000
AXNT20 KNHC 272327
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED MAR 27 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2245 UTC.

...THE ITCZ/THE MONSOON TROUGH... 

THE MONSOON TROUGH PASSES THROUGH THE COAST OF GUINEA-BISSAU AT 
11N15W INTO THE EASTERN TROPICAL ATLC ALONG 7N19W EQ24W. THE 
ITCZ BEGINS AT EQ24W AND CONTINUES ALONG EQ35W 3S41W. SCATTERED 
STRONG CONVECTION IS FROM 1N-5N BETWEEN 11W-15W. ISOLATED 
MODERATE CONVECTION IS FROM 3N-6N BETWEEN 16W-23W.  

...DISCUSSION...

THE GULF OF MEXICO... 

SURFACE RIDGING DOMINATES THE GULF OF MEXICO ANCHORED BY A 1031 
MB HIGH OVER THE MISSISSIPPI/ALABAMA BORDER NEAR 33N89W. THIS 
PATTERN IS PROVIDING 10-15 KT ANTI-CYCLONIC FLOW ACROSS THE AREA 
WITH SOME 20 KT WINDS IN THE FAR SE GULF NEAR THE YUCATAN 
CHANNEL. SKIES ARE MOSTLY CLEAR EXCEPT FOR SOME OVERCAST AREAS 
ALONG THE COAST OF MEXICO. ALOFT...MAINLY ZONAL WESTERLY FLOW IS 
PRESENT. A BROAD UPPER RIDGE IS CURRENTLY OVER TEXAS AND 
MEXICO...WHICH IS SUPPORTING THE SURFACE RIDGE. DRY AIR ALOFT IS 
ALSO HELPING MAINTAIN THE FAIR WEATHER ACROSS THE BASIN. THE 
SURFACE RIDGE IS EXPECTED TO STAY MOSTLY STATIONARY FOR THE NEXT 
COUPLE OF DAYS BEFORE DRIFTING EAST OVER THE WEEKEND. 

THE CARIBBEAN SEA...

A SHEAR AXIS CONTINUES TO SPREAD ACROSS THE WESTERN CARIBBEAN 
FROM NW HISPANIOLA AT 19N73W TO THE HONDURAS/NICARAGUA BORDER AT 
15N84W. STRONG NORTHERLY WINDS UP TO 20 KT ARE NORTH OF THE AXIS 
WITH LIGHTER 10-15 KT TO THE SOUTH. LOW-LEVEL CLOUDS ALSO SPREAD 
TO THE NORTH OF THE AXIS WITH POSSIBLE ISOLATED SHOWERS. THE 
REMAINDER OF THE BASIN IS UNDER MOSTLY FAIR CONDITIONS DUE TO 
DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE WITH AXIS EAST OF THE 
BASIN. TRADEWIND FLOW OF 15-20 KT IS ACROSS THE EASTERN 
CARIBBEAN. THE SHEAR AXIS IS EXPECTED TO DISSIPATE OVER THE NEXT 
24 HOURS WITH LITTLE CHANGE ELSEWHERE. .  

THE ATLANTIC OCEAN... 

A COLD FRONT CONTINUES TO IMPACT THE WEST ATLC INTO THE CENTRAL 
ATLC ENTERING THE DISCUSSION AREA NEAR 32N46W CONTINUING TO 
HISPANIOLA ALONG 26N60W 19N73W WHERE IT TRANSITIONS INTO A SHEAR 
AXIS IN THE CARIBBEAN. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS 
ARE WITHIN 100 NM EAST OF THE AXIS WITH ISOLATED SHOWERS UP TO 
100 NM WEST OF THE AXIS. THE FRONT IS SUPPORTED BY UPPER LEVEL 
TROUGHING WELL TO THE NORTH OF THE AREA. AN UPPER LEVEL RIDGE TO 
THE EAST ALONG 50W SUPPORTS A 1018 MB HIGH NEAR 25N31W...WHICH 
IS PROVIDING FAIR CONDITIONS ACROSS THE CENTRAL AND EASTERN 
ATLC. AN UPPER LEVEL TROUGH EXTENDING FROM SPAIN AND DOWN THE 
WEST AFRICAN COAST SUPPORTS A DISSIPATING COLD FRONT ALONG 
31N14W TO 29N19W. NO SHOWER ACTIVITY IS NEAR THE FRONT. 

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

$$
WALTON