[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 140559
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT WED SEP 14 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0345 UTC.

...SPECIAL FEATURE...

HURRICANE OPHELIA IS CENTERED NEAR 32.8N 77.9W...OR 87 NM S OF
WILMINGTON NORTH CAROLINA AND 110 NM E OF CHARLESTON SOUTH
CAROLINA...AT 14/0600 UTC AND IS STATIONARY. ESTIMATED MINIMUM
CENTRAL PRESSURE IS 982 MB. MAXIMUM SUSTAINED WIND SPEED IS 65
KT WITH GUSTS TO 80 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND THE PUBLIC ADVISORY
UNDER HEADERS MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. THE SYS OF
OPHELIA HAS BECOME BETTER DEFINED ON WSR-88D RADAR AS WELL AS
INFRARED SATELLITE IMAGERY. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION NOW SURROUNDS THE EYE WITHIN WITHIN 75/90 NM IN ALL
QUADRANTS. UPPER LEVEL OUTFLOW IS RELATIVELY CIRCULAR BUT IS
SLIGHTLY SHEARED TO THE S DUE TO THE REMNANT DRY AIR.

...TROPICAL WAVES...

E ATLC TROPICAL WAVE ALONG 38W S OF 17N MOVING W 15 KT. WAVE
REMAINS A LOW LATITUDE WAVE AND HAS ACQUIRED A STRONGER
LOW-LEVEL CURVATURE AS IT BECOMES MORE EMBEDDED IN THE TRADE
WINDS. WAVE IS ALSO EMBEDDED IN A COPIOUS AMOUNT OF TROPICAL
MOISTURE PRODUCING CLUSTERS OF SCATTERED MODERATE/ISOLATED
STRONG CONVECTION COVERING A LARGE AREA FROM 2N-17N BETWEEN
33W-40W.

CENTRAL ATLC TROPICAL WAVE TILTED ALONG 5N51W 15N50W 21N48W
MOVING W 10-15 KT. WAVE CONTINUES TO DISPLAY A WELL-DEFINED
AND SHARP CURVATURE...BUT IT CONTINUES TO BE AFFECTED BY
MODERATE SW SHEAR THAT IS KEEPING ALL CONVECTION TO THE E.
SCATTERED SHOWERS/THUNDERSTORMS FROM THE ITCZ AXIS TO 17N
BETWEEN 43W-48W.

W CARIBBEAN TROPICAL WAVE ALONG 89W S OF 20N MOVING W 15 KT.
WAVE IS INLAND OVER CENTRAL AMERICA/YUCATAN PENINSULA WITH THE
CURVATURE IS EASILY DEFINED IN THE E PACIFIC REGION...BUT NOT
IN THE CARIBBEAN OR GULF OF MEXICO. SCATTERED MODERATE/STRONG
CONVECTION IS MOSTLY OVER LAND AND IN THE GULF OF HONDURAS S OF
18N W OF 86W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 13N16W 9N26W 11N45W 8N62W. SCATTERED
MODERATE/STRONG CONVECTION MOVING OFF THE W COAST OF AFRICA E OF
A LINE FROM 11N17W-15N21W TO JUST INLAND OVER GUINEA BISSAU...
GAMBIA...AND SENEGAL. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS WITHIN 120 NM S OF THE AXIS FROM 40W-45W.
SCATTERED CLUSTERS OF SIMILAR CONVECTION DOT THE AREA S OF THE
ITCZ AXIS TO 2N BETWEEN 24W-50W.

...DISCUSSION...

GULF OF MEXICO...
HURRICANE OPHELIA CONTINUES TO PULL DRIER CONTINENTAL AIR ACROSS
NE FLORIDA BUT NOT MAKING IT INTO THE GULF OF MEXICO. TO THE
W...AN UPPER LEVEL TROUGH/SHEAR AXIS EXTENDS ACROSS LOUISIANA TO
THE W BAY OF CAMPECHE AND IS DRAWING SOME TROPICAL MOISTURE N
OVER THE E/CENTRAL GULF AHEAD OF A BUILDING UPPER RIDGE THAT
EXTENDS FROM THE YUCATAN PENINSULA NE TO THE CENTRAL FLORIDA
PENINSULA. DIFFLUENCE OVER THE YUCATAN AND BAY OF CAMPECHE IS
GENERATING CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION
INLAND AND WITHIN 75 NM ALONG THE COAST FROM 90W-95W WITH
ISOLATED SHOWERS S OF 26N FROM 87W-93W. WEAK 1018 MB HIGH IS IN
THE CENTRAL ATLC NEAR 27N87W. THIS PATTERN IS EXPECTED TO BE
MAINTAINED UNTIL A DRIER SURGE OF AIR MOVES IN LATE THU.

CARIBBEAN...
THE UPPER LEVEL FLOW OVER THE CARIBBEAN IS DOMINATED BY A LARGE
UPPER LOW CENTERED S OF JAMAICA NEAR 16N78W. THE DEEPEST
MOISTURE IS CURRENTLY LOCATED OVER THE SW CARIBBEAN WHERE
CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF
17N W OF 79W TO INLAND OVER CENTRAL AMERICA. ELSEWHERE...THERE
ARE SOME PATCHES OF UPPER MOISTURE MOVING AROUND THE CIRCULATION
ASSOCIATED WITH THE UPPER LOW...BUT LOW-LEVEL CONDITIONS ARE
GENERALLY TOO DRY FOR WIDESPREAD CONVECTION. SCATTERED SHOWERS
ARE WITHIN 75 NM S OF CUBA FROM THE WINDWARD PASSAGE TO THE ISLE
OF YOUTH AND ISOLATED SHOWERS DOT THE E CARIBBEAN E OF 70W.

WEST ATLANTIC...
HURRICANE OPHELIA CONTINUES TO PULL DRIER CONTINENTAL AIR ACROSS
NE FLORIDA BUT NOT MAKING IT INTO THE GULF OF MEXICO. UPPER
RIDGE EXTENDS FROM NEAR OPHELIA SSE TO PUERTO RICO. DEEP LAYERED
MID-LATITUDE TROUGH DIGS INTO THE CENTRAL ATLC IS BREAKING THE
SUBTROPICAL SURFACE RIDGE DOWN FORMING A WEAK RIDGE EXTENDING
FROM BERMUDA SW TO THE S BAHAMA ISLANDS. A SURFACE TROUGH IS
TRYING TO DEVELOP FROM THE CENTRAL ATLC TO PUERTO RICO AND THEN
MOVE NW OVER THE BAHAMAS...WHICH COULD INCREASE THE CHANCE OF
SHOWERS/ THUNDERSTORMS OVER THE AREA THROUGH THE END OF THE WEEK.

CENTRAL/EAST ATLANTIC...
AN UNSEASONABLY STRONG UPPER LEVEL TROUGH HAS DUG DOWN OVER THE
SUBTROPICAL WATERS N OF 22N BETWEEN 38W-67W AND APPEARS NEAR
STATIONARY AT THIS TIME. THE TROUGH HAD PUSHED A COLD FRONT
THROUGH THE AREA BUT HAS COME UP STATIONARY FRONT THAT NOW
EXTENDS THROUGH 32N36W TO 22N52W. SCATTERED SHOWERS/STRONG
THUNDERSTORMS ARE WITHIN 90 NM OF LINE 23N60W-24N49W-32N37W. A
SECOND SURGE IN THE FORM OF AN UPPER SHORTWAVE TROUGH WITH AN
ATTENDANT COLD FRONT IS APPROACHING THE N PORTION OF THE CENTRAL
ATLC. A WEAKENING UPPER LEVEL LOW IS LOCATED NEAR 22N44W AT THE
AND IS BEING PULLED NE AHEAD OF THE UPPER TROUGH. AN UPPER HIGH
HAS DEVELOPED DEEP IN THE TROPICS NEAR 14N32W WITH A RIDGE
EXTEND N TO 30N35W AND IS PROVIDING A FAIRLY DECENT AMOUNT OF
MOISTURE AND DIFFLUENCE ASSOCIATED WITH THE TROPICAL WAVE ALONG
38W. AN UPPER TROUGH EXTENDS FROM THE NE ATLC OFF THE AFRICAN
COAST ALONG 32N16W JUST W OF THE CANARY ISLANDS TO THE CAPE
VERDE ISLANDS NEAR 14N36W.

$$
WALLACE


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