[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201143
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE OCT 20 2015

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR
13N17W TO A 1011 MB LOW NEAR 09N28W TO ANOTHER 1011 MB LOW NEAR
10N39W TO 10N44W. SCATTERED MODERATE CONVECTION IS FROM 02N-16N
AND E OF 33W. ISOLATED MODERATE CONVECTION IS FROM 06N-13N
BETWEEN 35W-42W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER-LEVEL TROUGH OVER THE NW ATLANTIC SUPPORTS A FRONTAL
SYSTEM ANALYZED AS A STATIONARY FRONT ACROSS THE SE GULF OF
MEXICO FROM 25N88W TO 25N81W. ISOLATED SHOWERS ARE ALONG THE
FRONT. TO THE E...A SURFACE TROUGH PREVAILS NEAR THE BAY OF
CAMPECHE EXTENDING FROM 27N93W TO 20N92W WITH ISOLATED
CONVECTION. SCATTEROMETER DATA AND LATEST SURFACE OBSERVATIONS
DEPICT A MODERATE TO FRESH EASTERLY FLOW PREVAILS ACROSS THE
EASTERN HALF OF THE BASIN WHILE A GENTLE TO MODERATE N-EASTERLY
FLOW PREVAILS ACROSS THE WESTERN GULF. OVER THE NEXT 24
HOURS...THE FRONTAL BOUNDARY WILL BEGIN WEAKENING WITH ISOLATED
CONVECTION STILL POSSIBLE. DISSIPATION IS EXPECTED THROUGH MID
WEEK.

CARIBBEAN SEA...

UPPER-LEVEL RIDGING EXTENDS OVER CENTRAL AMERICA IS COVERING THE
WESTERN HALF OF THE BASIN WHILE AN ELONGATED UPPER-LEVEL LOW
PREVAILS ACROSS THE SE CARIBBEAN AND EXTENDS NE ACROSS THE
TROPICAL ATLANTIC. AT THE SURFACE...A SURFACE TROUGH PREVAILS
ACROSS THE WESWTEN CARIBBEAN EXTENDING FROM 21N86W TO 16N87W.
SCATTERED MODERATE CONVECTION IS OBSERVED IN THE VICINITY OF THE
TROUGH MAINLY W OF 82W SUPPORTED BY A DIFFLUENT FLOW ALOFT. A
SIMILAR DIFFLUENT FLOW IS ALSO NOTED OVER CUBA AND HISPANIOLA
SUPPORTING ISOLATED MODERATE CONVECTION OVER THE ISLANDS AND
ADJACENT WATERS. DRY AIR AND SUBSIDENCE PERSISTS ACROSS THE
CENTRAL AND E CARIBBEAN INHIBITING CONVECTION EXCEPT DIURNAL
ACTIVITY OVER THE GREATER ANTILLES. GENTLE TO MODERATE TRADES
PREVAIL ACROSS THE BASIN AS NOTED IN SCATTEROMETER DATA. OVER
THE NEXT 24 HOURS...CONVECTION WILL CONTINUE OVER THE NW
CARIBBEAN.

...HISPANIOLA...

A DIFFLUENT FLOW PREVAILS OVER THE ISLAND SUPPORTING ISOLATED
MODERATE CONVECTION ACROSS THE NORTHERN HALF. THIS PATTERN
COMBINED WITH DIURNAL HEATING IS EXPECTED TO ENHANCE MORE
CONVECTION IN THE AFTERNOON/EVENING HOURS ACROSS THE WHOLE
ISLAND.

ATLANTIC OCEAN...

A BROAD MID/UPPER-LEVEL TROUGH MOVING ACROSS THE NW ATLANTIC
CONTINUES TO SUPPORT TO A FRONTAL SYSTEM THAT BEGINS AS A
STATIONARY FRONT FROM 25N80W TO 25N73W THEN TRANSITIONS INTO A
COLD FRONT FROM THAT LAST POINT TO 27N71W TO 31N53W. A PRE-
FRONTAL TROUGH IS SE OF THE COLD FRONT AND EXTENDS FROM 22N63W
TO 31N51W. CLUSTERS OF MODERATE CONVECTION PREVAIL ACROSS THE W
ATLANTIC MAINLY W OF 51W. TO THE S...A SURFACE TROUGH IS AT
ABOUT 440NM E OF THE WINDWARD ISLANDS EXTENDING FROM 14N53W TO
09N54W. A DIFFLUENT FLOW ALOFT IS SUPPORTING ISOLATED CONVECTION
E OF THIS SURFACE TROUGH FROM 13N-19N BETWEEN 43W-52W. FURTHER
E...A FRONTAL SYSTEM WAS ANALYZED AS A STATIONARY FRONT FROM
23N23W TO 24N15W THEN TRANSITIONS INTO A COLD FRONT ACROSS NW
AFRICA. ISOLATED CONVECTION IS ALONG THE FRONTS. NEAR GALE FORCE
WINDS ARE POSSIBLE N OF 32N E OF 15W DUE TO A STRONG PRESSURE
GRADIENT BEHIND THIS COLD FRONT. OVER THE NEXT 24 HOURS...
CONVECTION WILL CONTINUE SE OF THE COLD FRONT OVER THE W
ATLANTIC AS IT GRADUALLY TRANSITIONS TO A STATIONARY FRONT.

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

$$

ERA
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