[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291236 AAA
TWDAT

TROPICAL WEATHER DISCUSSION...UPDATED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE AUG 29 2006

UPDATED TO INCLUDE THE 29/1200 UTC POSITION AND PRESSURE


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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...SPECIAL FEATURE...
THE CENTER OF TROPICAL STORM ERNESTO IS NOW OVER WATER AGAIN
NEAR 22.8N 79.3W AT 29/1200 UTC. THIS POSITION IS ABOUT
175 NM/320 KM SOUTHEAST OF KEY WEST FLORIDA...AND ABOUT
185 NM/350 KM SOUTH-SOUTHEAST OF MIAMI FLORIDA. THE ESTIMATED
MINIMUM CENTRAL PRESSURE IS 1007 MB. THE MAXIMUM SUSTAINED WIND
SPEEDS ARE 40 KT WITH GUSTS TO 50 KT. ERNESTO IS MOVING TOWARD
THE NORTHWEST NEAR 12 KT...AND THIS GENERAL MOTION IS EXPECTED
TO CONTINUE FOR THE NEXT 24 HOURS. ON THE FORECAST TRACK...THE
CENTER OF ERNESTO WILL BE NEAR THE FLORIDA KEYS OR SOUTHEAST
FLORIDA BY THIS EVENING. HOWEVER...SQUALLY RAINBANDS WILL BE
MOVING ONSHORE THESE AREAS DURING THE AFTERNOON.PLEASE REFER TO
THE LATEST NHC FORECAST ADVISORY UNDER HEADERS MIATCMAT5/WTNT25
KNHC AND THE PUBLIC ADVISORY MIATCPAT5/WTNT35 KNHC FOR MORE
DETAILS. RADAR IMAGERY FROM MIAMI AND CAMAGUEY CUBA SHOWS
NUMEROUS SHOWERS AND TSTMS SPIRALING CYCLONICALLY THROUGH THE
FLORIDA STRAITS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
ALSO PERSISTS OVER ERN CUBA AIDED BY UPSLOPE FLOW ON THE SE
SEMICIRCLE OF ERNESTO.

...TROPICAL WAVES...
A LOW AMPLITUDE TROPICAL WAVE IS ALONG 27W/28W S OF 15N...MOVING
W NEAR 15 KT. THIS WAVE IS DIFFICULT TO LOCATE AS IT IS
SUPERIMPOSED ON THE MONSOON TROUGH. HOWEVER...BROAD CYCLONIC
CURVATURE IS EVIDENT IN NEARBY SURFACE OBSERVATIONS AND LOW TO
MID CLOUD MOTIONS ON SATELLITE IMAGERY. A NEW BURST OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION HAS DEVELOPED FROM 11N-13N
BETWEEN 25W-29W. A SMALLER CLUSTER IS NOTED NEAR 8N28W.

A HIGH AMPLITUDE TROPICAL WAVE IS ALONG 41W S OF 22N MOVING W
NEAR 15 KT. A 1010 MB LOW IS ALONG THE WAVE NEAR 17N. BROAD
CYCLONIC TURNING REMAINS VERY EVIDENT IN THE LOW TO MID CLOUD
FIELD AROUND THE WAVE AXIS AND SURFACE LOW...THOUGH DEEP
CONVECTION IS MINIMAL.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 13N13W 11N25W 11N30W 13N38W 10N44W
TO THE COAST OF SOUTH AMERICA NEAR 9N61W. CLUSTERS OF SCATTERED
MODERATE CONVECTION CONTINUE TO MOVE W THROUGH WRN AFRICA AND
THE ADJACENT ATLC WATERS FROM FROM 8N-16N BETWEEN
12W-22W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-13N
BETWEEN 30W-40W. THE WRN HALF OF THE AXIS TO THE SOUTH AMERICAN
COAST REMAINS FAIRLY QUIET...THOUGH NUMEROUS STRONG SHOWERS AND
TSTMS CONTINUE TO MOVE W THROUGH NW SOUTH AMERICA WHICH IS
LIKELY AT LEAST PARTLY ASSOCIATED WITH THE ITCZ.

...DISCUSSION...

THE GULF OF MEXICO...
ALL EYES REMAIN ON TROPICAL STORM ERNESTO AS THIS SYSTEM WILL
HAVE AN IMPACT ON THE WEATHER IN FLORIDA AND THE ERN GULF OVER
THE NEXT COUPLE OF DAYS. RAINFALL TOTALS OF 5 TO 10 INCHES ARE
POSSIBLE OVER PORTIONS OF EASTERN AND SOUTHERN FLORIDA AND THE
KEYS THROUGH WEDNESDAY...WITH ISOLATED AMOUNTS UP TO 15 INCHES
POSSIBLE OVER SOUTHEASTERN FLORIDA. FOR MORE INFORMATION REFER
TO THE SPECIAL FEATURE SECTION ABOVE. ELSEWHERE IN THE GULF...A
CLUSTER OF SCATTERED MODERATE CONVECTION IS SEEN JUST SW OF CAPE
SAN BLAS FLORIDA. THIS SEEMS MOST ASSOCIATED WITH UPPER
DIFFLUENT AIR BETWEEN THE UPPER HIGH SEEN SPINNING OVER THE SE
US AND THE UPPER LOW MOVING W THROUGH THE FLORIDA STRAITS. MID
TO UPPER LEVEL CYCLONIC FLOW IS DOMINATING THE WRN HALF OF THE
GULF THIS EVENING...AROUND A WELL DEFINED UPPER LOW CENTERED
NEAR 23N94W. ISOLATED SHOWERS AND TSTMS CONTINUE TO WRAP AROUND
THIS UPPER LOW IN THE WRN GULF. A FAIRLY WEAK SURFACE GRADIENT
IS OVER THE GULF...WITH ASSOCIATED LIGHT WINDS AND LOW SEAS
BEING OBSERVED. CONSIDERABLY HIGHER WINDS AND SEAS SHOULD BE
EXPECTED NEAR ERNESTO.

THE CARIBBEAN SEA...
THE CENTER OF TROPICAL STORM ERNESTO IS NOW OVER WATER JUST
NORTH OF CENTRAL CUBA. THE REMAINDER OF THE CARIBBEAN OUTSIDE OF
THE VICINITY OF ERNESTO IS FAIRLY QUIET WITH MINIMAL SHOWER/TSTM
ACTIVITY NOTED. DRY/STABLE AIR IS OVER THE FAR NW CARIBBEAN IN
ASSOCIATION WITH A WEAK UPPER HIGH IN THE AREA. DRY/STABLE AIR
CONTINUES TO BE ADVECTED W INTO THE ERN AND CNTRL CARIBBEAN
AROUND THE SRN PERIPHERY OF AN UPPER HIGH. TRADE WINDS ARE A
FAIRLY LIGHT 5-15KT ACROSS MUCH OF THE AREA DUE TO A WEAKENING
OF THE GRADIENT S OF ERNESTO.

THE ATLANTIC OCEAN...
A MID-UPPER LEVEL RIDGE CENTERED OVER THE SE US HAS RIDGING THAT
STRETCHES E TO 65W ALONG 31N/32N. AN UPPER TROUGH LIES TO THE E
OF THE RIDGE BETWEEN 40W-60W MAINLY N OF 20N...WITH AN UPPER LOW
CENTER SEEN NEAR 22N57W. A WEAK SURFACE TROUGH/OLD FRONTAL
BOUNDARY IS UNDER THIS VICINITY ALONG 26N61W 32N53W....ALONG
WITH A PAIR OF WEAK SURFACE LOWS NEAR 30N57W AND 32N51W.
CLUSTERS OF MODERATE CONVECTION AND SCATTERED SHOWERS AND TSTMS
ASSOCIATED WITH THIS LOW LEVEL CONFLUENT ZONE ARE SEEN FROM
28N-35N BETWEEN 45W-60W. ANOTHER CLUSTER OF MODERATE CONVECTION
IS SEEN NEAR 26N45W ASSOCIATED WITH UPPER DIFFLUENCE BETWEEN THE
UPPER TROUGH TO THE NORTH...AND AND UPPER HIGH SPINNING ABOUT
500NM ESE OF THE WINDWARD ISLANDS. THE REMAINDER OF THE ATLC IS
DOMINATED BY A BROAD UPPER RIDGE EXTENDING FROM AFRICA TO NEAR
50W WITH MULTIPLE HIGH CENTERS.  A COUPLE OF WEAK BENIGN UPPER
LOWS ARE ON THE W PERIPHERY OF THE RIDGE PRODUCING LITTLE...IF
ANY...WEATHER. ANOTHER UPPER LOW CLIPS THE AREA CENTERED JUST
OFF THE COAST OF MOROCCO NEAR 31N15W. AT THE SURFACE...A WEAK
PRES GRAD EXISTS W OF 50W DUE TO THE WEAK TROUGH DRAPED ACROSS
THE NRN PORTION OF THE AREA. STRONGER GRAD IN THE E ATLC AS A
1025 MB HIGH IS CENTERED NE OF THE AZORES INTERACTING WITH A
1011 MB LOW ALONG A TROPICAL WAVE NEAR 17N41W.

$$
WILLIS


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