[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 080603
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU SEP 08 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 FEATURES...

TROPICAL STORM OPHELIA IS CENTERED NEAR 28.7N 79.5W...OR 60 NM
ENE OF CAPE CANAVERAL FLORIDA...AT 08/0600 UTC AND NEARLY
STATIONARY. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO
55 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 994 MB. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC
AND THE PUBLIC ADVISORY UNDER HEADERS MIATCPAT1/WTNT31 KNHC FOR
MORE DETAILS. OPHELIA SATELLITE PRESENTATION IS RAGGED AT BEST
WITH TWO MAIN AREAS OF CONVECTION. SCATTERED MODERATE/STRONG
CONVECTION IS CLOSEST TO THE CENTER FROM 28N-31N W OF 79W TO
INLAND OVER NE FLORIDA. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS NE OF THE CENTER WITHIN 60 NM OF 30.5N FROM
76W-79W. OTHER HEAVY RAINBANDS ARE ONSHORE OVER THE GEORGIA
COAST AND AS FAR S AS LAKE OKEECHOBEE.

HURRICANE NATE IS CENTERED NEAR 29.8N 64.8W...OR 150 NM S OF
BERMUDA...AT 08/0600 UTC MOVING ENE AT 7 KT. MAXIMUM SUSTAINED
WIND SPEED IS 75 KT WITH GUSTS TO 90 KT. ESTIMATED MINIMUM
CENTRAL PRESSURE 979 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/ WMO HEADERS MIATCMAT5/WTNT25 KNHC AND THE PUBLIC ADVISORY
UNDER HEADERS MIATCPAT5/WTNT35 KNHC FOR MORE DETAILS. DEEP
CONVECTION ASSOCIATED WITH NATE IS BEING SHEARED TO THE E DUE TO
AN UPPER HIGH WITH THE MOISTURE IS THEN BEING DRAWN INTO MARIA.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 27N-32.5N
60W-67W INCLUDING BERMUDA.

HURRICANE MARIA CENTERED NEAR 37.5N 49.4W...OR 1060 NM W OF THE
AZORES...AT 07/0300 UTC MOVING NE AT 12 KT. MAXIMUM SUSTAINED
WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. ESTIMATED MINIMUM
CENTRAL PRESSURE 982 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/ WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS.
WATER VAPOR IMAGERY INDICATES THAT MARIA IS EMBEDDED WITHIN AN
UPPER LEVEL SHORTWAVE TROUGH AND NOW S SHEAR IS PARTIALLY
EXPOSING THE LOW LEVEL CENTER. THE HURRICANE IS BECOMING MORE
EXTRATROPICAL IN CHARACTERISTICS WITH THE ASSOCIATED DEEP
CONVECTION SPREADING AND WITH WARMER CLOUD TOPS. SCATTERED
SHOWERS/THUNDERSTORMS COVER A BROAD AREA FROM 35N-46N BETWEEN
42W-54W.

...TROPICAL WAVES...

E ATLC TROPICAL WAVE WAS INTRODUCED OFF THE COAST OF AFRICA
ALONG 18W S OF 19N MOVING W 10-15 KT BASED ON THE DAKAR UPPER
AIR SOUNDING AND SATELLITE SIGNATURE. BROAD MID LEVEL TURNING IS
OBSERVED ALONG THE WAVE AXIS NEAR 9N. SCATTERED MODERATE/STRONG
CONVECTION IS WITHIN 30 NM OF LINE 12N18.5W-14N17W.

CENTRAL ATLC TROPICAL WAVE ALONG 44W S OF 22N MOVING W 15-20 KT.
HIGH AMPLITUDE WAVE SIGNATURE CURVATURE WITH SCATTERED CLUSTERS
OF SCATTERED SHOWERS/THUNDERSTORMS WITHIN 120 NM OF LINE
16N47W-24N41W.

TROPICAL WAVE LOCATED ABOUT 300 NM E OF THE LESSER ANTILLES
ALONG 56W S OF 20N MOVING W 10-15 KT. THE WAVE IS LOCATED ALONG
THE LEADING EDGE OF THE SAHARAN DUST SURGE AND THE TRAILING EDGE
OF AN UPPER LOW GENERATING SCATTERED SHOWERS/THUNDERSTORMS FROM
13N-18N BETWEEN 54W-59W.

CENTRAL CARIBBEAN TROPICAL WAVE ALONG 70W/71W S OF 20N MOVING W
10-15 KT. THE NORTHERN PORTION WAS BROKEN FROM THE MAIN WAVE
AXIS AND IS NOW A SURFACE TROUGH MOVING NW AT 5-10 KT AND IS
INTERACTING WITH THE FLOW AROUND HURRICANE NATE. WAVE IS MOVING
INTO A DRIER ENVIRONMENT. THUS...ONLY ISOLATED SHOWERS TRAIL THE
WAVE WITHIN 90 NM OF LINE 15N67W TO OVER HISPANIOLA NEAR 18N71W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N19W 10N32W 15N42W THEN ALONG
13N45W 12N55W. THE FAR E ITCZ IS BEING PUSHED S E OF 25 DUE TO
THE APPEARANCE OF THE TROPICAL WAVE THAT JUST MOVED OFF THE
COAST OF AFRICA. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE
FROM 5N-12N BETWEEN 19W-27W AND FROM 10N-14N BETWEEN 42W-49W.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 6N-9N BETWEEN
28W-45W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LOW IS OVER THE MEXICAN PLATEAU NEAR 22N100W WITH FLOW
COVERING THE GULF W OF 92W. THE LOW IS WRAPPING DRY AIR OFF THE
PLATEAU INTO THE S SIDE OF THE CIRCULATION FROM MEXICO CITY TO
VERACRUZ. HOWEVER...A BROAD PLUME OF TROPICAL MOISTURE IS BEING
ADVECTED UP THE E SIDE OF THE LOW OVER THE ENTIRE W GULF. IN
ADDITION...AN ILL-DEFINED 1010 MB LOW IS OVER THE W BAY OF
CAMPECHE NEAR 20N94W WITH A TROUGH EXTENDING NW TO 27N96W AND IS
INTERACTING WITH THE DEEP MOISTURE PLUME TO PRODUCE SCATTERED
SHOWERS/THUNDERSTORMS FROM W OF 88W. FARTHER E...A SURFACE
TROUGH NEAR THE TAIL END OF T.S. OPHELIA EXTENDS FROM SOUTH
FLORIDA W TO 26N90W AND IS PRODUCING ISOLATED SHOWERS OVER THE
NE GULF N OF 25N E OF 85W. UPPER RIDGE FROM OVER CENTRAL AMERICA
AND THE YUCATAN PENINSULA IS GENERATING SCATTERED
MODERATE/STRONG CONVECTION OVER THE E BAY OF CAMPECHE S OF 20N E
OF 94W.

CARIBBEAN...
LARGE UPPER LEVEL TROUGH IS OVER THE CENTRAL CARIBBEAN WITH AN
AXIS EXTENDING FROM W CUBA TO THE N COAST OF COLOMBIA...AND IS
ASSOCIATED WITH A SUBSTANTIAL AREA OF MODERATE/STRONG SUBSIDENCE
BETWEEN 72W-82W. W/NW FLOW FEEDING INTO THE TROUGH FROM AN UPPER
RIDGE OVER CENTRAL AMERICA AND THE YUCATAN PENINSULA AND IS
ADVECTING MOISTURE E ACROSS CENTRAL AMERICA FROM THE E PACIFIC
WITH SCATTERED MODERATE/STRONG CONVECTION ALONG THE COAST OF
HONDURAS AND GUATEMALA TO BELIZE. FARTHER E...A LARGE UPPER LOW
IS APPROACHING THE LEEWARD ISLANDS FROM THE CENTRAL ATLC
PRODUCING MODERATE NE FLOW OVER THE E CARIBBEAN. THE BULK OF THE
MOISTURE ASSOCIATED WITH THE TROPICAL WAVE ALONG 70W/71W. THE
CARIBBEAN WILL REMAIN MOSTLY DRY OVER THE NEXT SEVERAL DAYS
EXCEPT IN THE SW PORTION WHERE MOISTURE LEVELS WILL REMAIN HIGH.

ATLANTIC...
BROAD UPPER RIDGE EXTENDS ACROSS THE W ATLC FROM THE FLORIDA/
GEORGIA BORDER E 29N50W...SPANNING OVER BOTH T.S. OPHELIA AND
HURRICANE NATE. PATCH OF DRY AIR EXTENDS BETWEEN THE TWO SYSTEMS
S OF 29N BETWEEN 69W TO 80W S OF T.S. OPHELIA. AN UPPER LEVEL
TROUGH EXTENDS ACROSS THE CENTRAL ATLC FROM 28N45W 22N54W
THROUGH AN UPPER LOW NEAR 18N57W TO 11N60W. THE LOW IS DRAWING
MOISTURE N TO ITS E...AND SUPPORTING SHOWER ACTIVITY ASSOCIATED
WITH THE TROPICAL WAVE NEAR 56W. A LARGE UPPER HIGH IS CENTERED
NEAR 20N35W WITH A RIDGE EXTENDING SW TO 7N48W BUT IT IS BEING
PUSHED TO THE W BY A DIGGING UPPER TROUGH THAT EXTENDS FROM THE
CAPE VERDE ISLANDS E OF 25W. ONE SURGE OF SAHARAN DUST HAS
CROSSED THE LESSER ANTILLES...BUT A SECOND MORE CONCENTRATED
SURGE IS ALIGNED E OF A LINE FROM 30N40W 17N35W 10N30W.

$$
WALLACE


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