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Atlantic Tropical Weather Discussion (Text)



000
AXNT20 KNHC 261019
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUL 26 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
1030 UTC.

...TROPICAL WAVES...                                     

TROPICAL WAVE IS OVER THE EASTERN ATLC WITH AXIS EXTENDING FROM 
18N28W TO 9N30W MOVING W AT 15-20 KT DURING THE PAST 24 HOURS. 
METEOSAT SAL TRACKING IMAGERY INDICATE THE WAVE CONTINUES 
EMBEDDED IN THE DRY SAHARAN AIRMASS WHICH IS INHIBITING 
CONVECTION AT THE TIME.

TROPICAL WAVE IS OVER THE WINDWARD ISLANDS AND SE CARIBBEAN WITH 
AXIS EXTENDING FROM 13N60W TO 8N61W MOVING W AT 20-25 KT IN THE 
PAST 24 HOURS. DEEP LAYER MOISTURE IN THE WAVE ENVIRONMENT IS 
SUPPORTING SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS FROM 
9N-16N BETWEEN 55W-65W. 

TROPICAL WAVE IS ON THE WESTERN CARIBBEAN WITH AXIS EXTENDING 
FROM 21N78W TO 10N78W MOVING W AT 20 KT DURING THE PAST 24 
HOURS. MODERATE LOW-LEVEL MOISTURE IS NOTED IN THE WAVE 
ENVIRONMENT...HOWEVER DRY AIR SUBSIDENCE FROM ALOFT AND STRONG 
DEEP LAYER ENVIRONMENTAL SHEAR HINDER THE DEVELOPMENT OF 
CONVECTION.

...ITCZ/MONSOON TROUGH...                                     

THE MONSOON TROUGH EXTENDS FROM THE COAST OF WEST AFRICA NEAR 
12N16W AND THEN CONTINUES ALONG 9N27W TO 9N35W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 9N35W TO 7N48W 
TO 9N55W. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL 
WAVES...SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE 
FROM 6N-9N E OF 16W...FROM 8N-10N BETWEEN 20W-35W AND FROM 6N-
10N BETWEEN 43W-52W.

...DISCUSSION...

GULF OF MEXICO...                                               

LOW-LEVEL MOISTURE ACROSS THE GULF HAS SLIGHTLY REDUCED IN THE 
LAST COUPLE OF HOURS WHICH ALONG MIDDLE-LEVEL AND SURFACE 
RIDGING CONTINUE TO SUPPORT STABILITY AND MAINLY CLEAR SKIES 
BASIN-WIDE. THE SURFACE RIDGE IS BEING ANCHORED BY A 1017 MB 
HIGH NEAR 26N87W WHICH IS PROVIDING VARIABLE WINDS OF 5-15 KT 
ACROSS THE BASIN. AN UPPER-LEVEL CYCLONIC CIRCULATION OVER THE 
EASTERN GULF AND AN ANTICYCLONE CENTERED OVER THE SW N ATLC ARE 
GENERATING DIVERGENT WIND FLOW ALOFT OVER PORTIONS OF THE 
FLORIDA PENINSULA. THIS ALONG WITH MODERATE DEEP LAYER MOISTURE 
IS SUPPORTING ISOLATED SHOWERS AND TSTMS OVER THE SOUTH FLORIDA 
PENINSULA AND ADJACENT WATERS. SURFACE RIDGING AND FAIR WEATHER 
IS FORECAST ACROSS MUCH OF THE BASIN FOR THE NEXT TWO DAYS. 
SHOWERS ARE EXPECTED FOR THE SW GULF MONDAY MORNING AS A 
TROPICAL WAVE MOVES TOWARDS THE BAY OF CAMPECHE.  

CARIBBEAN SEA...                                               

AN ANTICYCLONE CENTERED OVER THE SW N ATLC ALONG WITH AN 
INVERTED TROUGH OVER THE CENTRAL CARIBBEAN ARE GENERATING 
DIFFLUENT FLOW ALOFT WHICH ALONG LOW-LEVEL MOISTURE SUPPORT 
ISOLATED SHOWERS AND TSTMS OVER THE WINDWARD PASSAGE AS WELL AS 
WESTERN AND EASTERN CUBA. A TROPICAL WAVE IS MOVING OVER THE 
WESTERN CARIBBEAN WATERS WHILE ANOTHER WAVE ENTERS THE WINDWARD 
ISLANDS THIS MORNING. SEE TROPICAL WAVE SECTION FOR DETAILS. THE 
PASSAGE OF THE TROPICAL WAVE ACROSS THE CENTRAL CARIBBEAN ALONG 
WITH THE CONTINUATION OF A TIGHT PRESSURE GRADIENT IN THE REGION 
SUPPORT TRADES OF 20-30 KT S OF 17N E OF 79W WITH GALE FORCE 
WINDS ALONG THE COAST OF COLOMBIA. STRONG DEEP LAYER 
ENVIRONMENTAL WIND SHEAR AND DRY AIR SUBSIDENCE FROM ALOFT 
SUPPORT CLEAR SKIES ACROSS THE REMAINDER BASIN. THE WESTERNMOST 
TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE YUCATAN PENINSULA 
BY MON MORNING WHILE THE SECOND WAVE MOVES S OF PUERTO RICO.

...HISPANIOLA...                                                

AN ANTICYCLONE CENTERED OVER THE SW N ATLC ALONG WITH AN 
INVERTED TROUGH OVER THE CENTRAL CARIBBEAN IS GENERATING 
DIFFLUENCE ALOFT WHICH ALONG LOW-LEVEL MOISTURE IS SUPPORTING 
SCATTERED SHOWERS AND TSTMS OVER THE WINDWARD PASSAGE. THIS 
PATTERN ALOFT ALSO SUPPORT CLOUDINESS ACROSS THE ISLAND. EXCEPT 
FOR AFTERNOON/EARLY EVENING SHOWERS...FAIR WEATHER IS FORECAST 
FOR THE ISLAND SAT AND SUN.

ATLANTIC OCEAN...                                              

A DIFFLUENT ENVIRONMENT ALOFT BEING GENERATED BY AN UPPER-LEVEL 
CYCLONIC CIRCULATION OVER THE EASTERN GULF AND AN ANTICYCLONE 
CENTERED OVER THE SW N ATLC SUPPORT ISOLATED SHOWERS AND TSTMS N 
OF 25N W OF 77W. FARTHER EAST...A MID-UPPER LEVEL LOW CENTERED 
NEAR 27N62W ENHANCES SCATTERED SHOWERS AND ISOLATED TSTMS FROM 
23N-29N BETWEEN 59W-67W. OVER THE E ATLC...A MID-UPPER LEVEL LOW 
N OF THE AREA EXTENDS A TROUGH SW WITH A BASE NEAR 24N. THIS 
CYCLONIC CIRCULATION AND ASSOCIATED TROUGH SUPPORT A FRONTAL 
BOUNDARY ANALYZED AS A STATIONARY FRONT FROM 30N31W SW TO 26N36W 
TO 24N43W WITH NO CONVECTION ASSOCIATED WITH IT. THE REMAINDER 
BASIN IS FAIRLY DRY AND UNDER THE INFLUENCE OF A SURFACE RIDGE 
ANCHORED BY A 1022 MB HIGH NEAR 38N43W. THESE TWO FACTORS 
SUPPORTS FAIR WEATHER ELSEWHERE IN THE BASIN. OTHERWISE...SEE 
ABOVE THE TROPICAL WAVES SECTION. SURFACE RIDGING WILL DOMINATE 
ACROSS THE CENTRAL AND WESTERN ATLC. THE FRONT IS FORECAST TO 
DISSIPATE TONIGHT.

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

$$
NR


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Page last modified: Saturday, 26-Jul-2014 10:19:37 UTC