[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280613
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI SEP 28 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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...METEOROLOGICAL ANALYSIS...
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURES...

TROPICAL STORM KAREN HAS SHOWN SIGNS OF WEAKENING DURING THE
PAST 6 HOURS BUT IS STILL A TROPICAL STORM OVER THE OPEN WATERS
OF THE CENTRAL ATLANTIC.  AT 28/0300 UTC KAREN WAS NEAR 14.8N
49.5W OR ABOUT 780 NM EAST OF THE WINDWARD ISLANDS...MOVING WEST
NORTHWEST NEAR 12 KT.  ESTIMATED MINIMUM CENTRAL PRESSURE IS
1005 MB.  MAXIMUM SUSTAINED WINDS ARE 50 KT WITH GUSTS TO 60 KT.
SEE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER
MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS.  STRONG SWLY SHEAR
CONTINUES TO HINDER ANY DEVELOPMENT. IN FACT CONVECTION NEAR THE
CENTER HAS DIMINISHED SIGNIFICANTLY DURING THE PAST 6 HOURS.
A GRADUAL WEAKENING IS FORECAST FOR THE NEXT FEW DAYS.  A BAND
OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF THE
CENTER FROM 11N-17N BETWEEN 43W-47W.

HURRICANE LORENZO IS CENTERED NEAR 20.5N 96.5W AT 28/0300 UTC OR
OR ABOUT 70 MILES...110 KM...EAST-SOUTHEAST OF TUXPAN MEXICO
MOVING WEST AT 5 KT.  ESTIMATED MINIMUM CENTRAL PRESSURE IS 990
MB.  MAXIMUM SUSTAINED WIND SPEED IS 70 KT GUSTS 85 KT.  SEE
LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT3/
WTNT33 KNHC FOR MORE DETAILS.  LORENZO SHOULD MAKE LANDFALL
ALONG THE COAST OF MEXICO WITHIN THE NEXT 12 HOURS.  LORENZO IS
EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 10
INCHES OVER THE MEXICAN STATE OF VERACRUZ...WITH POSSIBLE
ISOLATED MAXIMUM AMOUNTS OF 15 INCHES.  HURRICANE FORCE WINDS
ONLY EXTEND 10-20 NM FROM THE CENTER.  MEXICAN RADAR FROM
ALVARADO SHOWS A SMALL COMPACT EYE ALONG THE MEXICAN COAST WITH
A SMALL AREA OF CONVECTION MOVING WEST.  SCATTERED MODERATE TO
STRONG CONVECTION IS FROM 19N-22N BETWEEN 95W-98W.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE E ATLC ALONG 27W SOUTH OF 19W MOVING
W 10-15 KT. THE WAVE SHOWS UP WELL IN LOW LEVEL SATELLITE
DERIVED WINDS AND VORTICITY...AND THE UW CIMSS TPW PRODUCTS WITH
A GOOD MOISTURE SURGE.  SIGNIFICANT DEVELOPMENT OF THIS SYSTEM
IS NOT ANTICIPATED FOR THE NEXT 24 HOURS.  A CLUSTER OF
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF THE
WAVE AXIS FROM 13N-16N BETWEEN 24W AND 26W.  SIMILAR CONVECTION
IS W OF THE WAVE AXIS FROM 12N-14N BETWEEN 27N-29N.

A TROPICAL WAVE IS OVER THE CARIBBEAN ALONG 74W/75W S OF 22N
MOVING W NEAR 10-15 KT.  THIS WAVE IS PRODUCING CLUSTERS OF
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION OVER THE
SOUTHERN BAHAMAS FROM 20N-24N BETWEEN 72W-75W.  CONVECTION
ASSOCIATED WITH THIS WAVE IS FORECAST TO SPREAD OVER EASTERN
CUBA AND JAMAICA TOMORROW.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N12W 11N25W 9N35W 13N45W 9N60W.
BESIDES THE CONVECTION MENTIONED ABOVE WITH T.S. KAREN AND THE
TROPICAL WAVE OVER THE E ATLC...ISOLATED MODERATE CONVECTION IS
FROM 4N-6N BETWEEN 20W-28W.

DISCUSSION...

GULF OF MEXICO...
HURRICANE LORENZO...WHICH IS ABOUT TO MAKE LANDFALL ON THE
MEXICAN COAST IS THE MAIN WEATHER FEATURE ACROSS THE GULF OF
MEXICO.  THE SLOW MOTION OF LORENZO WILL LIKELY PRODUCE
TORRENTIAL RAINFALL ALONG ITS PATH. SEE SPECIAL FEATURES ABOVE
FOR MORE DETAILS.  IN THE UPPER LEVELS...AN UPPER HIGH IS OVER
LORENZO WITH A RIDGE AXIS EXTENDING NE TO N FLORIDA.  DRIER AIR
IS FILTERING INTO THE N GULF.  BESIDES FOR LORENZO IN THE FAR SW
GULF STRONG SUBSIDENCE PREVAILS.  EXPECT CONVECTION OVER THE W
GULF W OF 95W DURING THE NEXT 24 HOURS MOSTLY DUE TO LORENZO.

CARIBBEAN SEA...
A TROPICAL WAVE IS MOVING WWD ACROSS THE CENTRAL CARIBBEAN WITH
CONVECTION N OF HISPANIOLA. SEE TROPICAL WAVE SECTION.  ISOLATED
MODERATE CONVECTION IS INLAND OVER N COLOMBIA FROM 5N-10N
BETWEEN 72W-77W.  SCATTERED MODERATE CONVECTION IS ALONG THE
COAST OF W CUBA FROM 19N-20N BETWEEN 77W-79W.  TRADE WINDS
REMAIN LIGHT TO MODERATE ACROSS THE BASIN.  IN THE UPPER
LEVELS...A SMALL UPPER LEVEL LOW IS OVER THE NW CARIBBEAN NEAR
19N83W.  AN UPPER LEVEL HIGH IS S OF HISPANIOLA NEAR 15N73W.
ANTICYCLONIC FLOW IS BETWEEN 60W-80W.  SIGNIFICANT UPPER LEVEL
MOISTURE AND BROKEN HIGH CLOUDS COVERS THE ENTIRE CARIBBEAN.
EXPECT CONVECTION OVER MOST OF THE CARIBBEAN AND CENTRAL
AMERICA W OF 75W.

ATLANTIC OCEAN...
A 1012 MB LOW IS OVER THE W ATLANTIC NEAR 30N78W.  A SURFACE
TROUGH EXTENDS SW FROM THE LOW TO S FLORIDA.  CLUSTERS OF
SCATTERED MODERATE CONVECTION IS E OF THE LOW FROM 27N-32N
BETWEEN 70W-76W.  A SURFACE TROUGH IS OVER THE CENTRAL ATLANTIC
ALONG 28N47W 20N61W.  ISOLATED MODERATE CONVECTION IS FROM
22N-26N BETWEEN 50W-60W.  A 1023 MB HIGH IS OVER THE E ATLANTIC
NEAR 30N30W.  IN THE UPPER LEVELS...A RIDGE IS N OF 20N BETWEEN
60W-70W.  AN UPPER LEVEL LOW IS CENTERED OVER THE CENTRAL
ATLANTIC NEAR 30N56W.  WLY FLOW IS OVER THE E ATLANTIC N OF 20N
E OF 40W.  A LARGE UPPER LEVEL HIGH IS OVER THE TROPICS NEAR
11N35W.  ANTICYCLONIC FLOW IS FROM EQ-20N BETWEEN 20W-50W.

$$
FORMOSA






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