LOGIN | REGISTER

Atlantic Tropical Discussion

Active Tropical Systems Basin Outlooks Satellite
Atlantic Basin Tropical Discussion
 
487 
AXNT20 KNHC 011754
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI AUG 01 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...SPECIAL FEATURES...                                          
TROPICAL STORM BERTHA IS CENTERED NEAR 14.5N 60.3W AT 01/1800 
UTC OR ABOUT 39 NM E OF MARTINIQUE AND ABOUT 100 NM NNW OF 
BARBADOS MOVING WNW AT 19 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 
IS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 
50 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 120-240 NM OF THE CENTER IN THE NE SEMICIRCLE. 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.

...TROPICAL WAVES...                                     
TROPICAL WAVE EXTENDS FROM 1013 MB LOW PRES NEAR 10.5N24W TO 
20N24W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH A FAIRLY 
AMPLIFIED 700 MB TROUGH ALONG 22W WITH A MAXIMUM IN 850 MB 
RELATIVE VORTICITY CENTERED NEAR THE LOW. THE LOW REMAINS A 
CIRCULATION EMBEDDED WITHIN THE MONSOON TROUGH AXIS. CONVECTION 
HAS DIMINISHED WITH MAINLY SCATTERED SHOWERS ACCOMPANYING THE 
WAVE AXIS AND LOW.
                              
TROPICAL WAVE EXTENDS FROM 1012 MB LOW PRES NEAR 09.5N35W TILTED 
TO THE NW TO 17N39W MOVING W AT 10-15 KT. 700 MB TROUGHING 
EXTENDS N-NW FROM THE SOUTHERN EXTENT OF THE WAVE WITH AN 850 MB 
RELATIVE VORTICITY MAXIMUM NOTED TO THE SE OF THE WAVE. THE LOW 
REMAINS EMBEDDED WITHIN THE MONSOON TROUGH AXIS. CONVECTION IS 
LIMITED WITH ISOLATED TO SCATTERED SHOWERS NEAR THE WAVE AXIS 
AND LOW.
 
TROPICAL WAVE EXTENDS FROM 12N63W TILTED SLIGHTLY NW TO 19.5N65W 
APPROACHING THE E COAST OF PUERTO RICO AND MOVING W AT 15 KT. 
THE WAVE REMAINS TO THE W OF TROPICAL STORM BERTHA AND IS 
LARGELY SURROUNDED BY THE SAHARAN AIR LAYER TO THE NE OF THE  
AXIS. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT 
THIS TIME...HOWEVER ISOLATED SHOWERS ARE OCCURRING ACROSS THE 
US/UK VIRGIN ISLANDS AND MOVING ONSHORE INTO EASTERN PUERTO RICO.
 
...ITCZ/MONSOON TROUGH...                                     
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W  
TO A 1013 MB LOW PRES NEAR 10.5N24W TO A 1012 MB LOW PRES NEAR 
09.5N35W TO 05N40W. THE INTERTROPICAL CONVERGENCE ZONE AXIS 
EXTENDS FROM 05N40W TO 04N50W. NO SIGNIFICANT CONVECTION IS 
NOTED.

...DISCUSSION...

GULF OF MEXICO...                                              
BROAD LONGWAVE UPPER LEVEL TROUGHING IS OVER THE EASTERN HALF OF 
THE CONUS THAT SUPPORTS A SERIES OF MID-LEVEL IMPULSES MOVING 
OVER THE SE CONUS. A DISSIPATING STATIONARY FRONT IS ANALYZED 
OVER FLORIDA FROM NEAR 30N83W TO OFFSHORE OF PUNTA GORDA TO 
26N84W CONTINUING WESTWARD TO 25N90W AS A TROUGH. THE FRONT IS 
TRANSITIONING INTO A REMNANT TROUGH WITH THE DEWPOINT SPREAD ON 
EITHER SIDE OF IT BECOME LESS WITH TIME. ISOLATED TO SCATTERED 
SHOWERS AND TSTMS ARE OCCURRING WITHIN 30-45 NM EITHER SIDE OF 
THE FRONT/TROUGH AXIS OVER THE EASTERN GULF WATERS WITH ACTIVITY 
OVER FLORIDA ITSELF LIMITED AS OF EARLY THIS AFTERNOON. ANOTHER 
MID-LEVEL IMPULSE OF ENERGY IS NOTED OVER THE ARKLATEX REGION 
THAT IS SUPPORTIVE OF A 1014 MB LOW CENTERED ACROSS INLAND 
EASTERN TEXAS NEAR 31N94W. A STATIONARY FRONT EXTENDS SE OF THE 
LOW TO THE SE TIP OF LOUISIANA...AND ALSO SW OF THE LOW INTO 
MEXICO NEAR 28N100W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE 
ACROSS THE NW AND N CENTRAL GULF WATERS MAINLY N OF 26N W OF 
90W. OTHERWISE...THE REMAINDER OF THE GULF IS UNDER THE 
INFLUENCE OF VERY WEAK SURFACE RIDGING ANCHORED BY A 1016 MB 
HIGH CENTERED IN THE NE GULF NEAR 27.5N86W. THIS RIDGING IS 
FORECAST TO REMAIN ANCHORED IN THE NORTH-CENTRAL TO NE GULF WITH 
A RIDGE AXIS EXTENDING ACROSS THE WESTERN GULF WITH A WEAK 
PRESSURE PATTERN IN PLACE SUPPORTING MAINLY LIGHT/GENTLE WINDS 
AND 0-2 FT SEAS ACROSS THE GULF THROUGH THE WEEKEND...EXCEPT 
MODERATE WINDS AND 2-3 FT SEAS IN THE SW GULF.

CARIBBEAN SEA...                                       
RELATIVELY DRY AND STABLE CONDITIONS ALOFT ARE NOTED OVER MUCH 
OF THE CARIBBEAN EARLY THIS AFTERNOON. AN ELONGATED UPPER LEVEL 
LOW IS POSITIONED OVER THE NW CARIBBEAN WITH A CENTER NEAR 
18N83W. AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS TO THE SE  
CENTERED NEAR 11N75W WITH A RIDGE AXIS EXTENDING TO THE N TO 
ACROSS EASTERN CUBA. AN UPPER LEVEL LOW PROVIDING NW FLOW ALOFT 
FOR THE NE CARIBBEAN IS CENTERED IN THE SW NORTH ATLC NEAR 
21N64W WITH A TROUGH AXIS EXTENDING TO THE S ACROSS THE FAR 
EASTERN CARIBBEAN. SKIES ACROSS THE BASIN REMAIN MOSTLY CLEAR 
WITH ONLY A FEW ISOLATED SHOWERS OCCURRING ON THE NORTHERN 
PERIPHERY OF THE UPPER LEVEL LOW N OF 17N TO THE COAST OF THE 
DOMINICAN REPUBLIC AND ACROSS THE WINDWARD PASSAGE APPROACHES. 
SCATTERED SHOWERS AND TSTMS ARE ALSO OCCURRING IN THE SW 
CARIBBEAN W OF 80W NEAR THE COASTS OF NICARAGUA...COSTA RICA... 
AND WESTERN PANAMA SUPPORTED BY THE ELONGATED UPPER LOW AND 
TROUGHING IN THE NW CARIBBEAN. OTHERWISE...UPPER LEVEL NW TO W 
FLOW IS PROVIDING MOSTLY STABLE CONDITIONS FOR MOST OF THE 
EASTERN CARIBBEAN EVEN AS A TROPICAL WAVE IS ANALYZED ALONG 
64W/65W. A FEW ISOLATED SHOWERS ARE OCCURRING ACROSS THE US/UK 
VIRGIN ISLANDS AND MOVING ONSHORE INTO EASTERN PUERTO RICO EARLY 
THIS AFTERNOON. LIGHT/GENTLE WINDS AND 1-3 FT SEAS ARE FORECAST 
IN THE NW CARIBBEAN...WITH MODERATE TO FRESH TRADE WINDS AND 3-6 
FT SEAS ELSEWHERE...EXCEPT FRESH TO STRONG WINDS AND 7-10 FT 
SEAS IN THE S CENTRAL CARIBBEAN NEAR THE COAST OF COLOMBIA WHERE 
THE PRESSURE GRADIENT WILL BE TIGHT.
 
...HISPANIOLA...                                        
CURRENTLY...ISOLATED TO SCATTERED SHOWERS AND TSTMS CONTINUE 
ACROSS THE ADJACENT COASTAL WATERS INCLUDING THE WINDWARD 
PASSAGE DUE TO THE PRESENCE OF AN UPPER LEVEL LOW CENTERED IN 
THE SW NORTH ATLC NEAR 21N64W AND AN APPROACHING TROPICAL WAVE 
ALONG 64W/65W. WITH THE UPPER LEVEL LOW AND ASSOCIATED TROUGHING 
EXPECTED TO MOVE LITTLE DURING THE NEXT 24 HOURS...AN OVERALL 
UNSTABLE ENVIRONMENT WILL REMAIN IN PLACE ACROSS HISPANIOLA WITH 
SCATTERED SHOWERS AND TSTMS FORECAST THROUGH THIS EVENING DURING 
PEAK DAYTIME HEATING AND INSTABILITY.

ATLANTIC OCEAN...                                              
AN UPPER LEVEL TROUGH IS OVER THE EASTERN CONUS REMAINING 
LARGELY N OF 30N THAT SUPPORTS A 1014 MB LOW CENTERED NEAR 
SAVANNAH GEORGIA. A STATIONARY FRONT EXTENDS TO THE NE AWAY FROM 
THE LOW ALONG THE SOUTH CAROLINA COAST...WHILE A NOW 
DISCONNECTED DISSIPATING STATIONARY FRONT LINGERS ACROSS CENTRAL 
FLORIDA...CURRENTLY TRANSITIONING TO A REMNANT TROUGH. NUMEROUS 
SHOWERS AND SCATTERED TSTMS ARE OCCURRING WITHIN 120 NM OF SHORE 
N OF 29.5N ALONG THE FRONT AND BEING FUELED BY THE UPPER LEVEL 
TROUGHING. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 
21N64W WITH TROUGHING EXTENDING NW TO 31N71W AND TO THE S ACROSS 
THE FAR EASTERN CARIBBEAN SEA. THESE UPPER FEATURES ARE 
SUPPORTING A LARGE AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED 
TSTMS FROM 20N-28N BETWEEN 64W-75W. OTHERWISE...THE REMAINDER OF 
THE CENTRAL ATLC IS UNDER THE INFLUENCE OF A BROAD MIDDLE TO 
UPPER LEVEL RETROGRADING LOW CENTERED NEAR 31N52W THAT IS 
SUPPORTING A BROAD AREA OF LOWER SURFACE PRESSURE FOCUSED ON A 
1016 MB LOW CENTERED NEAR 29N46W. THE PRIMARY SURFACE TROUGH 
EXTENDS SW FROM THE LOW TO 25N50W THEN W-NW TO 27N60W WITH 
ISOLATED SHOWERS AND TSTMS OCCURRING WITHIN 30 NM EITHER SIDE OF 
THE BOUNDARY. TO THE NORTH OF THE PRIMARY BOUNDARY...ANOTHER 
WAVE OF ENERGY MANIFESTS ITSELF AS A SURFACE TROUGH EXTENDING 
FROM 28N48W SW TO 27N52W THEN W-NW TO 31N60W WITH SCATTERED 
SHOWERS AND ISOLATED TSTMS OCCURRING WITHIN 30-60 NM EITHER SIDE 
OF THIS BOUNDARY. FINALLY...THE EASTERN ATLC IS UNDER THE 
INFLUENCE OF A SURFACE RIDGE PROVIDING MOSTLY FAIR WEATHER 
CONDITIONS N OF 20N E OF 40W. MAINLY LIGHT TO MODERATE SE WINDS 
AND 3-5 FT SEAS ARE EXPECTED ACROSS THE NE HALF OF THE SW NORTH 
ATLC OFFSHORE WATERS...WITH MODERATE TO LOCALLY FRESH E-SE WINDS 
AND 4-7 FT SEAS ELSEWHERE OUTSIDE OF THE INFLUENCE OF BERTHA... 
EXCEPT 1-3 FT SEAS AND LIGHT TO MODERATE WINDS INSIDE THE 
BAHAMAS.

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

$$
LEWITSKY