[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 050000
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON AUG 04 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...
EDOUARD...THE FIFTH TROPICAL CYCLONE OF THE 2008 HURRICANE
SEASON IS CENTERED NEAR 28.4N 91.6W AT 05/0000 UTC OR ABOUT 110
NM...200 KM...SOUTH-SOUTHEAST OF LAFAYETTE LOUISIANA AND ABOUT
180 NM...330 KM...EAST-SOUTHEAST OF GALVESTON TEXAS MOVING
ERRATICALLY WESTWARD. ESTIMATED MINIMUM CENTRAL PRESSURE
REPORTED BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS
999 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH HIGHER GUSTS.
SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. EDOUARD IS GRADUALLY
BECOMING BETTER ORGANIZED. THE WIND FIELD IS EXPANDING...WITH
TROPICAL STORM FORCE NOW REACHING THE LOUISIANA COASTLINE.
MEANWHILE...THE TEXAS COAST HAS TO PREPARE FOR THE SECOND
LANDFALL THIS SEASON. ACCORDING TO THE OFFICIAL FORECAST
TRACK...A TURN TO THE WEST-NORTHWEST IS EXPECT TO OCCUR
TONIGHT...AND THE CENTER OF EDOUARD SHOULD BE VERY NEAR THE
UPPER TEXAS COAST BY MIDDAY TOMORROW WITH NEAR HURRICANE
STRENGTH. IT'S IMPORTANT TO REMEMBER THAT THERE IS VERY LITTLE
PRACTICAL DIFFERENCE BETWEEN A VERY STRONG TROPICAL STORM AND A
LOW-END HURRICANE. THE BIG PROBLEM WITH THIS TROPICAL CYCLONE
WILL BE THE RAIN. EDOUARD IS EXPECTED TO PRODUCE TOTAL RAIN
ACCUMULATIONS OF 3 TO 5 INCHES IN SOME LOUISIANA COASTAL
PARISHES. ACCUMULATIONS OF 4 TO 6 INCHES...WITH ISOLATED MAXIMUM
AMOUNTS OF 10 INCHES ARE POSSIBLE OVER SOUTHEASTERN TEXAS. OUTER
BANDS OF EDOUARD ARE ALREADY AFFECTING THE COAST OF LOUISIANA
WITH RAIN AND GUSTY WINDS.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 25W/26W SOUTH OF 20N MOVING WEST NEAR
15 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FOUND
NEAR THE INTERSECTION OF THE WAVE WITH THE ITCZ AXIS. A CYCLONIC
TURNING IS ALONG THE WAVE AXIS NEAR 15N WHERE THERE IS SOME
SHOWER ACTIVITY. THE UW-CIMSS TPW PRODUCT AND 850 MB SATELLITE
DERIVED VORTICITY SUPPORT THE POSITION OF THE WAVE.

A TROPICAL WAVE IS ALONG 43W S OF 17N MOVING W NEAR 20 KT. THIS
IS A LOW AMPLITUDE WAVE WAVE WITH NO SIGNIFICANT CONVECTION.
SCATTERED SHOWERS ARE CONFINED TO THE ITCZ.

A HIGH AMPLITUDE TROPICAL WAVE HAS ENTERED THE E CARIBBEAN. ITS
AXIS EXTENDS ALONG 61W/62W S OF 26N MOVING W NEAR 20 KT. A 1013
MB LOW IS ALONG THE WAVE AXIS NEAR 21N. SCATTERED MODERATE
CONVECTION ON THE NORTHERN END OF THE WAVE AND JUST N OF THE SFC
LOW FROM 22N-26N BETWEEN 60W-64W. THE WAVE IS ALSO GENERATING
SOME SHOWER ACTIVITY OVER THE WINDWARD ISLANDS AND NE VENEZUELA.
WHILE THE N PART OF THE WAVE IS FORECAST TO BREAK AWAY AND MOVE
NWD...THE REMAINDER OF THE WAVE WILL CONTINUE TO MOVE WWD ACROSS
THE E CARIBBEAN SPREADING ITS MOISTURE OVER THE UK/US VIRGIN
ISLANDS AND PUERTO RICO TOMORROW.

AN ACTIVE TROPICAL WAVE IS OVER THE WESTERN CARIBBEAN ALONG 83W
SOUTH OF 22N MOVING WEST NEAR 10 KT. THE WAVE PAIRED WITH AN
UPPER-LEVEL LOW SPINNING OVER BELIZE IS GENERATING A LARGE AREA
OF SHOWERS WITH EMBEDDED TSTMS OVER THE W CARIBBEAN PARTICULARLY
FROM 11N-20N WEST OF 80W. SHOWERS AND TSTMS HAVE ALSO FLARED UP
OVER PARTS OF THE YUCATAN PENINSULA AND N CENTRAL AMERICA. THE
TOTAL PRECIPITABLE WATER...MIMIC-TPW...SHOWS A NORTH-SOUTH
MOISTURE MAXIMUM ASSOCIATED WITH THIS WAVE WHICH IS FORECAST TO
MOVE ACROSS THE YUCATAN PENINSULA/N CENTRAL AMERICA THIS
TUESDAY. AN ELY SURGE FOLLOWS THIS TROPICAL WAVE.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 13N16W 10N30W 11N40W 10N50W 10N59W.
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE
FROM 8N-11N BETWEEN 23W-31W.

...DISCUSSION...

GULF OF MEXICO...
ATTENTION REMAINS FOCUSED ON TROPICAL STORM EDOUARD THAT IS
FORECAST TO MAKE LANDFALL IN LESS THAN 24 HOURS VERY NEAR THE
UPPER TEXAS COAST BY MIDDAY TOMORROW. THIS TROPICAL CYCLONE IS
MOVING TO THE SOUTH OF A MID-LEVEL RIDGE OVER THE SOUTH-CENTRAL
UNITED STATES. UPPER DIFFLUENCE ASSOCIATED WITH AN UPPER-LEVEL
HIGH TO THE E OF EDOUARD IS ENHANCING CONVECTION OVER THE STATE
OF FLORIDA WHILE AN UPPER-LEVEL LOW LOCATED OVER BELIZE IS
BRINGING SOME SHOWER/TSTM ACTIVITY OVER THE SE PORTION OF THE
GULF AND THE YUCATAN PENINSULA. HIGH PRES WILL RE-BUILD ACROSS
THE GULF AS EDOUARD MOVES WELL INLAND TUE THROUGH THU.

CARIBBEAN SEA...
AS TYPICAL FOR THIS TIME OF THE YEAR...THERE ARE FOUR TROPICAL
WAVES BETWEEN AFRICA AND THE YUCATAN PENINSULA. A COUPLE OF THEM
ARE CURRENTLY OVER THE CARIBBEAN SEA. SEE TROPICAL WAVE SECTION
FOR DETAILS. ELSEWHERE...SCATTERED SHOWERS AND TSTMS ARE OVER
PARTS OF CUBA AND HISPANIOLA. A DIFFLUENT PATTERN ALOFT BETWEEN
AN UPPER-LEVEL LOW SITUATED NEAR THE SE BAHAMAS AN THE UPPER
HIGH OVER THE E GULF IS HELPING TO INDUCE THIS CONVECTIVE
ACTIVITY. IN ADDITION...THE TROPICAL WAVE OVER THE W CARIBBEAN
IS ALSO SUPPORTING THE DEVELOPMENT OF THIS ACTIVITY OVER W CUBA
AND THE ISLE OF YOUTH. TIGHT PRES GRADIENT BETWEEN THE ATLC
RIDGE  AND THE COLOMBIAN LOW IS PRODUCING MODERATE TO STRONG
TRADE WINDS ACROSS THE BASIN WITH AN EARLIER QSCAT PASS SHOWING
A COUPLE OF UNCONTAMINATED WIND BAR OF 30 KT NEAR THE COLOMBIAN
COAST.

ATLANTIC OCEAN...
A 1023 MB HIGH CENTERED NEAR 31N47W EXTENDS A RIDGE ALONG
29W/30W COVERING THE DISCUSSION AREA WITH MOSTLY FAIR WEATHER.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE OVER THE W ATLC W OF
70W MORE CONCENTRATED OVER THE NW BAHAMAS. AN UPPER-LEVEL
TROUGH OVER THE W ATLC CLIPS THE NW PORTION OF THE AREA. ANOTHER
UPPER-LEVEL TROUGH ENTERS THE REGION NEAR 31N60W THEN CONTINUES
SW TO THE UPPER-LEVEL LOW LOCATED NEAR THE SE BAHAMAS. SLY FLOW
BETWEEN THIS TROUGH AND A LARGE UPPER-LEVEL HIGH CENTERED 32N44W
IS LIMITING THE DEVELOPMENT OF THE SFC LOW EMBEDDED IN THE
TROPICAL WAVE ALONG 61W/62W. PATCHES OF MID/HIGH CLOUDS ARE OVER
THE CENTRAL ATLC N OF 25N ROTATING AROUND THE PREVIOUSLY
MENTIONED LARGE UPPER-LEVEL HIGH. THIS UPPER FEATURE ENVELOPS
THE TROPICAL NORTH ATLC. AN UPPER-LEVEL LOW OVER THE E ATLANTIC
N OF AREA HAS AN UPPER TROUGH ALONG 31N24W 26N28W THEN CONTINUES
SW AND WEST ALONG 19W/20N TO 19N45W.

$$
GR





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