[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270552
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 06N11W TO
04N15W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
04N15W TO 03N30W TO 03N40W TO THE EQUATOR NEAR 48W. ISOLATED
MODERATE CONVECTION IS FROM 02N-05N BETWEEN 24W-37W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES SOUTHWESTERLY FLOW ALOFT OVER THE
GULF THIS EVENING 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 OVER THE GULF TO THE 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 1014 MB LOW CENTERED NEAR 20N94W IS ALSO
PROVIDING FOCUS FOR ISOLATED SHOWER AND TSTM ACTIVITY THIS
EVENING. ACROSS THE SE GULF...ANOTHER SURFACE TROUGH IS ANALYZED
FROM 27N83W TO THE YUCATAN CHANNEL NEAR 22N86W. LOW-LEVEL
MOISTURE CONVERGENCE TO THE NORTHWEST OF THE BOUNDARY IS
GENERATING ISOLATED SHOWERS AND TSTMS FROM 24N-27N 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 70W. SKIES REMAIN MOSTLY FAIR THIS EVENING WITH THE EXCEPTION
OF A FEW LOW-TOPPED ISOLATED SHOWERS OCCURRING ACROSS THE NW
CARIBBEAN. OTHERWISE...THE MAIN FEATURE IMPACTING THE EASTERN
CARIBBEAN IS A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING
FROM 20N63W SE TO A BASE NEAR 08N59W. 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 EVENING AND FROM
09N-18N BETWEEN 48W-61W. TRADES ARE EXPECTED TO REMAIN FAIRLY
TRANQUIL OVERNIGHT INTO FRIDAY AS A BROAD SURFACE PRESSURE
GRADIENT REMAINS IN PLACE ACROSS THE BASIN AND TO THE NORTH
ACROSS THE SW NORTH ATLC ONLY TO INCREASE SOMEWHAT BETWEEN 68W-
80W LATE FRIDAY 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 45N65W THAT SUPPORTS A
COLD FRONT ANALYZED FROM 32N77W TO 30N80W. A PRE-FRONTAL SURFACE
TROUGH IS ANALYZED TO THE SOUTH OF THE FRONT FROM THE NW BAHAMAS
NEAR 25N79W TO 30N76W. 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 NW OF A LINE FROM 31N70W TO
26N80W. 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 32N39W TO 32N43W AND BECOMES
STATIONARY WESTWARD TO 31N55W. ISOLATED SHOWERS ARE OCCURRING
WITHIN 120 NM EITHER SIDE OF THE FRONT. OTHERWISE THE REMAINDER
OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A
SURFACE RIDGE ANCHORED BY A 1028 MB HIGH CENTERED NEAR 29N38W.
THE ONLY PRECIPITATION NOTED WITHIN THE INFLUENCE OF THE RIDGE
IS ASSOCIATED WITH AN UPPER LEVEL TROUGH EXTENDING FROM 20N64W
TO 08N59W. MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED EAST OF
THE TROUGH AXIS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED
TSTMS FROM 08N-18N BETWEEN 48W-61W.

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

$$
HUFFMAN


This weather bulletin was brought to you by:
www.nashvilleweather.net