[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 112351
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI OCT 11 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...
A LARGE LOW PRESSURE AREA IS LOCATED ABOUT 955 NM W-SW OF THE
CAPE VERDE ISLANDS IS ANALYZED AS A 1008 MB LOW CENTERED NEAR
12N38W. THERE IS POTENTIAL FOR A TROPICAL DEPRESSION TO FORM IN
THIS AREA DURING THE NEXT DAY OR SO BEFORE UPPER LEVEL WINDS
BECOME LESS CONDUCIVE FOR TROPICAL CYCLONE FORMATION. THIS
SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS IT MOVES W TO W-NW AT 9 TO 13 KT. NUMEROUS
STRONG CONVECTION IS WITHIN 90 NM SE OF THE CENTER WITH
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION COVERING THE
REMAINDER OF THE AREA FROM 7N-15N BETWEEN 34W-39W.

...TROPICAL WAVES...

TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS FROM 23N57W TO
11N60W MOVING W 15-20 KT. WAVE IS BENEATH THE WESTERN PORTION OF
AN UPPER TROUGH WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
FROM 16N-24N BETWEEN 51W-58W.

TROPICAL WAVE IN THE W CARIBBEAN EXTENDS FROM 18N82W TO 11N83W
MOVING W NEAR 10 KT. WAVE IS AT THE BASE OF AN UPPER TROUGH WITH
NO ASSOCIATED DEEP CONVECTION.

...THE ITCZ/THE MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 14N17W AND CONTINUES ALONG 7N26W THROUGH THE 1008 MB
LOW IN THE SPECIAL FEATURES NEAR 12N38W TO 8N45W WHERE THE ITCZ
BEGINS AND CONTINUES ALONG 8N51W TO 10N60W. SCATTERED MODERATE/
STRONG CONVECTION IS FROM 9N-11N BETWEEN 38W-42W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS MOVING ACROSS W AFRICA TO
ALONG THE IMMEDIATE COAST FROM GUINEA BISSAU TO DAKAR SENEGAL.
CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 10N-15N
BETWEEN 42W-53W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER RIDGE DOMINATES THE GULF ANCHORED OVER MEXICO NEAR
MEXICO CITY. WATER VAPOR SATELLITE IMAGERY SHOWERS DRY STABLE
AIR ALOFT COVERING THE GULF. A SURFACE RIDGE COVERS THE GULF
ANCHORED BY A 1020 MB HIGH OVER N ALABAMA GIVING THE NW GULF
RETURN SURFACE FLOW. THIS SURFACE FLOW IS GENERATING ISOLATED
SHOWERS AND A POSSIBLE ISOLATED THUNDERSTORM N OF 25N W OF 92W.
THE REMAINDER OF THE GULF IS UNDER CLEAR SKIES THIS EVENING.
SURFACE RIDGE WILL GRADUALLY MOVE E OVER THE NEXT FEW DAYS
ALLOWING FOR SOUTHERLY RETURN FLOW TO CONTINUE OVER THE
NW GULF THROUGH WED.

CARIBBEAN SEA...
THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS OVER THE W
CARIBBEAN W OF 83W. ISOLATED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORM ARE IN THE GULF OF HONDURAS S OF 18N W OF 83W. AN
UPPER TROUGH OVER THE W ATLC EXTENDS ACROSS CENTRAL CUBA TO 11N
BETWEEN 75W-83W. A SURFACE TROUGH EXTENDS FROM 17N75W THROUGH
THE WINDWARD PASSAGE/E CUBA NEAR 20N74W TO THE TURKS AND CAICOS
NEAR 22N73W. SCATTERED TO HEAVY SHOWERS/SCATTERED THUNDERSTORMS
ARE OVER JAMAICA...W CUBA...AND HISPANIOLA N OF 18N BETWEEN 71W-
80W. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 9N76W TO
ACROSS COSTA RICA NEAR 10N83W AND COUPLED WITH THE UPPER TROUGH
ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N
W OF 79W AND FROM 12N-15N W OF 83W TO INLAND OVER CENTRAL
AMERICA. AN UPPER RIDGE COVERS THE REMAINDER OF THE CARIBBEAN E
OF 75W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT
THE CENTRAL CARIBBEAN N OF 12N TO ACROSS THE GREATER ANTILLES
BETWEEN 66W-73W. W CARIBBEAN TROPICAL WAVE WILL MOVE INLAND
CENTRAL AMERICA SAT. W TROPICAL ATLC TROPICAL WAVE WILL ENTER
THE E CARIBBEAN SAT THEN MOVE ACROSS THE CENTRAL CARIBBEAN
THROUGH SUN NIGHT AND THE W CARIBBEAN MON.

HISPANIOLA...
SCATTERED TO HEAVY SHOWERS/SCATTERED THUNDERSTORMS ARE CURRENTLY
ACROSS MOST OF HAITI AND THE W PORTION OF THE DOMINICAN REPUBLIC
WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOTTING THE
REMAINDER OF THE ISLAND. THIS ACTIVITY IS DUE TO THE UPPER
TROUGH OVER THE CENTRAL CARIBBEAN AND THE SURFACE TROUGH MOVING
THROUGH THE WINDWARD PASSAGE. THE UPPER TROUGH WILL CONTINUE TO
GIVE HISPANIOLA SOUTHERLY FLOW ALOFT THROUGH THE WEEKEND AND IS
ADVECTING MOISTURE OVER THE ISLAND. SHOWERS/THUNDERSTORMS WILL
CONTINUE THROUGH THE WEEKEND AS A TROPICAL WAVE MOVES FROM THE W
TROPICAL ATLC INTO THE E CARIBBEAN SAT AND ACROSS HISPANIOLA SUN
INTO MON.

ATLANTIC OCEAN...
AN UPPER TROUGH COVERS THE FAR W ATLC W OF 73W TO THE FLORIDA
PENINSULA AND CONTINUES S INTO THE CENTRAL CARIBBEAN SUPPORTING
A FRONTAL SYSTEM THAT EXTENDS A STATIONARY FRONT INTO THE W ATLC
NEAR 32N69W TO 26N74W. AN UPPER RIDGE IS TO THE E ANCHORED NEAR
27N59W COVERING THE AREA N OF 20N BETWEEN 47W-73W AND IS
PROVIDING DIFFLUNCE ALOFT TO GENERATE CLUSTERS OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS W OF LINE FROM SAN JUAN PUERTO
RICO TO 31N58W WESTWARD TO THE FRONT AND S OF 28N BETWEEN 73W-
79W. ANOTHER UPPER TROUGH EXTENDS INTO THE E/CENTRAL ATLC
THROUGH 32N33W 22N43W THEN S OF THE ABOVE UPPER RIDGE TO 17N60W
SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N32W ALONG
29N35W 29N42W TO 31N47W WHERE IT BECOMES A STATIONARY FRONT.
ISOLATED SHOWERS ARE POSSIBLE IMMEDIATELY ALONG THE FRONT. A
SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC BASIN W OF 60W
ANCHORED BY A 1024 MB HIGH WELL N OF THE DISCUSSION AREA AND A
WEAK 1019 MB HIGH NEAR 32N21W. W ATLC STATIONARY FRONT WILL
WEAKEN TO A TROUGH TONIGHT INTO SAT THEN SLOWLY MOVE EASTWARD
THROUGH SUN.

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

$$
PAW


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