[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260553
TWDAT

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

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N11W TO
06N13W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
06N13W TO 04N30W TO 04N44W TO 02N51W. ISOLATED MODERATE
CONVECTION IS FROM 04N-07N BETWEEN 18W-30W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 02N-10N BETWEEN 31W-59W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES SOUTHWESTERLY FLOW ALOFT OVER THE
GULF THIS EVENING 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
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. ACROSS THE SE GULF...A DISSIPATING
STATIONARY FRONT IS ANALYZED FROM THE STRAITS OF FLORIDA NEAR
25N80W TO THE NE TIP OF THE YUCATAN PENINSULA NEAR 22N87W. 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 70W. SKIES REMAIN MOSTLY FAIR FOR THE OVERNIGHT PERIOD INTO
THURSDAY WITH THE EXCEPTION OF A FEW LOW-TOPPED ISOLATED SHOWERS
OCCURRING N OF 15N BETWEEN 68W-82W...AND ALONG THE YUCATAN
PENINSULA AND BELIZE COASTS...INCLUDING THE GULF OF HONDURAS...S
OF 20N W OF 85W. OTHERWISE...THE MAIN FEATURE IMPACTING THE
EASTERN CARIBBEAN IS A MIDDLE TO UPPER LEVEL LOW CENTERED NEAR
17N65W. THIS UPPER LEVEL LOW IS INDUCING BROAD-SCALE SURFACE
TROUGHING ACROSS MUCH OF THE CENTRAL AND EASTERN CARIBBEAN
FOCUSED ON A SURFACE TROUGH ANALYZED FROM 12N69W TO 25N68W IN
THE SW NORTH ATLC. WHILE THE SURFACE FEATURE REMAINS RELATIVELY
WEAK...THE MIDDLE TO UPPER LEVEL LOW IS ADVECTING MOISTURE
NORTHWARD BETWEEN 55W-65W...GENERATING SCATTERED SHOWERS AND
ISOLATED TSTMS ACROSS PORTIONS OF THE EASTERN CARIBBEAN AND THE
LESSER ANTILLES THIS EVENING. THIS MOISTURE FEEDS NORTHWARD INTO
FRONTAL TROUGHING BETWEEN 50W-70W IN THE WESTERN ATLC IN
ASSOCIATION WITH A COLD 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 E-SE NEAR 17N65W. THE LOW IS FORECAST TO
BEGIN DRIFTING 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 32N59W. THE COLD FRONT
EXTENDS SW TO 29N69W AND BECOMES STATIONARY TO THE NW BAHAMAS
NEAR 26N77W THEN INTO THE FLORIDA STRAITS AND INTO THE SE GULF
OF MEXICO. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER
SIDE OF THE FRONT. A PRE-FRONTAL TROUGH IS NOTED EAST OF THE
COLD FRONT FROM 32N56W TO 25N61W AND CONTINUES TO GENERATE
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 25N-34N BETWEEN
50W-63W. TO THE SOUTH OF THIS AREA...A MIDDLE TO UPPER LEVEL LOW
CENTERED OVER THE NE CARIBBEAN SEA IS ADVECTING MOISTURE
NORTHWARD INTO THE FRONTAL TROUGHING AND GENERATING WIDELY
SCATTERED SHOWERS AND ISOLATED TSTMS FROM 10N-25N BETWEEN 55W-
65W...INCLUDING THE LESSER ANTILLES. OTHERWISE...THE REMAINDER
OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A 1029 MB HIGH CENTERED NEAR 31N34W.

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

$$
HUFFMAN


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