[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 150554
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE SEP 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURE...

A 1012 MB LOW IS CENTERED NEAR 11N41W ALONG A TROPICAL WAVE THAT
EXTENDS FROM 18N40W THROUGH THE LOW TO 9N40W MOVING W-NW NEAR 10
KT. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION
ARE WITHIN 30/45 NM OF LINE FROM 9N41W ALONG 11N44W 13N42W TO
15N37W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 9N-
13N BETWEEN 38W-40W. SOME DEVELOPMENT OF THIS LOW IS POSSIBLE
DURING THE NEXT COUPLE OF DAYS AFTER WHICH THE UPPER LEVEL WINDS
ARE EXPECTED TO BECOME UNFAVORABLE. THERE IS A MEDIUM CHANCE OF
TROPICAL FORMATION OVER THE NEXT 48 HOURS.

A 1011 MB LOW IS CENTERED NEAR 9N21.5W ALONG A TROPICAL WAVE
THAT EXTENDS FROM 17N22W THROUGH THE LOW TO 8N21W MOVING W NEAR
10 KT OVER THE PAST 12 HOURS. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 7N-10N BETWEEN 22W-25W AND FROM 11N-12N
BETWEEN 20.5W-22.5W. THE ACTIVITY SHOWS SIGNS OF ORGANIZATION
AND ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE CONDUCIVE FOR
FURTHER DEVELOPMENT. THERE IS A MEDIUM CHANCE OF TROPICAL
FORMATION OVER THE NEXT 48 HOURS.

...TROPICAL WAVES...

TROPICAL WAVE IN THE E CARIBBEAN EXTENDS ALONG 62W FROM 11N-21N
MOVING W NEAR 15 KT OVER THE PAST 24 HOURS. SSMI TPW INDICATES
THE WAVE IS EMBEDDED WITHIN SURGE OF DEEP MOISTURE. ANY
CONVECTION AROUND THIS WAVE IS ASSOCIATED WITH AN UPPER FEATURE
AND IS BEING ENHANCED BY THE TROPICAL WAVE.

TROPICAL WAVE ANALYZED IN THE W CARIBBEAN EXTENDS ALONG 80W-81W
FROM 10N-19N MOVING W 10-15 KT OVER THE PAST 24 HOURS. SSMI TPW
INDICATES THE CARIBBEAN IS COVERED IN MODERATE MOISTURE. NO
ASSOCIATED DEEP CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 1N517W THROUGH THE 1011 MB LOW ALONG THE EASTERN MOST
TROPICAL WAVE CONTINUING TO JUST E OF THE 1012 MB LOW ALONG THE
NEXT TROPICAL NEAR 11N40W. THE ITCZ BEGINS W OF THE SECOND WAVE
NEAR 11N42W AND CONTINUES ALONG 9N50W TO SOUTH AMERICA NEAR
8N59W. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM OF LINE FROM
4N24W TO 8N29W. THE REMAINDER OF THE CONVECTION IS ASSOCIATED
WITH THE TROPICAL WAVES IN THE SPECIAL FEATURES.

...DISCUSSION...

GULF OF MEXICO...
A NARROW UPPER TROUGH IN THE NW ATLC IS SUPPORTING A COLD FRONT
IN THE W ATLC THAT ENTERS THE GULF OF MEXICO AS A STATIONARY
FRONT AT 15/0300 UTC ACROSS CENTRAL FLORIDA JUST N OF WEST PALM
BEACH TO FORT MYERS THEN ALONG 26N85W TO 26N91W WHERE IT
DISSIPATES TO 28N95W. A SURFACE RIDGE EXTENDS FROM CENTRAL
MEXICO INTO THE GULF NEAR VERACRUZ COVERING THE GULF MEXICO AND
THE NW CARIBBEAN AND IS PROVIDING DIFFLUENCE ALOFT ACROSS THE
ENTIRE GULF. SCATTERED TO NUMEROUS SHOWERS/ISOLATED
THUNDERSTORMS ARE WITHIN 120 NM N OF THE FRONT BETWEEN 88W-
94W...WITHIN 90 NM S OF THE FRONT BETWEEN 85W-93W...S OF 25N
INTO THE BAY OF CAMPECHE AND OVER S MEXICO BETWEEN 91W-96W. A
WEAK 1012 MB LOW IS JUST OFF THE COAST NEAR TAMPICO MEXICO WITH
A WEAK SURFACE TROUGH EXTENDING N TO 24N97W WITH SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS FROM 20N-24W W OF 96W. A SURFACE
TROUGH IN THE W ATLC/STRAITS OF FLORIDA E OF THE FLORIDA KEYS IS
GENERATING ISOLATED SHOWERS/THUNDERSTORMS S OF 25N E OF 83W
INCLUDING S FLORIDA AND THE FLORIDA KEYS. THE FRONT IS EXPECTED
TO SHIFT SLIGHTLY S ACROSS THE CENTRAL GULF BEFORE DISSIPATING
MON. THE STRAITS OF FLORIDA SURFACE TROUGH WILL MOVE W THROUGH
TUE BEFORE STALLING ALONG 88W BY WED NIGHT. A TROPICAL WAVE WILL
PASS ACROSS THE YUCATAN PENINSULA TUE AND TUE NIGHT AND THE SW
GULF WED NIGHT.

CARIBBEAN SEA...
AN UPPER RIDGE EXTENDS ALONG 20N FROM OVER MEXICO AND THE GULF
OF MEXICO TO 73W COVERING THE NW CARIBBEAN. A SECOND UPPER RIDGE
EXTENDS FROM THE W ATLC OVER THE E CARIBBEAN. AN UPPER LOW IS IN
THE SW CARIBBEAN NEAR 10N77W AND EXTENDS AN UPPER TROUGH NW
ALONG 16N73W TO OVER HISPANIOLA. AT THE SURFACE ARE TWO TROPICAL
WAVES...PLEASE REFER TO THE SECTION ABOVE FOR DETAILS. THE UPPER
RIDGES ARE PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS OFF THE S COAST OF CUBA WITHIN
30/45 NM OF LINE FROM 20N78W 21N81W TO 22N84W AND IN THE E
CARIBBEAN W OF LINE FROM 12N63W 15N70W TO PUERTO RICO 18N66W
INCLUDING THE LESSER ANTILLES AND THE VIRGIN ISLANDS. W
CARIBBEAN TROPICAL WAVE WILL REACH THE YUCATAN PENINSULA BY TUE.
E CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE REMAINDER OF THE
E CARIBBEAN THROUGH TUE NIGHT REACHING THE CENTRAL CARIBBEAN WED
AND THE W CARIBBEAN THU.

...HISPANIOLA...
SKIES ARE CLEAR ACROSS THE ISLAND TONIGHT. THE UPPER TROUGH THAT
EXTENDS FROM THE SW CARIBBEAN WILL PERSIST THROUGH TUE THEN
SHIFT W WED TO OVER HAITI. MOISTURE WILL INCREASE TUE AHEAD OF
THE E CARIBBEAN TROPICAL WAVE THAT WILL MOVE ACROSS THE ISLAND
TUE NIGHT AND WED. THIS WILL INCREASE THE CHANCE OF SHOWERS/
THUNDERSTORMS FOR TUE EVENING THROUGH WED.

ATLANTIC OCEAN...
A NARROW UPPER TROUGH IN THE NW ATLC IS SUPPORTING A COLD FRONT
THAT ENTERS THE W ATLC AT 15/0300 UTC NEAR 32N67W AND EXTENDS TO
28N76W WHERE IT BECOMES STATIONARY ACROSS CENTRAL FLORIDA INTO
THE GULF OF MEXICO JUST N OF WEST PALM BEACH. SCATTERED SHOWERS
AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 75 NM NW OF THE
FRONT AND WITHIN 60 NM S OF THE FRONT W OF 74W. A SURFACE
TROUGH...REMNANTS OF GRACE...EXTENDS FROM 26N79W INTO THE
STRAITS OF FLORIDA TO OVER CUBA NEAR 22N81W GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS S OF 25N TO OVER CUBA W OF 77W
INCLUDING ANDROS ISLAND. A TUTT EXTENDS FROM THE E ATLC THROUGH
A SERIES OF UPPER LOWS...CENTERED NEAR 28N22W 24N43W AND 20N55W
THEN CONTINUES TO 22N58W. A SURFACE TROUGH IN THE W/CENTRAL ATLC
EXTENDS FROM 29N60W TO 25N62W WITH A SECOND SURFACE TROUGH IN
THE E/CENTRAL ATLC FROM 26N37W TO 21N38W AND A THIRD IN THE E
ATLC FROM FROM 28N22W TO 26N20W. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE FROM 24N-30N BETWEEN 52W-66W...N OF 30N
BETWEEN 55W-61W... AND FROM 23N-28N BETWEEN 43W-50W. THE ABOVE
SURFACE TROUGHS ARE WEAKNESSES IN THE SURFACE RIDGE THAT
DOMINATES THE ATLC E OF THE W ATLC FRONT AND ANCHORED BY A 1026
MB HIGH ABOUT 500 NM W-SW OF THE AZORES NEAR 35N37W. W ATLC
FRONT WILL WEAKEN TONIGHT WITH A PORTION S OF 31N DISSIPATING
TUE WHILE THE REMAINDER N OF 31N WILL CONTINUE TO MOVE E. THE
SURFACE TROUGH...REMNANTS OF GRACE...WILL MOVE ACROSS THE
STRAITS OF FLORIDA TONIGHT. THE E CARIBBEAN TROPICAL WAVE WILL
REACH THE WINDWARD PASSAGE WED NIGHT.

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

$$
PAW
This weather bulletin was brought to you by:
www.nashvilleweather.net