[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251757
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN AUG 25 2013

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...

A 1008 MB LOW IS IN THE BAY OF CAMPECHE NEAR 19N94W MOVING W 5-
10 KT. SCATTERED TO HEAVY SHOWERS WITH EMBEDDED ISOLATED
THUNDERSTORMS COVER THE AREA S OF 23N TO INLAND OVER MEXICO
BETWEEN 92W-97W. THIS SYSTEM HAS BECOME BETTER ORGANIZED OVER
THE PAST SEVERAL HOURS. ENVIRONMENTAL CONDITIONS APPEAR
CONDUCIVE FOR DEVELOPMENT AND A TROPICAL DEPRESSION COULD FORM
BEFORE THE SYSTEM REACHES THE COAST OF THE STATE OF VERACRUZ
MEXICO TONIGHT OR MONDAY. THIS SYSTEM HAS A HIGH CHANCE OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. AN AIR
FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO
INVESTIGATE THE SYSTEM LATER THIS AFTERNOON.

...TROPICAL WAVES...
TROPICAL WAVE W OF THE CAPE VERDE ISLANDS EXTENDS FROM 21N33W TO
11N33W MOVING W NEAR 15 KT. THE N AND S PORTIONS OF THIS WAVE
ARE EMBEDDED WITHIN DEEP MOISTURE WHILE DRIER AIR IS BEING
INTRODUCED TO THE CENTRAL PORTION OF THE WAVE AS DEPICTED ON THE
TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS MOVING BENEATH AN
UPPER LOW WHICH IS GENERATING ISOLATED MODERATE CONVECTION N OF
THE WAVE FROM 20N-25N BETWEEN 31W-35W. OTHERWISE NO ASSOCIATED
SHOWERS/CONVECTION.

TROPICAL WAVE IN THE E CARIBBEAN EXTENDS FROM 17N67W TO INLAND
OVER VENEZUELA NEAR 8N68W MOVING W NEAR 15 KT. WAVE IS EMBEDDED
WITHIN AN AREA OF DEEP MOISTURE THAT COVERS THE E CARIBBEAN AS
DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 13N-18N
BETWEEN 66W-74W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 12N16W AND CONTINUES ALONG 9N25W 12N34W TO 10N42W
WHERE THE ITCZ BEGINS AND CONTINUES ALONG 7N51W TO SOUTH AMERICA
NEAR 7N58W. A 1012 MB LOW IS CENTERED NEAR 12N47W WITH SCATTERED
MODERATE/ISOLATED STRONG CONVECTION FROM 11N-13N BETWEEN 47W-
50W. SCATTERED MODERATE/STRONG CONVECTION FROM 12N-15N E OF 20W
TO INLAND OVER W AFRICA. CLUSTERS OF SCATTERED MODERATE/ISOLATED
STRONG CONVECTION ARE FROM 6N-11N E OF 18W TO INLAND OVER W
AFRICA...FROM 5N-8N BETWEEN 15W-25W...FROM 7N-13N BETWEEN 31W-
46W...AND S OF 9N TO INLAND OVER SOUTH AMERICA BETWEEN 58W-61W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH OVER THE NW ATLC NARROWS AS IT EXTENDS ALONG THE
N GULF COAST SUPPORTING A COLD FRONT THAT ENTERS THE GULF AT
25/1500 UTC NEAR CEDAR KEY FLORIDA AND CONTINUES ALONG 29N86W TO
INLAND OVER SE LOUISIANA NEAR NEW ORLEANS. SCATTERED TO HEAVY
SHOWERS AND ISOLATED THUNDERSTORMS ARE N OF 27N BETWEEN 87W-95W
TO INLAND OVER LOUISIANA AND E TEXAS. CLUSTERS OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS DOT THE REMAINDER OF THE N GULF N
OF 24N E OF 94W. A SURFACE TROUGH IS OVER THE NW GULF EXTENDING
AT 25/1500 UTC FROM 29N94W ALONG 27N96W TO 24N97W. ISOLATED
SHOWERS/THUNDERSTORMS ARE WITHIN 75/90 NM EITHER SIDE OF THE
TROUGH AXIS. AN UPPER RIDGE EXTENDS FROM NEAR VERACRUZ MEXICO
ACROSS THE GULF WATERS TO OVER FLORIDA NEAR TAMPA. THE 1008 MB
LOW IN THE SPECIAL FEATURES IS BENEATH THIS UPPER RIDGE. THE
COLD FRONT WILL WEAKEN THROUGH MON BEFORE DISSIPATING TUE.

CARIBBEAN SEA...
CARIBBEAN IS DOMINATED NORTHERLY FLOW OVER THE W CARIBBEAN AND
SOUTHERLY FLOW OVER THE E CARIBBEAN WITH AN INVERTED TROUGH
EXTENDING ACROSS THE CENTRAL CARIBBEAN FROM E PANAMA TO THE
WINDWARD PASSAGE. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR
9N75W ALONG 10N79W TO ACROSS W PANAMA/COSTA RICA NEAR 9N83W.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 11N W OF 80W
TO INLAND OVER PANAMA TO S NICARAGUA AND SCATTERED SHOWERS S OF
10N TO INLAND OVER PANAMA BETWEEN 77W-80W. THE ACTIVITY OVER THE
E/CENTRAL CARIBBEAN IS ASSOCIATED WITH THE TROPICAL WAVE LEAVING
THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS
AFTERNOON. MODERATE TO FRESH TRADE WINDS ARE EXPECTED IN THE W
AND CENTRAL CARIBBEAN THROUGH MON THEN WILL DIMINISH TUE AND
WED. CARIBBEAN TROPICAL WAVE WILL REACH THE W CARIBBEAN EARLY
MON AND MOVE THROUGH THE SW CARIBBEAN MON NIGHT THROUGH TUE.

HISPANIOLA...
SKIES ARE MOSTLY CLEAR ACROSS THE ISLAND THIS AFTERNOON.
HOWEVER...SHOWERS AND POSSIBLE OF THUNDERSTORMS ARE ALONG THE S
COAST DUE TO THE TROPICAL WAVE. THIS TROPICAL WAVE WILL MOVE
INTO THE W CARIBBEAN AWAY FROM HISPANIOLA MON REDUCING THE
CHANCE OF SHOWERS/THUNDERSTORMS BY TUE. AFTERNOON HEATING COULD
PRODUCE ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS
THROUGH THU.

ATLANTIC OCEAN...
AN UPPER TROUGH IS OVER THE NW ATLC THEN NARROWS AS IT CROSSES
NE FLORIDA TO ALONG THE N GULF COAST SUPPORTING A COLD FRONT
THAT AT 25/1500 UTC EXTENDS THROUGH 32N65W ALONG 30N73W TO
ACROSS FLORIDA NEAR DAYTONA BEACH INTO THE GULF OF MEXICO.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 29N BETWEEN
63W-74W...WITHIN 90 NM N OF THE FRONT E OF 73W...AND FROM 24N-TO
THE FRONT W OF 77W TO INLAND OVER FLORIDA. THE UPPER RIDGE OVER
THE GULF OF MEXICO EXTENDS ACROSS S FLORIDA INTO THE W ATLC S OF
30N TO 70W. A SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC
ANCHORED BY A SERIES OF HIGHS N OF THE DISCUSSION AREA. THE
SURFACE RIDGE WILL DRIFT SE TODAY AS THE WEAK COLD FRONT SINKS S
INTO THE W ATLC. THE FRONT WILL BECOME STATIONARY WHILE
GRADUALLY DISSIPATING FROM BERMUDA TO CENTRAL FLORIDA TONIGHT
AND MON. SURFACE RIDGE WILL THEN RE-ESTABLISH ALONG 29N/30N TUE
THROUGH THU.

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

$$
PAW


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