[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 230005
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON SEP 22 2014

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
2345 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS MOVING ACROSS THE CAPE VERDE ISLANDS WITH
AXIS EXTENDING FROM 22N24W TO A 1010 MB LOW NEAR 17N25W TO
11N26W MOVING W AT 10-15 KT. THE GOES-R SEVIRI AIRMASS PRODUCT
DEPICT A SLOT OF WARM DRY AIR W OF THE LOW CENTER WHICH THE SSMI
TPW AND THE METEOSAT SAL IMAGERY SHOW ENTRAINING THE SYSTEM.
SAHARAN DUST IS ALSO ENTRAINING THE WAVE ENVIRONMENT AS DEPICTED
IN THE GOES-R DUST PRODUCT. AS A RESULT CONVECTION HAS DECREASED
TO ISOLATED SHOWERS WITHIN 300 NM OF THE LOW CENTER...EXCEPT IN
THE NW QUADRANT.

A TROPICAL WAVE IS ON THE CENTRAL ATLC WITH AXIS EXTENDING FROM
17N41W TO 9N44W...MOVING W AT 20 KT. THE WAVE REMAINS WEAKER DUE
THE PRESENCE OF DRY AND STABLE SAHARAN AIR KEEPING CONVECTION TO
A MINIMUM AND LARGELY CONFINED TO THE MONSOON TROUGH REGION S OF
12N BETWEEN 40W-50W.

A TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN WITH AXIS
EXTENDING FROM 21N63W TO 10N64W...MOVING W AT 10 KT. MAINLY DEEP
LAYER MODERATE MOISTURE ACCOMPANIES THE WAVE WHICH ALONG LOW
LEVEL MOISTURE CONVERGENCE AND UPPER LEVEL DIFFLUENCE SUPPORT
SCATTERED MODERATE CONVECTION E OF 68W...INCLUDING PUERTO RICO
AND THE LESSER ANTILLES.

TROPICAL WAVE IS ON THE WESTERN CARIBBEAN WITH AXIS EXTENDING
FROM 22N82W TO 9N82W...MOVING W AT 10 KT. DRY AIR SUBSIDENCE
FROM ALOFT IS HINDERING DEVELOPMENT OF DEEP CONVECTION AHEAD OF
THE WAVE. SCATTERED MODERATE CONVECTION IS ON THE CENTRAL
CARIBBEAN...INCLUDING JAMAICA AND HISPANIOLA.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 16N19W TO A 1010 MB LOW NEAR
17N25W TO 11N31W TO 10N41W 6N50W. ASIDE FROM CONVECTION
OCCURRING WITH THE TROPICAL WAVES...SCATTERED MODERATE
CONVECTION IS FROM 9N-15N BETWEEN 33W-40W.

...DISCUSSION...

GULF OF MEXICO...

A MIDDLE TO UPPER LEVEL TROUGH ALONG THE EASTERN CONUS EXTENDS
ITS BASE ACROSS THE EASTERN GULF AND THE FLORIDA PENINSULA. THIS
TROUGH ALOFT SUPPORT A PAIR OF FRONTAL SYSTEMS...A STATIONARY
FRONT ANALYZED ACROSS NORTHERN FLORIDA SW TO A 1013 NEAR 28N85W
TO 25N90W AND A COLD FRONT ACROSS THE SE CONUS EXTENDING TO
LOUISIANA. THIS FRONT IS FORECAST TO MERGE WITH THE STATIONARY
FRONT ON TUESDAY. EAST AND WEST OF THE TROUGH ALOFT...RIDGING IS
GENERATING DIFFLUENT FLOW WHICH ALONG ABUNDANT LOW-LEVEL
MOISTURE BEING ADVECTED FROM THE CARIBBEAN SUPPORT SCATTERED
MODERATE CONVECTION SOUTH OF THE STATIONARY FRONT E OF 90W. THE
FRONT WILL DISSIPATE WED MORNING WHILE MOVING ACROSS CENTRAL
FLORIDA. A TROPICAL WAVE MOVES INTO THE BAY OF CAMPECHE THU
MORNING.

CARIBBEAN SEA...

TWO TROPICAL WAVES ARE IMPACTING THE CARIBBEAN THIS EVENING...
ONE ALONG 64W AND THE OTHER ALONG 82W. THE EASTERN-MOST TROPICAL
WAVE CONTINUES TO SUPPORT SHOWERS AND TSTMS ACROSS THE LESSER
ANTILLES AND PUERTO RICO. THE WESTERN-MOST TROPICAL WAVE IS
LARGELY PROVIDING SCATTERED SHOWERS TO THE OPEN WATERS OF THE
CENTRAL CARIBBEAN AS WELL AS HISPANIOLA AND JAMAICA. SEE THE
TROPICAL WAVES SECTION ABOVE. LOW LEVEL MOISTURE CONVERGENCE IS
ENHANCING SCATTERED MODERATE CONVECTION ALONG CUBA.
OTHERWISE...THE MONSOON TROUGH AXIS EXTENDS FROM COSTA RICA TO
COLOMBIA WITH SCATTERED SHOWERS OCCURRING S OF 13N. THE TROPICAL
WAVE ON THE EASTERN CARIBBEAN IS EXPECTED TO MOVE ACROSS
HISPANIOLA AND CENTRAL BASIN TUE THROUGH WED MORNING.

...HISPANIOLA...

SCATTERED SHOWERS AND CLOUDY SKIES ARE ACROSS THE ISLAND TONIGHT
BEING ENHANCED BY ABUNDANT MOISTURE TRAILING THE TROPICAL WAVE
CURRENTLY OVER THE WESTERN CARIBBEAN. INCREASED CONVECTIVE
ACTIVITY IS EXPECTED TUESDAY TO WED MORNING AS THE TROPICAL WAVE
CURRENTLY OVER THE EASTERN CARIBBEAN MOVES ACROSS THE ISLAND AND
ADJACENT WATERS.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE EASTERN CONUS THAT
SUPPORTS A STATIONARY FRONT ANALYZED FROM 30N74W SW TO 29N81W
AND THEN ACROSS THE NE GULF OF MEXICO. SCATTERED SHOWERS AND
TSTMS ARE OCCURRING N OF 23N W OF 73W ACROSS A PORTION OF THE SW
NORTH ATLC...INCLUDING THE FLORIDA PENINSULA. THE FRONT IS
EXPECTED TO MERGE WITH A COLD FRONT CURRENTLY TO THE NORTH ON
TUESDAY. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR
24N53W THAT SUPPORTS A BROAD AREA OF CLOUDINESS WITH EMBEDDED
AREAS OF ISOLATED SHOWERS AND TSTMS OCCURRING FROM 24N-31N
BETWEEN 46W-58W. THE TAIL END OF A FRONTAL BOUNDARY ANALYZED AS
A STATIONARY FRONT FROM 27N43W TO 29N51W EXTENDS INTO THIS AREA
OF CONVECTION PROVIDING ENHANCED FOCUS ON CONVECTION OCCURRING
NEAR THE FRONT. TO THE EAST...A DISSIPATING COLD FRONT ENTERS
THE DISCUSSION AREA NEAR 30N32W AND EXTENDS SW TO 27N42W.
ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THIS
FRONT.

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

$$
NR


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