[Tropical] Tropical Weather Discussion

[Nashville EMWIN]

AXNT20 KNHC 161742
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON 16 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
1715 UTC.

...SPECIAL FEATURES...
TROPICAL STORM EARL HAS DEGENERATED INTO A TROPICAL WAVE LOCATED
OVER THE CENTRAL CARIBBEAN AT 1500UTC.  PRESENT MOVEMENT IS
TOWARD THE WEST-NORTHWEST AT 22 KT.  MAX SUSTAINED WINDS 25 TO
35 KT WITH GUST TO 45 KT OVER THE CENTRAL CARIBBEAN SEA.
SCATTERED MODERATE CONVECTION IS ASSOCIATED WITH THE WAVE ALONG
THE WAVE AXIS FROM 6N-18N BETWEEN 66N-70N.  SOME DEVELOPMENT IS
POSSIBLE.

HURRICANE DANIELLE IS NEAR 18.2N 37.7W AT 16/1500 UTC MOVING NW
15 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 970 MB.  MAXIMUM
SUSTAINED WIND SPEED IS 90 KT GUSTS 110 KT. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC
FOR MORE DETAILS.  SATELLITE IMAGERY SHOWS A SMALL AND SOMEWHAT
CLOUD-FILLED EYE WITH IR IMAGES INDICATING A GENERAL COOLING
TREND IN THE EYEWALL TEMPS.  THERE ARE NO SIGNS YET IN THE CLOUD
PATTERN OF S TO SW SHEAR FORECAST TO AFFECT DANIELLE AND HALT
ITS DEVELOPMENT.  NUMEROUS MODERATE WITHIN 90 NM OF THE CENTER.

...TROPICAL WAVES...

TROPICAL WAVE ADDED ALONG 22W S OF 16N MOVING W NEAR 20KT.
THIS SYSTEM MOVED OFF THE AFRICAN COAST YESTERDAY.  POSITION OF
WAVE WAS BASED ON A COMBINATION OF VISIBLE SATELLITE IMAGERY AND
SOUNDINGS FROM DAKAR AND SAL. THE WAVE HAS SCATTERED MODERATE
CONVECTION FROM 7N-12N BETWEEN 20W-24W.  THE GFS MODEL SUGGEST
THAT SOME DEVELOPMENT IS POSSIBLE LATER IN THE WEEK.

TROPICAL WAVE ALONG 41W S OF 13N MOVING W NEAR 20 KT.  THIS
SYSTEM SPAWNED FROM DANIELLE AND HAS CONTINUED MOVING WESTWARD.
CONVECTION IS LIMITED MOSTLY TO THE ITCZ.  THIS IS A
LOW-LATITUDE WAVE AND ENHANCED SHOWERS FROM IT ARE EXPECTED TO
BE LIMITED TO THE WINDWARD ISLANDS WED/THU.  WIDELY SCATTERED
MODERATE WITHIN 60 NM OF THE WAVE AXIS FROM 6.5N-7.5N.

TROPICAL WAVE IS LOCATED IN THE WESTERN CARIBBEAN ALONG 81W S OF
19N MOVING W 20-25 KT.  POSITION BASED ON EXTRAPOLATION.  WIDELY
SCATTERED MODERATE CONVECTION S OF 16N E OF 80W COULD BE FROM
THE WAVE.

...ITCZ...
ITCZ AXIS IS ALONG 10N14W 11N30W 6N50W 7N58W.  SCATTERED
MODERATE FROM 7N-12N BETWEEN 21W-224W NEAR A TROPICAL WAVE.
ISOLATED MODERATE CONVECTION BETWEEN 39W-59W WITHIN 60NM EITHER
SIDE OF AXIS.

...DISCUSSION...
GULF OF MEXICO AND SUBTROPICAL ATLC W OF 75W...
COOL TEMPERATURES AND DRY AIR CONTINUE FOR THE GULF COAST W OF
93W CENTRAL GULF.  ZONAL FLOW REMAINS OVER THE NW GULF W OF 89W
N OF 26N..LEADING TO ONLY A SLOW MODERATION OVER THE NEXT FEW
DAYS WITH MORE TYPICAL HEAT/HUMIDITY VALUES RETURNING TO THE NW
GULF STATES BY WED.  AFOREMENTIONED SURFACE TROUGH IS SLOWLY
MIGRATING WESTWARD THRU THE CENTRAL GULF FROM THE SW TIP OF
GEORGIA SW TO 30N86W 19N96W. WEAK UPPER TROF S OF 25N ALONG 90W
ASSISTING SCATTERED TSTMS WITHIN 60 NM OF SURFACE TROF.  UPPER
HIGH IS OVER S-CENTRAL FLORIDA WITH TYPICAL SUMMERTIME DIURNAL
CONVECTION FOR THE PENINSULA LIKELY TODAY.

CARIBBEAN SEA...
DEEP ELY FLOW IS N OF 16N W OF JAMAICA.  FURTHER S... MID-
OCEANIC TROF RUNS FROM NICARAGUA THRU E JAMAICA INTO THE SE
BAHAMAS.  TROF COUPLED ALONG WITH THE TROPICAL WAVE IN THE
WESTERN CARIBBEAN IS FUELING TSTMS OVER SW CARIBBEAN FROM 9N-19N
BETWEEN 78W-86W.  TO THE E... UPPER RIDGE IS POKING INTO THE E
CARIBBEAN FROM THE NE LEEWARD ISLANDS TO 16N74W.   COMPUTER
MODELS INSIST THE RIDGE WILL BUILD WESTWARD.

SUBTROPICAL ATLANTIC...
MID/UPPER LOW IS NEAR 30N68W WITH TROF SOUTHWARD INTO THE SE
BAHAMAS.  COOL MID/UPPER TEMPERATURES NEAR THE TROF AXIS HAVE
ALLOWED ISOLATED SHOWERS TO FORM N OF THE AREA.  UPPER RIDGING
ALONG WITH STRONG SUBSIDENCE AND DRY AIR IS FROM 39W-64W... IS
BEGINNING TO BE SQUISHED BY A DEEPENING DEEP-LAYER TROF IN THE
CENTRAL ATLC.  TROF IS ALONG 31N31W 22N45W 29N55W AND IS THE
MAIN PLAYER IN DANIELLE'S FORECASTED TURN TO THE N.  A FEW TSTMS
ARE WITHIN 60 NM OF 27N43W NEAR AN EMBEDDED UPPER LOW.  THE FAR
E ATLC IS BASICALLY COVERED WITH ANTICYCLONIC FLOW AND
RELATIVELY DRY AIR.

TROPICAL ATLANTIC...
UPPER HIGH IS NEAR 17N53W RIDGING WESTWARD INTO THE NE LEEWARD
ISLANDS.  UPPER HIGH LOCATED NEAR 21N14W WITH RIDGING EXTENDING
WEST TO JUST NORTH OF DANIELLE NEAR 19N34W THEN E OVER AFRICA.
MID/UPPER LEVEL DRY AIR IS PRESENT FROM 41W-60W WITH INCREASING
VALUES IN THE E ATLC WITH GENERAL ELY FLOW ALOFT.  PRESSURES ARE
CONSIDERABLY HIGHER-THAN-AVERAGE FOR MID-AUGUST.

$$
JP/EH



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