[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211754
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE 21 SEP 2004

CORRECTION TO MOVE TROPICAL WAVE ALONG 29W/30W INFORMATION
INTO THE SPECIAL FEATURES SECTION

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND ATLC 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
XX15 UTC.

...SPECIAL FEATURES...

HURRICANE JEANNE CENTERED NEAR 27.5N 69.3W OR ABOUT 485 MILES...
785 KM...EAST OF GREAT ABACO ISLAND IN THE BAHAMAS...MOVING
EAST-NORTHEAST 5 KT. STEERING CURRENT ARE WEAKENING...JEANNE IS
MOVE ESE AT 6 KT. MAXIMUM SUSTAINED WIND SPEED 80 KT GUSTS 100
KT.  ESTIMATED MINIMUM CENTRAL PRESSURE 972 MB. SEE LATEST NHC
PUBLIC ADVISORY OR NHC FORECAST/ ADVISORY UNDER AWIPS/WMO
HEADERS MIATCPAT1/WTNT31 KNHC OR MIATCMAT1/ WTNT21 KNHC FOR MORE
DETAILS. JEAN CONTINUES TO LOOK RAGGED... WEEK VERTICAL SHEAR
WILL CONTINUE TO WEAKEN THE SYSTEM OVER THE NEXT 36-48 HOURS.
SATELLITE IMAGERY SHOWS LITTLE CHANGE WITHIN THE SYSTEM DURING
THE LAST FEW HOURS.  MODERATE CONVECTION EXTENDS OUT 41 NM FROM
THE CENTER.

HURRICANE KARL CENTERED NEAR 21.4N 448.0W OR ABOUT 1005
MILES/1620 KM...ENE OF THE NORTHERN LEEWARD ISLANDS...MOVING
NNW 14 KT. MAXIMUM SUSTAINED WIND SPEED 110 KT GUSTS 135 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE 944 MB. SEE LATEST NHC
FORECAST/ ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT2/WTNT22 KNHC
FOR MORE DETAILS. KARL HAS BECOME A LITTLE LESS ORGANIZED IN THE
LAST FEW HOURS AND HAS WEEKEND SOME DUE TO STRONG VERTICAL SHEAR
ON THE SW QUADRANT. SCATTERED MODERATE/NUMEROUS STRONG
CONVECTION EXTENDS OUT 110 NM FROM THE CENTER.

TROPICAL STORM LISA CENTERED NEAR 14.2N 39.7W OR ABOUT 1055
MILES/1695 KM WEST OF THE CAPE VERDE ISLANDS...MOVING WNW 10
KT. MAXIMUM SUSTAINED WIND SPEED 60 KT GUSTS 75 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE 990 MB. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT3/WTNT23 KNHC
FOR MORE DETAILS. LISA CONTINUE TO STRENGTHEN OVER THE TROPICAL
ATLANTIC.  LISA REMAINS A VERY COMPACT SYSTEM WITH ASSOCIATED
SCATTERED MODERATE TO STRONG CONVECTION EXTENDING OUT 80 NM FROM
THE CENTER.

...TROPICAL WAVES...

TROPICAL WAVE LOCATED 370 NM WEST OF THE CAPE VERDE ISLANDS
ALONG 30W/31W SOUTH OF 17N MOVING WEST 10-15 KT. SATELLITE
IMAGERY SHOWS A  WELL-DEFINED LOW LEVEL CIRCULATION.  CLUSTER OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS LOCATED NORTH
OF THE LOW FROM 9N-13N BETWEEN 29W-31W. WIDELY SCATTERED SHOWERS
BETWEEN 4N-9N BETWEEN 32W-36W.

...ITCZ...

ITCZ EXTENDS ALONG 9N14W TO 5N5W 6N30W  7N37W  8N60W...
WIDELY SCATTERED MODERATE CONVECTION IS NOTED FROM 9N-11N
BETWEEN 5W-10W. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION
ASSOCIATED WITH TROPICAL WAVE IS NOTED  FROM 5N-13N BETWEEN
28W-36W.

...DISCUSSION...

GULF OF MEXICO...
MID/UPPER LEVEL TROUGH WHICH MOVED OFF THE E COAST OF THE UNITED
STATES EARLIER THIS WEEK HAS BEGUN TO BECOME ELONGATED AND SPLIT
WITH THE MAIN TROUGH REMAINING NE OF THE AREA.  MID/UPPER LEVEL
LOW CENTERED NEAR THE BAY OF CAMPECHE. STRONG  UPPER LEVEL
WESTLYS  DOMINATES THE GULF E OF 89W PROVIDING SHEAR TO THE
SURFACE LOW JUST OFF THE COAST OF NAPLES FL.  STATIONARY FRONT
LOCATED NEAR VENICE FL EXTENDS EAST OVER THE FLORIDA PENINSULA
TO THE WESTERN ATLANTIC NEAR 29N66W.  SCATTERED MODERATE
CONVECTION IS NOTED ALONG THE FRONTAL AXIS.  ELSEWHERE....WIDELY
SCATTERED MODERATE CONVECTION OVER THE REMAINDER OF THE GULF
WEST OF 97W.

CARIBBEAN SEA...
MID/UPPER LEVEL HIGH LOCATED NEAR 16N81W WITH STRONG RIDGING
EXTENDING NE OVER HISPANIOLA AND INTO THE EASTERN ATLANTIC NEAR
29N52W.  AN UPPER LEVEL TROUGH PUSHES SOUTHWARD OVER THE EXTREME
EASTERN PORTION OF THE GULF. ANTICYCLONIC FLOW AROUND THE RIDGE
HAS PUSHED VERY DRY MIDDLE TO UPPER LEVEL AIR FROM THE TROPICAL
ATLC WESTWARD INTO THE EASTERN CARIBBEAN SEA...ELSEWHERE EAST OF
75W. A WEAK LOWER TO MIDDLE LEVEL TROUGH TRAILING SWD FROM
HURRICANE JEANNE OVER THE ATLC CONTINUES TO SPARK CONVECTION
OVER E CUBA AND W HISPANIOLA.

SUBTROPICAL ATLANTIC...
STRONG MID/UPPER LEVEL TROUGH JUST N OF THE AREA EXTENDS SWD
OVER THE W ATLC FROM WELL NORTH OF THE AREA TO JUST OFF THE
MID-ATLANTIC COAST. A SURFACE STATIONARY FRONT EXTEND FROM
VENICE IN THE GULF OF MEXICO EASTWARD N OF JEANNE TO NEAR 30N59W
WITH A COLD FRONT EXTENDING NE WELL NORTH OF THE AREA.  WIDELY
SCATTERED MODERATE CONVECTION IS NOTED WITHIN 100 NM OF THE
AXIS.  ELSEWHERE...UPPER LEVEL RIDGE EXTENDS OUT OF THE
CARIBBEAN OVER HISPANIOLA NORTH INTO THE EASTERN ATLANTIC NEAR
30N51W.  ADDITIONALLY... OVER THE CENTRAL ATLC...MID/UPPER LEVEL
TROUGH EXTENDS ALONG 20N54W CONTINUES SOUTHWARD INTO THE EASTERN
CARIBBEAN.  A HIGH AMPLITUDE MID/UPPER LEVEL RIDGE EXTENDS FROM
E OF KARL NWD ALONG 45W COVERING THE AREA WITH ANTICYCLONIC FLOW
FROM 28W TO 56W. AT THE SURFACE...SUBTROPICAL RIDGE ENTERS AREA
IN BETWEEN HURRICANE KARL AND HURRICANE JEANNE ALONG 30N50W SW
TO HISPANIOLA.

TROPICAL ATLANTIC...
MID/UPPER LEVEL RIDGING WHICH TYPICALLY EXTENDS E/W ACROSS THE
AREA REMAINS DISRUPTED BY HURRICANE KARL AND TROPICAL STORM
LISA. A WEAK RIDGE EXTENDS E/W ALONG 12N/13N FROM CAPE VERDE TO
43W.

$$
JP/HC



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