[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280007
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN AUG 27 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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 FEATURES...
ERNESTO IS DOWNGRADED TO A TROPICAL STORM BUT STILL BRINGING
TORRENTIAL RAINS TO HAITI AND THE DOMINICAN REPUBLIC. IT IS
CENTERED NEAR 18.2N 74.4W AT 28/0000 UTC MOVING NW AT 6 KT. THIS
POSITION IS VERY NEAR THE SOUTHWESTERN TIP OF HAITI AND ABOUT
120 NM SSE OF GUANTANAMO CUBA. ESTIMATED MINIMUM CENTRAL
PRESSURE HAS RISEN TO ABOUT 1004 MB. THE MAXIMUM SUSTAINED WIND
HAVE DECREASED TO NEAR 45 KT WITH HIGHER GUSTS. SEE THE LATEST
NHC FORECAST/ADVISORY UNDER HEADERS MIATCMAT5/WTNT25 KNHC FOR
MORE DETAILS. APPARENTLY...THE HIGHLY MOUNTAINOUS TERRAIN OF THE
SOUTHWESTERN PENINSULA OF HAITI HAS DISRUPTED THE CIRCULATION OF
ERNESTO AND THE LOW-LEVEL CENTER HAS BECOME BROAD AND
ILL-DEFINED. THIS TROPICAL CYCLONE IS FORECAST TO STRENGTHEN
AFTER IT MOVES AWAY FROM SOUTHWESTERN HAITI AND IT COULD REGAIN
HURRICANE STATUS BEFORE IT REACHES THE SOUTH COAST OF EASTERN
CUBA TOMORROW MORNING. OUTER RAINBANDS CONTINUE TO AFFECT
HISPANIOLA. RAINFALL AMOUNTS OF 6 TO 12 INCHES...WITH POSSIBLE
ISOLATED AMOUNTS OF UP TO 20 INCHES...ARE EXPECTED OVER
HAITI...THE DOMINICAN REPUBLIC...AND PORTIONS OF CUBA.  THESE
RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.
SCATTERED MODERATE TO STRONG CONVECTION IS FROM 17N-19N BETWEEN
73W-75W.  CLUSTERS OF SIMILAR CONVECTION ARE ALONG THE CARIBBEAN
COAST OF DOMINICAN REPUBLIC.

TROPICAL DEPRESSION DEBBY IS CENTERED NEAR 31.5N 48.6W AT
27/2100 UTC MOVING N AT 15 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE IS 1012 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 25 KT
WITH GUSTS TO 35 KT. DEBBY IS LOOKING RATHER ELONGATED AND
CONTINUES TO GENERATE LIMITED AND INTERMITTENT BURSTS OF
CONVECTION TO THE NORTH OF THE CENTER. BECAUSE OF THE LACK OF
PERSISTENT ORGANIZED CONVECTION...DEBBY IS NO LONGER A TROPICAL
CYCLONE. THE LAST ADVISORY WAS ISSUED AT 27/2100 UTC.

...TROPICAL WAVES...
HIGH AMPLITUDE TROPICAL WAVE IS ALONG 33W S OF 23N WITH A 1010
MB LOW ALONG THE WAVE AXIS NEAR 17N MOVING W 15-20 KT. WAVE/LOW
REMAINS EMBEDDED WITHIN AN AREA OF DRY AIR AND AFRICAN DUST
LIMITING ACTIVITY ALONG THE WAVE.  ISOLATED SHOWERS AND
THUNDERSTORMS ARE ASSOCIATED WITH THE LOW CENTER.

TROPICAL WAVE IS INLAND OVER SOUTH MEXICO INTO THE EPAC ALONG
93/94W S OF 18N MOVING W 15-20 KT. MOST OF THE CONVECTIVE
ACTIVITY RELATED TO THIS WAVE IS ON THE PACIFIC SIDE.

...THE ITCZ...
ITCZ IS CENTERED ALONG 15N17W 9N30W 7N45W 7N58W.  SCATTERED
MODERATE CONVECTION IS FROM 7N-11N BETWEEN 22W-28W. CLUSTERS OF
MODERATE/ISOLATED STRONG CONVECTION ARE ALONG THE WEST COAST OF
AFRICA FROM 7N-14N. ISOLATED SHOWERS AND TSTMS ARE ELSEWHERE.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE COVERS THE SE U.S. WITH AN UPPER HIGH OVER
CENTRAL GEORGIA. THE RIDGE ALSO DOMINATES THE GULF AND THE W
ATLC. THIS SYSTEM IS PRODUCING ELY UPPER LEVEL FLOW OVER THE N
GULF. AT THE SURFACE...A 1017 MB HIGH IS CENTERED OVER THE GULF
NEAR 27N89W. LIGHT AND VARIABLE WINDS ARE FOUND OVER THE E GULF
UNDER THE INFLUENCE OF THIS HIGH. THE REMAINDER OF THE GULF HAS
10-15 KT SLY FLOW.  SCATTERED SHOWERS AND TSTMS AREA OVER THE E
GULF. A CLUSTER OF MODERATE CONVECTION IS OVER THE YUCATAN
PENINSULA...PROBABLY ASSOCIATED WITH AN UPPER LOW MOVING ACROSS
THIS AREA. ACCORDING TO THE CURRENTLY OFFICIAL FORECAST TRACK...
ERNESTO...AS A HURRICANE IS EXPECTED TO MOVE INTO THE SE GULF ON
WED.

CARIBBEAN SEA...
THE MAIN FEATURE TO FOLLOW THIS EVENING IS TROPICAL STORM
ERNESTO THAT IS MOVING TOWARD EASTERN CUBA. A HURRICANE WARNING
REMAINS IN EFFECT FROM CAMAGUEY TO GUANTANAMO. FOR MORE DETAILS
SEE SPECIAL FEATURES ABOVE. IN ADDITION...CLUSTERS OF SCATTERED
MODERATE CONVECTION IS INLAND OVER WESTERN VENEZUELA AND
NORTHERN COLOMBIA DUE PRIMARILY TO THE ITCZ. A LARGE UPPER LOW
COVERS THE NW CARIBBEAN WEST OF 83W...NORTHERN CENTRAL AMERICA
AND THE YUCATAN PENINSULA. THIS LOW IS FORECAST TO MOVE INTO THE
BAY OF CAMPECHE TOMORROW. BROAD UPPER HIGH DOMINATES THE EASTERN
CARIBBEAN. A DIFFLUENCE PATTERN ALOFT IS OVER ERNESTO. ERNESTO
WILL CONTINUE TO BE THE PREDOMINATE WEATHER PRODUCER IN THE
CARIBBEAN DURING THE NEXT 24-36 HOURS.

ATLANTIC OCEAN...
THE UPPER RIDGE THAT COVERS THE SE U.S EXTENDS INTO THE W ATLC W
OF 70W. A WEAK UPPER TROUGH IS ALONG 31N65W 22N74W. THE UPPER
RIDGE OVER THE E CARIBBEAN EXTENDS NEWD ACROSS PUERTO RICO TO
NEAR 31N55W. A LARGER UPPER LOW IS OVER THE CENTRAL ATLANTIC
NEAR 25N52W PRODUCING SLY UPPER LEVEL SHEAR OVER T.D. DEBBY
WEAKENING THE SYSTEM. UPPER LEVEL RIDGING IS ACROSS THE
REMAINDER OF THE ATLC AND W AFRICA. AT THE SURFACE...A TROUGH
LIES ALONG 31N55W 28N62W 30N70W. WIDELY SCATTERED CONVECTION IS
ALONG AND AHEAD OF THIS TROUGH. ANOTHER SURFACE TROUGH EXTENDS
FROM T.D. DEBBY TO 22N54W. A HIGH PRESSURE LOCATED NEAR THE
AZORES EXTENDS A RIDGE OVER THE CENTRAL-EAST ATLC EAST OF 45W.

$$
GR






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