[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290609
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT SEP 29 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...

KAREN IS WEAKENING UNDER STRONG UPPER LEVEL SOUTHWESTERLY FLOW
BUT IS STILL A MINIMAL TROPICAL STORM OVER THE OPEN WATERS OF
THE CENTRAL ATLANTIC. AT 29/0300 UTC KAREN WAS NEAR 16.2N 51.9W
OR ABOUT 660 MILES...1060 KM...EAST OF THE LEEWARD ISLANDS...
MOVING WEST NORTHWEST NEAR 8 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE IS 1008 MB.  MAXIMUM SUSTAINED WINDS ARE 35 KT WITH
GUSTS TO 45 KT. SEE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER
MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS.  KAREN STILL HAS SOME
CONVECTION NEAR THE CENTER AND A LOT MORE E OF THE CENTER. A
GRADUAL WEAKENING IS FORECAST FOR THE NEXT FEW DAYS DUE TO THE
UNFAVORABLE UPPER WIND ENVIRONMENT.  SCATTERED MODERATE TO
STRONG CONVECTION IS FROM 16N-19N BETWEEN 47W-53W...AND FROM
13N-16N BETWEEN 45W-50W.

TROPICAL DEPRESSION FOURTEEN AT 28/2100 UTC IS NEAR 14.2N 27.5W
OR ABOUT 265 MILES...425 KM...WEST-SOUTHWEST OF THE CAPE VERDE
ISLANDS MOVING WEST NEAR 5 KT.  ESTIMATED MINIMUM CENTRAL
PRESSURE IS 1008 MB.  MAXIMUM SUSTAINED WINDS ARE 30 KT WITH
GUSTS TO 40 KT.  SEE LATEST NHC FORECAST ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY
UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS.  THE CLOUD PATTERN
HAS REMAINED THE SAME FOR THE PAST 18 HOURS DESPITE STRONG
WESTERLY SHEAR.  THE CENTER IS IS ON THE W SIDE OF THE
ELLIPTICAL SIZED CONVECTION AREA.  THE SYSTEM IS FORECAST TO
INTENSIFY 5 KT TO A TROPICAL STORM SHORTLY...THEN DISSIPATE TO A
REMNANT LOW BY 120 HOURS DUE TO PERSISTENT VERTICAL SHEAR.
PRESENTLY SCATTERED MODERATE TO STRONG CONVECTION IS FROM
13N-16N BETWEEN 24W-28W.

...TROPICAL WAVES...

A TROPICAL WAVE IS BETWEEN T.D. FOURTEEN AND T.S. KAREN ALONG
34W SOUTH OF 20W MOVING W 10-15 KT.  THE WAVE SHOWS UP IN LOW
LEVEL SATELLITE DERIVED WINDS AND VORTICITY...AND THE UW CIMSS
TPW PRODUCTS WITH A LOW AMPLITUDE MOISTURE SURGE.  WIDELY
SCATTERED MODERATE CONVECTION IS NEAR THE INTERSECTION OF THE
WAVE AND THE ITCZ FROM 10N-13N BETWEEN 33W-36W.

A TROPICAL WAVE IS OVER THE CARIBBEAN ALONG 81W/82W S OF 21N
MOVING W NEAR 10-15 KT.  AN AREA OF SCATTERED MODERATE
CONVECTION IS E OF NICARAGUA FROM 13N-16N BETWEEN 79W-82W.  THE
WAVE IS ALSO ENHANCING SCATTERED MODERATE CONVECTION OVER
EASTERN CUBA AND JAMAICA FROM 17N-20N BETWEEN 75W-79W.  MOISTURE
FROM THIS WAVE WILL CONTINUE TO AFFECT CUBA AND CENTRAL AMERICA
TONIGHT AND TOMORROW.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N13W 9N20W 14N27W 9N40W 13N50W
10N62W. BESIDES THE CONVECTION MENTIONED ABOVE WITH TROPICAL
CYCLONES AND THE TROPICAL WAVE OVER THE EASTERN
ATLANTIC...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS
ALONG THE COAST OF W AFRICA FROM 9N-11N BETWEEN 14W-16W.
SIMILAR CONVECTION IS FURTHER S FROM 3N-7N BETWEEN 16W-18W.

DISCUSSION...

GULF OF MEXICO...
A COLD FRONT IS OVER THE NORTHERN GULF WATERS FROM N FLORIDA TO
E TEXAS NEAR CORPUS CHRISTI ALONG 31N84W 30N90W 28N97W.  THE
FRONT IS DELINEATED BY A WIND SHIFT AND SLIGHT THERMAL COOLING.
NO SHOWERS OR CONVECTION ARE ALONG THE FRONT.  A SURFACE TROUGH
EXTENDS N/S OVER THE W GULF OF MEXICO ALONG 26N96W 20N94W.
SCATTERED MODERATE CONVECTION IS FROM 23N-26N BETWEEN 93W-96W.
THE REMAINDER OF THE GULF OF MEXICO HAS LIGHT ELY SURFACE FLOW
WITH MOSTLY FAIR WEATHER.  IN THE UPPER LEVELS...AN UPPER HIGH
WITH SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE W GULF NEAR
23N94W WITH A RIDGE AXIS EXTENDING N TO LOUISIANA.  THE BASE OF
A TROUGH WITH STRONG SUBSIDENCE IS OVER NE GULF AND N FLORIDA N
OF 27N AND E OF 90W.  THIS TROUGH IS HOSTING THE FRONTAL SYSTEM
MENTIONED ABOVE.  EXPECT THE COLD FRONT TO PUSH DOWN THE FLORIDA
PENINSULA DURING THE NEXT 24 HOURS.  EXPECT CONVECTION OVER S
FLORIDA.  ALSO EXPECT ONSHORE FLOW TO PRODUCE CONVECTION ALONG
THE TEXAS COAST DURING THE NEXT 24 HOURS.

CARIBBEAN SEA...
A TROPICAL WAVE IS MOVING WWD ACROSS THE W CARIBBEAN WITH
CONVECTION. SEE TROPICAL WAVE SECTION.  SCATTERED MODERATE TO
STRONG CONVECTION IS INLAND OVER EL SALVADOR AND SW HONDURAS
FROM 12N-14N BETWEEN 86W-91W.  SIMILAR CONVECTION IS INLAND OVER
S MEXICO AND THE GULF OF TEHUANTEPEC FROM 15N-18N BETWEEN
93W-95W.  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 N OF
COLOMBIA NEAR 12N77W.  ANTICYCLONIC FLOW IS OVER THE CENTRAL AND
EASTERN CARIBBEAN.  SIGNIFICANT UPPER LEVEL MOISTURE AND BROKEN
HIGH CLOUDS COVERS THIS AREA.  EXPECT CONVECTION OVER MOST OF
THE CARIBBEAN AND CENTRAL AMERICA W OF 65W DURING THE NEXT 24
HOURS.

ATLANTIC OCEAN...
A SURFACE TROUGH IS OVER THE W ATLANTIC EXTENDING S TO CENTRAL
CUBA ALONG 30N76W 23N80W.  CLUSTERS OF SCATTERED MODERATE
CONVECTION IS E OF THE TROUGH AXIS FROM 25N-32N BETWEEN 70W-76W.
A 1024 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 32N45W.
ANOTHER 1020 MB HIGH IS OVER THE E ATLANTIC NEAR 27N28W.  IN THE
UPPER LEVELS...A TROUGH IS OVER THE W ATLANTIC N OF 25N W OF
75W.  A RIDGE IS N OF 20N BETWEEN 70W-75W.  A LARGE UPPER LEVEL
LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 26N61W.  WLY FLOW
IS OVER THE E ATLANTIC N OF 20N E OF 40W.  A LARGE UPPER LEVEL
HIGH IS OVER THE TROPICS NEAR 12N35W.  ANTICYCLONIC FLOW IS FROM
EQ-20N BETWEEN 20W-50W.

$$
FORMOSA







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