Tropical Weather Discussion
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000
AXNT20 KNHC 311047
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI JUL 31 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 10N44W TO 20N46W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH 700 MB TROUGHING BETWEEN 40W-50W AND
LIES TO THE WEST OF A LOW-LEVEL MONSOONAL GYRE FOCUSED ON A 1009
MB LOW CENTERED ALONG THE MONSOON TROUGH NEAR 12N31W. NO
SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 09N76W TO 19N74W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 70W-
80W. ISOLATED MODERATE CONVECTION IS POSSIBLE FROM 12N-16N
BETWEEN 74W-81W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR
20N16W TO 16N20W TO A 1009 MB LOW NEAR 12N31W TO 08N48W. THE
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N48W TO
06N56W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS
FROM 10N-16N BETWEEN 18W-26W. ISOLATED MODERATE CONVECTION IS
FROM 07N-15N BETWEEN 28W-35W...AND FROM 05N-09N BETWEEN 36W-45W.

...DISCUSSION...

GULF OF MEXICO...
NORTHEASTERLY FLOW ALOFT PREVAILS OVER THE GULF THIS MORNING ON
THE SOUTHEASTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC
CIRCULATION CENTERED OVER CENTRAL TEXAS. WHILE THE RIDGING IS
THE MAIN SYNOPTIC FEATURE PROVIDING AN OVERALL DIFFLUENT
ENVIRONMENT OVER THE GULF...AN UPPER LEVEL SHORTWAVE TROUGH AXIS
REMAINS EMBEDDED WITHIN THE RIDGING EXTENDING FROM OFFSHORE OF
THE DELMARVA REGION SW TO OVER CENTRAL ALABAMA. THE TROUGHING
SUPPORTS A COLD FRONT EXTENDING FROM THE CENTRAL CAROLINAS SW TO
SOUTHERN ALABAMA AND SW LOUISIANA. WEAK LOW-LEVEL MOISTURE
CONVERGENCE ALONG AND MOSTLY SOUTH OF THE FRONT FOCUSED ALONG A
SURFACE TROUGH EXTENDING FROM THE FLORIDA PANHANDLE TO 28N90W
CONTINUES TO GENERATE SCATTERED SHOWERS AND TSTMS ACROSS
PORTIONS OF THE CENTRAL GULF FROM 22N-29N BETWEEN 86W-94W. THE
MAJORITY OF THIS ACTIVITY IS OCCURRING ON THE NORTHERN PERIPHERY
OF A WEAK SURFACE RIDGE AXIS ANCHORED BY A PAIR OF 1018 MB
HIGHS...ONE CENTERED IN THE WESTERN GULF NEAR 25N94W AND THE
OTHER CENTERED ACROSS THE NW CARIBBEAN SEA NEAR 20N84W. THE WEAK
AREA OF LOWER PRESSURE AND FRONTAL TROUGHING IS EXPECTED TO
LINGER ACROSS THE NORTHERN GULF WATERS THROUGH SUNDAY NIGHT LATE
AS IT FINALLY LIFTS NORTH OF THE COASTAL PLAIN BY MONDAY.
SURFACING RIDGING IS EXPECTED TO RE-ESTABLISH ITSELF ACROSS THE
GULF BASIN EARLY NEXT WEEK.

CARIBBEAN SEA...
MOST OF THE CARIBBEAN BASIN REMAINS FAIRLY TRANQUIL THIS MORNING
WITH WATER VAPOR IMAGERY INDICATING RELATIVELY DRY CONDITIONS
ALOFT FOCUSED ON VERY BROAD TROUGHING EXTENDING OVER THE NORTH-
CENTRAL CARIBBEAN FROM AN UPPER LEVEL LOW NORTH OF HISPANIOLA
NEAR 23N73W. THE TROUGHING EXTENDS WESTWARD INTO ANOTHER UPPER
LEVEL LOW WITH SMALLER AREAL INFLUENCE CENTERED OVER THE GULF OF
HONDURAS NEAR 17N85W. SHORTWAVE INFRARED SATELLITE IMAGERY
INDICATES GENERALLY CLEAR SKIES WITH ONLY A FEW POSSIBLE
ISOLATED SHOWERS AND TSTMS OCCURRING IN ASSOCIATION WITH A
TROPICAL WAVE EXTENDING ALONG 76W. LOW-LEVEL MOISTURE AND
CLOUDINESS EXTEND FARTHER EAST...WITH POSSIBLE ISOLATED SHOWERS
OCCURRING E OF 67W. FINALLY...THE PRIMARY IMPACT FOR THE BASIN
REMAINS FRESH TO STRONG BREEZE CONDITIONS GENERALLY S OF 16N
BETWEEN 68W-79W. AS SURFACE RIDGING TO THE NORTH RE-ESTABLISHES
HOLD ACROSS THE SW NORTH ATLC DURING THE WEEKEND...THESE TRADES
ARE FORECAST TO GRADUALLY INCREASE SUNDAY INTO MONDAY ACROSS THE
CENTRAL CARIBBEAN.

...HISPANIOLA...
CURRENTLY...MOSTLY CLEAR SKIES AND FAIR CONDITIONS PREVAIL
ACROSS THE ISLAND THIS MORNING. A FEW ISOLATED SHOWERS REMAIN
EMBEDDED WITHIN THE TRADE WINDS TO THE EAST AND SOUTHEAST...
HOWEVER NO SIGNIFICANT DEEP CONVECTION IS EXPECTED ACROSS THE
ISLAND FRIDAY.

ATLANTIC OCEAN...
NORTHEASTERLY FLOW ALOFT PREVAILS OVER MUCH OF THE SW NORTH ATLC
BETWEEN A BROAD UPPER LEVEL RIDGE COVERING MUCH OF THE SE AND
SOUTH-CENTRAL CONUS AND AN ELONGATED UPPER LEVEL LOW CENTERED
NORTH OF HISPANIOLA NEAR 23N73W. GLOBAL MODEL GUIDANCE INDICATES
PLENTY OF MID-LEVEL ENERGY N OF 27N W OF 75W AND THIS ENERGY
SUPPORTS A 1010 MB LOW CENTERED NEAR 33N76W AND ASSOCIATED
SURFACE TROUGH EXTENDING SW TO 30N77W. SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING N OF 24N BETWEEN 74W-80W. THE
REMAINDER OF THE SW NORTH ATLC BETWEEN 55W-75W REMAINS FAIRLY
TRANQUIL UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A
1023 MB HIGH CENTERED NEAR 28N60W. FINALLY...THE CENTRAL AND
EASTERN ATLC IS ALSO UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A 1023 MB HIGH CENTERED S-SW OF THE AZORES NEAR
32N33W.

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

$$
HUFFMAN



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