[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 212354
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON SEP 21 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 IDA IS CENTERED NEAR 21.2N 48.8W AT 21/2100 UTC
OR ABOUT 825 NM E-NE OF THE NORTHERN LEEWARD ISLANDS MOVING N-NW
AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. MAXIMUM
SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 18N-21N BETWEEN 43W-48W.
PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS ALONG 20W/21W FROM 7N-17N MOVING W 10-15
KT OF THE PAST 24 HOURS. SSMI TPW INDICATES THE WAVE IS EMBEDDED
WITHIN A SURGE OF DEEP MOISTURE WITH NO ASSOCIATED DEEP
CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 15N17W TO E OF THE TROPICAL WAVE NEAR 12N20W THEN
RESUMES W OF THE WAVE NEAR 10N22W ALONG 8N25W TO 7N35W WHERE THE
ITCZ BEGINS AND CONTINUES ALONG 8N42W TO 9N49W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60/75 NM OF THE
MONSOON TROUGH BETWEEN 27W-30W. SCATTERED MODERATE CONVECTION IS
WITHIN 120 NM N OF ITCZ BETWEEN 38W-41W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH EXTENDS OVER THE MISSISSIPPI VALLEY INTO THE N
GULF OF MEXICO SUPPORTING A COLD FRONT THAT EXTENDS ACROSS THE
FLORIDA PANHANDLE NEAR PANAMA CITY ALONG 29N90W TO INLAND OVER
TEXAS JUST S OF GALVESTON. AN UPPER RIDGE EXTENDS FROM CENTRAL
MEXICO INTO THE GULF JUST N OF TAMPICO ALONG 22N89W TO THE
FLORIDA PENINSULA NEAR FORT MYERS. AT THE SURFACE IS A TROUGH
THAT EXTENDS FROM 27N83W THROUGH A WEAK 1012 MB LOW NEAR 26N87W
TO 25N93W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN
120 NM N OF THE SURFACE TROUGH BETWEEN 85W-88W AND ISOLATED
SHOWERS WITHIN 90 NM OF THE REMAINDER OF THE SURFACE TROUGH.
AFTERNOON THUNDERSTORMS THAT HAVE DEVELOPED INLAND OVER W CUBA
HAVE MOVED INTO THE GULF WATERS S OF 24N BETWEEN 81W-85W. THE
FRONT WILL DISSIPATED BY EARLY TUE. THE SURFACE TROUGH TUE
AFTERNOON.

CARIBBEAN SEA...
AN ELONGATED UPPER LOW IS CENTERED S OF JAMAICA NEAR 15N79W WITH
A TROUGH AXIS EXTENDING N ALONG 19N80W THEN W TO W CUBA NEAR
22N84W GENERATING SCATTERED TO NUMEROUS SHOWERS/ISOLATED
THUNDERSTORMS W OF A LINE FROM 18N84W ALONG 13N81W TO PANAMA
NEAR 10N80W TO INLAND OVER CENTRAL AMERICA WITH SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS FROM 15N-17N BETWEEN 76W-78W.
AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND OVER
HISPANIOLA...CUBA...AND JAMAICA. THE ACTIVITY THAT DEVELOPED
OVER PUERTO RICO HAS MOVED INTO THE CARIBBEAN WATERS WITHIN 75
NM ALONG THE S COAST. THIS IS LEAVING THE REMAINDER OF THE
CARIBBEAN E OF 75W WITH CLEAR SKIES THIS EVENING. WEAK SURFACE
RIDGE OVER THE SW ATLC WILL SUPPORT GENTLE TO MODERATE TRADE
WINDS ACROSS MOST OF THE CARIBBEAN THROUGH WED EXCEPT FOR
MODERATE TO FRESH WINDS IN THE S/CENTRAL CARIBBEAN.

...HISPANIOLA...
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS THE ISLAND
THIS EVENING. DAYTIME HEATING COUPLED WITH OROGRAPHIC LIFTING
WILL CONTINUE TO GENERATE AFTERNOON SHOWERS/THUNDERSTORMS ACROSS
THE ISLAND TUE AND WED.

ATLANTIC OCEAN...
A NARROW UPPER TROUGH EXTENDS THROUGH 32N72W TO E OF THE BAHAMA
ISLANDS NEAR 24N72W SUPPORTING A 1009 MB LOW NEAR 32N72W WITH A
SURFACE TROUGH EXTENDING S ALONG 27N73W OVER THE BAHAMAS TO
24N78W. ISOLATED SHOWERS/THUNDERSTORMS ARE FROM 27N-30N BETWEEN
67W-71W. A WEAK 1014 MB HIGH IS LOCATED TO THE E NEAR 27N61W. AN
UPPER LOW IS CENTERED N OF THE LEEWARD ISLANDS NEAR 21N62W
COVERING THE AREA FROM 10N-28N BETWEEN 52W-68W INCLUDING THE E
CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
FROM 20N-25N BETWEEN 56W-62W AND FROM 20N-25N BETWEEN 66W-69W. A
SURFACE TROUGH IS IN THE CENTRAL ATLC EXTENDING FROM 31N56W
28N53W TO 26N52W GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS. A
SURFACE RIDGE COVERS THE E ATLC N OF 25N W OF 55W ANCHORED BY A
1030 MB HIGH N OF THE AZORES. W ATLC SURFACE TROUGH WILL REMAIN
NEARLY STATIONARY ACROSS THE AREA THROUGH WED THEN BEGIN TO
DRIFT W. A WEAK SURFACE RIDGE ALONG 23N/25N WILL PERSIST E OF
THE BAHAMAS THROUGH WED.

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

$$
PAW
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