[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 031129
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU SEP 03 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...

TROPICAL STORM FRED IS CENTERED NEAR 20.8N 33.2W AT 03/0900 UTC
OR ABOUT 600 NM W-NW OF THE CAPE VERDE ISLANDS MOVING W-NW AT 7
KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM
SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 21N-23N BETWEEN 30W-33W.
PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE WAS INTRODUCED AT 03/0600 UTC ASSOCIATED WITH
THE 1012 MB LOW PREVIOUSLY DESCRIBED ALONG THE MONSOON TROUGH.
THE TROPICAL WAVE EXTENDS FROM 18N24W ACROSS THE CAPE VERDE
ISLANDS THROUGH THE 1012 MB LOW NEAR 12N23.5W TO 10N23W MOVING W
NEAR 10 KT OVER THE PAST 6 HOURS. SSMI TPW INDICATES THE WAVE IS
EMBEDDED WITHIN A SURGE OF DEEP MOISTURE. CLUSTERS OF SCATTERED
MODERATE CONVECTION ARE FROM 10N-14N BETWEEN 23W-26W.

TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS ALONG 48W FROM 7N-14N
MOVING W NEAR 10 KT OVER THE PAST 24 HOURS. SSMI TPW INDICATED
THE WAVE IS EMBEDDED WITHIN A VERY LOW AMPLITUDE SURGE OF
MODERATE MOISTURE. NO ASSOCIATED DEEP CONVECTION.

TROPICAL WAVE IN THE SW CARIBBEAN EXTENDS FROM 17N80W TO 10N82W
MOVING W-SW 20-25 KT OVER THE PAST 24 HOURS. SSMI TPW INDICATES
THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-14N W OF THE
WAVE TO JUST INLAND OVER NICARAGUA.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM OVER AFRICA INTO THE E
TROPICAL ATLC NEAR 12N15W ALONG 11N18W TO A 1012 MB LOW NEAR
12N23.5W CONTINUING ALONG 13N30W 10N41W TO 7N49W WHERE THE ITCZ
BEGINS AND CONTINUES INTO SOUTH AMERICA NEAR 6N57W. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 9N-13N BETWEEN 30W-41W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 9N-13N E
OF 17W TO INLAND OVER W AFRICA. CLUSTERS OF SCATTERED MODERATE
CONVECTION ARE FROM 6N-9N E OF 17W TO JUST INLAND OVER AFRICA.

...DISCUSSION...

GULF OF MEXICO...
NARROW UPPER TROUGH EXTENDS ACROSS THE LOWER MISSISSIPPI VALLEY
INTO THE GULF NEAR LAKE CHARLES LOUISIANA TO AN UPPER LOW NEAR
25N95W TO 22N94W WHERE IT MEETS AN INVERTED TROUGH THAT EXTENDS
FROM E BAY OF CAMPECHE. A SURFACE TROUGH AT 03/0900 UTC EXTENDS
FROM 24N94W TO INLAND OVER S MEXICO NEAR 18N95W. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE W OF LINE FROM PANAMA CITY
FLORIDA ALONG 23N89W TO 19N91W. AN UPPER RIDGE DOMINATES THE
REMAINDER OF THE GULF ANCHORED NEAR 27N87W. ISOLATED SHOWERS/
THUNDERSTORMS DOT THE SE GULF S OF 27N BETWEEN 81W-86W. A WEAK
SURFACE RIDGE COVERS THE E GULF ANCHORED BY A 1016 MB HIGH NEAR
28N85W. WEAK SURFACE RIDGE WILL ALIGN NW TO SE TONIGHT THROUGH
FRI THEN SHIFT SLOWLY SE INTO THE SE CENTRAL GULF SAT.

CARIBBEAN SEA...
AN UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC ACROSS PUERTO RICO
TO 17N74W THEN THROUGH AN UPPER LOW NEAR 18N84W CONTINUING TO
OVER THE YUCATAN PENINSULA AND CENTRAL AMERICA. THIS IS
GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
N OF 18N BETWEEN 74W-86W. THE MONSOON TROUGH EXTENDS FROM
COLOMBIA NEAR 9N76W ALONG 10N81W THEN ACROSS COSTA RICA NEAR
10N84W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
WITHIN 30/45 NM OF LINE FROM 11N82W TO COLOMBIA NEAR 9N76W
INCLUDING PORTIONS OF E PANAMA. THIS IS LEAVING THE E CARIBBEAN
WITH CLEAR SKIES THIS MORNING. FRESH TO STRONG TRADE WINDS WILL
PULSE IN THE S/CENTRAL CARIBBEAN THROUGH SAT AS THE WEAK SURFACE
RIDGE ACROSS THE W ATLC SHIFTS SLOWLY SE AND WEAKENS. THE SW
CARIBBEAN TROPICAL WAVE WILL MOVE OUT OF THE AREA FRI MORNING.

...HISPANIOLA...
SKIES HAVE CLEARED ACROSS THE ISLAND THIS MORNING. AN UPPER
TROUGH EXTENDS FROM THE CENTRAL ATLC ACROSS PUERTO RICO TO
17N74W THEN THROUGH AN UPPER LOW NEAR 18N84W. THIS UPPER TROUGH
WILL GRADUALLY BECOME N/S ORIENTATED TONIGHT GIVING THE ISLAND N
FLOW ALOFT FRI AND SAT. MOISTURE WILL INCREASE AGAIN SAT MORNING
INCREASING THE CHANCE OF AFTERNOON SHOWERS/THUNDERSTORMS SAT.

ATLANTIC OCEAN...
AN UPPER RIDGE IS ANCHORED IN THE GULF OF MEXICO EXTENDS OVER
THE W ATLC TO 70W WITH A SHORTWAVE MID/UPPER TROUGH MOVING JUST
OFF THE SE COAST GENERATING SCATTERED TO NUMEROUS SHOWERS/
ISOLATED THUNDERSTORMS N OF 27N BETWEEN 77W-80W. A WEAK SURFACE
RIDGE COVERS THE W ATLC WITH A 1016 MB HIGH NEAR 25N65W. A BROAD
UPPER TROUGH EXTENDS OVER THE CENTRAL ATLC N OF 25N BETWEEN 45W-
65W SUPPORTING A BROAD SURFACE TROUGH THAT EXTENDS THROUGH
32N47W ALONG 26N54W TO 24N60W WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS N OF 27N TO THE SURFACE TROUGH BETWEEN 46W-50W.
ISOLATED SHOWERS/THUNDERSTORMS DOT THE AREA WITHIN 150 NM SE OF
THE SURFACE TROUGH. A FRONT N OF THE DISCUSSION AREA IS
GENERATING SCATTERED TO NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS
N OF 27N BETWEEN 59W-69W. A WEAK SURFACE RIDGE IN THE E ATLC IS
BEING INTRUDED BY T.S. FRED AND IS ANCHORED BY A 1022 MB HIGH
BETWEEN THE MADEIRA AND THE AZORES. W ATLC SURFACE RIDGE WILL
DRIFT SE AND GRADUALLY WEAKEN THROUGH SAT AS A WEAK TROUGH SINKS
SLOWLY SE INTO THE W ATLC OFF NE FLORIDA THEN SETTLES ACROSS THE
NW BAHAMAS TO THE NE BY SUN.

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

$$
PAW
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