000
AXNT20 KNHC 061751
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE MAR 06 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N10W 5N20W 2N35W CROSSING THE 
EQUATOR AT 47W AND INTO COASTAL NE BRAZIL NEAR 1S52W. CLUSTERS 
OF SCATTERED MODERATE CONVECTION DOT THE AREA FROM 1N-5N BETWEEN 
9W-22W. SIMILAR ACTIVITY IS FROM 2S-EQ BETWEEN 26W-32W...WITHIN 
150 NM N OF THE AXIS BETWEEN 33W-37W...AND JUST OFF THE COAST OF 
NE BRAZIL FROM EQ-5N BETWEEN 47W-52W. 

...DISCUSSION...

THE GULF OF MEXICO...
NICE WEATHER DAY ACROSS THE GULF THIS AFTERNOON WITH COOL AND 
DRY CONDITIONS PREVAILING...AS SFC HIGH PRESSURE EXTENDS INTO 
THE AREA FROM THE N. A SCATTERED TO BROKEN AREA OF COOL AIR 
STRATOCUMULUS CLOUDS NOTED S OF 28N W OF 85W. A LOWER STRATUS 
DECK IS SEEN BANKING UP AGAINST THE MEXICO COAST WITH ONSHORE 
FLOW IN THE SW BAY OF CAMPECHE S OF 22N. MOSTLY CLEAR SKIES ARE 
NOTED ELSEWHERE. SFC WINDS IN THE SRN GULF CONTINUE TO DIMINISH 
THOUGH REMAIN NE TO 20 KT S OF 25N AND E OF 87W. SFC HI PRES 
RIDGING ALONG THE N GULF COAST WILL DOMINATE THROUGH SAT...WITH 
THE WINDS AND SEAS S OF 25N CONTINUING TO SLOWLY RELAX. 
ALOFT...BROAD NW FLOW DOMINATES AROUND RIDGING FILLING IN BEHIND 
THE LONGWAVE TROUGHING OFF THE EAST COAST. THERE IS A BAND OF 
UPPER MOISTURE HUGGING THE N GULF COAST BUT OVERALL VERY DRY MID 
TO UPPER AIR DOMINATES THE BASIN. 

THE CARIBBEAN SEA...
REMNANT FRONTAL TROUGH EXTENDS FROM ERN CUBA TO NEAR THE ERN TIP 
OF HONDURAS ALONG 21N77W 19N81W 16N83W. THIS MORNINGS QUIKSCAT 
PASS SHOWED THE BOUNDARY IS MOSTLY MARKED BY WEAK LOW LEVEL 
CONFLUENCE AND A SPEED GRADIENT...WITH NLY WINDS 20-25 KT W OF 
THE TROUGH AND NE WINDS 15-20 KT E OF THE TROUGH. BROKEN LOW TO 
MID CLOUDS WITH EMBEDDED SHOWERS ARE ALSO OVER THE NW CARIB W OF 
THE TROUGH. MODERATE TRADES GENERALLY DOMINATE OVER THE CENTRAL 
AND ERN CARIB WHICH ARE ADVECTING TYPICAL PATCHES OF LOW LEVEL 
MOISTURE WWD...WITH THE MOST CONCENTRATED OF THESE PATCHES NOTED 
BETWEEN PUERTO RICO AND THE ABC ISLANDS. MODERATE TO FRESH 
TRADES EXPECTED TO TAKE OVER THROUGH THE SECOND HALF OF THE WEEK 
AS THE FRONTAL TROUGH DISSIPATES. ALOFT...DEEP LAYER TROUGHING 
OFF THE U.S. EAST COAST EXTENDS INTO THE NW CARIB. UPPER HIGH 
JUST NE OF THE LEEWARD ISLANDS IS AFFECTING THE ERN CARIB. UPPER 
CONFLUENCE BETWEEN THESE FEATURES IS SUPPORTING THE VERY DRY AIR 
SEEN IN THE ERN CARIBBEAN. 

THE ATLANTIC OCEAN...
A 1030 MB SFC HIGH OVER MISSISSIPPI IS BUILDING INTO THE WRN 
ATLC BEHIND THE STATIONARY FRONT THAT ENTERS THE AREA NEAR 
31N56W AND CONTINUES SW TO ERN CUBA NEAR 21N76W. OVERCAST DEEP 
LAYER CLOUDINESS WITH EMBEDDED SHOWERS ARE WITHIN 120NM NW OF 
THE FRONT. SCATTERED TO BROKEN COOL AIR STRATOCUMULUS CLOUDS 
ARE ELSEWHERE NW OF THE FRONT EXCEPT FOR CLEAR SKIES JUST 
OFFSHORE THE SE U.S. COAST. FRONT IS ASSOCIATED WITH THE DEEP 
LAYER TROUGHING OFF THE EAST COAST. THE REMAINDER OF THE CENTRAL 
AND ERN ATLC SFC PATTERN IS DOMINATED BY THE SRN PERIPHERY OF 
THE 1032 MB HIGH NEAR 32N28N. PATCHES OF LOW TO MID CLOUDS ARE 
ROTATING ANTICYCLONICALLY AROUND THIS HIGH. AN UPPER HIGH NE OF 
THE LEEWARD ISLANDS NEAR 21N58W HAS RIDGING OVER MUCH OF THE 
CENTRAL ATLC. HOWEVER...A DISTINCT MID TO UPPER LOW REMAINS NEAR 
22N44W. UPPER DIFFLUENCE BETWEEN THIS LOW AND RIDGING JUST OFF 
THE AFRICAN COAST IS SUPPORTING THE MOISTURE RICH REGION SEEN IN 
WV IMAGERY FROM 10N-25N E OF 44W. THERE MAY BE SHOWERS JUST S 
AND SE OF THE UPPER LOW MAINLY WITHIN 120 NM OF A LINE FROM 
8N51W 18N35W...WHERE MOISTURE CONTENT IS HIGHEST AND CLOUD TOPS 
ARE COLDEST. 

$$
WILLIS