000
AXNT20 KNHC 072322
TWDAT 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL 
805 PM EDT SUN APR 07 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.

...ITCZ/MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA NEAR 11N15W 
INTO THE TROPICAL EAST ATLC ALONG 4N17W EQ22W 1S24W. THE ITCZ 
BEGINS NEAR 1S24W AND CONTINUES ALONG 1S31W 3S39W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-6N BETWEEN 13W-
18W.

...DISCUSSION...

GULF OF MEXICO... 
ZONAL WESTERLY FLOW AND DRY AIR ALOFT ARE 
MAINTAINING FAIR CONDITIONS ACROSS MUCH OF THE GULF OF MEXICO 
THIS EVENING. AT THE SURFACE...RIDGING DOMINATES EXTENDING FROM 
A 1027 MB HIGH IN THE WEST ATLC NEAR 36N72W. THIS PATTERN 
PROVIDES MAINLY EAST TO SOUTHEAST WINDS RANGING FROM 10-20 KT. 
AS THE SURFACE RIDGE MOVES EASTWARD OVER THE NEXT COUPLE OF 
DAYS...THE AREA OF 20 KT WINDS WILL SPREAD ACROSS THE BASIN 
UNTIL A COLD FRONT PUSHES OFF THE COAST OF TEXAS LATE 
WEDNESDAY/EARLY THURSDAY. 

CARIBBEAN SEA... 
BROAD UPPER RIDGING IS SETTLING OVER THE 
CARIBBEAN AS AN UPPER LEVEL TROUGH OVER THE WEST ATLC LIFTS 
NORTH. DRY AIR ALOFT IS PROVIDING MOSTLY CLEAR SKIES ACROSS THE 
BASIN EXCEPT FOR A FEW ISOLATED SHOWERS ACROSS THE NE ISLANDS. A 
DISSIPATING STATIONARY FRONT EXTENDING FROM EASTERN CUBA TO THE 
HONDURAS/PANAMA BORDER HAS NOW FURTHER DISSIPATED INTO A SURFACE 
TROUGH...AS OF 2100 UTC. THE TROUGH EXTENDS FROM 19N81W TO 
16N83W. ISOLATED SHOWERS ARE WITHIN 120 NM WEST OF THE AXIS. 
TRADEWIND FLOW OF 15-20 KT DOMINATES THE REMAINDER OF THE AREA. 
THE TROUGH IS EXPECTED TO DISSIPATE WITHIN THE NEXT 24 HOURS 
WITH LITTLE CHANGE EXPECTED ELSEWHERE.

ATLANTIC OCEAN... 
SURFACE RIDGING IS BEGINNING TO BUILD ACROSS 
THE FAR WESTERN ATLC AROUND A 1027 MB HIGH NEAR 36N72W. TO THE 
EAST...A SHORTWAVE UPPER TROUGH NEAR 60W SUPPORTS A COLD FRONT 
ENTERING THE DISCUSSION AREA NEAR 32N57W AND CONTINUING ALONG 
25N63W 21N72W. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF 
THE AXIS...EXCEPT FOR AN AREA OF SCATTERED SHOWERS FROM 27N-31N 
BETWEEN 56W-58W. A SURFACE TROUGH TRAILS BEHIND THE FRONT 
EXTENDING FROM A LOW CENTER TO THE NORTH ASSOCIATED WITH THE 
SYSTEM. THE LOW IS CENTERED NEAR 33N60W WITH THE SURFACE TROUGH 
EXTENDING FROM THE CENTER TO 28N66W. NO SHOWERS ARE NEAR THE 
TROUGH. BROAD SURFACE RIDGING COVERS THE MAJORITY OF THE EASTERN 
ATLC AROUND A 1028 MB HIGH NEAR 31N36W. IT IS SUPPORTED BY AN 
UPPER LEVEL RIDGE EXTENDING FROM NEAR 20N53W TO THE AZORES 
ISLANDS. A NARROW UPPER TROUGH WITH AXIS BETWEEN THE MADEIRA AND 
CANARY ISLANDS SUPPORTS A WEAK 1017 MB SURFACE LOW NEAR 31N21W. 
A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO 28N24W...WHILE A 
DISSIPATING COLD FRONT WRAPS AROUND THE CENTER ALONG 30N19W 
24N25W. POSSIBLE ISOLATED SHOWERS ARE EAST OF THE FRONT. THIS 
SYSTEM IS EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS. 

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

$$
WALTON