000
AXNT20 KNHC 230003
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 PM EDT THU JUL 22 2010

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2350 UTC.

...SPECIAL FEATURES...

TROPICAL DEPRESSION THREE IS NOW UPDATED TO TROPICAL STORM 
BONNIE WITH A LOW CENTER LOCATED NEAR 23.1N 75.9W AS OF FEB 23 
AT 0000 UTC. THIS LOCATION IS ABOUT 165 MI...265 KM SE OF 
NASSAU...AND ABOUT 385 MI...615 KM ESE OF KEY WEST FLORIDA. THIS 
SYSTEM IS MOVING NW TOWARDS THE FLORIDA STRAITS. THE ESTIMATED 
MINIMUM CENTRAL PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WINDS OF 
35 KT WITH GUSTS TO 45 KT ARE FOCUSED ON THE NE QUADRANT OF THE 
STORM. THIS SYSTEM IS EMBEDDED IN A REGION OF DEEP LAYER 
MOISTURE AS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. WATER 
VAPOR IMAGERY INDICATES AN ELONGATED UPPER LEVEL LOW SPINNING 
NEAR 24N80W. THIS UPPER LEVEL FEATURE IS FURTHER ENHANCING THE 
CONVERGENCE WITH THIS SYSTEM...PRODUCING A BROAD AREA OF 
CONVECTION COVERING THE NORTHERN CARIBBEAN NORTH OF 15N BETWEEN 
63W AND 80W...AND THE FAR WESTERN ATLANTIC WEST OF 72W SOUTH OF 
27N...AFFECTING THE GREATER ANTILLES...TURKS AND CAICOS...AND 
THE BAHAMAS. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCPAT3/WTNT33 KNHC AND THE FULL 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC 
FOR MORE DETAILS.

A 1007 MB LOW IS CENTERED OVER THE SW GULF OF MEXICO NEAR 
21N96W...MOVING SLOWLY WESTWARD TOWARDS THE COAST OF MEXICO. 
SIGNIFICANT DEEP LAYER MOISTURE IS ACROSS THE WRN GULF 
ASSOCIATED WITH THIS SYSTEM. DIFFLUENCE ALOFT BETWEEN UPPER 
RIDGING OVER THE WRN GULF AND UPPER LEVEL TROUGHING OVER N 
CENTRAL MEXICO IS ENHANCING CONVECTION NEAR THE SURFACE LOW 
PRESSURE SYSTEM. NUMEROUS STRONG CONVECTION COVER THE BAY OF 
CAMPECHE AND THE WESTERN GULF FROM WEST OF 90W S OF 27N. 
ALTHOUGH THIS SYSTEM CONTINUES TO SHOW SIGNS OF 
ORGANIZATION...THE PROXIMITY TO LAND WILL LIKELY INHIBIT ANY 
SIGNIFICANT DEVELOPMENT. THERE IS A MEDIUM CHANCE OF THIS SYSTEM 
BECOMING A TROPICAL CYCLONE BEFORE IT REACHES THE COAST OF 
MEXICO IN THE NEXT 24 TO 36 HOURS. 

...TROPICAL WAVES...

LOW AMPLITUDE TROPICAL WAVE IS FROM 17N26W TO 7N30W MOVING W 
NEAR 15 KT. INFRA-RED SATELLITE IMAGERY AND SATELLITE DERIVED 
WINDS INDICATE WEAK LOW-LEVEL CYCLONIC FLOW IN THE NORTHERN 
EXTENT OF THE WAVE AXIS. THE WAVE ALSO LIES AHEAD OF A SURGE IN 
DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. 
HOWEVER...THIS WAVE IS FOUND WITHIN A BROAD AREA OF SAHARAN AIR 
LAYER SUPPRESSING ANY DEEP CONVECTION WITHIN AND IN THE VICINITY 
OF THE WAVE.

TROPICAL WAVE IN THE THE CENTRAL ATLC EXTENDING ALONG 50W S OF 
22N MOVING W NEAR 15 KT. THE WAVE FOLLOWS AHEAD OF AN AREA OF 
MODERATE TO HIGH VALUES OF DEEP LAYER MOISTURE EVIDENT IN TOTAL 
PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY AND SATELLITE 
DERIVED WINDS ALSO SHOW BROAD CYCLONIC FLOW IN THE VICINITY OF 
THE WAVE AXIS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH 
THE WAVE DUE TO SAHARAN AIR LAYER I THE VICINITY OF THE WAVE.

...THE ITCZ...

THE ITCZ AXIS IS ANALYZED FROM THE WESTERN AFRICAN COAST OF 
GUINEA-BISSAU NEAR 11N16W WESTWARD ALONG 15N27W 10N32W 7N42W 
7N52W 10N60W. SCATTERED WEAK TO MODERATE CONVECTION IS WITHIN 90 
NM ON EITHER SIDE OF THE ITCZ. 

...DISCUSSION...

THE GULF OF MEXICO...
A 1007 MB LOW CONTINUES TO BRING SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IN THE SOUTHWEST GULF OF MEXICO WEST OF 90W 
SOUTH OF 27N. REEFER TO SPECIAL FEATURES SECTION ABOVE FOR MORE 
DETAILS REGARDING THIS LOW. RELATIVELY DRY AND STABLE CONDITIONS 
DOMINATE THE ATMOSPHERE ELSEWHERE ACROSS THE REGION. HOWEVER...A 
1019 MB HIGH IS IN THE NORTHEAST GULF NEAR 29N86W. THE SURFACE 
PRESSURE GRADIENT BETWEEN THE SURFACE LOW IN THE SOUTHWEST AND 
THE SURFACE HIGH IN THE NORTHEAST IS GENERATING SOUTHEAST WINDS 
15 TO 20 KT ACROSS MUCH OF THE WEST...CENTRAL...AND SE GULF. 
EXPECT STRONG CONVECTION TO ENTER THE EASTERN GULF AS TROPICAL 
STORM BONNIE APPROACHES THE STRAITS OF FLORIDA OVER THE NEXT 24 
HOURS.  

THE CARIBBEAN SEA...
DEEP LAYER MOISTURE AND UNSTABLE CONDITIONS ASSOCIATED WITH 
TROPICAL STORM BONNIE EXTEND ACROSS THE NORTHERN CARIBBEAN 
PRODUCING SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS 
NORTH OF 15N BETWEEN 63W AND 80W...INCLUDING INLAND PORTIONS OF 
CUBA...HISPANIOLA...AND PUERTO RICO. RELATIVELY DRY AND STABLE 
CONDITIONS DOMINATE THE ATMOSPHERE ELSEWHERE ACROSS THE REGION. 
EXPECT SHOWERS/THUNDERSTORMS TO REMAIN OVER NORTHERN PORTIONS OF 
THE CARIBBEAN AS TROPICAL STORM BONNIE MOVES INTO THE STRAITS OF 
FLORIDA. FOR MORE INFORMATION REGARDING TROPICAL STORM BONNIE 
SEE SPECIAL FEATURES ABOVE.

THE ATLANTIC OCEAN...
TROPICAL STORM BONNIE IS THE MAIN WEATHER THREAT OVER THE 
WESTERN ATLANTIC. THIS SYSTEM IS PRODUCING MODERATE TO HEAVY 
SHOWERS AND THUNDERSTORMS ACROSS THE GREATER ANTILLES...TURKS 
AND CAICOS...AND THE BAHAMAS. SEE SPECIAL FEATURES ABOVE FOR 
MORE DETAILS. FARTHER EAST...SURFACE RIDGING DOMINATES THE 
REMAINDER OF THE BASIN ANCHORED BY A 1026 MB HIGH NEAR 35N36W 
PROVIDING FAIR WEATHER CONDITIONS ACROSS THE AREA. 
    
FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA