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000
AXNT20 KNHC 011157
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...SPECIAL FEATURES...
TROPICAL STORM BERTHA IS CENTERED NEAR 13.6N 57.9W AT 01/1200
UTC OR ABOUT 96 NM ENE OF BARBADOS AND ABOUT 191 NM ESE OF
MARTINIQUE MOVING WNW AT 17 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH
GUSTS TO 50 KT. SCATTERED MODERATE AND ISOLATED STRONG
CONVECTION IS WITHIN 150 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 11N22W TO 20N22W 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 A 1014 MB LOW ALONG THE WAVE AXIS NEAR 16N. THE SOUTHERN
VORTICITY MAXIMUM IS FOCUSED ON A 1013 MB LOW CENTERED NEAR
11N22N AND REMAINS A CIRCULATION EMBEDDED WITHIN THE MONSOON
TROUGH AXIS. ISOLATED MODERATE CONVECTION IS FROM 09N-12N
BETWEEN 21W-24W.

TROPICAL WAVE EXTENDS FROM 11N35W 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. A 1012 MB SURFACE LOW IS CENTERED NEAR 10N33N
AND LARGELY REMAINS EMBEDDED WITHIN THE MONSOON TROUGH AXIS.
SCATTERED MODERATE CONVECTION IS FROM 11N-13N BETWEEN 34W-37W.

TROPICAL WAVE EXTENDS FROM 12N62W TO 19N65W MOVING W AT 15 KT.
THE WAVE REMAINS TO THE W OF TROPICAL STORM BERTHA AND LARGELY
SURROUNDED BY THE SAHARAN AIR LAYER TO THE NE OF THE WAVE AXIS.
NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS
TIME...HOWEVER ISOLATED SHOWERS ARE OCCURRING ACROSS THE US/UK
VIRGIN ISLANDS THIS MORNING.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO
A 1013 MB LOW PRES NEAR 10N22W TO A 1012 MB LOW PRES NEAR 10N33W
TO 04N39W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
04N39W TO 04N50W. WIDELY SCATTERED MODERATE CONVECTION IS FROM
06N-09N BETWEEN 23W-29W.

...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 1014 MB LOW IS CENTERED ACROSS THE EASTERN
FLORIDA PANHANDLE NEAR 31N84W. A STATIONARY FRONT IS ANALYZED S-
SE FROM THE LOW CENTER ACROSS THE CENTRAL FLORIDA PENINSULA THEN
SW TO THE GULF COAST NEAR FORT MYERS. THE FRONT CONTINUES TO
25N83W AND BECOMES A SURFACE TROUGH W-SW TO 23N89W. ISOLATED
SHOWERS AND TSTMS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE
FRONT AND SURFACE TROUGH ACROSS THE GULF WATERS. ANOTHER MID-
LEVEL IMPULSE OF ENERGY IS NOTED OVER THE ARKLATEX REGION THAT
IS SUPPORTIVE OF A 1013 MB LOW CENTERED ACROSS INLAND EASTERN
TEXAS NEAR 31N95W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE
NOTED ON DOPPLER RADAR IMAGERY N OF 28N BETWEEN 92W-97W.
OTHERWISE...THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF
VERY WEAK SURFACE RIDGING ANCHORED BY A 1016 MB HIGH CENTERED IN
THE VICINITY OF THE MISSISSIPPI RIVER DELTA REGION NEAR 30N89W.
THIS RIDGING IS FORECAST TO REMAIN ANCHORED IN THE NORTH-CENTRAL
GULF WITH AXIS EXTENDING ACROSS THE WESTERN GULF PROVIDING E-SE
WINDS IN THE RANGE OF 10 TO 20 KT THROUGH EARLY SATURDAY.

CARIBBEAN SEA...
RELATIVELY DRY AND STABLE CONDITIONS ALOFT ARE NOTED OVER MUCH
OF THE CARIBBEAN THIS MORNING FOCUSED ON AN ELONGATED UPPER
LEVEL LOW CENTERED OVER THE NW CARIBBEAN NEAR 18N83W...AN UPPER
LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 11N75W...AND AN
UPPER LEVEL LOW PROVIDING NW FLOW ALOFT FOR THE NE CARIBBEAN
CENTERED IN THE SW NORTH ATLC NEAR 22N63W. ACROSS THE NW
CARIBBEAN...SKIES REMAIN MOSTLY CLEAR WITH ONLY A FEW ISOLATED
SHOWERS OCCURRING ON THE NORTHERN PERIPHERY OF THE UPPER LEVEL
LOW N OF 19N BETWEEN 76W-85W. THE ONLY SIGNIFICANT WEATHER
OCCURRING IN ASSOCIATION WITH THE UPPER LEVEL ANTICYCLONE IS
ISOLATED SHOWERS AND TSTMS OCCURRING FROM 08N-12N BETWEEN 81W-
86W...IN AN AREA OF MAXIMUM UPPER LEVEL DIFFLUENCE AND IN CLOSE
PROXIMITY TO THE MONSOON TROUGH AXIS ALONG 10N. FARTHER EAST...
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. A FEW ISOLATED SHOWERS ARE OCCURRING S OF
13N E OF 64W...AND ACROSS THE US/UK VIRGIN ISLANDS THIS MORNING.
FINALLY...MODERATE TO FRESH TRADES PERSIST WITH THE STRONGEST
AREA OF WINDS EXPECTED S OF 15N BETWEEN 68W-78W.

...HISPANIOLA...
CURRENTLY...ISOLATED SHOWERS CONTINUE ACROSS THE ADJACENT
COASTAL WATERS DUE TO THE PRESENCE OF AN UPPER LEVEL LOW
CENTERED IN THE SW NORTH ATLC NEAR 22N63W AND AN APPROACHING
TROPICAL WAVE ALONG 64W. WITH THE UPPER LEVEL 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 FRIDAY AFTERNOON INTO THE
EVENING WITH 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 ACROSS THE
EASTERN FLORIDA PENINSULA NEAR 31N83W. A WARM FRONT EXTENDS NE
FROM THE LOW TO THE SOUTH CAROLINA COAST WITH SCATTERED SHOWERS
AND TSTMS OCCURRING S OF THE FRONT FROM 29N BETWEEN 77W-81W IN
AN AREA OF MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE AND UPPER
LEVEL DIFFLUENCE. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED
NEAR 22N63W GENERATING AN AREA OF WIDELY SCATTERED SHOWERS AND
ISOLATED TSTMS FROM 19N-27N BETWEEN 63W-73W. OTHERWISE...THE
REMAINDER OF THE CENTRAL ATLC IS UNDER THE INFLUENCE OF A BROAD
MIDDLE TO UPPER LEVEL RETROGRADING LOW CENTERED NEAR 31N49W THAT
IS SUPPORTING A BROAD AREA OF LOWER SURFACE PRESSURE FOCUSED ON
A 1015 MB LOW CENTERED NEAR 28N46W. THE PRIMARY SURFACE TROUGH
EXTENDS SW FROM THE LOW TO 26N50W THEN W-NW TO 28N60W WITH
ISOLATED SHOWERS 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
29N49W W-NW TO 32N58W. WIDELY SCATTERED SHOWERS AND ISOLATED
TSTMS WITHIN 60 NM ACCOMPANY 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.

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

$$
HUFFMAN