000
AXNT20 KNHC 142351
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI SEP 14 2012

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2345 UTC.

...SPECIAL FEATURES...

TROPICAL STORM NADINE IS CENTERED NEAR 28.8N 53.4W 14/2100 UTC 
OR ABOUT ABOUT 720 MI...1160 KM ESE OF BERMUDA AND ABOUT 1645 
MI...2645 KM WSW OF THE AZORES. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 988 MB. MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH 
GUSTS TO 75 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED 
MODERATE TO STRONG CONVECTION IS FROM 27N-33N BETWEEN 48W-56W.

...TROPICAL WAVES...

A TROPICAL WAVE MOVES ACROSS THE CENTRAL TROPICAL ATLC WITH AXIS 
ANALYZED FROM 14N48W TO 7N45W MOVING W 10-15 KT. THIS SYSTEM IS 
EMBEDDED IN A SURGE OF MODERATE MOISTURE VALUES ON TPW IMAGERY. 
SCATTERED WEAK TO ISOLATED MODERATE CONVECTION FROM 10N-15N 
BETWEEN 45W-52W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS IS ANALYZED FROM THE COAST OF GUINEA 
BISSAU NEAR 12N16W ALONG 9N23W TO 9N30W...WHERE THE ITCZ AXIS 
CONTINUES TO 10N40W. SCATTERED MODERATE CONVECTION IS WITHIN 120 
NM O NEITHER SIDE OF BOTH THE ITCZ AND MONSOON TROUGH.  

...DISCUSSION...

GULF OF MEXICO...
THE WEATHER ACROSS THE ERN...NW...AND SW BASINS CONTINUE UNDER 
THE INFLUENCE OF CONVECTIVE FEATURES FOR EACH AREA. A WEAK LOW 
PRESSURE SYSTEM IS ANALYZED INLAND OVER THE CENTRAL COAST OF 
TEXAS EXTENDING A NEARLY STATIONARY FRONT THAT RUNS PARALLEL 
ALONG THE SRN COAST OF TEXAS TO INLAND ACROSS NE MEXICO. THIS 
SYSTEM IS GENERATING SCATTERED SHOWERS AND THUNDERSTORMS EVIDENT 
ON DOPPLER RADAR IMAGERY N OF 25N W OF 94W. SIMILAR CONVECTION 
COVERS THE BAY OF CAMPECHE AND COASTAL WATERS OF TAMPICO S OF 
24N W OF 93W. A SURFACE TROUGH AXIS IS ANALYZED FROM THE WRN 
ATLANTIC TO ACROSS THE STRAITS OF FLORIDA TO 27N87W...GENERATING 
SCATTERED SHOWERS AND THUNDERSTORMS OVER A GREAT PORTION OF THE 
ERN GULF E OF 87W. WATER VAPOR IMAGERY SHOWS A BROAD UPPER 
LOW/TROUGH SPINNING NEAR THE GULF CENTER. THIS FEATURE IS 
SUPPORTING ALL THREE AREAS OF CONVECTION THIS EVENING. THE 
WEATHER ACROSS THE GULF WILL REMAIN UNSTABLE DURING THE NEXT 24 
HOURS.

CARIBBEAN SEA...
A SURFACE TROUGH IS JUST A FEW NM N OF CUBA COASTAL WATERS 
GENERATING SCATTERED SHOWERS INLAND W OF 77W...SOME OF THESE 
REACHING THE WATERS NEAR THE YUCATAN CHANNEL. THE REMAINDER OF 
THE NW AND CENTRAL BASIN ARE DOMINATED BY DRY AIR AND STRONG 
SUBSIDENCE ALOFT...SUPPRESSING DEEP CONVECTION AND ONLY ALLOWING 
FOR A FEW ISOLATED LOW-TOP SHOWERS DOTTING THE DISCUSSION AREA 
TONIGHT. STRONG SHOWERS AND THUNDERSTORMS ARE NOTED S OF 14N W 
OF 77W...ASSOCIATED TO THE ERN PACIFIC MONSOON TROUGH EXTENDING 
ACROSS COSTA RICA TO NRN COLOMBIA. OTHERWISE...LIGHT TO MODERATE 
TRADE WINDS ARE ACROSS THE BASIN WITH LOCALLY FRESH TRADES IN 
THE S CENTRAL CARIBBEAN. ASIDE THE SW BASIN...FAIR WEATHER 
CONDITIONS WITH A FEW ISOLATED SHOWERS WILL PREDOMINATE ACROSS 
THE DISCUSSION AREA DURING THE NEXT 24 HOURS.
 
ATLANTIC OCEAN...
AN UPPER LEVEL LOW IS NOTED ON WATER VAPOR IMAGERY MOVING ACROSS 
THE WRN ATLANTIC NEAR 35N70W. THIS FEATURE SUPPORTS A STATIONARY 
FRONT EXTENDING INTO OUR DISCUSSION AREA AS A SURFACE TROUGH 
ALONG 31N67W 27N70W TO ACROSS THE BAHAMAS NEAR 23N76W AND INTO 
THE ERN GULF OF MEXICO ACROSS THE STRAITS OF FLORIDA. SCATTERED 
SHOWERS AND ISOLATED THUNDERSTORMS ARE NOTED WITHIN 170 NM N OF 
THE AXIS W OF 73W. ISOLATED WEAK SHOWERS ARE ALSO WITHIN 80 NM 
ON EITHER SIDE E OF 70W. THIS FRONTAL BOUNDARY IS EXPECTED TO 
SPLIT OVERNIGHT. AS THE BOUNDARY CONTINUES TO WEAKEN...HIGH 
PRESSURE WILL BUILD IN ITS WAKE THROUGH EARLY NEXT WEEK. 
TROPICAL STORM NADINE IS OVER THE CENTRAL ATLC. SEE SPECIAL 
FEATURE ABOVE FOR MORE DETAILS ON NADINE. THE REMAINDER OF THE 
ATLC BASIN DISCUSSION AREA IS DOMINATED BY A SURFACE RIDGE OF 
HIGH PRESSURE ANCHORED BY A 1020 MB HIGH NEAR 27N44W. THE 
OVERALL FAIR WEATHER IS ENHANCED ALOFT BY THICK LAYER OF SAHARAN 
DUST NOTED ON METEOSAT-9 SAL PRODUCT E OF 40W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA