[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 072347
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON SEP 07 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...

TROPICAL STORM GRACE IS CENTERED NEAR 14.0N 37.5W AT 07/2100 UTC
OR ABOUT 790 NM W OF THE CAPE VERDE ISLANDS MOVING W AT 16 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED
WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. GRACE HAS LOST ALL
ASSOCIATED DEEP CONVECTION. PLEASE SEE LATEST NHC FORECAST/
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE
DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE OFF THE COAST OF AFRICA IS ALONG 20W FROM 9N-19N
MOVING W NEAR 10 KT OVER PAST 24 HOURS. THE 1012 MB LOW IS NO
LONGER DISCERNIBLE. SSMI TPW INDICATES THE WAVE IS EMBEDDED
WITHIN A HIGH AMPLITUDE SURGE OF DEEP MOISTURE. NO ASSOCIATED
DEEP CONVECTION.

TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS ALONG 46W/47W
FROM 7N-16N MOVING W NEAR 15 KT OVER THE PAST 24 HOURS. SSMI TPW
INDICATES THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE.
CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 11N-13N
BETWEEN 35W-48W.

TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 58W/59W FROM
8N-15N MOVING W-SW 10-15 KT OVER THE PAST 24 HOURS. SSMI TPW
INDICATED THE WAVE IS EMBEDDED WITHIN A SURGE OF MODERATE
MOISTURE. NO ASSOCIATED DEEP CONVECTION.

TROPICAL WAVE IN THE W CARIBBEAN IS ALONG 75W/76W FROM 11N-20N
MOVING W 15-20 KT OVER PAST 24 HOURS. SSMI TPW INDICATES THE
WAVE IS EMBEDDED WITHIN A WEAK SURGE OF DEEP MOISTURE. NO
ASSOCIATED DEEP CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM OVER AFRICA INTO THE E
TROPICAL ATLC NEAR 15N17W ALONG 12N22W TO 14N28W. THE ITCZ
BEGINS NEAR 10N48W AND CONTINUES ALONG 9N53W TO 10N58W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 12N-14N E
OF 18W TO INLAND OVER W AFRICA. CLUSTERS OF SCATTERED MODERATE
CONVECTION ARE FROM 8N-10N BETWEEN 37W-40W AND BETWEEN 47W-50W.

...DISCUSSION...

GULF OF MEXICO...
AN ELONGATED UPPER LOW IS OVER THE N GULF NEAR MOBILE ALABAMA
WITH A TROUGH AXIS EXTENDING S TO OVER THE E BAY OF CAMPECHE AND
DOMINATES THE GULF THIS EVENING. A WEAK 1013 MB LOW IS IN THE NE
GULF NEAR 28N84W. THE UPPER LOW IS GENERATING SCATTERED TO
NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS FROM 22N-27N BETWEEN
83W-92W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 24N E
OF 83W TO OVER FLORIDA. THIS IS LEAVING THE REMAINDER OF THE
GULF WITH CLEAR SKIES THIS EVENING. THE LOW WILL LIFT N WHILE
WEAKENING TO A SURFACE TROUGH ALONG THE FLORIDA PANHANDLE EARLY
TUE. ATLC SURFACE RIDGE WILL BEGIN TO BUILD W ACROSS THE AREA
ALONG 27N BEGINNING ON TUE.

CARIBBEAN SEA...
AN UPPER RIDGE COVERS THE CARIBBEAN W OF 73W AND IS ANCHORED IN
THE SW CARIBBEAN NEAR 11N79W. A SECOND UPPER RIDGE IS ANCHORED
IN THE W TROPICAL ATLC COVERING THE E CARIBBEAN E OF 67W. A
INVERTED SURFACE TROUGH IS BETWEEN THESE UPPER RIDGES EXTENDING
FROM COLOMBIA TO HISPANIOLA. AFTERNOON THUNDERSTORMS HAVE
DEVELOPED INLAND OVER CUBA AND JAMAICA. SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS ARE MOVING ACROSS THE WINDWARD ISLANDS S
OF 14N BETWEEN 60W-64W. THE MONSOON TROUGH EXTENDS ACROSS PANAMA
NEAR 9N81W TO 10N82W THEN ACROSS COSTA RICA NEAR 10N84W
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF LINE
FROM NICARAGUA NEAR 11N84W TO PANAMA NEAR 9N78W. THIS IS LEAVING
THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES THIS
EVENING. FRESH TO STRONG TRADE WINDS WILL PULSE IN THE S/CENTRAL
CARIBBEAN THROUGH TUE. CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS
THE W CARIBBEAN THROUGH LATE TUE. A SECOND TROPICAL WAVE
APPROACHING THE WINDWARD ISLANDS AND WILL MOVE INTO THE E
CARIBBEAN TUE.

...HISPANIOLA...
AFTERNOON SHOWERS/THUNDERSTORMS THAT DEVELOPED OVER N HAITI DUE
TO THE TROPICAL WAVE HAVE DISSIPATED LEAVING SKIES CLEAR ACROSS
THE ISLAND THIS EVENING. DAYTIME HEATING COUPLED WITH OROGRAPHIC
LIFTING COULD PRODUCE ISOLATED SHOWERS IN THE AFTERNOON/EVENING
HOURS THROUGH TUE.

ATLANTIC OCEAN...
AN UPPER RIDGE EXTENDS FROM HISPANIOLA NEAR 20N72W TO BEYOND
32N77W AND IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED TO
NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS FROM 27N-31N W OF 79W TO
INLAND OVER FLORIDA. A SURFACE TROUGH EXTENDS ACROSS THE W ATLC
FROM 29N71W TO N OF THE BAHAMA ISLANDS NEAR 27N79W WITH
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90
NM EITHER SIDE OF THE TROUGH AXIS. AN UPPER TROUGH EXTENDS OVER
THE CENTRAL ATLC SUPPORTING A STATIONARY FRONT THAT EXTENDS
THROUGH 32N38W ALONG 29N49W THROUGH A 1009 MB LOW NEAR 31N61W TO
30N66W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 29N
BETWEEN 56W-63W. A SURFACE TROUGH PRECEDES THE FRONT AND EXTENDS
FROM 31N38W TO 27N42W WITH ISOLATED SHOWERS AND POSSIBLE
ISOLATED THUNDERSTORMS N OF 26N TO THE FRONT BETWEEN 35W-43W. A
1018 MB HIGH IS LOCATED OVER THE W/CENTRAL ATLC NEAR 25N63W. A
WEAK SURFACE RIDGE COVERS THE E ATLC ANCHORED BY A 1022 MB HIGH
N OF THE AREA AND A 1020 MB HIGH NEAR 28N28W. THE W ATLC SURFACE
TROUGH WILL DRIFT W TO ALONG THE E FLORIDA COAST THROUGH TUE AND
DISSIPATE.

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

$$
PAW
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