000
AXNT20 KNHC 171755
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST MON JAN 17 2011

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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND 
RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS EXTENDS FROM LIBERIA NEAR 5N9W ALONG 4N20W 2N30W TO 
THE EQUATOR AT 50W. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM 
EITHER SIDE OF THE AXIS BETWEEN 18W-27W. SCATTERED MODERATE 
CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 
42W-50W ALONG THE COAST OF NE BRAZIL.  

...DISCUSSION...

GULF OF MEXICO...
MAINLY SWLY FLOW ALOFT COVERS THE GULF OF MEXICO BETWEEN A BROAD 
UPPER RIDGE ACROSS THE W ATLC AND AN UPPER TROUGH ACROSS THE 
CENTRAL GULF...WITH UPPER CYCLONIC FLOW AROUND THE TROUGH. A 
SHORTWAVE UPPER TROUGH SUPPORTS A WEAKENING COLD FRONT THAT 
EXTENDS FROM A 1010 MB SURFACE LOW OVER E TEXAS EXTENDING ALONG 
30N94W 28N95W 26N97W. WIDESPREAD SHOWERS ARE N AND W OF THE 
FRONT TO INLAND OVER TEXAS AND LOUISIANA. A PRE-FRONTAL SURFACE 
TROUGH EXTENDS FROM 30N93W TO 27N94W WITH SCATTERED SHOWERS AND 
POSSIBLE THUNDERSTORMS WITHIN 120 NM E OF THE TROUGH. ANOTHER 
SURFACE TROUGH WITH AN EMBEDDED 1011 MB LOW EXTENDS FROM 28N85W 
THROUGH THE LOW NEAR 27N87W TO 24N88W. HEAVY SHOWERS AND 
THUNDERSTORMS ARE E OF THIS SYSTEM AND AFFECTING MUCH OF 
FLORIDA. THIS LOW IS EXPECTED TO MOVE QUICKLY NE OUT OF THE AREA.
THE WEAK COLD FRONT IN THE NW GULF IS EXPECTED TO CONTINUE TO 
WEAKEN. SEVERAL FRONTAL BOUNDARIES ARE FORECAST TO MOVE INTO THE 
GULF WATERS THROUGHOUT THE NEXT WEEK.  
 
CARIBBEAN SEA...
A MOSTLY DRY AIR MASS COVERS THE BASIN WITH MAINLY SWLY FLOW 
ALOFT AROUND A BROAD UPPER LEVEL RIDGE CENTERED OVER ERN BRAZIL. 
PATCHES OF LOW CLOUDS AND POSSIBLE ISOLATED SHOWERS ARE ACROSS 
THE E PORTION OF THE BASIN E OF 66W TO THE LESSER ANTILLES AND 
FROM 12N-18N BETWEEN 68W-72W. OVERALL...RELATIVELY FAIR WEATHER 
IS ACROSS THE BASIN TODAY.

ATLANTIC OCEAN...
A STATIONARY FRONT CONTINUING AS A SURFACE TROUGH ENTERS THE NW 
PORTION OF THE DISCUSSION AREA NEAR 32N69W BECOMING A TROUGH 
NEAR 31N73W AND EXTENDING INTO CENTRAL FLORIDA NEAR 29N81W. 
ISOLATED SHOWERS ARE POSSIBLE ALONG THE BOUNDARY. SCATTERED TO 
HEAVY SHOWERS WITH THUNDERSTORMS ARE MOVING ACROSS N FLORIDA 
ENTERING THE ATLANTIC BASIN W OF 78W PUSHING EAST OF THE 
WEAKENING REMNANT BOUNDARY. A BROAD UPPER RIDGE COVERS MUCH OF 
THE WRN ATLC SUPPORTING A BROAD SURFACE RIDGE ANCHORED BY A 1029 
MB HIGH NEAR 32N43W WEAKENING A SECOND FRONTAL BOUNDARY 
CONSISTING OF A STATIONARY FRONT EXTENDING ALONG 29N52W 29N63W 
25N68W 24N71W WITH POSSIBLE ISOLATED SHOWERS ALONG THE BOUNDARY. 
A WEAK UPPER TROUGH EXTENDS ACROSS THE CAPE VERDE ISLANDS 
SUPPORTING A SURFACE TROUGH ENTERING THE AREA NEAR 32N25W 
EXTENDING TO 30N26W WITH SCATTERED SHOWERS WITHIN 60 NM EITHER 
SIDE OF THE AXIS. THE REMAINDER OF THE BASIN HAS RELATIVELY FAIR 
WEATHER TODAY. 

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

$$
MONTALVO/HUFFMAN