[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 131124
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN OCT 13 2013

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 14N71W TO 20N69W MOVING W AT 15-20
KT. THE WAVE LIES BENEATH INCREASED SOUTH-SOUTHWESTERLY UPPER
LEVEL DIFFLUENT FLOW...HOWEVER UNDER INCREASING WIND SHEAR AS
WELL. ISOLATED MODERATE CONVECTION IS FROM 14N-18N BETWEEN 69W-
73W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO
05N15W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
05N15W TO 05N20W TO 10N29W TO A 1011 MB LOW NEAR 07N32W TO
05N36W TO 07N43W...THEN RESUMES NEAR 08N50W TO 06N56W. SCATTERED
MODERATE CONVECTION IS FROM 03N-11N BETWEEN 13W-19W...FROM 11N-
15N BETWEEN 23W-31W...FROM 06N-09N BETWEEN 31W-35W...AND FROM
10N-16N BETWEEN 39W-52W. THE LAST AREA OF CONVECTION LISTED IS
ASSOCIATED WITH A 1008 MB LOW CENTERED NEAR 12N45W ANALYZED
ALONG A SURFACE TROUGH EXTENDING FROM 09N49W THROUGH THE LOW
CENTER TO 16N43W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED
OVER NE MEXICO NEAR 24N99W THAT IS PROVIDING THE GULF BASIN WITH
NORTHWEST TO NORTHERLY FLOW ALOFT THIS MORNING. WATER VAPOR
IMAGERY INDICATES THE FLOW IS MOSTLY DRY AIR AND VERY STABLE
RESULTING IN MOSTLY CLEAR SKIES AND FAIR CONDITIONS AT THE
SURFACE. A 1019 MB HIGH CENTERED IN THE NORTH-CENTRAL GULF
WATERS NEAR 29N89W FURTHER PROMOTES THE FAIR CONDITIONS WITH
ONLY A FEW ISOLATED SHOWERS OCCURRING ALONG THE GULF COAST FROM
28N-30N BETWEEN 90W-95W. SURFACE RIDGING IS EXPECTED TO REMAIN
ACROSS THE GULF THROUGH LATE WEDNESDAY WHEN THE NEXT FRONTAL
BOUNDARY IS FORECAST TO EMERGE OFF THE TEXAS GULF COAST.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED NEAR 17N81W AND EXTENDS A TROUGH
AXIS SW TO NEAR 11N85W. WEST OF THE TROUGH AXIS...WATER VAPOR
IMAGERY INDICATES VERY DRY AND STABLE AIR WITHIN NORTH-
NORTHEASTERLY FLOW ALOFT PROVIDING FOR RELATIVELY QUIET
CONDITIONS THIS MORNING N OF 16N W OF 81W. HOWEVER THE REMAINDER
OF THE CENTRAL AND SW CARIBBEAN COMES UNDER THE INFLUENCE OF THE
UPPER LEVEL LOW AND THE ASSOCIATED LIFTING DYNAMICS WHICH
CONTINUE TO GENERATE SCATTERED SHOWERS AND ISOLATED TSTMS
BETWEEN 70W-80W AND S OF 16N BETWEEN 80W-84W. FARTHER EAST...A
WEAK TROPICAL WAVE IS ANALYZED ALONG 71W IMPACTING THE CENTRAL
CARIBBEAN WITH ISOLATED SHOWERS AND TSTMS N OF 14N BETWEEN 70W-
74W. A SECONDARY WAVE OF ENERGY CONTINUES TO USHER IN LOW-LEVEL
MOISTURE AND ISOLATED SHOWERS E OF 65W THIS MORNING WITH THE
STRONG ACTIVITY OCCURRING ACROSS THE WINDWARD ISLANDS S OF 15N.

HISPANIOLA...
CURRENTLY THE ISLAND FALLS WITHIN AN AREA OF MIDDLE TO UPPER
LEVEL DIFFLUENCE NOTED TO THE EAST OF AN UPPER LEVEL LOW
CENTERED NEAR 17N81W. THE ADVECTION OF MOISTURE FROM THE EAST
PACIFIC NEAR THE BASE OF THE TROUGHING AND MOISTURE FROM
NORTHERN SOUTH AMERICA NORTHWARD ACROSS THE CENTRAL CARIBBEAN
SEA AND OVER THE SW NORTH ATLC IS PROVIDING FOR SCATTERED
SHOWERS AND ISOLATED TSTMS THIS MORNING. AS THE UPPER LEVEL LOW
IS FORECAST TO EVENTUALLY DRIFT SOUTHWEST BY LATE SUNDAY INTO
MONDAY...UNTIL THEN HISPANIOLA WILL LIKELY REMAIN IN AN UPPER
LEVEL DIFFLUENT PATTERN WITH INCREASED PROBABILITY OF ISOLATED
SHOWERS AND TSTMS THROUGHOUT THE MORNING AND EARLY AFTERNOON
HOURS. OF COURSE AS ALWAYS WITH PEAK DAYTIME HEATING AND
INSTABILITY...MAXIMUM AREAL COVERAGE OF CONVECTION IS LIKELY TO
OCCUR IN THE LATE AFTERNOON AND EVENING HOURS. THE ADDITION OF A
TROPICAL WAVE CURRENTLY ALONG 71W WILL ALSO INCREASE LOW-LEVEL
MOISTURE CONVERGENCE AND ENHANCE ANY CONVECTION THROUGH MONDAY
UNTIL THE WAVE ENERGY PASSES TO THE WEST.

ATLANTIC OCEAN...
A MID-LEVEL LOW IS CENTERED OFFSHORE OF THE MID-ATLC STATES NEAR
34N73W THAT SUPPORTS AN OCCLUDED 1015 MB LOW CENTERED NEAR
34N75W. A SURFACE TROUGH EXTENDS FROM THE LOW INTO THE
DISCUSSION AREA NEAR 32N74W TO 31N77W GENERATING ISOLATED
SHOWERS WITHIN 75 NM EITHER SIDE OF THE BOUNDARY. FARTHER
EAST...PLENTY OF MIDDLE TO UPPER LEVEL MOISTURE ADVECTION IS
NOTED ON WATER VAPOR IMAGERY EAST OF THE UPPER LEVEL TROUGH AXIS
EXTENDING FROM 33N73W TO THE UPPER LEVEL LOW CENTERED IN THE
WESTERN CARIBBEAN SEA NEAR 17N81W. A STATIONARY FRONT IS
SUPPORTED BY THE TROUGHING ANALYZED FROM 32N61W SW TO 28N70W
THEN BECOMING A SURFACE TROUGH TO THE SE BAHAMAS NEAR 22N74W.
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN
240 NM EITHER SIDE OF THE FRONT. ANOTHER WAVE OF LOW-LEVEL
MOISTURE ROUNDING CENTRAL ATLC RIDGING IS ALIGNED ALONG AN ARC
FROM 25N60W TO 18N63W TO 13N60W WITH EMBEDDED ISOLATED SHOWERS
OCCURRING WITHIN 120 NM EITHER SIDE OF THE ARC. FINALLY...THE
REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE
OF A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED NEAR
33N17W WITH A RIDGE AXIS EXTENDING WEST-SOUTHWEST FROM THE HIGH
TO 30N23W TO 27N40W TO 26N60W.

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

$$
HUFFMAN


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