[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 151036
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED JUN 15 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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.

...TROPICAL WAVES...

EAST ATLANTIC TROPICAL WAVE REPOSITIONED ALONG 20W S OF 16N
MOVING W NEAR 10 KT. THE WAVE IS CHARACTERIZED BY WELL-DEFINED
MID-LEVEL VORTICITY RESULTING FROM HORIZONTAL SHEAR ACROSS A
STRONG AFRICAN EASTERLY JET WHICH LIES ROUGHLY ALONG 10N. THE
WAVE IS REPOSITIONED A LITTLE FARTHER E FROM ITS PREVIOUS
POSITION BASED ON A STRONGER VORTICITY SIGNATURE CROSSING 20W AS
SEEN ON MET-8 VIS IMAGERY. THE GFS LATCHES ON TO THIS FEATURE...
EVENTUALLY AMPLIFYING THE WAVE AS IT APPROACHES THE CAPE VERDE
ISLANDS LATER TODAY. WIDELY SCATTERED MODERATE CONVECTION
ALIGNED ALONG THE ITCZ FROM 6N-11N BETWEEN 18W-23W.

CENTRAL ATLANTIC TROPICAL WAVE ALONG 43W S OF 15N MOVING W 15-20
KT. THE WAVE HAS A FAINT SIGNATURE IN SATELLITE IMAGERY WITH A
WEAK INVERTED-V NOTED IN THE MID-LEVEL CLOUD FIELD. NO
ASSOCIATED DEEP CONVECTION.

TROPICAL WAVE CROSSING THE LESSER ANTILLES ALONG 7N63W 19N61W
MOVING W 15 KT. THE WAVE IS BEGINNING TO ENTER AN ENVIRONMENT
CHARACTERIZED BY WESTERLY SHEAR...SO MOST OF THE SHOWERS/TSTMS
ARE RE-DEVELOPING TO THE E OF THE AXIS. WIDELY SCATTERED
SHOWERS/TSTMS WITH EMBEDDED ISOLATED MODERATE CONVECTION IS FROM
10N-15N BETWEEN 55W-62W. SOME OF THE HEAVIER SHOWERS ARE
APPROACHING TOBAGO AND ST. LUCIA.

CENTRAL CARIBBEAN TROPICAL WAVE ALONG 76W S OF 18N MOVING W 10
KT. THE WAVE IS INTERACTING WITH A BROAD SFC LOW W OF JAMAICA...
SO ITS SIGNATURE IS DIFFICULT TO LOCATE. HOWEVER... THE WAVE
DOES APPEAR TO BE ENHANCING CONVECTION TO THE W OF THE LOW AS
WELL AS NEAR LAKE MARACAIBO. NUMEROUS STRONG CONVECTION FROM
14N-20N BETWEEN 73W-77W PARTIALLY ASSOCIATED WITH THE LOW NEAR
JAMAICA. SCATTERED MODERATE/STRONG FROM 4N-12N BETWEEN 71W-77W.

TROPICAL WAVE OVER THE BAY OF CAMPECHE ALONG 96W S OF 25N
MOVING W 10 KT. THE WAVE IS EMBEDDED WITHIN STRONG CYCLONIC SFC
FLOW FEEDING FROM THE N COAST OF THE YUCATAN PENINSULA DOWN TO
THE ISTHMUS OF TEHUANTEPEC. PATCHY SHOWERS EXTEND N OF THE BAY
OF CAMPECHE OVER THE W GULF IN ASSOCIATION WITH THE WAVE...AND A
FAIRLY PERSISTENT AREA OF TSTMS HAS BEEN TRAVERSING ACROSS THE
ISTHMUS AND ADJACENT WATERS. SCATTERED MODERATE CONVECTION FROM
17N-21N BETWEEN 91W-97W SPREADING OVER THE MEXICAN COAST NEAR
VERACRUZ.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 15N10W 9N20W 7N34W 9N50W 14N59W.
WIDELY SCATTERED MODERATE CONVECTION FROM 7N-11N BETWEEN 12W-16W
ALONG THE AFRICAN COAST. WIDELY SCATTERED MODERATE WITHIN 120 NM
OF THE AXIS BETWEEN 18W-33W. ISOLATED SHOWERS/TSTMS WITHIN 150
NM OF THE AXIS BETWEEN 33W-40W. WIDELY SCATTERED SHOWERS/TSTMS E
OF THE WINDWARD ISLANDS ASSOCIATED WITH TRPCL WAVE NEAR 62W.

...DISCUSSION...

GULF OF MEXICO...
A FAIRLY BENIGN WEATHER PATTERN IS ESTABLISHED OVER THE GULF OF
MEXICO WITH A SFC RIDGE EXTENDING FROM N/CNTRL FLORIDA WWD TO
THE TX COAST. A TROPICAL WAVE IS MOVING ACROSS THE BAY OF
CAMPECHE ON THE S PERIPHERY OF THE RIDGE WITH SCATTERED CLUSTERS
OF TSTMS EXTENDING FROM GUATEMALA AND BELIZE WWD TO THE ISTHMUS
OF TEHUANTEPEC NEAR VERACRUZ. THE UPPER LEVELS ARE DOMINATED BY
A LARGE CUT-OFF LOW CENTERED OVER WRN CUBA WHICH IS DRAGGING DRY
AIR OVER THE E GULF AND FLORIDA FROM THE N. ANOTHER STRIP OF DRY
AIR IS FLOWING FROM NE MEXICO TO THE NW GULF AND N GULF COAST
AHEAD OF AN AMPLIFYING TROF OVER THE SRN PLAINS. THE TROF WILL
MOVE E AND CONTINUE STRENGTHENING OVER THE NEXT 5 DAYS AS A
CUT-OFF LOW DEVELOPS OVER THE SRN APPALACHIANS...AND THIS WILL
BEGIN TO DRAW TROPICAL MOISTURE NWD OVER THE E GULF AND FLORIDA
BY THE WEEKEND EFFECTIVELY INCREASING THE CHANCE FOR TSTMS.

CARIBBEAN...
A DISORGANIZED SFC LOW...WITH 1008 MB PRES...IS DRIFTING W AWAY
FROM JAMAICA NEAR 19N80W WITH A TROF EXTENDING SW TO THE
HONDURAS COAST...AND NE TO NEAR GUANTANAMO BAY. THE SFC LOW LIES
ABOUT 200 NM SSE OF THE MID/UPPER LOW OVER W CUBA...AND THE
RESULTANT WESTERLY SHEAR IS KEEPING ALL ASSOCIATED CONVECTION TO
THE E OVER JAMAICA...E CUBA...HISPANIOLA...AND ADJACENT WATERS.
NUMEROUS MODERATE/STRONG CONVECTION IS FROM 14N-23N BETWEEN
72W-77W...AND WIDELY SCATTERED MODERATE IS OVER THE DOMINICAN
REPUBLIC. THE UPPER LOW IS KEEPING MOST OF THE NW CARIBBEAN
UNDER A SUBSIDENT REGIME WITH LIMITED CLOUD COVER. DEEP MOISTURE
IS THUS PUSHED S OVER CNTRL AMERICA AND THE SW CARIBBEAN WHERE
ISOLATED SHOWERS/TSTMS HAVE BEEN OCCASIONALLY POPPING
UP...ESPECIALLY OVER NICARAGUA. AN UPPER RIDGE EXTENDS E OF THE
SFC LOW FROM THE ABC ISLANDS NE ACROSS GUADELOUPE...WHICH IS
FUNNELING MOST OF THE MOISTURE N OF THE NRN LEEWARD ISLANDS. THE
FAVORED AREA OF CONVECTION WILL SHIFT TO THE W CARIBBEAN LATER
IN THE WEEK AS A DEEP TROF DEVELOPS OVER THE GULF OF MEXICO AND
DRIER AIR MOVES OVER THE E CARIBBEAN FROM THE ATLC.

ATLANTIC...
AN ACTIVE SUBTROPICAL JET EMERGES OUT OF THE CNTRL CARIBBEAN NE
OF ERN CUBA AND EXTENDS TO 26N70W 30N40W WITH A LARGE AREA OF
MID/UPPER LEVEL CLOUDINESS EXTENDING ACROSS A GOOD CHUNK OF THE
SUBTROPICAL ATLC W OF 30W. A QUICK-MOVING 1012 MB SFC LOW IS
EMBEDDED WITHIN THIS WESTERLY FLOW NEAR 26N51W WITH TROF
TRAILING WSW TO 2465W. A LARGE AREA OF UPPER DIFFLUENCE LIES
WITHIN THE RRQ OF A JET STREAK ALONG 26N50W 29N33W (PRODUCED
WHERE THE SUBTROPICAL AND POLAR JETS ARE MERGING)...AND THIS HAS
SUPPORTED A CLUSTER OF SCATTERED MODERATE CONVECTION FROM
20N-27N BETWEEN 40W-45W. OTHER SCATTERED MODERATE CELLS ARE
DEVELOPING CLOSER TO THE SFC LOW FROM 21N-27N BETWEEN 47W-57W.
FARTHER E...A NEARLY STATIONARY UPPER TROF EXTENDS FROM THE
COAST OF MOROCCO ACROSS THE CANARY ISLANDS TO 23N25W...THEN S OF
THE CAPE VERDE ISLANDS NEAR 13N25W. SUBSIDENCE IN THE TROF IS
PRODUCING A STRONG TRADE INVERSION AND SUBTROPICAL RIDGE...
KEEPING THE E ATLC RATHER DRY AND ALMOST CLOUD-FREE. THIS SET UP
IS ALSO KEEPING A RATHER THICK DUST PLUME AND HAZY SKIES ACROSS
THE ATLC S OF 22N. AN UPPER RIDGE ORIENTED ALONG 15N IS
SUPPORTING DEEP EASTERLY FLOW OVER THE ITCZ BUT AT THE MOMENT
THE AIR MASS IS TOO DRY TO SUPPORT MUCH CONVECTION. CONVECTION
IS INCREASING IN COVERAGE SE OF THE E ATLC UPPER TROF AS THE
TRPCL WAVE NEAR 20W MOVES INTO AN AREA OF UPPER DIFFLUENCE.

$$
BERG


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