[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 291222
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT OCT 29 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN SECTIONS
OF SOUTH AMERICA...AND 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
1015 UTC.

...SPECIAL FEATURE...

HURRICANE BETA AT 29/1200 UTC IS CENTERED NEAR 13.8N 81.6W...
OR ABOUT 30 NM/55 KM NORTH-NORTHWEST OF THE ISLAND OF
PROVIDENCIA...MOVING NW 3 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE IS 984 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH
GUSTS TO 80 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMAT1/WTNT21 KNHC AND THE PUBLIC ADVISORY UNDER
HEADERS MIATCPAT1/WTNT31 FOR MORE DETAILS. BETA HAS INCREASED
ITS INTENSITY FOR MUCH OF THE NIGHT. THE TSTM ACTIVITY COMES AND
GOES IN BURSTS WITH THE STRONGEST CONVECTION ISOLATED NEAR THE
CENTER. ONE PRIMARY SPIRAL BAND IS NOTED EXTENDING N AND
E...MELDING INTO ADDITIONAL CONVECTION WHICH HAS FORMED NEAR THE
CAYMAN ISLANDS. NUMEROUS MODERATE/ STRONG CONVECTION IS FROM
11N-16N BETWEEN 79W-83W. TEN TO FIFTEEN INCHES OF RAIN ARE
EXPECTED OVER PARTS OF NICARAGUA...NE HONDURAS...AND THE ISLANDS
OF SAN ANDRES AND PROVIDENCIA DUE TO THE SLOW N/NW MOVEMENT OF
BETA OVER THE NEXT FEW DAYS.

...TROPICAL WAVES...

CENTRAL ATLANTIC TROPICAL WAVE ALONG 47W S OF 19N MOVING
W 10-15 KT. A WELL-DEFINED AND ALMOST CIRCULAR LOW-LEVEL
CIRCULATION IS ASSOCIATED WITH THE WAVE.  CONVECTION REMAINS
LIMITED AND DISPLACED WEST WITH SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IN A SMALL AREA W OF THE WAVE FROM 12N-16N
BETWEEN 45W-51W.

EAST/CENTRAL CARIBBEAN TROPICAL WAVE ROUGHLY ALONG 71W S OF 22N.
WIDELY SCATTERED MODERATE/ ISOLATED STRONG CONVECTION EXTENDS
W OF THE WAVE FROM 10N-19N BETWEEN 70W-74W STRETCHING OVER
SOUTHERN ACROSS HISPANIOLA S TO THE COLOMBIA VENZUELA BORDER.


...ITCZ...

ITCZ AXIS IS ALONG 14N10W 9N20W 4N30W 14N439W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION  CONTINUES TO PUSHING OFF
THE COAST OF AFRICA FROM GUINEA S TO LIBERIA. WIDELY SCATTERED
MODERATE CONVECTION/ISOLATED STRONG CONVECTION FROM FROM EQ-20N
BETWEEN 14W-27W. SCATTERED MODERATE CONVECTION FROM 8N-17N
BETWEEN 55W-62W PARTLY DUE TO AN UPPER LOW NEAR 12N61W.

...DISCUSSION...

GULF OF MEXICO...
DRY AIR DOMINATES THE GULF OF MEXICO...COURTESY OF SUBSIDENCE
FLOW ON THE CONFLUENT SIDE OF A LARGE MID-LATITUDE UPPER TROUGH
EXTENDING FROM NEW ENGLAND TO THE SW GULF. AT THE SURFACE A BAND
OF LOW/MID LEVEL CLOUDS CONTINUES TO PUSH SOUTHWARD FROM NEAR
MELBOURNE FLORIDA SW TO VERACRUZ MEXICO AND IS LIKELY THE
LEADING EDGE OF A SECONDARY SURGE OF THE DRIER AIR.  LITTLE
CHANGE IS EXPECTED IN THE OVERALL PATTERN THROUGH THE REST OF
WEEKEND WITH DEEP TROPICAL MOISTURE STILL TRAPPED JUST EAST OF
THE AREA UNTIL AT LEAST EARLY NEXT WEEK. A COLD FRONT IS
EXPECTED TO MOVE OFF THE TEXAS COAST TUE MORNING WITH INCREASING
MOISTURE OVER THE E GULF AHEAD OF THE BOUNDARY.

CARIBBEAN...
HURRICANE BETA IS STILL LOCATED OFF THE COAST OF NICARAGUA AND
IS SLOWLY DRIFTING N PAST PROVIDENCIA ISLAND. SEE SPECIAL
FEATURES FOR FURTHER DISCUSSION. A LARGE UPPER LEVEL HIGH
CENTERED JUST S OF HISPANIOLA NEAR 18N74W CONTINUES TO INTERACT
WITH THE TROPICAL WAVE OVER THE CNTRL CARIBBEAN TO PRODUCE A
BROAD AREA OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION
EXTENDING S OF HAITI TO NRN COLOMBIA AND VENEZUELA. THE WAVE IS
USHERING IN DRIER AIR OVER THE E CARIBBEAN...FURTHER EAST
SCATTERED MODERATE CONVECTION IS BEGINNING TO PUSH INTO THE
LESSER ANTILLES.  ELSEWHERE...MOISTURE FROM BETA CONTINUES TO BE
DRAWN NWD BY THE SUBTROPICAL JET WHICH EXTENDS FROM THE PACIFIC
OCEAN OVER MEXICO CONTINUING NORTH OVER CUBA.  THIS COUPLED WITH
AMPLE LOW LEVEL CONVERGENCE IS PRODUCING SCATTERED
MODERATE/ISOLATED STRONG CONVECTION FROM 15N-20N BETWEEN 77W-82W
EXTENDING ACROSS THE CAYMAN ISLANDS AND CNTRL CUBA. DRIER
WEATHER EXTENDS W OF 86W TO THE YUCATAN PENINSULA DUE TO
SUBSIDENCE ASSOCIATED WITH THE GULF OF MEXICO UPPER TROUGH.

ATLANTIC...
AN UPPER LEVEL SHORTWAVE EXTENDS FROM THE COAST OF NORTH
CAROLINA TO CENTRAL FLORIDA AND IS EMBEDDED WITHIN A MUCH LARGER
UPPER LONG WAVE TROUGH OVER THE EASTERN UNITED STATES.  A 1009
MB SURFACE LOW IS LOCATED WELL NORTH OF THE AREA  NEAR 38N67W. A
COLD FRONT EXTENDS S OF THE LOW TO 30N71W TO 23N79W. WIDELY
SCATTERED SHOWERS EXTEND WITHIN 100 NM OF  THE AXIS OF THE COLD
FRONT. ELSEWHERE...A VIGOROUS UPPER LEVEL LOW IS LOCATED
NEAR 12N61W WITH AN INVERTED TROUGH EXTENDING N TO
19N60W...MOVING QUICKLY W TOWARDS THE WINDWARD ISLANDS AND
EXPECTED TO CROSS INTO THE E CARIBBEAN LATER TODAY. THE LOW IS
PRODUCING DRY WEATHER FROM 6N-18N BETWEEN 62W-67W...BUT
SCATTERED MODERATE CONVECTION CONTINUES TO PUSH TO THE
WEST...FROM 9N-12N BETWEEN 53W-60W. A LARGE UPPER HIGH CONTINUES
TO DOMINATE THE CENTRAL ATLANTIC NEAR 25N46W AND IS PUSHING THE
SUBTROPICAL JET WELL N OF THE AREA...ALLOWING A SURFACE RIDGE TO
BUILD ALONG 27N. A NEARLY STATIONARY UPPER TROUGH LIES E OF THE
HIGH FROM MOROCCO SW TO THE CAPE VERDE ISLANDS.  FARTHER S...AN
ELONGATED UPPER LOW IS CENTERED NEAR 11N34W AND IS INDUCING
SLIGHT UPPER DIFFLUENCE TO ITS E.

$$
JP/JR



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