[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271137
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI DEC 27 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
1115 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO
07N17W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
07N17W TO 02N30W TO 02N40W TO THE EQUATOR NEAR 46W. ISOLATED
MODERATE CONVECTION IS FROM 02N-05N BETWEEN 25W-37W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES SOUTHWESTERLY FLOW ALOFT OVER THE
GULF THIS MORNING EAST OF A MIDDLE TO UPPER LEVEL TROUGH AXIS
EXTENDING FROM WEST TEXAS NEAR 32N103W SOUTHWARD TO A BASE NEAR
23N106W. PRIMARILY MIDDLE TO UPPER LEVEL DIFFLUENT FLOW EAST OF
THE TROUGHING IS ADVECTING PLENTY OF MOISTURE NORTHEASTWARD FROM
OVER MEXICO TO OVER THE GULF...SE CONUS...AND FLORIDA PENINSULA.
SATELLITE IMAGERY AND MOSAIC DOPPLER RADAR IMAGERY ARE
INDICATING SCATTERED SHOWERS AND A FEW ISOLATED TSTMS OCCURRING
ACROSS THE GULF WITH THE EXCEPTION OF THE FAR SE GULF WATERS AND
YUCATAN CHANNEL. THIS AREA IS LARGELY UNDER THE INFLUENCE OF
WEAK RIDGING AT THE SURFACE...HOWEVER THE MIDDLE TO UPPER LEVEL
DYNAMICS REMAIN STRONG ENOUGH TO GENERATE THE ONGOING SHOWERS
AND CONVECTION. A WEAK SURFACE TROUGH ANALYZED ACROSS THE SW
GULF WITH A WEAK 1016 MB LOW CENTERED NEAR 19N94W IS ALSO
PROVIDING FOCUS FOR ISOLATED SHOWER AND TSTM ACTIVITY THIS
MORNING. ACROSS THE SE GULF...ANOTHER SURFACE TROUGH IS ANALYZED
FROM 24N88W TO 27N85W. LOW-LEVEL MOISTURE CONVERGENCE IN THE
VICINITY OF THE BOUNDARY IS GENERATING ISOLATED SHOWERS AND
TSTMS FROM 24N-28N BETWEEN 83W-87W. OTHERWISE...DURING THE NEXT
24 TO 36 HOURS...GENERALLY E-NE WINDS WILL PERSIST IN THE RANGE
OF 15 TO 25 KT. AS THE UPPER LEVEL TROUGHING STRENGTHENS OVER
THE SOUTHERN PLAINS AND THEN EJECTS NORTHEASTWARD EARLY SATURDAY
THROUGH SUNDAY...GLOBAL MODELS SUGGEST CYCLOGENESIS TO TAKE
PLACE OVER THE WEEKEND ACROSS THE CENTRAL AND NORTH-CENTRAL
PORTIONS OF THE GULF WITH THE ASSOCIATED SURFACE LOW AND FRONT
QUICKLY MOVING NORTHEAST ACROSS THE SE CONUS INTO THE MID-ATLC
WATERS BY LATE SUNDAY.

CARIBBEAN SEA...
THE WESTERN CARIBBEAN IS UNDER THE INFLUENCE OF AN UPPER LEVEL
RIDGE WHICH IS PROVIDING DRY AIR AND STRONG SUBSIDENCE ALOFT W
OF 65W. SKIES REMAIN MOSTLY FAIR THIS MORNING WITH THE EXCEPTION
OF A FEW LOW-TOPPED ISOLATED SHOWERS AND POSSIBLE TSTMS
OCCURRING ACROSS THE NW CARIBBEAN. OTHERWISE...THE MAIN FEATURE
IMPACTING THE EASTERN CARIBBEAN IS A MIDDLE TO UPPER LEVEL
TROUGH WITH AXIS EXTENDING FROM 20N65W SE TO A BASE NEAR 09N58W.
THIS UPPER LEVEL TROUGH IS ADVECTING PLENTY OF MOISTURE NORTH-
NORTHEASTWARD OVER THE WINDWARD ISLANDS AND AREAS TO THE EAST OF
THE LEEWARD ISLANDS E OF 60W...GENERATING WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS ACROSS PORTIONS OF THE WINDWARD
ISLANDS THIS MORNING AND FROM 09N-19N BETWEEN 48W-62W. TRADES
ARE EXPECTED TO REMAIN IN THE 10 TO 20 KT RANGE TODAY AS A BROAD
AND RELATIVELY WEAK SURFACE PRESSURE GRADIENT REMAINS IN PLACE
ACROSS THE BASIN AND TO THE NORTH ACROSS THE SW NORTH ATLC. THE
GRADIENT IS EXPECTED TO INCREASE SOMEWHAT BETWEEN 68W-80W EARLY
SATURDAY THROUGH EARLY NEXT WEEK AS THE PRESSURE GRADIENT
STRENGTHENS DUE TO THE PRESENCE OF A RE-ESTABLISHED BERMUDA HIGH.

...HISPANIOLA...
CURRENTLY CONDITIONS REMAIN MOSTLY DRY AND STABLE DUE TO
NORTHWESTERLY WINDS ALOFT AND OVERALL LIGHT E-SE TRADES ACROSS
THE REGION. CONDITIONS SHOULD REMAIN TRANQUIL OVER THE UPCOMING
WEEKEND.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR
IMAGERY OFF THE NEW ENGLAND COAST NEAR 46N61W THAT SUPPORTS A
COLD FRONT ANALYZED FROM 32N76W TO 30N80W. A PRE-FRONTAL SURFACE
TROUGH IS ANALYZED TO THE E-SE OF THE FRONT FROM THE NW BAHAMAS
NEAR 25N78W TO 32N74W. SOUTHWESTERLY FLOW ALOFT OVER THE
NORTHWESTERN PORTION OF THE SW NORTH ATLC...ALONG WITH THE
SURFACE FRONT IS PROVIDING FOCUS FOR WIDELY SCATTERED SHOWERS
AND A FEW ISOLATED TSTMS OCCURRING N OF 28N W OF 71W. THIS AREA
REMAINS WITHIN A WEAKNESS OF THE SUBTROPICAL RIDGE ACROSS THE SW
NORTH ATLC. FARTHER EAST...AN UPPER LEVEL TROUGH LOCATED OVER
THE NORTHEASTERN NORTH ATLC EXTENDS A COLD FRONT INTO THE
DISCUSSION AREA NEAR 32N35W TO 31N41W AND BECOMES STATIONARY
WESTWARD TO 30N52W THEN AS A SURFACE TROUGH SW TO 27N63W.
ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE
BOUNDARY. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN
ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A
1027 MB HIGH CENTERED NEAR 28N39W. THE ONLY PRECIPITATION NOTED
WITHIN THE INFLUENCE OF THE RIDGE IS ASSOCIATED WITH AN UPPER
LEVEL TROUGH EXTENDING FROM 20N65W TO 08N58W. MIDDLE TO UPPER
LEVEL DIFFLUENCE IS MAXIMIZED EAST OF THE TROUGH AXIS GENERATING
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 09N-19N BETWEEN
48W-62W.

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

$$
HUFFMAN

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