000
AXNT20 KNHC 260557
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
205 AM EDT MON JUL 26 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0550 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 25W S OF 19N MOVING W 10 TO 15 KT. LOW TO 
MID LEVEL CYCLONIC FLOW SURROUNDS THE WAVE AXIS EVIDENT IN BOTH 
SATELLITE DATA AND SATELLITE DERIVED WINDS. THE WAVE ALSO 
COINCIDES WITH A SURGE IN DEEP LAYER MOISTURE SEEN IN TOTAL 
PRECIPITABLE WATER IMAGERY. HOWEVER...THIS WAVE IS FOUND WITHIN 
A BROAD AREA OF SIGNIFICANT SAHARAN AIR LAYER SUPPRESSING ANY 
DEEP CONVECTION FROM DEVELOPING.

TROPICAL WAVE IS ALONG 43W S OF 19N MOVING WEST 5 TO 10 KT. 
SATELLITE DERIVED WINDS INDICATE VERY WEAK LOW-LEVEL CYCLONIC 
FLOW IN THE VICINITY OF THE WAVE AXIS. THE WAVE ALSO LIES AHEAD 
OF A SURGE IN DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE 
WATER IMAGERY. ALSO...THIS WAVE IS MOVING THROUGH A REGION OF  
VERY DRY AND STABLE AIR ALOFT. THEREFORE...NO DEEP CONVECTION 
ACCOMPANIES THE WAVE. 

...THE ITCZ...

THE ITCZ AXIS IS ANALYZED FROM THE WESTERN AFRICAN COAST OF THE 
GAMBIA NEAR 13N16W...WESTWARD ALONG 12N20W 10N30W 8N40W 9N50W 
8N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 
140 NM ON EITHER SIDE OF THE ITCZ. 

...DISCUSSION...

THE GULF OF MEXICO...
SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE OVER 
THE EASTERN HALF OF THE GULF EAST OF 88W INCLUDING THE FLORIDA 
STRAITS FROM BROAD CYCLONIC FLOW AROUND A MID/UPPER LEVEL LOW 
CURRENTLY SPINNING NEAR 25N85W. THIS SYSTEM WILL CONTINUE TO 
SPREAD CONVECTION ACROSS THE EAST...CENTRAL...AND NORTHERN GULF 
OVER THE NEXT 24 TO 36 HOURS. SCATTERED MODERATE TO HEAVY 
SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER ALONG THE WESTERN 
GULF COAST TO 60 NM OFFSHORE FROM MATAMOROS MEXICO SOUTH TO 
VERACRUZ...ENHANCED BY A SURFACE TROUGH ANALYZED INLAND OVER 
MEXICO. THE NE GULF NORTH OF 26N WEST OF 93W IS INFLUENCED BY 
CYCLONIC FLOW ALOFT FROM A BROAD UPPER LEVEL LOW SPINNING INLAND 
OVER SOUTHERN OKLAHOMA PRODUCING A FEW SCATTERED SHOWERS IN THIS 
AREA. 

THE CARIBBEAN SEA...
THE WESTERN CARIBBEAN WEST OF 78W CONTINUES UNDER THE INFLUENCE 
OF MID LEVEL TROUGHINESS AS INDICATED BY COMPUTER GENERATED 500 
MB STREAMLINE ANALYSIS. SCATTERED MODERATE TO HEAVY SHOWERS AND 
THUNDERSTORMS ARE ACROSS THIS REGION. COMPUTER MODELS INDICATE 
THE MID LEVEL TROUGH WILL MOVE WESTWARD OUT OF THE REGION OVER 
THE NEXT 24 HOURS...WITH SCATTERED CONVECTION LINGERING OVER THE 
FAR SW CARIBBEAN DUE TO THE PACIFIC ITCZ EXTENDING ACROSS THE 
LOWER REGIONS OF CENTRAL AMERICA. ABUNDANT SAHARAN DUST AND DRY 
STABLE AIR ALOFT IS NOTED ELSEWHERE EAST OF 78W...PROVIDING FAIR 
WEATHER CONDITIONS ACROSS THE CENTRAL AND EASTERN CARIBBEAN E OF 
78W.

THE ATLANTIC OCEAN...
NO SIGNIFICANT WEATHER IS OCCURRING ACROSS THE ATLANTIC. SURFACE 
RIDGING DOMINATES THE AREA OF DISCUSSION ANCHORED BY A 1022 MB 
HIGH CIRCULATING OVER WESTERN ATLANTIC NEAR 27N67W AND A BROAD 
1028 MB HIGH NORTH OF THE AZORES NEAR 40N26W PROVIDING FAIR 
WEATHER CONDITIONS ACROSS THE AREA.

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

$$

GARCIA