[Tropical] Tropical Weather Discussion

[Nashville EMWIN]

AXNT20 KNHC 140559
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURES...

HURRICANE CHARLEY IS NOW OFFSHORE OF NE FLORIDA NEAR 30.1N 80.8W
...OR 190 MILES SSW OF CHARLESTON S CAROLINA...AT 14/0600 UTC
MOVING NNE 22 KT. RECON MEASURED A MINIMUM CENTRAL PRESSURE OF
993 MB. MAXIMUM SUSTAINED WIND SPEED HAS DECREASED TO 75 KT WITH
GUSTS TO 90 KT. 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.  CHARLEY SPENT ABOUT 8 HOURS OVER LAND AND
WEAKENED FROM A CATEGORY 4 TO CATEGORY 1 HURRICANE.  DAYTONA
BEACH RECENTLY REPORTED SUSTAINED WINDS OVER 50 MPH AS WELL AS
THE CMAN NEAR ST. AUGUSTINE GUSTING TO 64 MPH.   THE HURRICANE
IS CAUGHT UP IN A DEEP UPPER TROUGH OVER THE MIDWEST.  SCATTERED
MODERATE FROM 29N-32N BETWEEN 77W-80W.

TROPICAL DEPRESSION FIVE IS NEAR 9.4N 48.3W AT 14/0300 UTC
MOVING W 18 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1009 MB.
MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. SEE
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS.  CONVECTION HAS EXPLODED
IN THE WESTERN SEMICIRCLE WITH A STRONG BAND APPEARING TO WRAP
AROUND THE LOW-LEVEL CIRCULATION.  THE DEPRESSION IS MOVING OVER
WATERS IN EXCESS OF 29C WITH LITTLE SHEAR AS EVIDENCED BY THE
EXPANDING OUTFLOW PATTERN...ESPECIALLY ON THE WESTERN SIDE.  THE
DEPRESSION IS PROBABLY ON AN INTENSIFICATION TREND AND TROPICAL
STORM WATCHES COULD BE ISSUED FOR THE LESSER ANTILLES LATER
TODAY.  SCATTERED STRONG FROM 8.5N-11N BETWEEN 48W-51W.

TROPICAL DEPRESSION FOUR IS NOW TROPICAL STORM DANIELLE CENTERED
NEAR 12.7N 24.8W A COUPLE HUNDRED MILES S OF THE CAPE VERDES AT
14/0300 UTC MOVING W 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE
IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO
45 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS.  DANIELLE EXHIBITS A
STRONG ROTATION IN THE LOW/MID LEVELS WITH BANDING PRONOUCED IN
THE SOUTHERN SEMICIRCLE.  THE SHEAR IS WEAK EASTERLY AND
CONTINUED DEVELOPMENT IS LIKELY FOR THE NEXT DAY OR TWO.
SCATTERED MODERATE/STRONG FROM 11N-13.5N BETWEEN 24.5W-27W.

...TROPICAL WAVES...

TROPICAL WAVE JUST E OF BARBADOS ALONG 58W S OF 17N MOVING W
10-15 KT.  AN INCREASE IN SHOWERS IS NOTED WITH THE WAVE IN THE
WINDWARD ISLANDS AND THESE SHOWERS WILL CONTINUE MOVING INTO THE
E CARIBBEAN THRU SAT NIGHT.

...ITCZ...

ITCZ AXIS EMERGES OFF THE COAST OF SENEGAL SW TO 7N30W 10N43W
BROKEN TO 5N45W 7N58W.  ISOLATED MODERATE WITHIN 45 NM OF LINE
8N26W 9N35W.

...DISCUSSION...

GULF OF MEXICO...
IT HAS BEEN A MONTH OF EXTREMES FOR THE GLOBE WITH HIGHER-THAN-
AVERAGE UPPER HEIGHTS OVER THE POLES (LINKED TO THE ALL-TIME
WARMTH RECORDED IN ICELAND) AND AMPLIFIED MID-LATITUDE FEATURES
(LIKE THE RARE DEEP TROUGH THAT DRAGGED A COLD FRONT FAR INTO
THE GULF).  CLOSER TO HOME... ALL-TIME COLD FOR AUGUST LIKELY TO
OCCUR OVERNIGHT IN THE SOUTHERN USA BEHIND A STRONG UPPER LEVEL
TROF/ STATIONARY FRONT SITTING OVER THE N GULF WATERS.  FRONT
LIES FROM TALLAHASSEE TO 22N94W WITH ISOLATED TSTMS N OF 28
WITHIN 60 NM OF THE 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.

CARIBBEAN...
DEEP EASTERLIES ARE PRESENT IN MOST OF THE CARIBBEAN WITH A
BROAD UPPER LOW IN THE SW CARIBBEAN NEAR 9N78W.  DRY
AIR/SUBSIDENCE IS PRESENT BETWEEN 70W-83W WITH LITTLE
CONVECTION.   THE MID/UPPER LEVELS ARE MOISTENING UP AGAIN WITH
A TROPICAL WAVE NEAR THE WINDWARD ISLANDS.  SURFACE TROF HAS
BEEN MOVING ACROSS THE MONA PASSAGE ALONG 17N69W 22N67W WITH A
CONTINUATION OF ISOLATED SMALL SHOWERS IN PUERTO RICO/US VIRGIN
ISLANDS.  THE NEXT SYSTEM TO WATCH IS TROPICAL DEPRESSION FIVE
FORECAST TO AFFECT THE WINDWARD ISLANDS IN THE NEXT 36-48 HOURS.

SUBTROPICAL ATLANTIC...
A NARROWING UPPER LEVEL RIDGE EXTENDS FROM THE NW BAHAMAS NEWD
TO 32N74W WITH BROAD SWLY FLOW TO THE W PUSHING HURRICANE
CHARLEY ACROSS CNTRL FLORIDA TOWARDS THE SOUTHEAST U.S. COAST.
WEAK SFC RIDGING EXTENDS INTO THE AREA ALONG 28N BUT AN UPPER
LOW NEAR 29N60W IS PRODUCING WIDELY SCATTERED MODERATE
CONVECTION FROM 27N-32N BETWEEN 53W-62W. A SECOND UPPER LEVEL
LOW/SHORTWAVE TROF IS LOCATED NEAR 29N46W AND IS PRODUCING ITS
OWN AREA OF WIDELY SCATTERED MODERATE FROM 30N-33N BETWEEN
47W-50W...WHICH HAPPENS TO BE JUST S OF A STATIONARY FRONT ALONG
33N. ELSEWHERE...A STRONG UPPER HIGH IS CENTERED NEAR 23N41W
WHILE A WEAK LEFTOVER UPPER TROF APPROACHES THE CANARY AND
MADEIRA ISLANDS FROM THE W.

TROPICAL ATLANTIC...
THE TROPICS HAVE GONE BONKERS SINCE THE BEGINNING OF AUGUST WITH
4 NAMED SYSTEMS... VERY ACTIVE CONSIDERING THAT IF TD 5 FORMS
INTO EARL AS FORECAST... THIS AUGUST WOULD BE TIED FOR 5TH MOST
ACTIVE IN THE NUMBER OF TROPICAL STORMS ONLY HALFWAY THRU THE
MONTH.  STRONG UPPER LEVEL HIGH REMAINS ANCHORED NEAR 23N40W
OVER THE CENTRAL ATLC...THE MAJORITY OF THE TROPICAL ATLC IS
UNDER THE INFLUENCE OF STRONG EASTERLY FLOW AND LOW VALUES OF
VERTICAL SHEAR. THE UPPER PATTERN IS DIFFLUENT OVER BOTH TD 5
AND DANIELLE SUPPORTING CONVECTION. THE RIDGE SHOULD SHIFT
SLIGHTLY FARTHER S TO 18N/19N OVER THE NEXT 48-72 HOURS...WITH
SOME INCREASING SHEAR POSSIBLE BETWEEN 40W-50W AS A CUT-OFF LOW
DEVELOPS OVER THE SUBTROPICS.

$$
BLAKE


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