000
AXNT20 KNHC 151026
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU MAR 15 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 
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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N10W 5N19W 2N27W 2N37W 4N46W 1N52W. 
SCATTERED MODERATE/STRONG CONVECTION IS FROM 1N-5N W OF 48W TO 
INLAND OVER SOUTH AMERICA. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS WITHIN 75 NM OF LINE EQ23W-2N27W. CLUSTERS OF 
SCATTERED MODERATE CONVECTION ARE FROM 6N TO S OF THE EQUATOR 
BETWEEN 33W-48W. 

...DISCUSSION...

GULF OF MEXICO...
THE UPPER LEVEL LOW CONTINUES TO MOVE E OVER LOUISIANA COVERING 
THE GULF ENHANCING THE HEAVY SHOWERS/SCATTERED THUNDERSTORMS N 
OF 27N BETWEEN 84W-93W WITH THE HEAVIEST THUNDERSTORMS OFFSHORE. 
AT 0900 UTC...A SURFACE TROUGH EXTENDS FROM A 1008 MB LOW OVER 
NE MEXICO ACROSS S TEXAS JUST N OF BROWNSVILLE TO A DEVELOPING 
1011 MB LOW ALONG THE COAST OF LOUISIANA NEAR 29N92W. UPPER 
RIDGE AXIS IS NOW IN THE W ATLC FROM OVER FLORIDA GIVING THE 
GULF SW TO W UPPER WINDS. THE SURFACE RIDGE EXTENDING FROM THE W 
ATLC COVERS THE E GULF E OF 85W. MODERATE TO STRONG S TO SE 
SURFACE WINDS COVER THE GULF. MODERATE/STRONG SUBSIDENCE AND DRY 
AIR NOW COVERS THE S GULF S OF 27N W OF 82W KEEPING THAT AREA 
SHOWER FREE. 
 
CARIBBEAN...
THE CARIBBEAN IS DOMINATED BY A BROAD UPPER RIDGE EXTENDING FROM 
THE W TROPICAL ATLC ACROSS THE WINDWARD ISLANDS TO E CUBA GIVING 
THE ENTIRE CARIBBEAN SW TO W UPPER FLOW. MODERATE TO STRONG 
SUBSIDENCE AND DRY UPPER AIR REMAINS ACROSS THE CARIBBEAN. 
PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE OVER THE ATLC AND 
THE LOWER PRESSURES IN THE TROPICS ARE GENERATING STRONG 
EASTERLY TRADE WINDS BRINGING IN THE LOW LEVEL MOISTURE WITH 
POSSIBLE ISOLATED SHOWERS DOTTING THE CARIBBEAN E OF 80W. 

ATLANTIC...
UPPER RIDGE THAT COVERS FLORIDA EXTENDS OVER THE W ATLC W OF 65W 
WITH THE AXIS ALONG 75W. BROKEN/OVERCAST MID/HIGH CLOUDS WITH 
ISOLATED SHOWERS ARE FROM 23N-31N W OF 73W TO OVER FLORIDA AND 
INCLUDING THE BAHAMA ISLANDS. BROAD DEEP LAYERED TROUGH COVERS 
THE REMAINDER OF THE W/CENTRAL ATLC N OF 18N FROM 43W-65W WITH 
THE ASSOCIATED COLD FRONT EXTENDING INTO THE AREA THROUGH 32N47W 
SSW TO 24N52W THEN CONTINUES AS A SURFACE TROUGH SW TO THE 
LEEWARD ISLANDS NEAR 17N63W. SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS ARE WITHIN 120/150 NM E OF THE FRONT N OF 26N WITH 
ISOLATED SHOWERS WITHIN 90/120 NM EITHER SIDE OF THE REMAINDER 
OF THE FRONT AND SURFACE TROUGH. A SURFACE RIDGE EXTENDS OVER 
THE W ATLC THROUGH 32N67W TO THE GREATER ANTILLES ANCHORED BY A 
1027 MB HIGH N OF BERMUDA AND COVERS THE AREA W OF THE ABOVE 
FRONT/TROUGH. WEAKENING UPPER LEVEL LOW OVER THE FAR E ATLC 
COVERS THE AREA N OF 18N E OF 28W TO INLAND OVER AFRICA WITH THE 
UPPER LOW MOVING S OF THE CANARY ISLANDS NEAR 26N16W. THE 
ASSOCIATED SURFACE 1012 MB LOW IS ALONG THE COAST OF THE WESTERN 
SAHARA NEAR 25N16W. A SURFACE RIDGE COVERS THE REMAINDER OF THE 
E AND CENTRAL ATLC N OF 16N BETWEEN 22W-45W ANCHORED BY A 1034 
MB HIGH JUST N OF THE AZORES. THE REMAINDER OF THE ATLC IS UNDER 
RATHER BENIGN UPPER LEVEL FEATURES AS WELL AS MODERATE/STRONG 
SUBSIDENCE AND VERY DRY AIR AT ALL LEVELS KEEPING THE REMAINDER 
OF THE ATLC QUIET AGAIN THIS MORNING. 

$$
WALLACE