[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 230001
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU SEP 22 200521

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...

RITA IS AN EXTREMELY DANGEROUS CATEGORY FOUR HURRICANE. AT
22/2100 UTC IT IS CENTERED NEAR 25.8N 89.5W OR ABOUT 405 MILES...
650 KM...SOUTHEAST OF GALVESTON TEXAS AND ABOUT 390 MILES... 630
KM...SOUTHEAST OF PORT ARTHUR TEXAS...MOVING WEST 8 KT.  THE
ESTIMATED MINIMUM CENTRAL PRESSURE IS 913 MB. THE MAXIMUM
SUSTAINED WIND SPEEDS ARE 125 KT WITH GUSTS TO 155 KT. SEE
LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY UNDER HEADERS
MIATCPAT3/WTNT33 KNHC FOR MORE DETAILS. THE EYE IS WELL-DEFINED
ON SATELLITE IMAGERY AND HAS A DIAMETER OF 20 NM.  NUMEROUS
STRONG CONVECTION IS AROUND THE CENTER FROM 24N-28N BETWEEN
87W-92W.  SCATTERED MODERATE CONVECTION ALSO EXTENDS FROM
23N-30N BETWEEN 84W-93W.

THE CENTER OF TROPICAL STORM PHILIPPE AT 22/2100 UTC IS
NEAR 27.5N 57.7W MOVING NORTH 15 KT. THE ESTIMATED MINIMUM
CENTRAL PRESSURE IS 1003 MB. THE MAXIMUM SUSTAINED WIND SPEEDS
ARE 35 KT WITH GUSTS TO 45 KT. SEE THE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC
FOR MORE DETAILS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING
THE NEXT 24 HOURS. PHILIPPE APPEARS TO BE LOSING TROPICAL
CHARACTERISTICS WITHIN A LARGER NON-TROPICAL AREA OF LOW
PRESSURE.  SCATTERED MODERATE TO STRONG CONVECTION IS FROM
27N-32N BETWEEN 55W-60W.  A BAND IS SE OF THE CENTER WITH
SCATTERED MODERATE TO STRONG CONVECTION FROM 20N-27N BETWEEN
52W-56W.

...TROPICAL WAVES...

A 1008 MB LOW IS OFF THE COAST OF W AFRICA NEAR 11N23W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 11N-13N
BETWEEN 25W-27W.

ATLANTIC OCEAN TROPICAL WAVE IS ALONG 47W SOUTH OF 18N MOVING
WEST 10 TO 15 KT. CYCLONIC CURVATURE IS NOTED ON SATELLITE
IMAGERY NEAR 15N47W.  SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION IS FROM 7N-12N BETWEEN 45W-51W.

ATLANTIC OCEAN TROPICAL WAVE IS ALONG 55W/56W SOUTH OF 15N
MOVING WEST 10 TO 15 KT. THIS WAVE IS SHOWS SLIGHT CYCLONIC
CURVATURE WITH NO SIGNIFICANT CONVECTION E OF TRINIDAD.

...ITCZ...

ITCZ IS CENTERED ALONG 13N17W 6N30W 5N40W 9N60W.  IN ADDITION TO
CONVECTION MENTIONED WITH THE TROPICAL WAVES...ISOLATED STRONG
CONVECTION IS FROM 5N-8N BETWEEN 20W-28W.

...DISCUSSION...

THE GULF OF MEXICO...
RITA IS A DANGEROUS CATEGORY FOUR HURRICANE CHURNING IN THE
CENTRAL GULF OF MEXICO MOVING W. IT IS FORECAST TO REACH THE
UPPER TEXAS COAST BY LATE FRIDAY OR EARLY SATURDAY MORNING AS A
MAJOR HURRICANE.  UPPER LEVEL SUBSIDENCE OVER TEXAS AND THE W
GULF W OF 94W DOES NOT SEEM TO EFFECT RITA.  A SLIGHT INCREASE
IN UPPER LEVEL SHEAR IS EXPECTED OVER RITA...HOWEVER...ANOTHER
WARM EDDY OVER THE W GULF WILL OFFSET ANY DECREASE IN WIND
SPEED.

THE CARIBBEAN SEA...
LOW LEVEL CYCLONIC FLOW IS NOTED OVER THE W CARIBBEAN W OF 75W
DUE TO RITA.  WINDS ARE BASICALLY FROM THE SOUTH...W OF 75W.
REGULAR TRADEWINDS ARE OVER THE E CARIBBEAN E OF 75W.  PATCHES
OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND
OVER HONDURAS AND NICARAGUA FROM 10N-16N BETWEEN 84W-90W.
SCATTERED MODERATE CONVECTION IS OVER PANAMA FROM 7N-13N BETWEEN
80W-83W.  SCATTERED MODERATE TO STRONG CONVECTION IS ALSO INLAND
OVER NW VENEZUELA AND N COLOMBIA FROM 6N-11N BETWEEN 69W-74W.
IN THE UPPER LEVELS... ANTICYCLONIC OUTFLOW FROM RITA IS
PRODUCING NE FLOW W OF 70W.  THE REMAINDER OF THE CARIBBEAN E OF
70W IS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH WITH AXIS
ALONG 65W.  EXPECT THE GREATEST POTENTIAL OF CONVECTION OVER THE
NEXT 24 HOUR TO EXTEND FROM NW VENEZUELA TO THE YUCATAN
PENINSULA.

THE ATLANTIC OCEAN...
A WEAK HIGH PRESSURE RIDGE IS OVER THE W ATLANTIC W OF 70W.
T.S. PHILIPPE IS OVER THE CENTRAL ATLANTIC.  A 1028 MB HIGH IS
SW OF THE AZORES NEAR 35N37W.  SURFACE EASTERLY FLOW IS OVER THE
E ATLANTIC FROM 20N-30N...E OF 50W.  IN THE UPPER
LEVELS...ANTICYCLONIC FLOW IS OVER THE W ATLANTIC W OF 70W.  A
CYCLONIC CIRCULATION IS CENTERED NEAR 25N63W.  THIS SYSTEM IS
PRODUCING SIGNIFICANT SHEAR OVER PHILIPPE.  AN ANTICYCLONIC
CIRCULATION IS FURTHER E NEAR 20N54W.  A CYCLONIC CIRCULATION IS
OVER THE E ATLANTIC NEAR 18N33W.  FINALLY A LARGE ANTICYCLONIC
CIRCULATION IS OVER W AFRICA NEAR 20N15W.  ANTICYCLONIC FLOW IS
E OF 25W.

$$
FORMOSA


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