[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180600
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI SEP 18 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 FEATURES...

TROPICAL DEPRESSION NINE IS CENTERED NEAR 17.3N 45.3W AT 18/0300
UTC OR ABOUT 930 NM E OF THE LESSER ANTILLES MOVING N-NW AT 6
KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. MAXIMUM
SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 17N-20N BETWEEN 42W-46W.
SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION
ARE FROM 15N-17N BETWEEN 42W-44W. PLEASE SEE THE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC
FOR MORE DETAILS.

A 1009 MB LOW W-SW OF THE CAPE VERDE ISLANDS IS CENTERED NEAR
13N35W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 75 NM OF
LINE FROM 12N35W TO 16N37W. CLUSTERS OF SCATTERED MODERATE/
ISOLATED STRONG CONVECTION COVERS A BROAD AREA FROM 5N-11N
BETWEEN 31W-45W...AND FROM 10N-17N BETWEEN 27W-35W. CONDITIONS
APPEAR FAVORABLE FOR ADDITIONAL DEVELOPMENT AND A TROPICAL
DEPRESSION COULD FORM DURING THE NEXT DAY OR TWO AS IT MOVES W-
NW 10-15 KT. THERE IS A HIGH CHANCE OF TROPICAL FORMATION OVER
THE NEXT 48 HOURS.

...TROPICAL WAVES...

TROPICAL WAVE IN THE CARIBBEAN IS ALONG 83W S OF 18N TO OVER
CENTRAL AMERICA MOVING W 15-20 KT OVER THE PAST 24 HOURS. SSMI
TPW INDICATES THE WAVE IS EMBEDDED WITHIN AN AREA OF DEEP
MOISTURE. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
ARE FROM 11N-18N BETWEEN 79W-86W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 13N16W TO 14N27W. THE ITCZ BEGINS SW OF T.D. NINE NEAR
10N51W AND CONTINUES INTO SOUTH AMERICA NEAR 9N61W. ALL OF THE
CONVECTION IS ASSOCIATED WITH T.D. NINE AND THE LOW IN THE
SPECIAL FEATURES.

...DISCUSSION...

GULF OF MEXICO...
A NARROW UPPER TROUGH EXTENDS ACROSS GEORGIA INTO THE GULF NEAR
APALACHICOLA FLORIDA ALONG THE W COAST OF THE YUCATAN PENINSULA
TO 18N92W. STRONG SUBSIDENCE AND DRY STABLE AIR WITH CLEAR SKIES
COVERS THE W GULF W OF 87W. A SURFACE TROUGH EXTENDS FROM THE W
ATLC ACROSS S FLORIDA BETWEEN FORT LAUDERDALE AND NAPLES TO A
1008 MB HIGH NEAR 26N84W THEN SW TO 22N91W. SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS ARE S OF 28N E OF 84W ACROSS FLORIDA AND
THROUGH THE STRAITS OF FLORIDA. SURFACE TROUGH/LOW WILL MEANDER
OVER THE E GULF FRI THEN MOVE NE ACROSS FLORIDA FRI NIGHT
BEFORE DISSIPATING. WEAK HIGH PRESSURE WILL MOVE INTO THE
N/CENTRAL GULF THIS WEEKEND.

CARIBBEAN SEA...
AN UPPER RIDGE ANCHORED IN THE NW CARIBBEAN NEAR 17N82W EXTENDS
A RIDGE AXIS NE ACROSS CUBA NEAR 22N78W INTO THE W ATLC COVERING
THE NW CARIBBEAN N OF 15N W OF 78W. AN UPPER TROUGH EXTENDS FROM
THE CENTRAL ATLC ACROSS PUERTO RICO/MONA PASSAGE TO S OF
HISPANIOLA TO JAMAICA COVERING THE E CARIBBEAN. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 19N ACROSS HISPANIOLA
AND CUBA BETWEEN 70W-80W. THE ACTIVITY IS THE SW CARIBBEAN IS
ASSOCIATED WITH THE TROPICAL WAVE. THIS IS LEAVING THE E
CARIBBEAN WITH CLEAR SKIES TONIGHT. THE CARIBBEAN TROPICAL WAVE
WILL MOVE ACROSS CENTRAL AMERICA THROUGH FRI.

...HISPANIOLA...
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE ACROSS
THE ISLAND TONIGHT. THE UPPER TROUGH THAT EXTENDS ACROSS PUERTO
RICO TO S OF HISPANIOLA WILL FORM A CUTOFF UPPER LOW JUST S OF
THE ISLAND EARLY FRI THEN WILL SHIFT S THROUGH SUN. MOISTURE AND
SHOWER/THUNDERSTORM ACTIVITY WILL PERSIST THROUGH EARLY SAT
WITH SOME CLEARING SAT NIGHT AND SUN.

ATLANTIC OCEAN...
A SURFACE TROUGH EXTENDS FROM 30N78W TO A 1010 MB LOW OFF THE
FLORIDA COAST NEAR VERO BEACH THEN CONTINUES ACROSS S FLORIDA
NEAR FORT LAUDERDALE GENERATING SCATTERED TO NUMEROUS SHOWERS/
ISOLATED THUNDERSTORMS N OF 26N BETWEEN 70W-79W WITH SCATTERED
SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE REMAINDER
OF THE W ATLC W OF 70W TO OVER FLORIDA AND THROUGH THE FLORIDA
STRAITS. AN UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN ACROSS
CUBA NEAR 22N78W ALONG 27N74W TO BEYOND 32N71W. A SURFACE RIDGE
COVERS THE W ATLC N OF 30N W OF 50W ANCHORED BY A PAIR OF 1021
MB HIGHS N OF THE DISCUSSION AREA. A BROAD UPPER TROUGH COVERS
THE CENTRAL ATLC FROM 40W-65W THEN EXTENDING A UPPER TROUGH AXIS
FROM 20N64W ACROSS PUERTO RICO/MONA PASSAGE INTO THE N
CARIBBEAN. THE BROAD UPPER TROUGH IS SUPPORTING A COLD FRONT N
OF THE AREA WITH A STATIONARY FRONT EXTENDING THROUGH 32N47W TO
29N55W AND IS GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 120 NM OF LINE FROM 22N45W ALONG 26N50W TO
29N58W. AN UPPER LOW IS CENTERED OVER N MOROCCO SUPPORTING A
DISSIPATING COLD FRONT THAT EXTENDS INTO THE E ATLC NEAR 29N10W
ACROSS THE CANARY ISLANDS NEAR 29N15W TO 31N25W GENERATING
ISOLATED SHOWERS WITHIN 60 NM OF THE FRONT. A WEAK 1021 MB HIGH
IS IN THE E ATLC NEAR 26N32W. THE W ATLC LOW WILL MOVE N-NE
THROUGH SUN TRAILING THE SURFACE TROUGH ACROSS S FLORIDA. WEAK
HIGH PRESSURE OVER THE NW ATLC WILL PERSIST THROUGH THE WEEKEND.

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

$$
PAW
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