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Atlantic Tropical Weather Discussion (Text)

000
AXNT20 KNHC 251011
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI JUL 25 2014

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1000 UTC.

...TROPICAL WAVES...                                     

TROPICAL WAVE IS OVER THE CAPE VERDE ISLANDS WITH AXIS EXTENDING 
FROM 17N24W TO 10N25W MOVING W AT 15 KT. METEOSAT SAL TRACKING 
IMAGERY INDICATE THE WAVE CONTINUES EMBEDDED IN THE DRY SAHARAN 
AIRMASS WHICH IS INHIBITING CONVECTION AT THE TIME.

TROPICAL WAVE IS EMBEDDED IN THE ITCZ WITH AXIS EXTENDING FROM 
13N50W TO 4N51W MOVING W AT 15-20 KT IN THE PAST 24 HOURS. DEEP 
LAYER MOISTURE IN THE WAVE ENVIRONMENT IS SUPPORTING SCATTERED  
MODERATE CONVECTION AND ISOLATED TSTMS FROM 7N-11N BETWEEN 47W-
57W. 

TROPICAL WAVE IS ON THE CENTRAL CARIBBEAN WITH AXIS EXTENDING 
FROM 19N67W TO 12N71W MOVING W AT 20-25 KT DURING THE PAST 24 
HOURS. MODERATE DEEP LAYER MOISTURE IS NOTED IN THE CENTRAL AND 
NORTHERN WAVE ENVIRONMENT WHICH IS ENHANCING ISOLATED SHOWERS N 
OF 14N BETWEEN 62W-70W...INCLUDING COASTAL WATERS OF PUERTO RICO 
AND EASTERN DOMINICAN REPUBLIC. ELSEWHERE...DRY AIR AND STRONG 
DEEP LAYER ENVIRONMENTAL SHEAR HINDER CONVECTION.

...ITCZ/MONSOON TROUGH...                                     
MONSOON TROUGH EXTENDS FROM THE COAST OF WEST AFRICA NEAR 12N16W 
TO 9N27W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
9N28W AND THEN CONTINUES ALONG 8N39W TO 9N49W. IT THEN RESUMES W 
OF A TROPICAL WAVE FROM 8N52W TO 8N59W. BESIDES THE CONVECTION 
MENTIONED ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED 
MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 7N-12N E OF 16W 
AND FROM 9N-13N W OF 57W. ISOLATED SHOWERS ARE FROM 7N-10N 
BETWEEN 20W-32W.

...DISCUSSION...

GULF OF MEXICO...                                               

MODERATE LOW-LEVEL MOISTURE IS ACROSS MUCH OF THE BASIN BEING 
ADVECTED FROM THE CARIBBEAN. HOWEVER...MIDDLE-LEVEL AND SURFACE 
RIDGING ARE SUPPORTING STABILITY AND MAINLY CLEAR SKIES BASIN-
WIDE. REMNANT SHOWERS AND ISOLATED TSTMS BEING ENHANCED BY A 
REGION OF DIFFLUENCE IN THE UPPER LEVELS ARE S OF 28N BETWEEN 
81W-86W. ISOLATED SHOWERS AND TSTMS ARE OVER THE BAY OF CAMPECHE 
S OF 21N E OF 95W ASSOCIATED WITH A SURFACE TROUGH EXTENDING 
FROM 21N90W TO 17N93W. OTHERWISE...VARIABLE WINDS OF 5-10 KT ARE 
ACROSS THE BASIN. SURFACE RIDGING AND FAIR WEATHER IS FORECAST 
ACROSS MUCH OF THE BASIN FOR THE NEXT THREE DAYS.  

CARIBBEAN SEA...                                               

A REGION OF UPPER-LEVEL DIFFLUENCE IS OVER THE NW CARIBBEAN 
BASIN WHICH ALONG MODERATE LOW-LEVEL MOISTURE SUPPORT ISOLATED 
SHOWERS AND TSTMS FROM 14N-19N BETWEEN 79W-83W. A SIMILAR 
ENVIRONMENT ALOFT IS OVER THE SE CARIBBEAN ALONG WITH DEEP LAYER 
MOISTURE SUPPORTING A SCATTERED MODERATE CONVECTION AND ISOLATED 
TSTMS FROM 10N-14N BETWEEN 57W-65W. SHOWERS WILL CONTINUE TO 
AFFECT THE WINDWARD ISLANDS THIS MORNING. OTHERWISE...A TROPICAL 
WAVE IS MOVING OVER THE CENTRAL CARIBBEAN WATERS. SEE TROPICAL 
WAVE SECTION FOR DETAILS. STRONG HIGH PRESSURE OVER THE ATLC 
BASIN IS SUPPORTING A TIGHT SURFACE PRESSURE GRADIENT OVER THE 
CENTRAL CARIBBEAN TO SUPPORT TRADES OF 20-25 KT S OF HISPANIOLA 
BETWEEN 66W-80W. THE TROPICAL WAVE IS FORECAST TO MOVE ACROSS 
EASTERN CUBA AND JAMAICA BY SAT MORNING WHILE A NEW WAVE ENTERS 
THE EASTERN CARIBBEAN.

...HISPANIOLA...                                                

FAIR WEATHER CONDITIONS PREVAILS OVER HAITI AND WESTERN 
DOMINICAN REPUBLIC THIS MORNING. HOWEVER...THE EASTERN DOMINICAN 
REPUBLIC IS EXPERIENCING ISOLATED SHOWERS AND TSTMS AS A 
TROPICAL WAVE STARTS MOVING ACROSS THE EASTERN ISLAND. THE WAVE 
IS FORECAST TO EXIT HAITI BY SATURDAY MORNING. SHOWER ACTIVITY 
IS EXPECTED TO INCREASE THIS AFTERNOON/EARLY EVENING BEING IGNITED BY 
DAYTIME HEATING. 

ATLANTIC OCEAN...                                              

EXCEPT FOR ISOLATED SHOWERS N OF 25N BETWEEN 63W-68W BEING 
ENHANCED BY MODERATE LOW-LEVEL MOISTURE AND A MID-LEVEL 
TROUGH...THE REMAINDER BASIN IS FAIRLY DRY AND UNDER THE 
INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH NEAR 
29N52W. THESE TWO FACTORS SUPPORTS FAIR WEATHER ELSEWHERE IN THE 
BASIN. OVER THE E ATLC...A MID-LEVEL LOW N OF THE AREA EXTENDS A 
TROUGH WITH A BASE JUST N OF THE CAPE VERDE ISLANDS. THIS 
CYCLONIC CIRCULATION AND ASSOCIATED TROUGH SUPPORT A COLD FRONT 
ANALYZED FROM 30N37W TO 30N43W WITH POSSIBLE ISOLATED SHOWERS 
WITHIN 20 NM AHEAD OF IT. OTHERWISE...SEE ABOVE THE TROPICAL 
WAVES SECTION. SURFACE RIDGING WILL DOMINATE ACROSS THE CENTRAL 
AND WESTERN ATLC. THE FRONT IS FORECAST TO SINK INTO THE EASTERN 
ATLC SUN AND MON WHERE IT WILL DISSIPATE.

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

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NR