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Atlantic Tropical Weather Discussion (Text)



000
AXNT20 KNHC 041731
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
205 PM EDT SAT JUL 04 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 
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1730 UTC.

...SPECIAL FEATURES... 

...GALE IN THE CARIBBEAN...

A GALE WARNING CONTINUES IN EFFECT FOR THE SW CARIBBEAN FROM 11N-
13N BETWEEN 73W-78W THROUGH SUNDAY MORNING. THESE WINDS ARE 
GENERATED BY A TIGHT PRESSURE GRADIENT BETWEEN THE STRONG 
SURFACE RIDGE THAT PREVAILS OVER THE ATLANTIC AND THE LOWER 
PRESSURES OVER SOUTH AMERICA. SEE THE LATEST NWS HIGH SEAS 
FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE 
DETAILS.

...TROPICAL WAVES... 

A TROPICAL WAVE IS IN THE E TROPICAL ATLANTIC WITH AXIS 
EXTENDING FROM 16N33W TO 06N35W. THIS WAVE HAS BEEN MOVING W AT 
ABOUT 20-25 KT OVER THE PAST 24 HOURS. CURRENT METEOSAT SAL 
IMAGERY DEPICTS A BROAD AREA OF SAHARAN DUST SURROUNDING THIS 
WAVE WHICH IS INHIBITING SIGNIFICANT CONVECTION.

A TROPICAL WAVE IS IN THE CENTRAL TROPICAL ATLANTIC WITH AXIS 
EXTENDING FROM 13N45W TO 04N47W EXTENDS ALONG 43W FROM 5N-12N 
...MOVING AT 15-20 KT OVER THE PAST 24 HOURS. THE TOTAL 
PRECIPITABLE WATER IMAGERY SHOWS THE WAVE EMBEDDED WITHIN LOW 
AMPLITUDE SURGE OF DEEP MOISTURE. ISOLATED CONVECTION IS ALONG 
09N BETWEEN 45W-49W.

A TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN WITH AXIS EXTENDING 
FROM 18N74W TO 10N76W. THIS WAVE HAS MOVED W AT 20-25 KT OVER 
THE PAST 24 HOURS. CURRENT METEOSAT SAL IMAGERY DEPICTS A BROAD 
AREA OF SAHARAN DUST PREVAILING ACROSS THE CARIBBEAN AND IN THE 
ENVIRONMENT OF THIS WAVE...THUS INHIBITING CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL 
ATLANTIC NEAR 14N17W TO 10N21W WHERE THE ITCZ BEGINS AND 
CONTINUES TO NEAR 09N34W THEN RESUMES W OF THE WAVE NEAR 08N37W 
TO 07N45W THEN AGAIN W OF A TROPICAL WAVE NEAR 07N49W TO 06N57W. 
ISOLATED CONVECTION PREVAILS IN THE PROXIMITY OF THE ITCZ AXIS 
BETWEEN 21W-23W AND 48W-54W.  

...DISCUSSION...

GULF OF MEXICO...

AN UPPER-LEVEL LOW IS CENTERED OVER THE SOUTHERN GULF NEAR 
22N89W AND EXTENDING ACROSS THE WHOLE BASIN. AN AREA OF UPPER-
LEVEL DIFFLUENCE IS SUPPORTING SCATTERED MODERATE CONVECTION 
ALONG THE MEXICO COAST BETWEEN 20N-25N AND W OF 97W. AT THE 
SURFACE...A BROAD SURFACE HIGH CENTERED OVER THE ATLANTIC 
EXTENDING ITS RIDGE ACROSS W REACHING THE NORTHERN GULF WATERS. 
A 1021 MB SURFACE HIGH IS CENTERED OVER THE FLORIDA PENINSULA 
NEAR 28N81W. A LIGHT TO GENTLE ANTICYCLONIC FLOW PREVAILS ACROSS 
THE BASIN. OVER THE NEXT 24 HOURS...EXPECT FOR THE SURFACE RIDGE 
TO PERSIST.

CARIBBEAN SEA... 

THE BASIN IS UNDER THE INFLUENCE OF A LARGE SAHARAN AIRMASS 
WHICH CONTINUES TO INHIBIT ANY SIGNIFICANT CONVECTION. A 
TROPICAL WAVE EXTENDS ACROSS THE CENTRAL CARIBBEAN...FOR MORE 
DETAILS PLEASE REFER TO THE SECTION ABOVE. AT THE SURFACE...THE 
HIGH PRESSURE THAT PREVAILS ACROSS THE ATLANTIC EXTENDS SW 
REACHING THE CARIBBEAN. THE PRESSURE GRADIENT BETWEEN THIS HIGH 
AND LOWER PRESSURES ACROSS SOUTH AMERICA IS GENERATING GALE 
FORCE WINDS ACROSS THE SOUTHERN CARIBBEAN. FOR MORE INFORMATION 
REFER TO THE SPECIAL FEATURES SECTION ABOVE. SCATTEROMETER DATA 
DEPICTS GENTLE TO MODERATE TRADES ACROSS THE REMAINDER OF THE 
AREA EXCEPT S OF 18N BETWEEN 71W-79W WHERE FRESH TO STRONG WINDS 
WERE ESTIMATED. OVER THE NEXT 24 HOURS...EXPECT A SIMILAR 
WEATHER PATTERN TO PREVAIL. 

...HISPANIOLA... 

FAIR WEATHER PREVAILS ACROSS THE ISLAND AS SAHARAN DUST 
CONTINUES INHIBITING ANY SIGNIFICANT CONVECTION. A TROPICAL WAVE 
IS S OF THE ISLAND NEAR THE WINDWARD PASSAGE. THIS WAVE WILL 
BRING A SLIGHT INCREASE IN MOISTURE ACROSS THE ISLAND WHICH 
COULD HELP IN THE DEVELOPMENT OF ISOLATED CONVECTION IN THE 
AFTERNOON. EXPECT A SIMILAR WEATHER PATTERN TO PREVAIL OVER THE 
NEXT 24 HOURS.

ATLANTIC OCEAN... 

A SMALL UPPER-LEVEL RIDGE IS DEVELOPING ALONG 78W AND COMBINED 
WITH AN UPPER-LEVEL LOW CENTERED NEAR 26N70W...A DIFFLUENT FLOW 
IS SUPPORTING ISOLATED MODERATE CONVECTION ACROSS THE W 
ATLANTIC WATERS N OF 26N AND W OF 76W. AN AREA OF ISOLATED 
SHOWERS IS FROM 20N-28N BETWEEN 60W-70W. THE REMAINDER OF THE 
ATLANTIC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1030 MB 
HIGH N OF THE AREA NEAR 34N43W AND EXTENDING A RIDGE AXIS 
THROUGH 32N56W TO ACROSS CENTRAL FLORIDA AND INTO THE GULF OF 
MEXICO. NOAA/NESDIS AEROSOL PRODUCT AND VISIBLE SATELLITE 
IMAGERY INDICATES THAT A LARGE AND DENSE PLUMB OF SAHARAN DUST 
COVERS THE TROPICAL ATLANTIC N OF 11N. WITH THIS...NO 
SIGNIFICANT CONVECTION IS EXPECTED. OVER THE NEXT 24 HOURS...THE 
SURFACE RIDGE AND SAHARAN AIRMASS WILL PERSIST. 

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

$$ 

ERA

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Page last modified: Saturday, 04-Jul-2015 17:31:50 UTC