[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 222359
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT AUG 22 2015

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...
HURRICANE DANNY HAS BEEN DOWNGRADED TO TROPICAL STORM AT 23/0000
UTC. TROPICAL STORM DANNY IS CENTERED NEAR 15.6N 54.1W AT
23/0000 UTC OR ABOUT 450 NM E-SE OF THE LEEWARD ISLANDS MOVING W-
NW AT 14 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB.
MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90 NM OF
THE CENTER OVER THE NE QUADRANT. PLEASE SEE THE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC
FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS ALONG 29W FROM 10N-
17N WITH A 1010 MB LOW NEAR 13N29W MOVING W NEAR 20 KT OVER THE
PAST 24 HOURS. SSMI TPW INDICATES THE WAVE IS EMBEDDED WITHIN A
SURGE OF DEEP MOISTURE THAT COVERS THE AREA FROM THE CAPE VERDE
ISLANDS TO 36W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE
FROM 11N TO 15N BETWEEN 27W AND 31W.

TROPICAL WAVE IN THE W CARIBBEAN EXTENDS ALONG 84W S OF 17N TO
INLAND OVER CENTRAL AMERICA MOVING W-SW 15-20 KT OVER THE PAST
24 HOURS. SSMI TPW INDICATES THE WAVE IS EMBEDDED WITHIN A
SURGE OF DEEP MOISTURE THAT COVERS THE CARIBBEAN S OF 15N W OF
67W TO OVER CENTRAL AMERICA. CLUSTERS OF SCATTERED MODERATE/
ISOLATED STRONG CONVECTION ARE INLAND AND WITHIN 60 NM ALONG THE
COAST OF NICARAGUA AND COSTA RICA BETWEEN 10N-14N. THIS ACTIVITY
IS BEING ENHANCED BY UPPER LEVEL FEATURES.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E
TROPICAL ATLC NEAR 21N16W ALONG 14N24W THROUGH THE 1010 MB LOW
CENTERED NEAR 13N29W ALONG 9N32W TO 7N38W WHERE IT IS DISRUPTED
BY TROPICAL STORM DANNY. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 17N-19N BETWEEN THE COAST OF AFRICA AND 20W.
CLUSTERS OF SIMILAR CONVECTION ARE FROM 7N-14N BETWEEN 14W-24W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LOW IS CENTERED OVER THE SW GULF NEAR 21N95W WHILE AN
UPPER LEVEL RIDGE IS ANCHORED IN THE W ATLC COVERING THE E GULF.
THE UPPER LOW IS GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS FROM 23N-27W BETWEEN 84W-90W. A WEAK SURFACE
TROUGH IS IN THE SW GULF FROM 24N98W TO 20N96W WITH ISOLATED
THUNDERSTORMS WITHIN 45 NM E OF THE SURFACE TROUGH. A SURFACE
RIDGE EXTENDS FROM THE E CONUS OVER THE GULF WITH A 1018 MB HIGH
NEAR THE MISSISSIPPI DELTA OF LOUISIANA. WEAK HIGH PRESSURE WILL
PREVAIL ACROSS THE N GULF THROUGH MON THEN SHIFT S ON MON NIGHT
AS A WEAK TROUGH STALLS OVER THE NE GULF.

CARIBBEAN SEA...
AN UPPER RIDGE COVERS THE SW CARIBBEAN S OF 19N W OF 76W TO OVER
CENTRAL AMERICA. AN ELONGATED UPPER LOW EXTENDS FROM THE CENTRAL
ATLC ACROSS THE VIRGIN ISLANDS TO 16N68W THEN W-NW TO THE CAYMAN
ISLANDS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 12N-
14N BETWEEN 80W-83W. AFTERNOON THUNDERSTORMS HAVE DEVELOPED
INLAND OVER PUERTO RICO...HISPANIOLA...JAMAICA...AND CUBA. THIS
IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR
SKIES THIS EVENING. CARIBBEAN TROPICAL WAVE WILL MOVE THROUGH
THE GULF OF HONDURAS TONIGHT THROUGH EARLY SUN. TROPICAL STORM
DANNY WILL PASS OVER THE N LEEWARD ISLANDS MON EVENING. FRESH TO
STRONG TRADES WILL CONTINUE TO PULSE ALONG THE NW COAST OF S
AMERICA THROUGH EARLY MON.

...HISPANIOLA...
AFTERNOON THUNDERSTORMS HAVE DEVELOPED INLAND OVER THE CENTRAL
PORTION OF THE ISLAND THIS EVENING. LINGERING MOISTURE COUPLED
WITH THE TRADE WINDS AND DAYTIME HEATING COULD BRING AFTERNOON
THUNDERSTORMS TO THE ISLAND THROUGH MON.

ATLANTIC OCEAN...
THE PRIMARY CONCERN THIS EVENING REMAINS TROPICAL STORM DANNY IN
THE W TROPICAL ATLC. SEE SPECIAL FEATURES ABOVE. AN UPPER RIDGE
IS ANCHORED IN THE W ATLC NEAR 29N79W COVERING THE AREA W OF 70W
AND EXTENDS INTO THE GULF OF MEXICO. A SMALL UPPER LOW IS
CENTERED NEAR 31N66W SUPPORTING A SURFACE LOW N OF THE AREA WITH
A SURFACE TROUGH EXTENDING THROUGH 32N63W ALONG 27N64W TO
24N71W. SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS
ARE WITHIN 90 NM E OF THE SURFACE TROUGH N OF 25N. A SECOND
UPPER LOW IS IN THE CENTRAL ATLC NEAR 32N48W SUPPORTING A
SURFACE TROUGH THAT EXTENDS INTO THE AREA NEAR 32N46W ALONG
30N46W TO 28N49W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE
BEING GENERATE BY THE UPPER LOW N OF 30N BETWEEN 45W-49W. THE
CENTRAL AND E ATLC ARE MOSTLY DOMINATE BY A SURFACE RIDGE THAT
IS ANCHORED BY A 1029 MB HIGH W OF THE AZORES. THE W ATLC
SURFACE TROUGH WILL SHIFT W TO ALONG 74W ON SUN REACHING ALONG
76W ON MON BEFORE DISSIPATING ALONG 79W ON TUE. TROPICAL STORM
DANNY WILL PASS OVER THE N LEEWARD ISLANDS MON EVENING.

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

$$
PAW
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