[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 020706
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT MAY 02 2009

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0330 UTC.

...THE ITCZ...

THE ITCZ AXIS EXTENDS FROM W AFRICA AT 06N10W TO 03N20W TO THE
EQUATOR AT 30W TO NE BRAZIL NEAR 03S39W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 03S TO 04N BETWEEN 11W AND 20W...AND
FROM 02N TO 05N BETWEEN 20W AND 26W. SCATTERED MODERATE
CONVECTION IS E OF 11W TO THE COAST OF AFRICA FROM 03N TO 06N.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH LIES ACROSS THE GULF OF MEXICO FROM THE NE GULF
THROUGH THE WESTERN BAY OF CAMPECHE...WITH STRONG SUBSIDENCE ON
THE EASTERN SIDE OF THE TROUGH AXIS OVER MUCH OF THE GULF N OF
25N WHERE FAIR WEATHER PREVAILS.  MOSTLY MID TO HIGH LEVEL
CLOUDINESS IS FOUND S OF 25N WHERE THE SUBTROPICAL UPPER JET ON
THE EASTERN SIDE OF THE TROUGH IS TRANSPORTING MOISTURE EASTWARD
OVER THE AREA.  THERE IS NO SIGNIFICANT CONVECTION OVER GULF
WATERS.  OVER MEXICO...NUMEROUS MODERATE CONVECTION CAN BE FOUND
NW OF MONTERREY AND S OF THE RIO GRANDE AND SCATTERED MODERATE
CONVECTION CAN BE FOUND S OF MEXICO CITY.  AT THE
SURFACE...SOUTHEASTERLY FLOW CAN BE FOUND OVER MOST OF THE AREA.
THE STRONGEST WINDS...IN THE 15 TO 20 KT RANGE...ARE IN THE
WESTERN GULF WHERE THE GRADIENT BETWEEN THE WESTERN EDGE OF THE
ATLC RIDGE AXIS OVER THE EASTERN GULF OF MEXICO AND TROUGHING
OVER TEXAS AND NORTHEASTERN MEXICO IS STRONGEST.  MEAN WINDS IN
AND JUST S OF THE FL KEYS HAVE DIMINISHED BELOW 20 KT AS THE
WESTERN EDGE OF THE ATLC RIDGE HAS WEAKENED SLIGHTLY OVER THE
LAST FEW HOURS.  HOWEVER...THE 2336 UTC QUIKSCAT PASS STILL
SHOWS A BROAD AREA OF WINDS TO 25 KT ALONG THE COAST OF CUBA
WITHIN THE STRAITS OF FL.  LITTLE CHANGE IN THE PATTERN IS
EXPECTED UNTIL LATE SUN WHEN A COLD FRONT IS EXPECTED TO PUSH
SOUTH TO THE TEXAS COAST WHILE HIGH PRES IN THE CENTRAL ATLC
MOVES SOUTHWARD...SHIFTING THE STRONGEST WINDS EASTWARD OVER THE
CENTRAL AND EASTERN GULF.

CARIBBEAN SEA...
AN UPPER LEVEL RIDGE CURRENTLY LIES OVER MUCH OF THE CARIBBEAN
ON THE SE SIDE OF THE TROUGH OVER THE GULF OF MEXICO.  THERE IS
LITTLE DEEP CONVECTION OVER FORECAST WATERS WITH THE EXCEPTION
OF SOME WIDELY SCATTERED SHOWERS IN THE GULF OF HONDURAS AND E
OF NICARAGUA TO 80W.  INLAND...SCATTERED MODERATE CONVECTION CAN
BE FOUND BETWEEN NW HONDURAS AND SOUTHERN MEXICO.  TO THE
EAST...A DEEP LAYER TROUGH NE OF THE CARIBBEAN IS FOCUSING MOIST
AIR OVER THE LEEWARD ISLANDS WHERE PRECIPITABLE WATER VALUES AND
SHOWER ACTIVITY HAVE BEEN INCREASING OVER THE LAST 24 HOURS. DRY
AIR ALOFT IS CURRENTLY WRAPPING S OF THE ASSOCIATED UPPER LEVEL
LOW...PASSING OVER THE NE CARIBBEAN. THE QUIKSCAT PASS FROM 2338
UTC SHOWS A BROAD AREA OF WINDS IN THE 20 TO 25 KT RANGE ACROSS
THE CENTRAL CARIBBEAN...WITH THE HIGHEST WINDS ALONG THE COAST
OF COLOMBIA AND IN THE WINDWARD PASSAGE.  ELSEWHERE...TRADE
WINDS ARE GENERALLY 20 KT OR LESS.  TRADE WINDS ARE EXPECTED TO
DIMINISH SLIGHTLY OVER THE NEXT DAY.

ATLANTIC OCEAN...
THE WEATHER OVER THE ATLC IS DOMINATED BY 1033 MB HIGH PRES NEAR
40N49W.  STRONG SUBSIDENCE CAN BE FOUND BETWEEN 59W AND 75W. A
DEEP LAYER TROUGH CAN BE FOUND IN THE VICINITY OF 57W FROM 15N
TO 25N.  THIS TROUGH IS POOLING LOW TO MID LEVEL MOISTURE
THROUGH THE LESSER ANTILLES NORTHWARD TO THE SURFACE TROUGH.
SCATTERED MODERATE CONVECTION ASSOCIATED WITH THE TROUGH CAN BE
FOUND FROM FROM 23N TO 26N BETWEEN 54W AND 57W WITH MORE
ISOLATED CONVECTION FOUND E OF THIS AREA TO 48W.  THE QUIKSCAT
PASSES FROM AROUND 2154 AND 2334 UTC SHOW THE HIGHEST WINDS
ALONG NW SIDE OF THIS TROUGH INTO THE SOUTHERN BAHAMAS AND
SOUTHERN STRAITS OF FL...MAINLY BETWEEN THE SURFACE TROUGH AND
THE RIDGE AXIS.  TRADE WINDS OVER 20 KT ARE CURRENTLY CONFINED
GENERALLY S OF 12N E OF 60W.  STRONG SUBSIDENCE S OF 12N E OF
45W IS LIMITING CONVECTION ALONG THE ITCZ.  OVER THE NEXT 24
HOURS...LOOK FOR THE DEEP LAYER TROUGH TO BREAKDOWN AS THE UPPER
LEVEL SYSTEM SHIFTS E AND MERGES WITH THE TROUGH JUST N OF THE
AREA ALONG 45W WHILE THE LOW LEVEL SYSTEM CONTINUES W WITH THE
MEAN FLOW S OF THE RIDGE AXIS.

$$
SCHAUER CLARK




This weather bulletin was brought to you by:
www.nashvilleweather.net