[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290004
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE JUN 28 2011

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
2315 UTC.

...SPECIAL FEATURE...
THE BROAD AREA OF LOW PRESSURE OVER THE S GULF OF MEXICO/E BAY
OF CAMPECHE WAS UPGRADED TO TROPICAL STORM ARLENE AT 29/0000
UTC. ARLENE IS CENTERED NEAR 21.2N 93.7W AT 29/0000 UTC OR ABOUT
210 NM FROM TUXPAN MEXICO MOVING WNW AT 6 KT. ESTIMATED MINIMUM
CENTRAL PRESSURE IS 1003 MB. MAXIMUM SUSTAINED WIND SPEED IS 35
KT WITH GUST TO 45 KT. SEE NHC INTERMEDIATE PUBLIC ADVISORY
UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL
FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC
FOR MORE DETAILS. BROAD AREA OF SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS COVER THE S GULF S OF 26N W OF 87W TO INLAND OVER
MEXICO WITH THE STRONGEST STORMS S OF 24N TO INLAND OVER THE
YUCATAN PENINSULA BETWEEN 88W-91W.

...TROPICAL WAVES...

TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS FROM 14N42W
TO 7N46W MOVING W NEAR 20 KT. WAVE REMAINS EMBEDDED WITHIN A
MOISTURE SURGE AS INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY
AND IS WELL DEFINED ON SATELLITE IMAGERY. NO ASSOCIATED DEEP
CONVECTION WITH ISOLATED SHOWERS DOTTING THE AREA FROM 9N-13N
BETWEEN 42W-47W.

TROPICAL WAVE IN THE CENTRAL CARIBBEAN THAT BECAME ELONGATED
OVERNIGHT LAST NIGHT HAS SPLIT WITH A SURFACE TROUGH IN THE SW
ATLC WHILE A WEAK TROPICAL WAVE REMAINS IN THE CENTRAL CARIBBEAN
ALONG 69W/70W BETWEEN 14N-19N MOVING W NEAR 10 KT. SEE ATLANTIC
OCEAN SECTION BELOW FOR THE SURFACE TROUGH. TROPICAL WAVE IS
EMBEDDED WITHIN A WEAK AREA OF MOISTURE AS INDICATED BY TOTAL
PRECIPITABLE WATER IMAGERY. AN UPPER LOW IS CENTERED JUST TO THE
W OF THE WAVE AXIS PARTIALLY MASKING THE SATELLITE SIGNATURE.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE INLAND OVER THE
DOMINICAN REPUBLIC.

TROPICAL WAVE IN W GULF OF MEXICO IS ALONG 96W-97W BETWEEN
20N-26N MOVING NW NEAR 10 KT. WAVE IS WEAKENING AND BEING
ABSORBED WITHIN THE BROAD LOW IN THE SPECIAL FEATURES.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA ALONG 16N9W W TO INTO
THE E TROPICAL ATLC NEAR 15N17W TO 10N24W WHERE IT CONTINUES AS
THE ITCZ AXIS ALONG 9N29W 6N37W TO INLAND OVER SOUTH AMERICA
NEAR 3N51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS
INLAND AND WITHIN 60 NM ALONG THE COAST OF SIERRA LEONE N OF 7N
TO THE BORDER OF GUINEA AND WITHIN 75 NM OF LINE FROM 5N46W TO
INLAND OVER BRAZIL NEAR 00N49W. CLUSTERS OF SIMILAR CONVECTION
ARE FROM 4N-10N BETWEEN 30W-38W.

...DISCUSSION...

GULF OF MEXICO...
THE PRIMARY FOCUS TONIGHT IS THE NEWLY UPGRADED TROPICAL STORM
ARLENE IN THE SPECIAL FEATURES ABOVE. AN UPPER TROUGH REMAINS
OVER THE N GULF EXTENDING FROM NEAR PENSACOLA FLORIDA SW TO NEAR
25N96W WITH DRY STABLE AIR NW OF THE UPPER TROUGH AXIS. THE
UPPER RIDGE TO THE SE EXTENDS FROM THE GENERAL AREA OF THE
TROPICAL STORM ALENE NE ACROSS THE FLORIDA PENINSULA NEAR NAPLES
INTO THE W ATLC. THE UPPER RIDGE IS PROVIDING A DIFFLUENT
ENVIRONMENT ALOFT ENHANCING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS OVER THE E GULF SE OF A LINE FROM 27N88W TO OVER
FLORIDA NEAR APALACHEE BAY. A SURFACE RIDGE EXTENDS FROM THE W
ATLC ROUGHLY ALONG 30N TO E TEXAS WITH A 1020 MB HIGH OVER NE
FLORIDA. THIS SCENARIO IS LEAVING THE NW GULF UNDER MOSTLY CLEAR
SKIES AGAIN THIS EVENING. THE WAVE IS EXPECTED TO CONTINUE TO
MOVE NW INLAND OVER MEXICO TONIGHT BEFORE DISSIPATING.

CARIBBEAN SEA...
THE UPPER RIDGE OVER THE E GULF OF MEXICO IS GIVING THE W
CARIBBEAN N FLOW ALOFT WHILE AN UPPER LOW IS CENTERED S OF HAITI
NEAR 17N79W DOMINATES THE REMAINDER OF THE BASIN. THE UPPER
RIDGE IS PROVIDING A DIFFLUENT ENVIRONMENT ALOFT ENHANCING
SCATTERED SHOWERS/THUNDERSTORMS THAT HAVE DEVELOPED OVER CUBA
MOVING S INTO THE NW CARIBBEAN WATERS AS WILL AS SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS W OF 86W TO INLAND OVER THE
YUCATAN PENINSULA FROM THE YUCATAN CHANNEL TO 17N. THE MONSOON
TROUGH HAS DRIFTED S TO INLAND OVER PANAMA AND COSTA RICA WITH
ANY SHOWER ACTIVITY INLAND AS WELL. FRESH TO STRONG E TRADE
WINDS ARE ACROSS MOST OF THE CARIBBEAN BASIN PRODUCING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS MAINLY S OF 14N TO INLAND OVER
SOUTH AMERICA E OF 68W TO ACROSS THE WINDWARD ISLANDS. THIS IS
LEAVING AN AREA OF THE CENTRAL CARIBBEAN UNDER MOSTLY CLEAR
SKIES THIS EVENING. THE CENTRAL CARIBBEAN TROPICAL WAVE WILL
MOVE TO NEAR 80W FRI AND ACROSS THE FAR W CARIBBEAN AND
GULF OF HONDURAS TO INLAND BELIZE AND THE YUCATAN PENINSULA LATE
FRI INTO SAT. ANOTHER TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC
IS FORECAST TO ENTER THE E CARIBBEAN SAT INTO SUN. THE FRESH TO
STRONG E TRADE WINDS WILL PERSIST OVER MOST OF THE CARIBBEAN
BASIN THROUGH FRI THEN DIMINISH SOME SAT AND SUN AS ATLC HIGH
PRESSURE WEAKENS.

ATLANTIC OCEAN...
THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS OVER THE W ATLC
ACROSS FLORIDA BETWEEN NAPLES AND MELBOURNE CONTINUING TO BEYOND
32N71W COVERING THE W ATLC OF 76W. THE UPPER LOW CENTERED IN THE
CENTRAL CARIBBEAN COVERS THE REMAINDER OF THE W ATLC S OF 27N
BETWEEN 63W-75W SUPPORTING A SURFACE TROUGH THAT WAS PART OF A
TROPICAL WAVE IN THE CARIBBEAN AND NOW EXTENDS FROM 24N66W TO
20N69W PRODUCING ISOLATED SHOWERS WITHIN 150 NM EITHER SIDE OF
THE TROUGH AXIS. A WEAK UPPER LOW COVERS THE CENTRAL ATLC
CENTERED NEAR 26N51W SUPPORTING A WEAK SURFACE TROUGH THAT
EXTENDS FROM 29N54W TO 27N55W PRODUCING CLUSTERS OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS FROM 26N-31N BETWEEN 51W-60W. A
BROAD UPPER TROUGH COVERS THE NE ATLC N OF 30N BETWEEN 14W-37W
SUPPORTING A SURFACE TROUGH THAT ENTERS THE DISCUSSION AREA NEAR
32N39W ALONG 29N41W TO 27N45W. A BROAD SURFACE RIDGE COVERS THE
ATLC N OF 20N NARROWING W OF 75W INTO THE GULF OF MEXICO WITH A
WEAKNESS IN THE IMMEDIATE VICINITY OF THE ABOVE SURFACE TROUGH
AND A 1025 MB HIGH NEAR 31N56W. THE REMAINDER OF THE ATLC WATERS
ARE UNDER FAIR CONDITIONS THIS EVENING WITH THE LAST VISIBLE
SATELLITE IMAGERY INDICATED AN AREA OF SAHARAN DUST COVERING THE
TROPICAL ATLC S OF 22N TO NEAR 65W.

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

$$
PAW





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