[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121711
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED JUL 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 57W/58W SOUTH OF 18N MOVING WEST
NEAR 15 KT. EARLY THIS MORNING CONVECTION HAS BLOSSOMED AROUND A
1014 MB LOW LOCATED ALONG OR JUST BEHIND THE WAVE AXIS NEAR 13N.
SCATTERED MODERATE CONVECTION LIES FROM 11N-14N BETWEEN 56W-58W.
THIS WAVE REMAINS IN A MARGINAL ATMOSPHERIC ENVIRONMENT FOR
FURTHER DEVELOPMENT. THE TROPICAL WAVE AND AREA OF LOW PRES WILL
SPREAD MOISTURE TO THE EASTERN CARIBBEAN ISLANDS LATER TONIGHT.

A CENTRAL/WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 77W SOUTH
OF 20N MOVING WEST 10-15 KT. THIS WAVE HAS LOST MUCH OF ITS
SIGNATURE AS IT TRAVELED WESTWARD IN A RATHER DRY/STABLE
ENVIRONMENT.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N14W 8N30W 6N46W 6N57W. THE ITCZ
IS FAIRLY ACTIVE WITH CLUSTERS OF SCATTERED MODERATE CONVECTION
WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 21W-47W. A
POSSIBLE WEAK LOW AMPLITUDE TROPICAL WAVE MIGHT BE ALONG 21W BUT
THIS IS RATHER INCONCLUSIVE FROM THE AVAILABLE DATA.

...DISCUSSION...
GULF OF MEXICO...
THE MAIN FEATURE IN THE GULF OF MEXICO IS AN UPPER LEVEL LOW
CENTERED NEAR 24N89W WITH ITS CYCLONIC CIRCULATION COVERING MUCH
OF THE REGION. THIS SYSTEM IS PRODUCING SCATTERED SHOWERS AND
ISOLATED TSTMS MAINLY ON THE MOIST E SIDE OF THE CIRCULATION
FROM THE YUCATAN PENINSULA TO THE EASTERN GULF. ONLY WIDELY
SCATTERED SHOWERS LIE ON THE W SIDE OF THE UPPER LOW. MORE
CONCENTRATED SHOWERS AND TSTMS ARE MOVING ACROSS THE WESTERN
BAHAMAS AND OVER SOUTH AND CENTRAL FLORIDA ASSOCIATED WITH A SFC
TROUGH ALONG 79W FROM 22N-27N ENHANCED BY THE MOIST UPPER LEVEL
ENVIRONMENT. GFS SUGGESTS THAT THIS MOISTURE WILL MOVE INTO THE
CENTRAL AND WESTERN GULF OVER THE NEXT COUPLE OF DAYS AS THE SFC
AND UPPER LEVEL FEATURES SLIDES WESTWARD.

CARIBBEAN SEA...
AN UPPER LEVEL TROUGH/RIDGE PATTERN LIES ACROSS THE CARIBBEAN
SEA. THE UPPER TROUGH EXTENDS FAR TO THE SOUTH WITH THE UPPER
AXIS EXTENDING FROM A WEAKENING UPPER LOW S OF HAITI TO PANAMA.
DRY/STABLE AIR ALOFT ACCOMPANIES THE TROUGH. DEBRIS MOISTURE
FROM THE GULF OF MEXICO'S UPPER LOW COVERS THE WESTERN PORTION
OF THE AREA W OF 82W. RIDGING LIES TO THE EAST OF THE TROUGH
ACROSS THE LESSER ANTILLES. UPPER LEVEL DIFFLUENCE IS GENERATING
AN AREA OF SCATTERED SHOWERS ON THE E SIDE OF THE UPPER LOW FROM
12N-18N BETWEEN 67W-72W. AN AREA OF UNSETTLED WEATHER ASSOCIATED
WITH AN APPROACHING TROPICAL WAVE AND ILL-DEFINED AREA OF LOW
PRES OR A LOW LEVEL VORTICITY MAXIMUM WILL BE SPREADING MOISTURE
ACROSS THE LESSER ANTILLES TONIGHT AND TOMORROW AND THE GREATER
ANTILLES ON THU AND FRI.  TRADE WINDS ARE IN THE 15-20 KT RANGE
E OF 80W WITH A BUOY REPORTING 25 KT BEHIND THE APPROACHING WAVE.

ATLANTIC OCEAN ...
A BERMUDA-AZORES SURFACE RIDGE IS WELL ESTABLISHED ACROSS THE
AREA WITH MULTIPLE SFC HIGH PRES CENTERS SCATTERED ACROSS THE
ATLANTIC NORTH OF THE DISCUSSION AREA. HIGH PRES IS SUPPLYING
MAINLY FAIR WEATHER ACROSS NEARLY THE ENTIRE BASIN SOUTH OF 32N.
A WEAK DISSIPATING BENIGN SFC TROUGH LIES FROM 28N59W TO 34N52W
CONTAMINATES THE RIDGE CAUSING A SLIGHT KINK IN THE ISOBARIC
PATTERN AND PRODUCING A LINE OF LOW-MID LEVEL CLOUDS. IN THE
UPPER LEVELS...RIDGING AND STRONG SUBSIDENCE COVERS THE AREA
NORTH OF 20N KEEPING MUCH OF THE AREA RAIN FREE.  LITTLE CHANGE
IS EXPECTED OVER THE NEXT COUPLE OF DAYS.

THE ONLY AREAS OF UNSETTLED WEATHER ACROSS THE ATLANTIC OCEAN IS
ASSOCIATED WITH A TROPICAL WAVE APPROACHING THE EASTERN
CARIBBEAN ISLANDS AND A SFC TROUGH JUST OFF THE FLORIDA
COASTLINE. FOR MORE INFORMATION ON THE WAVE REFER TO THE
TROPICAL WAVES AND CARIBBEAN SECTION AND REFER TO THE GULF OF
MEXICO SECTION FOR A DISCUSSION ON THE UNSETTLED WEATHER IN THE
BAHAMAS AND FLORIDA.

$$
CANGIALOSI


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