[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261147
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU SEP 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 19N42W TO 10N40W MOVING W NEAR 15 KT.
WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON
THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/STRONG
CONVECTION IS WITHIN 200 NM E OF THE WAVE S OF 15N. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 300 NM W OF THE
WAVE.

TROPICAL WAVE EXTENDS FROM 17N53W TO 9N50W MOVING W NEAR
15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF MODERATE TO DEEP
MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY.
THIS IS WAVE IS BENEATH AN UPPER LOW ENHANCING CLUSTERS OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 300 NM
E OF THE WAVE.

TROPICAL WAVE APPROACHING THE LEEWARD ISLANDS EXTENDS FROM
22N60W TO NEAR MARTINIQUE MOVING W NEAR 15 KT. WAVE IS EMBEDDED
WITHIN DRY AIR AS DEPICTED ON THE TOTAL PRECIPITABLE WATER
IMAGERY. ISOLATED SHOWERS ARE POSSIBLE WITHIN 45 NM W OF THE
WAVE INCLUDING THE LEEWARD ISLANDS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 14N17W AND CONTINUES ALONG 8N22W TO 6N28W WHERE THE
ITCZ BEGINS AND CONTINUES ALONG 6N32W 9N39W TO 8N43W. ANY
CONVECTION IS ASSOCIATED WITH THE TWO TROPICAL WAVES.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH EXTENDS FROM AN UPPER LOW OVER VIRGINIA ACROSS
NORTH CAROLINA THROUGH THE W ATLC THEN ACROSS FLORIDA NEAR CEDAR
KEY THEN ALONG 26N90W TO 25N96W. A COMPLEX SYSTEM IS ACROSS THE
N GULF WITH A LOW LEVEL SURFACE TROUGH EXTENDING FROM CEDAR KEY
FLORIDA ALONG 28N86W TO A WEAK 1009 MB NEAR 27N90W TO 26N94W.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE POSSIBLE WITHIN 45
NM OF THE SURFACE TROUGH E OF THE LOW. AN UPPER TROUGH IN THE
CENTRAL ATLC IS SUPPORTING A STATIONARY FRONT THAT CROSSES N
FLORIDA THROUGH JACKSONVILLE AND THE 1007 MB LOW NEAR 30N83W TO
A 1009 MB LOW NEAR 30N87W WHERE THE FRONT BECOMES COLD AND
CONTINUES ALONG 29N90W TO 27N93W. THIS FRONTAL BOUNDARY IS WELL
DEFINED IN DEW POINTS ONLY. AN UPPER RIDGE EXTENDS OVER S MEXICO
TO THE YUCATAN PENINSULA PROVIDING DIFFLUNCE ALOFT TO GENERATE
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 22N
INTO THE BAY OF CAMPECHE W OF 90W.

CARIBBEAN SEA...
AN UPPER RIDGE ANCHORED IN THE W ATLC COVERS THE FAR NW
CARIBBEAN N OF LINE FROM CENTRAL CUBA TO BELIZE. AN INVERTED
UPPER TROUGH AXIS EXTENDS FROM ACROSS COSTA RICA NEAR THE
NICARAGUA BORDER TO THE WINDWARD PASSAGE ENHANCING THE ACTIVITY
ASSOCIATED WITH THE MONSOON TROUGH AND GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS OVER THE GULF OF GONAVE AND SW
HAITI FROM 17N-20N BETWEEN 73W-76W. THE MONSOON TROUGH EXTENDS
FROM COLOMBIA NEAR 10N74W ALONG 11N78W TO ACROSS COSTA RICA NEAR
10N83W GENERATING SCATTERED TO NUMEROUS SHOWERS WITH SCATTERED
THUNDERSTORMS S OF 12N BETWEEN 73W-80W TO INLAND OVER COLOMBIA
AND PANAMA. EASTERLY TRADE WINDS WILL PREVAIL THROUGH MON.
TROPICAL WAVE APPROACHING THE LEEWARD ISLANDS WILL ENTER THE E
CARIBBEAN TODAY AND MOVE W ACROSS CARIBBEAN WITH LITTLE INCREASE
IN WIND OR SEAS.

HISPANIOLA...
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER SW HAITI AND
THE GULF OF GONAVE WHILE THE SKIES REMAIN MOSTLY CLEAR ACROSS
THE REMAINDER OF THE ISLAND THIS MORNING. EASTERLY FLOW ALOFT
AND AT THE SURFACE WILL CONTINUE THROUGH FRI. THE UPPER RIDGE
RESPONSIBLE FOR THE E FLOW ALOFT WILL THEN RETREAT E AS AN UPPER
RIDGE ANCHORED TO THE S CHANGES THE UPPER FLOW TO WESTERLY. THE
A WEAK TROPICAL WAVE WILL MOVE ACROSS THE ISLAND LATE TODAY
THROUGH SAT. THIS WILL POSSIBLY INCREASE OR INTENSIFY AFTERNOON
SHOWERS/THUNDERSTORMS.

ATLANTIC OCEAN...
THE UPPER RIDGE IS ANCHORED OVER THE W ATLC NEAR 25N71W
EXTENDING A RIDGE AXIS SW TO OVER W CUBA AND NE TO BEYOND
32N57W. THIS UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO
GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 26N
BETWEEN 68W-78W. AN UPPER TROUGH N OF 30N OVER THE CENTRAL ATLC
IS SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N56W
ALONG 28N64W TO 29N68W WHERE IT BECOMES A WARM FRONT TO A 1006
MB LOW NEAR 31N71W THEN CONTINUES AS STATIONARY TO A 1007 MB LOW
NEAR 30N77W THEN ACROSS FLORIDA NEAR JACKSONVILLE. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM E OF THE COLD
FRONT E OF 61W. THE REMAINDER OF THE ATLC IS DOMINATED BY A
SURFACE RIDGE ANCHORED BY A 1019 MB HIGH NEAR 25N39W. THE 1006
MB SURFACE LOW WILL MOVE E-NE S OF BERMUDA TODAY DRAGGING
FRONTAL BOUNDARY SE ACROSS W ATLC N OF 27N. THE 1007 MB SURFACE
LOW IS EXPECTED TO INTENSIFY THU AND MOVE SE TO 29N74W LATE FRI
NIGHT THEN LIFT NE WITH COLD FRONT RACING SE ACROSS BAHAMAS AND
FLORIDA LATE THU NIGHT REACHING CENTRAL BAHAMAS AND SE FLORIDA
LATE FRI NIGHT OR SAT BEFORE STALLING AND BECOMING DIFFUSE SAT
AND SUN.

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

$$
PAW


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