000
AXNT20 KNHC 172338
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST THU FEB 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2330 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM THE 
SOUTHERN COAST OF LIBERIA NEAR 5N9W SOUTH-WESTWARD ALONG 2N20W 
EQ25W 2N35W TO THE COAST OF BRAZIL NEAR 1S49W. SCATTERED 
MODERATE CONVECTION IS FROM 3S-5N BETWEEN 5W-14W. SIMILAR 
CONVECTION IS WITHIN 90 NM ON EITHER SIDE OF THE ITCZ BETWEEN 
14W-35W.    

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY SHOWS UPPER LEVEL RIDGING WITH STRONG 
SUBSIDENCE AND DRY AIR COVERING THE REGION. AT SURFACE...SE 
5-15 KT FLOW IS ACROSS THE BASIN...BECOMING SOUTHERLY OVER THE 
WESTERN GULF W OF 92W. MARINE OBS OVER THE FAR NE BASIN 
INDICATED AN AREA OF SHARP ANTI-CYCLONIC CURVATURE AND HIGHER 
PRESSURE ANALYZED AS A 1024 MB NEAR 30N84W. THIS WHOLE SCENARIO 
IS PROVIDING FAIR WEATHER CONDITIONS EVERYWHERE ACROSS THE 
BASIN. MOST COMPUTER MODELS AGREE WITH CONDITIONS REMAINING 
CONSTANT FOR AT LEAST THE NEXT 24 HOURS. 

CARIBBEAN SEA...
MODERATE TO FRESH TRADE WINDS ARE ACROSS THE AREA...TURNING ENE 
NEAR 77W. THE STRONGEST WINDS ARE NEAR THE COAST OF COLOMBIA 
AROUND A 1009 MB LOW SW OFF THE COAST OF CARTAGENA NEAR 9N76W. 
THE TRADE WIND FLOW IS BANKING SOME LOW LEVEL MOISTURE OVER THE 
FAR SW CARIBBEAN GENERATING SCATTER WEAK SHOWERS AFFECTING THE 
COASTAL WATERS OF PANAMA...COSTA RICA...AND NICARAGUA S OF 14N W 
OF 80W. SIMILAR ACTIVITY IS FOUND WITHIN 40 NM OFF THE COAST OF 
HONDURAS. MID-UPPER LEVEL TROUGH OVER THE CENTRAL ATLC EXTENDS 
AXIS SW TO HISPANIOLA GENERATING SCATTERED MODERATE TO ISOLATED 
HEAVY SHOWERS OVER THE FAR N CENTRAL BASIN...INCLUDING THE MONA 
PASSAGE...THE WINDWARD PASSAGE...AND WITHIN 20 NM OFF THE SRN 
COAST OF HISPANIOLA. FAIR WEATHER CONDITIONS ARE ELSEWHERE 
ACROSS THE BASIN THIS EVENING WITH A FEW ISOLATED WEAK SHOWERS 
EMBEDDED IN THE TRADES.

ATLANTIC OCEAN...
A BROAD UPPER LEVEL TROUGH COVERS THE NRN ATLC SUPPORTING A COLD 
FRONT THAT EXTENDS ACROSS THE DISCUSSION AREA FROM THE ERN ATLC 
NEAR 32N28W TO  24N50W...WHERE IT PARTIALLY BECOMES STATIONARY 
TO 23N55W...AND CONTINUES NRN HISPANIOLA NEAR 20N70W AS A SHEAR 
LINE. SHIP AND BUOY OBS ALONG WITH EARLIER ASCAT AND WINDSAT 
SCATTEROMETER PASSES INDICATED NNE WINDS UP TO 25 KT N OF THE 
SHEAR LINE...AND EASTERLY 5-10 KT S OF THE SHEAR LINE. SCATTERED 
MODERATE TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 
50 NM WEST OF THE COLD FRONT. SIMILAR ACTIVITY IS WITHIN 70 NM 
ON EITHER SIDE OF THE STATIONARY FRONT AND SHEAR LINE. SURFACE 
RIDGING BUILDS BEHIND THE FRONT ANCHORED BY A STRONG 1030 MB 
HIGH OVER THE WEST ATLC CENTERED NEAR 32N57W. THE REMAINDER OF 
THE EASTERN ATLANTIC AHEAD OF THE COLD FRONT IS EXPERIENCING 
FAIR WEATHER CONDITIONS SUPPORTED BY A 1021 MB HIGH EAST OF THE 
CANARY ISLANDS NEAR 29N20W. THIS FRONTAL BOUNDARY WILL CONTINUE 
TO SLOWLY EXPAND EASTWARD AND DISSIPATE OVER THE NEXT 24 TO 72 
HOURS. 

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

$$

GARCIA