[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 120601
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST THU DEC 12 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 AXIS EXTENDS ACROSS AFRICA INTO THE EAST
TROPICAL ATLC NEAR 06N11W TO 06N16W. THE ITCZ AXIS EXTENDS FROM
06N16W TO 04N26W TO 03N37W TO 0N50W. SCATTERED MODERATE
CONVECTION AND TSTMS ARE FROM 03N-06N BETWEEN 11W-19W. SCATTERED
MODERATE CONVECTION IS FROM 02N-13N BETWEEN 20W-42W. SIMILAR
CONVECTION IS WITHIN AN AREA ENCLOSED BY A LINE FROM 20N16W TO
12N28W AND A LINE EXTENDING FROM 21N19W TO 14N32W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD MIDDLE-LEVEL TROUGH WITH AXIS EXTENDING FROM THE NE
U.S.A CONUS TO THE CENTRAL GULF SUPPORTS A STATIONARY FRONT
ANALYZED FROM WESTERN-CENTRAL FLORIDA NEAR 27N82W SW TO 24N90W
TO THE BAY OF CAMPECHE NEAR 18N93W. A 1039 MB HIGH CENTERED IN
THE MIDDLE MISSISSIPPI VALLEY NEAR 40N95W EXTENDS A RIDGE AXIS
INTO THE GULF AND PROVIDES NORTHEASTERLY WIND FLOW UP TO 20 KT
ACROSS THE ENTIRE BASIN. EXCEPT FOR THE FAR WESTERN BASIN W OF
95W S OF 25N AND THE SE GULF S OF 25N...SSMI TPW IMAGERY DEPICT
DRY AIR ACROSS THE BASIN AT THE LOWER LEVELS WHICH IS SUSTAINING
FAIR WEATHER. IN THE SE GULF...A SURFACE TROUGH OVER THE FAR NW
CARIBBEAN SEA IS ADVECTING VERY MOIST AIR TO SUPPORT SCATTERED
SHOWERS OVER THE FLORIDA STRAITS AND THE YUCATAN CHANNEL. HIGH
PRESSURE AND NORTHEASTERLY WIND FLOW ARE EXPECTED TO CONTINUE
ACROSS THE GULF THROUGHOUT FRIDAY MORNING. THE FRONTAL BOUNDARY
IS FORECAST TO MOVE OUT OF THE GULF WATERS BY EARLY FRIDAY.

CARIBBEAN SEA...
LOW-LEVEL MOISTURE CONVERGENCE IS ALONG THE COASTLINE FROM THE
YUCATAN PENINSULA TO NORTHERN COSTA RICA TO SUPPORT SCATTERED
MODERATE CONVECTION WITHIN 120 NM OF THE COAST OF NICARAGUA AND
NORTHERN COSTA RICA. SIMILAR CONVECTION IS S OF 22N W OF 82W
ASSOCIATED WITH THE REMNANTS OF A SURFACE TROUGH THAT AT 0300
UTC EXTENDS FROM 20N86W TO NW HONDURAS NEAR 15N87W. OVER THE
CENTRAL BASIN...AN UPPER-LEVEL LOW OVER HISPANIOLA SUPPORTS A
SURFACE TROUGH ACROSS THE EASTERN ISLAND TO SOUTHERN ADJACENT
WATERS NEAR 15N. THE SURFACE TROUGH IS GENERATING ISOLATED
SHOWERS AND TSTMS ACROSS THE DOMINICAN REPUBLIC AND N OF 15N
BETWEEN 68W-73W. ALOFT AND ACROSS THE REMAINDER BASIN WESTERLY
WIND FLOW AND DRY AIR SUBSIDENCE DOMINATE AND SUPPORT FAIR
WEATHER. OTHERWISE...A RELATIVELY TIGHT PRESSURE GRADIENT OVER
THE CENTRAL-EASTERN BASIN SUPPORTS 20-25 KT WINDS EXPECTED TO
PERSIST THROUGHOUT SAT MORNING. RAINSHOWERS ASSOCIATED WITH THE
REMNANTS OF THE SURFACE TROUGH ARE EXPECTED THROUGHOUT THU
NIGHT.

HISPANIOLA...
AN UPPER-LEVEL LOW OVER HISPANIOLA SUPPORTS A SURFACE TROUGH
ACROSS THE EASTERN ISLAND TO SOUTHERN ADJACENT WATERS NEAR 15N.
THE SURFACE TROUGH IS GENERATING ISOLATED SHOWERS AND TSTMS
ACROSS THE DOMINICAN REPUBLIC AND N OF 15N BETWEEN 68W-73W.
SHOWERS ASSOCIATED WITH THIS TROUGH WILL CONTINUE THROUGHOUT THU
NIGHT.

ATLANTIC OCEAN...
A BROAD MIDDLE-LEVEL TROUGH WITH AXIS EXTENDING FROM THE NE
U.S.A CONUS TO THE CENTRAL GULF SUPPORTS A STATIONARY FRONT
ANALYZED FROM 30N67W SW TO THE EASTERN-CENTRAL FLORIDA COAST
NEAR 27N80W. VERY DRY AIR ACROSS THE SW NORTH ATLC AND CENTRAL
ATLC HINDERS CONVECTION AT THE TIME. FARTHER EAST OVER THE
CENTRAL-EASTERN ATLC...A 1027 MB HIGH IS NEAR 28N40W WHICH IS
EXPECTED TO DRIFT E OVER THE NEXT 24 HOURS MAINTAINING FAIR
WEATHER CONDITIONS. A MIDDLE TO UPPER LEVEL NARROW TROUGH ALONG
THE EASTERN ATLC SUPPORTS A FRONTAL SYSTEM ANALYZED AS A COLD
FRONT FROM 30N15W TO 24N18W TO 21N22W. SCATTERED SHOWERS AND
TSTMS ASSOCIATED WITH THIS FRONTAL SYSTEM ARE N OF 23N BETWEEN
13W-20W.

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

$$
NR


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