[Tropical] Tropical Weather Discussion

[Nashville EMWIN]

AXNT20 KNHC 141805 RRA
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT 14 AUG 2004

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...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND
SATELLITE IMAGERY THROUGH 1745 UTC.

...SPECIAL FEATURES...
HURRICANE CHARLEY HAS BEEN DOWNGRADED TO TROPICAL STORM CHARLEY.
THE CENTER AT 14/1800 UTC IS NEAR 34.8N 77.9W...OR ABOUT
35 MILES NORTH OF WILMINGTON NORTH CAROLINA...MOVING
NORTH-NORTHEAST 26 KT. ESTIMATED MINIMUM CENTRAL PRESSURE
IS 995 MB. MAXIMUM SUSTAINED WIND SPEED 60 KT WITH GUSTS TO
HURRICANE FORCE. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY
UNDER AWIPS/WMO HEADERS MIATCPAT3/WTNT33 KNHC AND THE FULL
FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC
FOR MORE DETAILS. SCATTERED TO NUMEROUS STRONG SHOWERS AND
THUNDERSTORMS FROM 34N TO 36N BETWEEN 77W AND 80W FROM THE
SOUTHEASTERN CORNER OF NORTH CAROLINA TO THE NORTHERN THIRD OF
THE STATE. RADAR AND SURFACE OBSERVATIONS SHOW THAT THE CENTER
OF CHARLEY IS ON THE COAST NEAR MYRTLE BEACH. CHARLY WILL WEAKEN
SOON BELOW HURRICANE STRENGTH OVER LAND IF IT HAS NOT DONE SO
ALREADY.

TROPICAL DEPRESSION FIVE CENTER AT 14/1800 UTC IS NEAR 10.5N
53.5W...OR ABOUT 455 MILES...735 KM...EAST-SOUTHEAST OF
BARBADOS...MOVING WEST-NORTHWEST 20 KT. THE ESTIMATED MINIMUM
CENTRAL PRESSURE IS 1008 MB. THE MAXIMUM SUSTAINED WIND SPEED
IS 30 KT GUSTS 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. WIDELY
SCATTERED MODERATE TO ISOLATED STRONG SHOWERS AND THUNDERSTORMS
FROM 9N TO 14N BETWEEN 52W AND 59W. A TROPICAL STORM WATCH IS IN
EFFECT FOR BARBADOS...ST. VINCENT...AND ST. LUCIA.  THIS WATCH
WILL LIKELY BE CHANGED TO A WARNING LATER TODAY.  INTERESTS
AROUND THE EASTERN CARIBBEAN SEA SHOULD CLOSELY MONITOR THE
PROGRESS OF THIS SYSTEM. THE LATEST SATELLITE IMAGES INDICATE
LITTLE CHANGE IN ORGANIZATION OF THE CLOUD PATTERN OF THE
DEPRESSION OVER THE PAST SEVERAL HOURS. THE SYSTEM APPEARS
TO BE SLIGHTLY ELONGATED ALONG A WEST-NORTHWEST TO
EAST-SOUTHEAST AXIS. THE ENVIRONMENT IS EXPECTED TO BE FAVORABLE
FOR STRENGTHENING IN THE FUTURE. T.D. FIVE IS EMBEDDED IN A DEEP
EASTERLY CURRENT SOUTH OF THE SUBTROPICAL RIDGE AND NUMERICAL
WEATHER PREDICTION MODELS INDICATE THAT THIS RIDGE WILL PERSIST
FOR THE NEXT FEW DAYS. A CONTINUED WEST-NORTHWESTERLY MOTION
IS INDICATED OVER THE FORECAST PERIOD.

TROPICAL STORM DANIELLE CENTER AT 14/1800 UTC IS NEAR 13.3N
27.3W MOVING WEST 12 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE
IS 1000 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 45 KT GUSTS
55 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO
STRONG SHOWERS AND THUNDERSTORMS FROM 12N TO 14N BETWEEN 27W AND
30W. DANIELLE IS GRADUALLY STRENGTHENING. SINCE THE SHEAR IS
EXPECTED TO REMAIN LOW AND SEA SURFACE TEMPERATURES ARE
CURRENTLY REASONABLY WARM...ADDITIONAL STRENGTHENING IS LIKELY.
HOWEVER A TONGUE OF SLIGHTLY COOLER WATER IN THE VICINITY OF 18N
MAY LIMIT INTENSIFICATION LATER IN THE PERIOD.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 61W/62W SOUTH OF 17N MOVING WEST 10-15 KT...
PASSING OVER THE ISLANDS OF THE EASTERN CARIBBEAN SEA. ISOLATED
MODERATE SHOWERS AND THUNDERSTORMS WITHIN 15 TO 30 NM ON EITHER
SIDE OF 13N63W 14N65W 15N66W 15N70W...WHICH MIGHT NOT HAVE
ANYTHING TO DO WITH THIS WAVE. THERE ARE LINES OF LOW CLOUDS AND
SOME OTHER POSSIBLE SHOWERS ELSEWHERE FROM 12N TO 16N BETWEEN
62W AND 70W.

...ITCZ...
ITCZ AXIS EMERGES OFF THE COAST OF MAURITANIA SW TO 7N31W THEN
10N58W. SCATTERED STRONG SHOWERS AND THUNDERSTORMS SOUTH OF 11N
BETWEEN 77W AND 81W IN THE SOUTWESTERN CARIBBEAN SEA. ISOLATED
MODERATE TO LOCALLY STRONG SHOWERS AND THUNDERSTORMS IN THE
ATLANTIC OCEAN FROM 10N TO 12N BETWEEN 19W AND 23W...AND FROM
7N TO 9N BETWEEN 30W AND 37W. ISOLATED MODERATE SHOWERS FROM
15N TO 19N BETWEEN 16W AT THE AFRICA COAST AND 22W.

...DISCUSSION...
THE GULF OF MEXICO...
THE UPPER-AIR PATTERN LOOKS MORE LIKE OCTOBER THAN AUGUST WITH A
DEEP TROUGH FROM THE MIDWEST INTO LOUISIANA AND THE NW GULF.
ALL-TIME COLD FOR AUGUST HAS OCCURRED IN PLACES OVER THE
SOUTHERN UNITED STATES. STATIONARY FRONT THROUGH NORTHEASTERN
FLORIDA NEAR 30N82W TO 1012 MB GULF OF MEXICO LOW PRESSURE
CENTER NEAR 29N84W...TO 25N90W...TO SOUTHWESTERN GULF OF MEXICO
NEAR 19N94W. ISOLATED MODERATE TO LOCALLY STRONG SHOWERS AND
THUNDERSTORMS WITHIN 60 TO 120 NM ON EITHER SIDE OF THIS FRONT.
LITTLE CHANGE IS LIKELY IN THE UPPER LEVEL FLOW PATTERN UNTIL
THE TROF BEGINS TO LIFT OUT ABOUT MON AND STRONGER RIDGING IS
RE-ESTABLISHED ACROSS THE GULF.

THE CARIBBEAN SEA...
DEEP EASTERLIES ARE PRESENT IN MOST OF THE CARIBBEAN WITH A
BROAD UPPER LOW IN THE SW CARIBBEAN NEAR 10N79W.  DRY
AIR/SUBSIDENCE IS PRESENT BETWEEN 70W-83W WITH LITTLE
CONVECTION.   THE MID/UPPER LEVELS ARE MOISTENING UP WITH A
TROPICAL WAVE NEAR THE WINDWARD ISLANDS.  POCKETS OF ISOLATED
SHOWERS ARE OVER THE GREATER ANTILLES E OF HISPANIOLA TO THE US
VIRGIN ISLANDS.  THE NEXT SYSTEM TO WATCH IS TROPICAL DEPRESSION
FIVE WITH INCREASING RAIN/WIND LIKELY OVERNIGHT SUN.

SUBTROPICAL ATLANTIC...
NARROW UPPER RIDGE EXTENDS FROM THE NW BAHAMAS NEWD TO 32N74W
WITH BROAD SWLY FLOW TO THE W PUSHING HURRICANE CHARLEY  TOWARD
THE SOUTHEAST U.S. COAST. WEAK SFC RIDGING EXTENDS INTO THE AREA
ALONG 28N BUT A DEEP-LAYERED LOW NEAR 28N62W IS SUPPORTING A
SURFACE TROUGH ALONG 30N57W 21N70W. ISOLATED MODERATE TO LOCALLY
STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN 90 TO 180 NM ON EITHER
SIDE OF THIS TROUGH. SECOND UPPER LOW IS LOCATED NEAR 29N41W
WITH LITTLE ASSOCIATED CONVECTION. ELSEWHERE...A STRONG UPPER
HIGH IS CENTERED NEAR 13N41W WHILE A WEAK UPPER TROF IS ALONG
THE CANARY ISLANDS.

TROPICAL ATLANTIC...
AFTER THE SECOND MAJOR HURRICANE OF THE YEAR....THE EARLIEST
SECOND MAJOR HURRICANE SINCE 1955...A STRONG UPPER LEVEL HIGH
IS NEAR 21N41W OVER THE CENTRAL ATLC.  MAJORITY OF THE TROPICAL
ATLC IS UNDER THE INFLUENCE OF STRONG ELY FLOW AND LOW VALUES OF
VERTICAL SHEAR THOUGH THERE IS RELATIVELY DRY AIR IN THE
MID/UPPER LEVELS BETWEEN DANIELLE/TD 5.  THE RIDGE SHOULD SHIFT
FARTHER SOUTH TO 18N/19N OVER THE NEXT TWO DAYS AS A TROUGH DIGS
AHEAD OF DANIELLE... POSSIBLY PROVIDING SHEAR BEYOND 36 HOURS.

$$
MT

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