[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131740
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI DEC 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR
09N13W TO 06N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 06N19W TO 03N30W TO 02N47W TO THE EQUATOR NEAR 50W.
ISOLATED MODERATE CONVECTION IS FROM 02N-04N BETWEEN 22W-34W.

...DISCUSSION...

GULF OF MEXICO...
WEST-NORTHWESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY
THIS AFTERNOON OVER THE GULF WITH MOST MIDDLE TO UPPER LEVEL
MOISTURE REMAINING NORTH OF 25N...INCLUDING INLAND PORTIONS OF
EASTERN TEXAS...LOUISIANA...MISSISSIPPI...AND ALABAMA. AT THE
SURFACE...SURFACE RIDGING DOMINATES ACROSS THE SE CONUS AND MOST
OF THE BASIN ANCHORED BY A 1030 MB HIGH CENTERED OVER THE
CAROLINAS NEAR 35N79W. MOSTLY EAST-SOUTHEASTERLY WINDS ARE NOTED
ON THE SOUTHWESTERN PERIPHERY OF THE RIDGE IN THE RANGE OF 10 TO
20 KT AND THESE WINDS WILL GRADUALLY VEER SOUTH-SOUTHEASTERLY
THROUGH EARLY SATURDAY AS THE HIGH SHIFTS OUT INTO THE SW NORTH
ATLC OVERNIGHT. AS THIS OCCURS EARLY SATURDAY...THE NEXT COLD
FRONT IS EXPECTED TO EMERGE OFF THE TEXAS AND LOUISIANA COASTS
USHERING IN ANOTHER ROUND OF STRONG NORTHERLY WINDS THAT WILL
SPREAD ACROSS THE GULF THROUGH THE WEEKEND INTO MONDAY.
OTHERWISE...A WEAKENING STATIONARY FRONT IS ANALYZED FROM ACROSS
THE SW NORTH ATLC INTO THE FLORIDA STRAITS NEAR 24N80W TO THE
YUCATAN PENINSULA NEAR 22N88W WHICH IS PROVIDING FOCUS FOR A FEW
ISOLATED SHOWERS WITHIN 90 NM EITHER SIDE OF THE BOUNDARY.

CARIBBEAN SEA...
MOSTLY NORTHWESTERLY TO WESTERLY FLOW DOMINATES ALOFT ACROSS THE
CARIBBEAN THIS AFTERNOON WITH A VERY WEAK AND BROAD UPPER LEVEL
TROUGH AXIS EXTENDING FROM 21N77W TO 17N80W. MOST OF THIS FLOW
IS EMBEDDED WITHIN DRY AND STABLE AIR ALOFT RESULTING IN OVERALL
TRANQUIL CONDITIONS AT THE SURFACE. THE ONLY FEATURES OF NOTE
ARE A GRADUALLY WEAKENING STATIONARY FRONT ANALYZED ACROSS THE
YUCATAN CHANNEL WITH ISOLATED SHOWERS OCCURRING WITHIN 90 NM
EITHER SIDE OF THE FRONT...AND A SURFACE TROUGH ANALYZED FROM
PUERTO RICO NEAR 18N67W TO 14N69W. LOW-LEVEL MOISTURE
CONVERGENCE IS GENERATING ISOLATED SHOWERS WITHIN 150 NM EITHER
SIDE OF THE SURFACE TROUGH AXIS. FINALLY...TRADE WINDS GENERALLY
IN THE RANGE OF 15 TO 25 KT PREVAIL...STRONGEST S OF 17N BETWEEN
66W-80W...WITH LOW-LEVEL CONVERGENCE OF THE TRADES ACROSS THE
WESTERN CARIBBEAN PROVIDING FOCUS FOR ISOLATED SHOWERS S OF 20N
W OF 80W...ALONG THE COAST OF CENTRAL AMERICA AND AREAS
IMMEDIATELY INLAND.

...HISPANIOLA...
CURRENTLY DRY WESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR
IMAGERY OVER HISPANIOLA PROVIDING FOR OVERALL DRY AND STABLE
CONDITIONS. AT THE SURFACE...A WEAK SURFACE TROUGH ANALYZED FROM
PUERTO RICO NEAR 18N67W TO 14N69W CONTINUES TO DRIFT WESTWARD
AND IS EXPECTED TO SKIRT SOUTH OF THE ISLAND...BUT WILL HOWEVER
INCREASE LATE AFTERNOON AND EARLY EVENING CHANCES FOR ISOLATED
SHOWERS AND TSTMS GIVEN PEAK DAYTIME HEATING AND INSTABILITY.
OTHERWISE...CONTINUED FAIR WEATHER IS EXPECTED THROUGH THE
WEEKEND WITH STRONG TRADE WIND FLOW.

ATLANTIC OCEAN...
A BROAD MIDDLE TO UPPER LEVEL TROUGH IS OVER MUCH OF THE WESTERN
NORTH ATLC THAT DIPS A BASE SOUTHWARD INTO THE DISCUSSION AREA
NEAR 23N75W. WHILE THE STRONGER DYNAMICS ARE WELL NORTH OF
35N...THE TROUGHING SUPPORTS A COLD FRONT ANALYZED FROM 32N55W
SW TO 27N65W TO 25N74W. THE FRONT THEN BECOMES STATIONARY INTO
THE FLORIDA STRAITS NEAR 24N80W. ISOLATED SHOWERS ARE OCCURRING
WITHIN 90 NM EITHER SIDE OF THE FRONT. A PRE-FRONTAL SURFACE
TROUGH IS ANALYZED TO THE SE OF THE COLD FRONT FROM 29N58W TO
21N66W. LOW-LEVEL MOISTURE CONVERGENCE IS GENERATING ISOLATED
SHOWERS FROM 22N-29N BETWEEN 56W-64W. OTHERWISE...THE REMAINDER
OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGING
ANCHORED BY A 1030 MB HIGH CENTERED ACROSS THE CAROLINAS NEAR
35N79W. FARTHER EAST...THE EASTERN ATLC IS ALSO UNDER THE
INFLUENCE OF A RELATIVELY STRONG SURFACE RIDGE ANCHORED BY A
1029 MB HIGH CENTERED NEAR 30N31W.

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

$$
HUFFMAN


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