000
AXNT20 KNHC 201751
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN JAN 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 05N08W TO 
04N13W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
04N13W TO 04N20W TO THE EQUATOR NEAR 36W. WIDELY SCATTERED 
MODERATE CONVECTION IS FROM THE EQUATOR TO 04N BETWEEN 24W-31W.

...DISCUSSION...

GULF OF MEXICO...
WESTERLY MIDDLE TO UPPER LEVEL FLOW IS OVER MUCH OF THE GULF 
THIS AFTERNOON AS THE GULF REMAINS RELATIVELY TRANQUIL ALOFT. AT 
THE SURFACE...RIDGING EXTENDS FROM A 1025 MB HIGH CENTERED 
ACROSS SOUTHERN MISSISSIPPI NEAR 31N89W TO A 2024 MB HIGH 
CENTERED ACROSS THE EASTERN COAST OF MEXICO NEAR 20N97W. MOSTLY 
NORTHEAST TO EAST WINDS PREVAIL OVER THE NE AND WESTERN PORTIONS 
OF THE GULF REMAINING IN THE RANGE OF 5 TO 15 KT. A WEAK SURFACE 
TROUGH IS ANALYZED OVER THE SE GULF FROM 25N84W TO 28N84W. WHILE 
NO SIGNIFICANT CONVECTION IS OCCURRING IN THE VICINITY OF THE 
SURFACE TROUGH AXIS...ISOLATED SHOWERS ARE NOTED ON MOSAIC 
DOPPLER RADAR IMAGERY ACROSS THE STRAITS OF FLORIDA BETWEEN 
79W-83W. OTHERWISE...FOR THE FIRST HALF OF THE WEEK...THE 
SURFACE RIDGING IS EXPECTED TO REMAIN IN PLACE ACROSS THE SE 
CONUS AND INFLUENCE THE GULF BASIN WITH MOSTLY FAIR WEATHER 
CONDITIONS.

CARIBBEAN SEA...
UPPER LEVEL TROUGHING IS EVIDENT ON WATER VAPOR IMAGERY OVER THE 
NW CARIBBEAN...BUT THIS TROUGHING ALOFT REMAINS EMBEDDED WITHIN 
DRY AIR AND OVERALL SUBSIDENCE. THE OVERRIDING WEATHER PATTERN 
IS A MID-LEVEL RIDGE ANCHORED OVER THE NE AND NORTH-CENTRAL 
CARIBBEAN NEAR 17N67W THAT CONTINUES TO PROVIDE A STABLE 
ATMOSPHERE AND A LACK OF ANY SIGNIFICANT DEEP CONVECTION. AT THE 
SURFACE...EASTERLY TRADES IN THE RANGE OF 10 TO 20 KT PREVAIL 
WITH STRONGER E-NE WINDS OF GALE FORCE LOCATED WITHIN CLOSE 
PROXIMITY OF THE COAST OF COLOMBIA. ISOLATED LOW-TOPPED SHOWERS 
CONTINUE TO MOVE WESTWARD WITH THE MOST CONCENTRATED AREAS OVER 
THE SE CARIBBEAN S OF 14N E OF 67W...N OF 16 E OF 73W...AND S OF 
18N W OF 80W...INCLUDING INLAND PORTIONS OF CENTRAL AMERICA. 
LITTLE CHANGE IS EXPECTED SYNOPTICALLY FOR THE BASIN THROUGH 
MIDWEEK.

ATLANTIC OCEAN...
BROAD MIDDLE TO UPPER LEVEL TROUGHING IS LOCATED OVER THE NE 
CONUS AND GREAT LAKES REGION THAT SUPPORTS A SHORTWAVE TROUGH 
NOTED ON WATER VAPOR IMAGERY NEAR 30N80W. THIS SHORTWAVE 
TROUGHING MANIFESTS ITSELF AT THE SURFACE AS A WEAK 1021 MB LOW 
CENTERED W-SW OF BERMUDA NEAR 32N67W. A WARM FRONT EXTENDS EAST 
FROM THE LOW CENTER TO 33N52W AND A STATIONARY FRONT MEANDERS 
W-SW FROM THE LOW CENTER TO THE FLORIDA PENINSULA COAST NEAR 
27N80W. ISOLATED SHOWERS ARE OCCURRING WITHIN 180 NM EITHER SIDE 
OF THE BOUNDARY. OTHERWISE THE REMAINDER OF THE CENTRAL AND 
EASTERN ATLC ARE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED 
NEAR 30N40W. FINALLY...AN UPPER LEVEL LOW IS CENTERED 19N38W 
THAT IS GENERATING AN AREA OF DIFFLUENCE AND WIDELY SCATTERED 
SHOWERS FROM 20N-24N BETWEEN 25W-36W.

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

$$
HUFFMAN