[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261142
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU DEC 26 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 07N11W TO
06N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
06N14W TO 03N30W TO 03N40W TO THE EQUATOR NEAR 49W. ISOLATED
MODERATE CONVECTION IS FROM 04N-07N BETWEEN 17W-23W. WIDELY
SCATTERED MODERATE CONVECTION IS FROM 02N-11N BETWEEN 31W-60W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES SOUTHWESTERLY FLOW ALOFT OVER THE
GULF THIS MORNING EAST OF A MIDDLE TO UPPER LEVEL SHORTWAVE
TROUGH EXTENDING FROM THE GREAT LAKES REGION SOUTHWESTWARD TO
WESTERN TEXAS THEN SOUTHWARD ALONG 104W INTO THE EASTERN PACIFIC
REGION. PRIMARILY MIDDLE TO UPPER LEVEL DIFFLUENT FLOW EAST OF
THE TROUGHING IS ADVECTING PLENTY OF MOISTURE NORTHEASTWARD FROM
OVER MEXICO 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 NW OF A LINE FROM THE TAMPA BAY REGION OF FLORIDA SW TO THE
NW TIP OF THE YUCATAN PENINSULA. 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
ALONG THE MEXICO COAST IS ALSO PROVIDING FOCUS FOR ISOLATED
SHOWER AND TSTM ACTIVITY THIS MORNING. ACROSS THE SE GULF...A
DISSIPATING STATIONARY FRONT IS ANALYZED FROM THE STRAITS OF
FLORIDA NEAR 25N80W TO THE YUCATAN CHANNEL NEAR 22N85W. LOW-
LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE FRONT IS
GENERATING ISOLATED SHOWERS AND TSTMS WITHIN 90 NM EITHER SIDE
OF THE BOUNDARY. OTHERWISE...DURING THE NEXT 24 TO 36 HOURS...
GENERALLY N-NE WINDS WILL PERSIST IN THE RANGE OF 10 TO 20 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 67W. SKIES REMAIN MOSTLY FAIR THIS MORNING WITH THE EXCEPTION
OF A FEW LOW-TOPPED ISOLATED SHOWERS OCCURRING N OF 15N BETWEEN
68W-83W...AND ALONG THE YUCATAN PENINSULA AND BELIZE COASTS...
INCLUDING THE GULF OF HONDURAS...S OF 20N W OF 86W. OTHERWISE...
THE MAIN FEATURE IMPACTING THE EASTERN CARIBBEAN IS A MIDDLE TO
UPPER LEVEL LOW CENTERED NORTH OF PUERTO RICO NEAR 20N65W. THIS
UPPER LEVEL LOW IS INDUCING BROAD-SCALE SURFACE TROUGHING ACROSS
MUCH OF THE BASIN FOCUSED ON A SURFACE TROUGH ANALYZED FROM
18N74W NE TO 26N61W IN THE SW NORTH ATLC. WHILE THE SURFACE
FEATURE REMAINS RELATIVELY WEAK...THE MIDDLE TO UPPER LEVEL LOW
IS ADVECTING MOISTURE NORTHWARD BETWEEN 50W-63W...GENERATING
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS PORTIONS OF
THE EASTERN CARIBBEAN AND THE LESSER ANTILLES. THIS MOISTURE
FEEDS NORTHWARD INTO FRONTAL TROUGHING BETWEEN 50W-70W IN THE
WESTERN ATLC IN ASSOCIATION WITH A DISSIPATING STATIONARY FRONT.
TRADES ARE EXPECTED TO REMAIN FAIRLY TRANQUIL THROUGH LATE
FRIDAY AS THE BROAD SURFACE TROUGHING REMAINS IN PLACE ACROSS
THE BASIN AND TO THE NORTH ONLY TO INCREASE SOMEWHAT BETWEEN 70W-
80W LATE FRIDAY THROUGH EARLY NEXT WEEK AS THE PRESSURE GRADIENT
STRENGTHENS DUE TO THE PRESENCE OF A RE-ESTABLISHED BERMUDA HIGH.

...HISPANIOLA...
CURRENTLY A FEW ISOLATED SHOWERS ARE OCCURRING ACROSS THE ISLAND
AND THE ADJACENT COASTAL WATERS AS A MIDDLE TO UPPER LEVEL LOW
IS CENTERED TO THE EAST NEAR 20N65W. THE LOW IS FORECAST TO
DRIFT NORTH-NORTHEASTWARD DURING THE NEXT FEW DAYS CARRYING THE
MOISTURE AND PRECIPITATION AWAY FROM HISPANIOLA. CONDITIONS
SHOULD REMAIN FAIRLY TRANQUIL OVER THE UPCOMING WEEKEND.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH HAS MOVED EAST OF THE CANADIAN
MARITIMES IN THE WESTERN NORTH ATLC THAT SUPPORTS A COLD FRONT
ANALYZED INTO THE DISCUSSION AREA NEAR 32N56W. THE COLD FRONT
EXTENDS SW TO 30N58W AND BECOMES STATIONARY TO THE NW BAHAMAS
NEAR 25N77W THEN INTO THE FLORIDA STRAITS AND SE GULF OF MEXICO.
ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE
FRONT. A PRE-FRONTAL TROUGH IS NOTED SOUTH OF THE STATIONARY
FRONT FROM 26N61W TO 18N74W THAT CONTINUES TO GENERATE ISOLATED
SHOWERS WITHIN 120 NM EITHER SIDE OF THE BOUNDARY. ON THE
EASTERN PERIPHERY OF THIS SURFACE TROUGHING...A MIDDLE TO UPPER
LEVEL LOW CENTERED NEAR 20N65W THAT IS ADVECTING MOISTURE
NORTHWARD INTO THE FRONTAL TROUGHING AND GENERATING WIDELY
SCATTERED SHOWERS AND ISOLATED TSTMS FROM 10N-24N BETWEEN 52W-
64W...INCLUDING THE LESSER ANTILLES. OTHERWISE...THE REMAINDER
OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A 1027 MB HIGH CENTERED NEAR 31N33W.

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

$$
HUFFMAN


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