weather.gov     
National Weather Service

Tropical Weather Discussion
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to SR-SRH.Webmaster@noaa.gov with any concerns.


Current Version
Previous Version:    01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  
[Printable]
152
AXNT20 KNHC 200005
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE AUG 19 2014

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
2345 UTC.

...SPECIAL FEATURES...

A TROPICAL WAVE IS ABOUT 300 NM EAST OF THE LESSER ANTILLES
ASSOCIATED WITH A 1009 MB LOW EMBEDDED IN THE MONSOON TROUGH.
HIGH DEEP LAYER MOISTURE ALONG WITH A MIDDLE TO UPPER LEVEL
DIFFLUENT ENVIRONMENT IS SUPPORTING SCATTERED MODERATE
CONVECTION AND ISOLATED TSTMS FROM 7N-13N BETWEEN 48W-55W. DRY
SAHARAN AIR AND DUST ARE PRESENT IN THE NORTHERN WAVE
ENVIRONMENT...WHICH IS HINDERING CONVECTION N OF 13N.
ENVIRONMENTAL CONDITIONS ARE FORECAST TO BE MORE CONDUCIVE FOR
GRADUAL DEVELOPMENT OF THIS SYSTEM DURING THE NEXT FEW DAYS AS
IT APPROACHES THE LESSER ANTILLES AND MOVES INTO THE CARIBBEAN
SEA. MEDIUM CHANCE OF DEVELOPMENT IS EXPECTED THROUGH 48 HOURS.
SEE LATEST NHC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS
MIATWOAT/ABNT20 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE CAME OFF THE WESTERN AFRICAN COAST EARLIER THIS
AFTERNOON WITH A WELL-DEFINED AXIS ALONG 18W. MOSTLY MEDIUM DEEP
LAYER MOISTURE IS ASSOCIATED WITH THIS SYSTEM WHICH ALONG UPPER-
LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION AND
ISOLATED TSTMS FROM 13N-17N E OF 20W. SAHARAN DRY AIR ENGULFS
THE NORTHERN PORTION OF THE WAVE...THUS DEVOIDING OF CONVECTION
THE REGION OF THE WAVE N OF 17N.

A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AXIS EXTENDING
FROM 24N39W TO 12N39W...MOVING W AT 15 KT. NORTH OF 14N THE WAVE
IS BEING AFFECTED BY THE DRY SAHARAN AIR LAYER WHICH IS
HINDERING CONVECTION IN THAT PORTION OF THE WAVE. SCATTERED
MODERATE CONVECTION IS CONFINED WITHIN 200 NM SOUTHWEST OF THE
WAVE AXIS FROM 12N-14N BETWEEN 39W-42W.

A TROPICAL WAVE IS NEAR 51W. SEE THE SPECIAL FEATURES SECTION OF
THE DISCUSSION.

A TROPICAL WAVE IS MOVING ACROSS THE YUCATAN
PENINSULA...GUATEMALA AND THE EASTERN PACIFIC WATERS WITH AXIS
EXTENDING FROM 22N88W TO 8N92W...MOVING W AT 15-20 KT. SCATTERED
HEAVY SHOWERS AND THUNDERSTORMS ARE MAINLY INLAND WITH SOME OF
THE CONVECTION ENTERING THE EASTERN BAY OF CAMPECHE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH BEGINS WEST OF A TROPICAL WAVE NEAR 14N21W AND
CONTINUES ALONG 13N39W TO A 1009 MB LOW NEAR 9N51W TO 8N61W.
BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE
SECTION...ISOLATED MODERATE CONVECTION IS FROM 10N-14N BETWEEN
24W-35W.

...DISCUSSION...

GULF OF MEXICO...

WEAK SURFACE RIDGING ACROSS NORTHEASTERN GULF OF MEXICO IS
SUPPORTING MAINLY 5 TO 10 KT ANTICYCLONIC WINDS WITH THE
EXCEPTION OF THE EASTERN BAY OF CAMPECHE WHERE 15 KT WINDS ARE
NOTED IN A SCATTEROMETER PASS AHEAD OF A TROPICAL WAVE TO MOVE
INTO THE SW GULF LATER TONIGHT. THE NORTHERN PORTION OF THIS
TROPICAL WAVE IS ALREADY ENHANCING SCATTERED HEAVY SHOWERS AND
THUNDERSTORMS ACROSS THE YUCATAN PENINSULA WHICH ARE BEGINNING
TO SPREAD INTO THE EASTERN BAY OF CAMPECHE. WEAK UPPER LEVEL
DIFFLUENCE IS SUPPORTING ISOLATED MODERATE CONVECTION ACROSS THE
WEST CENTRAL GULF FROM 24N-26N BETWEEN 90W-93W. ADDITIONAL
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE BAY OF
CAMPECHE THROUGH WED MORNING AS THE TROPICAL WAVE CONTINUES TO
MOVE WESTWARD. SURFACE RIDGING WILL DOMINATE ELSEWHERE WITHIN
THE NEXT THREE DAYS.

CARIBBEAN SEA...

MAINLY 10 TO 25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA. BASED
ON A SCATTEROMETER PASS...THE STRONGEST WINDS ARE OCCURRING
ACROSS THE SOUTHWESTERN BASIN S OF 15N. AN UPPER-LEVEL
DIFFLUENCE PATTERN ALONG WITH DEEP LAYER MOISTURE SUPPORT
SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS S OF 15N W OF
77W...INCLUDING NICARAGUA...COSTA RICA AND PANAMA. AN UPPER
LEVEL LOW IS CENTERED NE OF THE LEEWARD ISLANDS WHICH ALONG A
PATCH OF LOW-LEVEL MODERATE MOISTURE SUPPORT ISOLATED TO
SCATTERED SHOWERS ACROSS PUERTO RICO AND THE VIRGIN ISLANDS. THE
UPPER-LEVEL LOW NE OF THE LEEWARD ISLANDS ALONG WITH ANOTHER
UPPER-LEVEL LOW ON THE NW CARIBBEAN IS GENERATING A DIFFLUENT
ENVIRONMENT OVER HISPANIOLA. THIS ENVIRONMENT ALOFT ALONG WITH
MODERATE/HIGH DEEP LAYER MOISTURE SUPPORT SCATTERED HEAVY
SHOWERS AND TSTMS OVER WESTERN DOMINICAN REPUBLIC...HAITI AND
ADJACENT WATERS. ELSEWHERE...FAIR WEATHER DOMINATE BEING
INFLUENCED BY A DRY SAHARAN AIRMASS MOVING ACROSS THE REGION.
DUST AND HAZE ARE BEING REPORTED BY SEVERAL LOCATIONS ACROSS THE
CENTRAL AND EASTERN BASIN. THE NEXT TROPICAL WAVE IS FORECAST TO
ENTER THE EASTERN CARIBBEAN BY FRI MORNING.

...HISPANIOLA...

AN UPPER-LEVEL LOW CENTERED NE OF THE LEEWARD ISLANDS ALONG WITH
ANOTHER UPPER-LEVEL LOW ON THE NW CARIBBEAN IS GENERATING A
DIFFLUENT ENVIRONMENT OVER HISPANIOLA. THIS ENVIRONMENT ALOFT
ALONG WITH MODERATE/HIGH DEEP LAYER MOISTURE SUPPORT SCATTERED
HEAVY SHOWERS AND TSTMS OVER WESTERN DOMINICAN REPUBLIC...HAITI
AND ADJACENT WATERS. SHOWERS ARE EXPECTED TO CONTINUE DURING THE
NEXT 24 HOURS.

ATLANTIC OCEAN...

MODERATE LOW-LEVEL MOISTURE ASSOCIATED WITH THE PASSAGE OF THE
TROPICAL WAVE CURRENTLY MOVING ACROSS THE YUCATAN  PENINSULA IS
ENHANCING SCATTERED/ISOLATED SHOWERS ON THE FLORIDA STRAITS...AS
WELL AS THE NORTHERN AND CENTRAL BAHAMAS. OTHERWISE...BESIDES
THE TROPICAL WAVES ALREADY DISCUSSED...THE REMAINDER BASIN IS UNDER
THE INFLUENCE OF SURFACE RIDGING BEING ANCHORED BY A 1024 MB
HIGH NEAR 35N34W AND A 1019 MB HIGH NEAR 26N66W.

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

$$
NAR/ASL




U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE