[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091109
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUL 09 2012

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
1030 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS E OF THE CAPE VERDE ISLANDS EXTENDING FROM
21N26N TO 12N28W MOVING W NEAR 15 KT. WAVE IS ALONG THE LEADING
EDGE OF A SURGE OF DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL
PRECIPITABLE WATER IMAGERY. AN AREA OF SAHARAN DUST IS W OF THE
WAVE LIMITING CONVECTION.

TROPICAL WAVE EXTENDS FROM 25N62W THROUGH THE LEEWARD/VIRGIN
ISLANDS TO NEAR 17N64W MOVING W 15-20 KT. WAVE IS EMBEDDED
WITHIN AN AREA OF MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE
WATER IMAGERY. WAVE ALSO COINCIDES WITH AN UPPER RIDGE AND WITH
AN AREA OF SAHARAN DUST TO THE E OF THE WAVE LIMITING ANY DEEP
CONVECTION WITH ISOLATED SHOWERS FROM 18N-14N BETWEEN 61W-65W.

TROPICAL WAVE EXTENDS FROM 23N93W TO INLAND OVER S MEXICO NEAR
18N94W MOVING W NEAR 10 KT. WAVE IS EMBEDDED WITHIN A LARGE AREA
OF DEEP LAYERED MOISTURE COVERING THE ENTIRE GULF OF MEXICO AS
DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE W BAY OF CAMPECHE S
OF 21N AND W OF THE WAVE AXIS TO INLAND OVER MEXICO.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL
ATLC NEAR 13N17W S OF THE TROPICAL WAVE ALONG 10N27W TO 7N34W
WHERE THE ITCZ AXIS CONTINUES THROUGH A 1012 MB LOW NEAR 6N42W
TO INLAND OVER SOUTH AMERICA NEAR 2N51W. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION IS OFF THE COAST OF AFRICA FROM
7N-11N E OF 17W BETWEEN 15W-20W. CLUSTERS OF SCATTERED MODERATE/
ISOLATED STRONG CONVECTION ARE WITHIN 150 NM EITHER SIDE OF THE
MONSOON TROF/ITCZ BETWEEN 24W AND THE LOW...FROM 6N-10N BETWEEN
40W-48W AND WITHIN 120 NM ALONG THE COAST OF SOUTH AMERICA
BETWEEN 47W-57W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER RIDGE COVERS THE S GULF AND ANCHORED IS IN THE E
PACIFIC REGION. AN UPPER RIDGE COVERS THE W GULF AND IS ANCHORED
OVER THE CENTRAL PLAIN STATES. AN UPPER TROUGH EXTENDS FROM THE
CENTRAL ATLC THROUGH A SERIES OF UPPER LOWS TO AN UPPER LOW IN
THE SE GULF NEAR 27N84W COVERING THE E GULF. ISOLATED SHOWERS/
THUNDERSTORMS ARE S OF 28N E OF 85W TO OVER CUBA...THE FLORIDA
KEYS AND THROUGH THE STRAITS OF FLORIDA. AT THE SURFACE A WEAK
SURFACE RIDGE EXTENDS FROM THE ATLC ACROSS CENTRAL FLORIDA TO A
1018 MB HIGH NEAR 27N87W. THIS IS GIVING MOST OF THE N GULF
SOUTHERLY RETURN FLOW AND COUPLED WITH THE OPPOSING FLOW ALOFT
IS GENERATING SCATTERED SHOWERS N OF 28N W OF PENSACOLA FLORIDA
WITH SCATTERED THUNDERSTORMS N OF 29N BETWEEN PENSACOLA FLORIDA
TO LAKE CHARLES LOUISIANA. THE ACTIVITY IN THE BAY OF CAMPECHE
IS ASSOCIATED WITH THE TROPICAL WAVE. THIS IS LEAVING THE
REMAINDER OF THE GULF WITH FAIR WEATHER THIS MORNING. THE
SURFACE RIDGE WILL REMAIN THROUGH THU THEN RETRACT EASTWARD
ALLOWING A WEAK COLD FRONT TO MOVE INTO THE NW WATERS AND
IMMEDIATELY STALL. THE TROPICAL WAVE WILL SHIFT W ACROSS THE BAY
OF CAMPECHE TODAY AND TONIGHT. A SECOND TROPICAL WAVE WILL MOVE
THROUGH THE STRAITS OF FLORIDA THU THEN WEAKEN OVER THE S
CENTRAL WATERS ON FRI.

CARIBBEAN SEA...
THE UPPER RIDGE THAT COVERS THE S GULF OF MEXICO EXTENDS OVER
THE W CARIBBEAN TO 73W. AN UPPER RIDGE IN THE TROPICAL ATLC
EXTENDS TO OVER THE E CARIBBEAN. THE UPPER TROUGH OVER THE E
GULF OF MEXICO COVERS THE GREATER ANTILLES GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS N OF 18N TO INLAND OVER CUBA
BETWEEN 74W-84W. THE MONSOON TROUGH EXTENDS ACROSS THE SW
CARIBBEAN S OF 10N FROM COLOMBIA INTO THE E PACIFIC REGION OVER
THE PANAMA/COSTA RICA BORDER GENERATING SCATTERED SHOWERS/
THUNDERSTORMS WITHIN 60/75 NM ALONG THE COAST OF PANAMA AND
COSTA RICA FROM THE BORDER OF NICARAGUA W OF 81W. THIS IS
LEAVING THE REMAINDER OF THE CARIBBEAN WITH FAIR WEATHER THIS
MORNING. THE TROPICAL WAVE N OF THE LEEWARD ISLANDS WILL PASS
THROUGH THE ISLANDS AND THROUGH N/CENTRAL WATERS TUE THEN ACROSS
THE NW THU AND INTO THE YUCATAN PENINSULA BY FRI.

ATLANTIC OCEAN...
AN UPPER RIDGE COVERS MOST OF THE W ATLC ANCHORED OFF THE COAST
OF NORTH CAROLINA. AN UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC
THROUGH A SERIES OF UPPER LOWS NEAR 31N46W...27N56W...26N66W...
TO THE UPPER LOW IN THE SE GULF OF MEXICO GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS S OF 28N TO THE COAST OF CUBA W
OF 77W TO FLORIDA INCLUDING THE N BAHAMA ISLANDS. SIMILAR
ACTIVITY IS ASSOCIATED WITH THE UPPER LOW NEAR 27N567W COVERING
THE AREA FROM 22N-29N BETWEEN 52W-57W. A LARGE SURFACE RIDGE
DOMINATES THE ENTIRE ATLC ANCHORED BY A 1029 MB HIGH NW OF THE
AZORES AND A SURFACE RIDGE EXTENDING THROUGH 32N50W 28N66W
ACROSS CENTRAL FLORIA INTO THE GULF OF MEXICO GIVING THE
REMAINDER OF THE ATLC BASIN FAIR WEATHER THIS MORNING. SATELLITE
IMAGERY INDICATES A LARGE AREA OF SAHARAN DUST COVERING THE ATLC
E OF 55W TO AS FAR N AS 30N. SURFACE RIDGE WILL SHIFT N TO ALONG
31N ON WED THEN SHIFT N OF THE AREA THU AND FRI. A TROPICAL WAVE
WILL MOVE W ACROSS THE ATLC WATERS REACHING THE SE BAHAMAS TUE
AND THE CENTRAL BAHAMAS WED THEN THROUGH THE STRAITS OF FLORIDA
BY FRI.

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

$$
PAW






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