Tropical Weather Discussion
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000
AXNT20 KNHC 301047
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU JUL 30 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.

...SPECIAL FEATURES...
A STRENGTHENED PRESSURE GRADIENT IS NOTED ACROSS THE CENTRAL
CARIBBEAN SEA WITH NEAR GALE TO GALE FORCE WINDS OCCURRING FROM
11N-13N BETWEEN 74W-78W. THESE CONDITIONS ARE FORECAST TO
DIMINISH BELOW GALE FORCE WARNING CRITERIA BY 30/1800 UTC. SEE
LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/
FZNT02 KNHC FOR MORE DETAILS.

A 1010 MB LOW IS CENTERED NEAR 30N77W AND IS EXPECTED TO
INCREASE THE PRESSURE GRADIENT BETWEEN IT AND THE SURFACE RIDGE
TO THE EAST. NEAR GALE TO GALE FORCE WINDS ARE EXPECTED TO
MATERIALIZE WITHIN THE EASTERN SEMICIRCLE OF THE LOW BY 30/1200
UTC. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS
MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 10N34W TO 20N37W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH 700 MB TROUGHING BETWEEN 33W-42W AND
LIES ON THE WESTERN PERIPHERY OF A LOW-LEVEL MONSOONAL GYRE
EMBEDDED WITHIN THE MONSOON TROUGH AXIS THAT HAS SPUN UP A 1010
MB LOW CENTERED NEAR 12N25W. NO SIGNIFICANT CONVECTION IS
ASSOCIATED WITH THE WAVE AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 10N65W TO 20N65W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 62W-71W.
NO SIGNIFICANT CONVECTION IS OCCURRING WITH THE WAVE AT THIS
TIME.

TROPICAL WAVE EXTENDS FROM 09N86W TO 19N87W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 84W-92W.
SCATTERED MODERATE CONVECTION IS FROM 07N-11N BETWEEN 81W-86W.
ISOLATED MODERATE CONVECTION IS FROM 14N-20N BETWEEN 83W-87W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR
16N17W TO A 1010 MB LOW NEAR 12N25W TO 10N35W TO 09N40W TO
10N48W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
10N48W TO 11N59W. WIDELY SCATTERED MODERATE CONVECTION IS FROM
10N-15N BETWEEN 15W-20W...FROM 06N-13N BETWEEN 24W-31W IN
ASSOCIATION WITH THE 1010 MB LOW SOUTH OF THE CAPE VERDE
ISLANDS. ISOLATED MODERATE CONVECTION IS FROM 05N-07N BETWEEN
33W-39W.

...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. WATER VAPOR IMAGERY
INDICATES MOST ATMOSPHERIC MOISTURE IS NOTED N OF 20N E OF 94W
PRIMARILY AS CONVECTIVE DEBRIS MOISTURE ATTRIBUTED TO CONVECTION
OCCURRING ACROSS THE EASTERN AND NORTH-CENTRAL GULF WATERS. AN
AREA OF LOWER PRESSURE IS ANALYZED ACROSS THE NE GULF AND
FLORIDA PENINSULA FOCUSED ON A 1010 MB LOW CENTERED IN THE SW
NORTH ATLC WATERS NEAR 30N77W. SCATTERED SHOWERS AND ISOLATED
TSTMS ARE OCCURRING FROM 23N-30N BETWEEN 81W-92W. OTHERWISE...A
SURFACE RIDGE ANCHORED BY A 1018 MB HIGH CENTERED NEAR 26N93W IS
PROVIDING THE BASIN WITH GENTLE TO MODERATE ANTICYCLONIC BREEZE
CONDITIONS. THE HIGH IS FORECAST TO REMAIN NEARLY STATIONARY
THROUGH LATE FRIDAY NIGHT. THEREAFTER...WEAK FRONTAL TROUGHING
IS EXPECTED TO EXTEND ALONG THE COASTAL PLAIN AND NORTHERN GULF
WATERS THROUGH LATE SATURDAY.

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 CENTRAL
CARIBBEAN FROM AN UPPER LEVEL LOW NORTH OF HISPANIOLA NEAR
22N69W. THE TROUGHING EXTENDS WESTWARD TO ANOTHER UPPER LEVEL
LOW WITH SMALLER AREAL INFLUENCE CENTERED OVER THE NW CARIBBEAN
NEAR 16N86W. SHORTWAVE INFRARED SATELLITE IMAGERY INDICATES
GENERALLY CLEAR SKIES WITH ONLY A FEW ISOLATED SHOWERS AND TSTMS
OCCURRING IN ASSOCIATED WITH THE UPPER LEVEL LOW OVER THE NW
CARIBBEAN AND A TROPICAL WAVE EXTENDING ALONG 87W. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE OCCURRING W OF A LINE FROM 17N84W
TO 09N76W...INCLUDING INLAND PORTIONS OF CENTRAL AMERICA.
ANOTHER TROPICAL WAVE IS ALONG 65W HOWEVER IS ONLY GENERATING A
FEW ISOLATED SHOWERS ACROSS THE EASTERN CARIBBEAN E OF 68W AND
THE LESSER ANTILLES THIS MORNING. FINALLY...THE PRIMARY IMPACT
FOR THE BASIN REMAINS NEAR GALE TO GALE FORCE WINDS OCCURRING
WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA AND FRESH TO
STRONG TRADES ELSEWHERE ACROSS THE CENTRAL CARIBBEAN S OF 16N
BETWEEN 70W-80W.

...HISPANIOLA...
CURRENTLY...MOSTLY CLEAR SKIES AND FAIR CONDITIONS PREVAIL
ACROSS THE ISLAND FOR THE MORNING HOURS. GIVEN DRY AND STABLE
AIR ALOFT ALONG WITH RELATIVELY CLEAR SKIES NOTED ON SATELLITE
IMAGERY TO THE EAST...NO SIGNIFICANT DEEP CONVECTION IS EXPECTED
ACROSS THE ISLAND THROUGH THURSDAY INTO FRIDAY.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY
OVER THE WESTERN NORTH ATLC WITH AXIS EXTENDING FROM 38N56W TO
32N66W TO 29N77W. THIS TROUGHING SUPPORTS A 1010 MB LOW CENTERED
NEAR 30N77W WITH SURFACE TROUGHING EXTENDING N-NE TO BEYOND
33N76W AND SW TO THE FLORIDA PENINSULA NEAR CAPE CANAVERAL.
SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 25N-31N BETWEEN
75W-80W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE
INFLUENCE OF A SURFACE RIDGE WITH AXIS EXTENDING FROM 28N50W TO
THE FLORIDA STRAITS NEAR 24N80W. FARTHER EAST...THE CENTRAL AND
EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED
BY A 1027 MB HIGH CENTERED SW OF THE AZORES NEAR 33N34W.

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

$$
HUFFMAN



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