. A second surface trough is in the Yucatan 

The Caribbean Sea...

Please refer to the section that is about tropical waves...for 
more details about the two Caribbean Sea tropical waves.

A middle level to upper level trough passes through the southern 
Bahamas...cutting right through a 15n73w cyclonic 
circulation center. The trough continues from 15n73w into the 
southwestern corner of the northern Colombia near 
10n74w. The cyclonic circulation center was forecast by the GFS 
model at least 24 hours ago. A surface trough is along 82w/83w 
from 09n in Panama to 17n. Convective precipitation...isolated 
moderate in the Caribbean Sea from 14n to 20n between 70w and 
80w...including across Hispaniola during the last 3 to 6 hours. 
Isolated moderate has been active during the last 6 hours...and 
it continues to be active now...from 18n southward between 80w 
and 85w...including in eastern sections of Nicaragua.

The 24-hour rainfall totals in inches for the period ending at 
09/0000 UTC...according to The Pan American temperature and 
precipitation tables...miatptpan/sxca01 knhc...are 0.34 in 
Bermuda and 0.26 in Guadeloupe.  


Please refer to the section that is about tropical waves for 
more details about the two Caribbean Sea tropical waves. An 
upper level north-to-south oriented trough cuts through Haiti. 
An upper level cyclonic circulation center is near 15n73w... 
forecast correctly by the GFS model 24 hours ago. Convective 
precipitation...isolated moderate to strong within a 30 nm 
radius of 20n73w in northwestern Haiti. Rainshowers are possible 
in the southern coastal waters of Hispaniola. 

Current the Dominican Republic...rainshowers 
with thunder are in Santo Domingo...and they were being observed 
in La Romana as late as 09/0300 UTC. Few low level clouds are in 
Punta Cana. Rainshowers with thunder are being reported in 
Santiago and in Puerto Plata. 

The GFS model forecast for 250 mb shows that the current 15n73w 
cyclonic circulation center will be to the south of and move 
onshore across Hispaniola during the next 30 hours or so. The 
cyclonic circulation center eventually will open itself into a 
trough for the rest of the 48-hour forecast period. The GFS 
model forecast for 500 mb shows that a northeasterly wind flow 
will cover Hispaniola for the first 24 hours. An inverted trough 
will cover Hispaniola for the second 24 hours. The GFS model for 
700 mb shows that a few inverted troughs will cross Hispaniola 
during the next 48 hours.

The Atlantic Ocean...                                

a middle level to upper level trough passes through 32n74w to 
26n73w 22n72w...cutting right through 16n74w...into 
northern Colombia. A cold front passes through 32n66w to 31n70w. 
A surface trough continues from 31n70w to 27n78w...cutting 
across South Florida near 26n81w...into the Gulf of Mexico near 
25n86w and 22n92w. Convective precipitation...widely scattered 
moderate to isolated strong within 270 nm to the north and 
northwest of the line that passes through 32n58w 28n63w 26n70w 

A middle level to upper level trough extends from 29n57w to 
26n54w 22n53w and 18n52w. Convective precipitation...debris 
clouds and possible rainshowers are elsewhere from 19n to 28n 
between 46w and 60w. 

Broad middle level to upper level cyclonic wind flow covers 
the area from 10n to 24n between 30w and 45w.

An Atlantic Ocean ridge extends from a 1021 mb high pressure 
center that is near 38n16w...through 32n21w to 26n29w...through 
a 1020 mb high pressure center that is near 
26n69w...across the central Bahamas and central Cuba...into the 
northwestern corner of the Caribbean Sea near 18n86w.

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