[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171622
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1205 PM EDT FRI JUN 17 2011

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
1515 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 11N49W TO 04N52W MOVING W-NW AT 10-15
KT.  WAVE REMAINS EMBEDDED IN ITCZ WITH WELL DEFINED VORTICITY
AT SURFACE NEVERTHELESS ITS SIGNATURE AT 700 MB REMAINS WEAKER.
ABUNDANT MOISTURE ASSOCIATED WITH WAVE PRODUCE SCATTERED
CONVECTION WITHIN 240 NM E OF WAVE AXIS.

TROPICAL WAVE MOVING ACROSS WESTERN CARIBBEAN S OF 16N ALONG 80W
MOVES W-NW AT 10-15 KT.  WAVE EMBEDDED IN A SURGE OF DEEP
MOISTURE UNDER MONSOONAL TROUGH.  SCATTERED MODERATE CONVECTION
WITHIN 180 NM W AND 240 NM E OF WAVE AXIS.

...ITCZ/MONSOON TROUGH...

MONSOON TROUGH EXTENDS FROM INLAND GUINEA-BISSAU IN WEST AFRICA
...ENTERING ATLC FROM 11N16W SW TO 07N22W.  ITCZ AXIS CONTINUES
THEN TO 04N43W TO 08N50W TO 07N58W.  SCATTERED MODERATE TO
STRONG CONVECTION MOVES OUT OF COAST OF SIERRA  LEONE...GUINEA
...AND NORTHERN LIBERIA E OF 24W FROM 3N-10N. SIMILAR CONVECTION
WITHIN 180 NM N OF ITCZ AXIS MERGES WITH AFOREMENTIONED TROPICAL
WAVE.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR SATELLITE IMAGERY SHOWS VERY DRY AIR DUE TO STRONG
SUBSIDENCE ALOFT COVERING ENTIRE GULF OF MEXICO.  AT LOWER
LEVELS...HIGHER PRESSURES OVER NE GULF BRINGS FLAT GRADIENT AND
FAIR WEATHER WITH A MODERATE BREEZE ACROSS BASIN.  SCATTERED
SHOWERS OVER YUCATAN PENINSULA ARE ASSOCIATED WITH MOISTURE
OUTFLOW FROM EAST PACIFIC TROPICAL FEATURES.  NO SIGNIFICANT
CHANGES EXPECTED DURING NEXT 24 HOURS.

CARIBBEAN SEA...
TROPICAL WAVE COMBINES WITH MOIST WARM AIR MASS ASSOCIATED WITH
MONSOON TROUGH PRODUCES SCATTERED DEEP CONVECTION OVER SW
CARIBBEAN WHILE ISOLATED TSTMS DOT THE NW PART OF BASIN.
EASTERN CARIBBEAN REMAINS UNDER FAIR WEATHER FOR THE TIME BEING
AS A SECOND TROPICAL WAVE APPROACHES TROPICAL ATLANTIC ZONE.
SCATTERED TSTMS MOSTLY S OF 13N LIKELY TO DAMPEN SKIES E OF 60W
THIS AFTERNOON...TONIGHT AND SAT.  ANTI CYCLONIC OUT FLOW ALOFT
FROM ANTICYCLONIC GYRE OVER NW COLOMBIA CONTRIBUTES IN
MAINTAINING A DRY EASTERN CARIBBEAN.  ISOLATED SHOWERS SE OF
HISPANIOLA AND NE OF JAMAICA.

ATLANTIC OCEAN...
UPPER LEVEL TROUGH MOVES ACROSS NW ATLC SUPPORTING COLD FRONT
EXTENDING SW ALONG 31N55W TO 26N65W TO 26N70W CAUSING SCATTERED
TSTMS WITHIN 90 NM ON E OF FRONT N OF 27N.  HEALTHY RIDGE BUILDS
BEHIND FRONT ACROSS BASIN ANCHORED BY 1020 MB HIGH PRESSURE
CENTER AT 36N65W. REMAINDER OF ATLC E OF FRONT DOMINATED BY
BROAD SURFACE RIDGE ANCHORED BY STRONG STATIONARY 1029 MB HIGH
PRESSURE CENTERED AT 35N31W.

F0R ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
WALLY BARNES




This weather bulletin was brought to you by:
www.nashvilleweather.net