000
AXNT20 KNHC 151059
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT APR 15 2006

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...WEATHER OBSERVATIONS... 
RADAR...AND METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0915 UTC.

...THE ITCZ...
ITCZ 7N9W 6N10W 3N20W 3N30W 3N40W 3N50W 2N57W. SCATTERED TO 
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE OFF THE COAST OF 
SIERRA LEONE AND LIBERIA IN AFRICA FROM 4N TO 7N BETWEEN 12W AND 
14W. WIDELY SCATTERED TO SCATTERED MODERATE SHOWERS/ISOLATED 
STRONG THUNDERSTORMS ARE WITHIN 30 NM TO 60 NM ON EITHER SIDE
OF 1N22W 3N30W...BECOMING ISOLATED MODERATE SHOWERS AND POSSIBLE
THUNDERSTORMS FROM 5N TO 6N BETWEEN 43W AND 51W.

...DISCUSSION...

THE GULF OF MEXICO...
SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS CONTINUE THANKS TO 
AN UPPER LEVEL RIDGE OVER THE NORTHERN GULF. SHOWERS ARE POSSIBLE
IN A FEW LINES OF CONFLUENT LOW CLOUDS IN THE STRAITS OF FLORIDA
AND IN THE GULF NORTH OF 22N WEST OF 90W. A SURFACE RIDGE 
EXTENDS FROM THE ATLANTIC OCEAN NEAR 30N73W TO LAKE OKEECHOBEE 
IN FLORIDA TO A NORTH CENTRAL GULF 1018 MB HIGH CENTER NEAR 
28N87W TO 25N95W. A SURFACE RIDGE WAS FORECAST FROM THE STRAITS 
OF FLORIDA INTO THE NORTH CENTRAL GULF AND THE NORTHWESTERN GULF 
AT 72 HOURS. THERE IS A CHANCE THAT RAIN MAY REACH NORTH AND 
CENTRAL FLORIDA ON TUESDAY ASSOCIATED WITH A WEAK COLD FRONT 
THAT MAY REACH SOUTH FLORIDA TUESDAY NIGHT INTO WEDNESDAY. 

THE CARIBBEAN SEA AND THE ATLANTIC OCEAN WEST OF 50W...
THE PERSISTENT UPPER LEVEL SOUTHWESTERLY FLOW AND AN APPROACHING 
MASS OF DRY AIR FROM THE GULF OF MEXICO COASTAL U.S.A HELPED TO
PUSH TO THE NORTHEAST...MORE INTO THE ATLANTIC WATERS...THE 
WELL-DEFINED LOW CENTER AND TROUGH WHICH WERE PERSISTENT IN THE 
NORTH CENTRAL AND NORTHWESTERN CARIBBEAN SEA...THE SOUTHEASTERN 
GULF OF MEXICO...AND THE ATLANTIC OCEAN WEST OF 60W ONLY
48 TO 56 HOURS AGO. THE REMNANT OF THAT TROUGH IS NOT AS WELL 
DEFINED EITHER IN WATER VAPOR IMAGERY OR CIMSS SATELLITE DERIVED 
WIND DATA FROM 15/0600 UTC. AN ATLANTIC OCEAN TROUGH IS ALONG 
25N72W BEYOND 32N66W. THIS IS NOT A SHARPLY-DEFINED TROUGH AND 
IS NOT ASSOCIATED WITH ANY SURFACE FEATURE. AN AREA OF 
COMPARATIVELY DRIER AIR FROM SUBSIDENCE COVERS PARTS OF THE
GULF OF MEXICO...THE CARIBBEAN SEA...AND THE ATLANTIC OCEAN FROM 
20N TO 26N BETWEEN 72W AND 92W. UPPER LEVEL SOUTHWESTERLY WINDS 
CUT ACROSS CENTRAL AMERICA FROM NICARAGUA AND SOUTH OF THERE 
INTO THE CENTRAL CARIBBEAN WATERS AND EXIT ACROSS THE 
NORTHEASTERN CORNER INTO THE ATLANTIC OCEAN. OTHER UPPER LEVEL 
SOUTHWESTERLY WINDS ALSO CONTINUE TO COME FROM NORTHERN 
VENEZUELA AND THEY CURVE ANTICYCLONICALLY IN ACCORD WITH THE 
TROPICAL ATLANTIC RIDGE ALONG 10N26W 11N42W 13N60W. A STATIONARY
FRONT PASSES THROUGH 32N46W TO 29N54W TO A 1007 MB LOW PRESSURE
CENTER NEAR 26N58W TO A 1010 MB LOW PRESSURE CENTER NEAR 23N60W.
A SURFACE TROUGH CONTINUES FROM THE 1010 MB LOW CENTER TO THE 
ISLANDS JUST EAST OF PUERTO RICO NEAR 18N64W...ON TOP OF THE 
NETHERLANDS ANTILLES TO VENEZUELA NEAR 10N70W. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND SCATTERED MODERATE SHOWERS TO ISOLATED 
STRONG THUNDERSTORMS ARE FOUND WITHIN 210 NM ON EITHER SIDE OF 
21N60W 28N49W BEYOND 32N46W. THESE CLOUDS AND PRECIPITATION ARE 
TAKING PLACE IN THE AREA OF THE UPPER LEVEL RIDGE TO THE EAST 
OF THE SURFACE FRONT/TROUGH. LOW CLOUDS AND POSSIBLE 
PRECIPITATION ARE FOUND FROM 11N TO 20N BETWEEN 76W AND 88W
IN AN AREA OF BROAD SURFACE TO LOW LEVEL CYCLONIC TURNING.

THE REST OF THE ATLANTIC OCEAN...
STRONG MIDDLE TO UPPER RIDGE PREVAILS ACROSS THE CENTRAL ATLANTIC
EXTENDING FROM AN UPPER HIGH LOCATED IN THE TROPICS NEAR 10N50W.
CONDITIONS ALOFT ARE QUITE DRY IN THE TROPICAL ATLANTIC SOUTH OF
20N WITH LIMITED MOISTURE. AN UPPER TROUGH IS IN PLACE IN THE 
NORTHEASTERN ATLANTIC FROM THE MADEIRA ISLANDS TO THE CANARY 
ISLANDS SOUTHWARD TO JUST SOUTH OF THE CAPE VERDE ISLANDS. THE 
SOUTHERN END OF A SURFACE TROUGH RUNS FROM 28N21W BEYOND 32N16W.
NO DEEP CONVECTIVE ACTIVITY IS PRESENT AT THIS TIME. PLENTY OF 
HIGH CLOUDS COVER THE NORTHEASTERN ATLANTIC NORTH OF 20N EAST
OF 40W WITH LIMITED PRECIPITATION. DRY AIR IN SUBSIDENCE
IS SOUTH OF 20N EAST OF 50W UNDER THE UPPER LEVEL TROPICAL 
ATLANTIC RIDGE.

$$
MT