[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290604
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT WED OCT 29 2014

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0545 UTC.

...SPECIAL FEATURES...

A 1010 MB LOW...FORMERLY ASSOCIATED WITH THE TROPICAL WAVE OVER THE
EASTERN CARIBBEAN...IS BEING SUPPORTED BY AN UPPER-LEVEL TROUGH.
THE LOW IS EMBEDDED IN A HIGH DEEP LAYER MOIST ENVIRONMENT THAT
ALONG WITH DIFFLUENT FLOW ALOFT CONTINUE TO ENHANCE SCATTERED
MODERATE/ISOLATED STRONG CONVECTION E OF THE LOW CENTER FROM 16N-
23N BETWEEN 56W-61W. ISOLATED SHOWERS ARE ELSEWHERE WITHIN 180
NM OF THE LOW. DUE TO MARGINAL CONDUCIVE UPPER-LEVEL
WINDS...GRADUAL DEVELOPMENT OF THIS DISTURBANCE IS POSSIBLE
WHILE IT MOVES W-NW THE NEXT COUPLE OF DAYS. TROPICAL CYCLONE
FORMATION CHANCES THROUGH 48 HOURS REMAIN MEDIUM. SEE LATEST NHC
TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20
KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN WITH AXIS
EXTENDING FROM 17N63W TO 9N66W...MOVING W AT 15-20 KT. THE WAVE
IS BEING SUPPORTED BY A LOW TO MIDDLE LEVEL INVERTED TROUGH AND
IT IS EMBEDDED IN A SHALLOW MODERATE MOIST ENVIRONMENT. DRY AIR
SUBSIDENCE FROM ALOFT IN THIS REGION OF THE BASIN HINDERS THE
DEVELOPMENT OF DEEP CONVECTION AT THE TIME.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 12N16W AND CONTINUES TO 10N20W. THE ITCZ BEGINS NEAR
10N20W AND CONTINUES ALONG 7N36W TO 7N59W. SCATTERED MODERATE
CONVECTION AND ISOLATED TSTMS ARE FROM 4N-12N E OF 35W AND FROM
4N-11N BETWEEN 40W-53W.

...DISCUSSION...

GULF OF MEXICO...

A BROAD UPPER-LEVEL RIDGE IS OVER THE WEST ATLC...THUS
SUPPORTING A SURFACE RIDGE THAT EXTENDS AN AXIS SW ACROSS THE
FLORIDA PENINSULA TO THE NW GULF. HOWEVER...IN THE MIDDLE-
LEVELS...THE BASE OF A BROAD TROUGH OVER THE EASTERN CONUS
EXTENDS S TO THE CENTRAL GULF TO SUPPORT A WEAKNESS IN THE
SURFACE RIDGE ANALYZED AS A SURFACE TROUGH ALONG 30N88W TO
25N88W. SHALLOW MOIST AIR FROM THE ATLC FRONT ENVIRONMENT AND
FORMER TROPICAL CYCLONE HANNA HAS BEEN STREAMING INTO THE
GULF...THUS SUPPORTING CLOUDINESS NEARBY THE SURFACE TROUGH AND
BAY OF CAMPECHE. STRONG DRY AIR SUBSIDENCE FROM ALOFT ACROSS THE
REMAINDER BASIN SUSTAINS FAIR WEATHER. WINDS ARE FROM THE E-SE
IN THE RANGE OF 5-15 KT. A COLD FRONT WILL REACH THE NE BASIN
AND NORTHERN FLORIDA BY WED NIGHT...CONTINUING E-SE ACROSS
SOUTHERN FLORIDA THROUGH THU NIGHT.

CARIBBEAN SEA...

THE REMNANTS OF HANNA ARE BEING ANALYZED AS A SURFACE TROUGH
EXTENDING FROM 21N84W TO 15N87W...WHICH CONTINUE TO SUPPORT
SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE YUCATAN
BASIN...BELIZE AND NORTHERN HONDURAS. LINGERING MOISTURE
ASSOCIATED WITH A FORMER SURFACE TROUGH ACROSS HISPANIOLA
CONTINUE TO ENHANCE ISOLATED SHOWERS AND TSTMS IN THE ISLAND AS
WELL AS ADJACENT WATERS. THE SHOWERS ARE BEING SUPPORTED BY AN
UPPER LEVEL TROUGH DIPPING ACROSS THE CENTRAL AND EASTERN
CARIBBEAN. A TROPICAL WAVE IS MOVING OVER THE EASTERN BASIN.
THIS WAVE IS BEING SUPPORTED BY AN INVERTED LOW- TO MIDDLE-LEVEL
TROUGH...HOWEVER STRONG DRY AIR SUBSIDENCE FROM ALOFT IN THIS
REGION OF THE BASIN IS HINDERING THE DEVELOPMENT OF CONVECTION.
SEE TROPICAL WAVES SECTIONS ABOVE FOR MORE DETAILS. A LOW
PRESSURE SYSTEM CENTERED NE OF THE LEEWARD ISLANDS IS EXPECTED
TO DRIFT WESTWARD TOWARDS HISPANIOLA BY FRIDAY NIGHT. THIS AREA
OF LOW PRESSURE IS EXPECTED TO GENERATE SHOWERS ACROSS PUERTO
RICO WED THROUGH THU AND FOR HISPANIOLA THU TO SAT.

HISPANIOLA...

LINGERING MOISTURE ASSOCIATED WITH A FORMER SURFACE TROUGH
ACROSS HISPANIOLA CONTINUE TO ENHANCE ISOLATED SHOWERS AND TSTMS
IN THE ISLAND AS WELL AS ADJACENT WATERS. THE SHOWERS ARE BEING
SUPPORTED BY AN UPPER LEVEL TROUGH DIPPING ACROSS THE CENTRAL
AND EASTERN CARIBBEAN. A LOW PRESSURE SYSTEM CENTERED NE OF THE
LEEWARD ISLANDS IS EXPECTED TO DRIFT WESTWARD TOWARDS HISPANIOLA
BY FRIDAY NIGHT. THIS AREA OF LOW PRESSURE IS EXPECTED TO
GENERATE SHOWERS ACROSS HISPANIOLA THU TO SAT.

ATLANTIC OCEAN...

THE HIGHLIGHT IN THE BASIN IS A DISTURBANCE JUST NE OF THE
LEEWARD ISLANDS...WHICH IS DISCUSSED IN THE SPECIAL FEATURES
SECTION. A MIDDLE TO UPPER LEVEL TROUGH OVER THE CENTRAL ATLC N
OF 28N CONTINUE TO SUPPORT A COLD FRONT ANALYZED FROM 30N45W SW
TO 25N57W WHERE A SURFACE TROUGH CONTINUES TO 22N66W. THERE IS
NO CONVECTION ASSOCIATED WITH THESE FEATURES AT THE TIME. EAST
AND WEST OF THE FRONTAL BOUNDARY...SURFACE RIDGING AND FAIR
WEATHER DOMINATE.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR


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