[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231805
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI AUG 23 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.

...TROPICAL WAVES...
A TROPICAL WAVE ASSOCIATED WITH A SURFACE LOW PRESSURE CAME OFF
THE AFRICAN COAST THIS MORNING. ITS AXIS EXTENDS FROM 17N19W TO
A 1011 MB LOW EMBEDDED IN THE MONSOON TROUGH NEAR 10N20W TO
07N21W. THE WAVE IS EMBEDDED IN A HIGH MOIST ENVIRONMENT WHICH
ALONG UPPER LEVEL DIFFLUENCE SUPPORTS SCATTERED MODERATE
CONVECTION FROM 07N-14N BETWEEN 18W-31W.

A TROPICAL WAVE IS WEST OF THE ITCZ AXIS AND ABOUT 450 NM SE OF
THE LESSER ANTILLES. ITS AXIS EXTENDS FROM 16N46W TO 07N59W AND
IS MOVING W-NW NEAR 15 KT. THE WAVE IS EMBEDDED IN A MODERATE
MOIST ENVIRONMENT IN THE LOWER LEVELS AND THERE IS NO CONVECTION
ASSOCIATED WITH IT.

A TROPICAL WAVE IS OVER THE FAR WESTERN CARIBBEAN WITH AXIS
EXTENDING FROM 23N86W IN THE YUCATAN CHANNEL TO 12N86W IN
NICARAGUA. THIS WAVE HAS BEEN MOVING WESTWARD NEAR 5 KT AND IT
IS FOUND IN A HIGH MOIST ENVIRONMENT. AN UPPER LEVEL LOW
CENTERED N OF THE YUCATAN PENINSULA AS WELL AS UPPER LEVEL
DIFFLUENCE OVER THE WESTERN CARIBBEAN SUPPORT SCATTERED MODERATE
CONVECTION AND TSTMS FROM 12N-22N BETWEEN 80W-89W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR
16N16W TO A 1011 MB LOW NEAR 10N20W TO 11N28W 11N35W 11N42W. THE
ITCZ AXIS EXTENDS FROM 11N42W TO 12N49W. BESIDES THE CONVECTION
ASSOCIATED WITH THE TROPICAL WAVES ALREADY DISCUSSED...SCATTERED
MODERATE CONVECTION IS FROM 07N-14N BETWEEN 36W-48W.

...DISCUSSION...

GULF OF MEXICO...
SURFACE TROUGHINESS DOMINATES THE GULF WATERS WITH WINDS RANGING
FROM 5-15 KT. AN UPPER LEVEL TROUGH EXTENDING SW ALONG THE
EASTERN CONUS TO LOUISIANA SUPPORTS A SURFACE TROUGH FROM
SOUTHERN ALABAMA NEAR 30N88W TO 24N92W. NUMEROUS MODERATE
CONVECTION AND TSTMS ASSOCIATED WITH THIS TROUGH ARE N OF 26N E
OF 89W. SCATTERED MODERATE CONVECTION IS OVER THE WESTERN GULF S
OF 26N W OF 96W. ISOLATED SHOWERS AND TSTMS ARE OVER THE YUCATAN
CHANNEL ASSOCIATED WITH A TROPICAL WAVE THAT IS EXPECTED TO MOVE
ACROSS THE PENINSULA LATER TODAY.

THE TROUGH OVER THE CENTRAL GULF WILL CONTINUE TO MOVE W-NW AND
IS EXPECTED TO MOVE INLAND FROM SOUTHERN TEXAS TO NEAR TAMPICO
MEXICO BY EARLY SUNDAY. THE TROPICAL WAVE WILL MOVE ACROSS THE
YUCATAN PENINSULA TONIGHT...IT WILL BE OVER THE BAY OF CAMPECHE
ON SUNDAY AND IS EXPECTED TO ENTER EASTERN MEXICO EARLY ON
MONDAY. RAINSHOWERS ARE EXPECTED OVER THE CENTRAL AND
WESTERN GULF THROUGHOUT THIS PERIOD.

CARIBBEAN SEA...
A TROPICAL WAVE IS EMBEDDED IN A HIGH MOIST ENVIRONMENT OVER THE
FAR WESTERN CARIBBEAN WITH AXIS EXTENDING FROM 23N86W IN THE
YUCATAN CHANNEL TO 12N86W IN NICARAGUA. AN UPPER LEVEL LOW
CENTERED N OF THE YUCATAN PENINSULA AND DIFFLUENCE OVER THE
WESTERN CARIBBEAN SUPPORT SCATTERED MODERATE CONVECTION AND
TSTMS FROM 12N-22N BETWEEN 80W-89W. SIMILAR CONVECTION
ASSOCIATED WITH THE WAVE IS WITHIN SOUTHERN CUBA AND JAMAICA
BETWEEN 75W-78W. OVER THE SOUTHERN CARIBBEAN...ISOLATED SHOWERS
ASSOCIATED WITH THE MONSOON TROUGH ARE S OF 11N BETWEEN 78W-83W.
AN ELONGATED UPPER LEVEL LOW CENTERED OVER THE MONA PASSAGE
EXTENDS ACROSS THE EASTER CARIBBEAN SUPPORTING A SURFACE TROUGH
ALONG 20N63W TO 18N66W 14N68W. THIS SYSTEM OR THE REMNANTS OF
ERIN IS GENERATING RAINSHOWERS AND TSTMS AS IT MOVES ACROSS
PUERTO RICO THIS AFTERNOON. THESE SHOWERS EXTENDS 90 NM FROM THE
SOUTHERN COAST OF THE ISLAND.

PRECIPITATION ACTIVITY IS EXPECTED TO CONTINUE ACROSS PUERTO
RICO UNTIL EARLY THIS EVENING. WEATHER CONDITIONS IMPROVE FOR
SATURDAY AND SUNDAY AS A DRY AIRMASS IS EXPECTED TO ENTER THE
EASTERN CARIBBEAN. THE TROPICAL WAVE OVER THE WESTERN BASIN IS
EXPECTED TO CROSS NORTHERN CENTRAL AMERICA AND THE YUCATAN
PENINSULA TONIGHT.

HISPANIOLA...
FAIR WEATHER IS ACROSS THE ISLAND THIS AFTERNOON BEING SUPPORTED
BY LOW MOISTURE IN THE LOWER LEVELS AND DRY AIR SUBSIDENCE FROM
THE MIDDLE LEVELS. RAINSHOWERS WILL DEVELOP LATE IN THE
AFTERNOON/EARLY EVENING ASSOCIATED WITH THE SURFACE
TROUGH/REMNANTS OF ERIN CURRENTLY MOVING ACROSS PUERTO RICO.

ATLANTIC OCEAN...
A WEAK UPPER LEVEL RIDGE CENTERED OVER THE NE GULF WHICH EXTENDS
INTO THE SW N ATLC SUPPORTS A 1017 MB HIGH NEAR 30N72W. FURTHER
EAST A SURFACE TROUGH EXTENDS FROM 29N56W TO 25N61W WITH NO
CONVECTION ASSOCIATED WITH IT. IN THE CENTRAL TROPICAL ATLC...A
1014 MB LOW IS ANALIZED NEAR 15N37W WITH NO CONVECTION
ASSOCIATED WITH IT. THIS LACK OF CONVECTION IS ASSOCIATED IN
PART TO SAHARAN DRY AIR SPREADIING OVER ITS ENVIRONMENT. OTHER
THAN THAT...BESIDES THE TROPICAL WAVES ALREADY
DISCUSSED...SURFACE RIDGING AND FAIR WEATHER DOMINATE THE
REMAINDER BASIN.

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

$$
NR


This weather bulletin was brought to you by:
www.nashvilleweather.net