000
AXNT20 KNHC 120513
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT WED MAR 12 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
SECTIONS OF SOUTH AMERICA...AND THE 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0345 UTC.

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 3N16W 1N23W CROSSING THE 
EQUATOR NEAR 27W THEN ALONG 2S32W TO 3S42W. CLUSTERS OF 
SCATTERED/NUMEROUS STRONG CONVECTION ARE FROM THE COAST OF SW 
AFRICA TO S OF THE EQUATOR W OF 10W ACROSS THE PRIME MERIDIAN. 
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 
WITHIN 180 NM OF THE ITCZ AXIS FROM 10W-32W. 

...DISCUSSION...

GULF OF MEXICO...
DEEP LAYERED UPPER TROUGH COVERS THE E U.S. AND THE GULF N OF 
26N WITH AN ACCOMPANYING COLD FRONT EXTENDING ACROSS THE GULF 
FROM A 1013 MB LOW OFF THE FLORIDA COAST NEAR 29N86W SW ALONG 
25N88W INTO THE BAY OF CAMPECHE TO OVER S MEXICO AND THE ISTHMUS 
OF TEHUANTEPEC. A REMNANT STATIONARY BOUNDARY IS ALONG THE E 
SLOPES OF THE SIERRA MADRE MOUNTAINS OF MEXICO. MODERATE/STRONG 
SUBSIDENCE AND DRY STABLE AIR ARE ACROSS THE N GULF LIMITING ANY 
SHOWER ACTIVITY. SCATTERED CLUSTERS OF SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS ARE E OF THE FRONT. THE S GULF IS 
DOMINATED BY THE BROAD UPPER RIDGE THAT COVERS THE W ATLC AND 
CARIBBEAN GIVING THE AREA W UPPER FLOW. A SURFACE RIDGE IS 
BUILDING BEHIND THE FRONT ANCHORED OVER E TEXAS. SCATTERED/ 
BROKEN COLD AIR STRATOCUMULUS CLOUDS ARE ACROSS THE N GULF. A 
JETSTREAM WITH WINDS FROM 90 TO 130 KT IS ACROSS THE GULF N OF A 
LINE FROM JUST S OF BROWNSVILLE TEXAS ACROSS FLORIDA NEAR THE 
FLORIDA KEYS. THE FRONT WILL EXIT THE GULF LATER THIS MORNING 
AND WEAKEN IN THE W ATLC ON LATE IN THE DAY INTO TONIGHT. THE 
NEXT FRONT IS EXPECTED TO ENTER THE GULF ON SAT. 

CARIBBEAN SEA...
BROAD UPPER RIDGE DOMINATES THE CARIBBEAN WITH A RIDGE AXIS 
EXTENDING FROM CENTRAL AMERICA ACROSS HISPANIOLA. MODERATE NE TO 
E TRADE WINDS CONTINUE TO DOMINATE THE ENTIRE CARIBBEAN. STRONG 
SUBSIDENCE AND DRY STABLE AIR DOMINATES THE CARIBBEAN WITH SOME 
SCATTERED SHOWERS WITHIN 75 NM OF LINE FROM S OF PUERTO RICO 
NEAR 18N67W OVER JAMAICA TO NEAR 17N80W USHERED IN ON THE TRADE 
WINDS. LITTLE CHANGE IS EXPECTED THROUGH FRI. 
 
ATLANTIC OCEAN...
A WEAK COLD FRONT EXTENDS FROM THE CENTRAL ATLC ENTERING THE 
AREA NEAR 32N50W TO 27N61W WHERE IT WEAKENS TO 26N68W AND 
BECOMES A REMNANT FRONTAL BOUNDARY OVER THE N BAHAMA ISLANDS. 
OVERCAST LOW/MID CLOUDS WITH ISOLATED SHOWERS ARE WITHIN 120 NM 
W OF THE FRONT N OF 27N. SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS DOT THE FAR W ATLC N OF REMNANT FRONT W OF 77W. A 
BROAD UPPER RIDGE COVERS THE W INTO THE CENTRAL ATLC AND 
INCLUDES THE CARIBBEAN AND S GULF OF MEXICO. AN UPPER TROUGH IS 
IN THE E ATLC EXTENDING THROUGH NEAR 32N31W S TO 21N36W. A WEAK 
SURFACE TROUGH EXTENDS FROM 32N43W TO NEAR 24N47W AND A SECOND 
WEAK TROUGH IS TO THE S EXTENDING FROM 23N42W TO 15N46W BUT DUE 
TO THE MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR THAT 
DOMINATES THE AREA THERE IS ONLY SCATTERED LOW CLOUDS PRESENT. A 
SURFACE RIDGE COVERS THE E ATLC E OF 40W ANCHORED BY A 1026 MB 
HIGH BETWEEN THE AZORES AND THE MADEIRA ISLANDS. AN UPPER HIGH 
IS IN THE TROPICAL ATLC S OF THE CAPE VERDE ISLANDS NEAR 12N23W 
AMPLIFYING NORTHWARD AND COVERS THE TROPICAL ATLC E OF 30W. 

$$
WALLACE