[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181746
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN JUN 18 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 22W/23W S OF 15N MOVING W 10-15 KT. BROAD
MID LEVEL CIRCULATION IS OBSERVED ON VISIBLE SATELLITE IMAGERY.
MOST OF THE CONVECTIVE ACTIVITY IS CONFINED TO THE ITCZ AXIS.

A GOOD LOOKING TROPICAL WAVE IS ALONG 50W/51W S OF 16N MOVING W
15-20 KT. BROAD LOW/MID LEVEL CURVATURE SIGNATURE IS OBSERVED ON
VISIBLE SATELLITE IMAGERY. GRIDDED QUIKSCAT DATA HAS SHOWN THAT
THE WAVE IS VERY WELL DEFINED IN THE WIND FIELD. A CLUSTER OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-15N
BETWEEN 47W-52W. COMPUTER MODELS HAVE MOISTURE FROM THIS WAVE
AFFECTING THE LESSER ANTILLES LATE MONDAY AND THE VIRGIN ISLANDS
AND PUERTO RICO ON TUESDAY. ACCORDING TO THE 18/1500 UTC CIMSS
SAHARAN AIR LAYER A HUGE AREA OF AFRICAN DUST IS BEHIND THIS
WAVE.

TROPICAL WAVE THAT WAS PREVIOUSLY ANALYZED ALONG 66W/67W ON THE
06Z SURFACE MAP WAS RELOCATED ALONG 65W/66W BASED ON THE SAN
JUAN 12Z SOUNDING AND LATEST VISIBLE SATELLITE IMAGERY. THIS
WAVE IS MOVING SLOWLY WESTWARD AT AROUND 10 KT. WAVE SIGNATURE
CURVATURE REMAINS WEAK AS IT CROSSES THE E CARIBBEAN. THE WAVE
AND ITS ASSOCIATED MOISTURE IS ENHANCING THE SHOWER/TSTM
ACTIVITY OVER THE VIRGIN INLAND AND PUERTO RICO...INCLUDING THE
SAN JUAN METRO AREA.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N15W 4N30W 7N40W 7N50W 7N60W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 100-120
NM N OF THE AXIS BETWEEN 24W-32W AND S OF THE AXIS BETWEEN
32W-37W. SIMILAR CONVECTION IS ALSO FOUND WITHIN 100 NM SOUTH OF
THE AXIS BETWEEN 40W-46W. SCATTERED MODERATE SHOWERS AND TSTMS
ARE WEST OF 50W.

...DISCUSSION...
GULF OF MEXICO...
MID/UPPER LEVEL TROUGH REMAINS OVER THE CENTRAL US INTO TEXAS
AND THE NW CORNER OF THE GULF. THIS LEAVES THE REMAINDER OF THE
GULF UNDER A MID/UPPER HIGH LOCATED NEAR 26N90W WITH A SHARP
RIDGE AXIS EXTENDING NE OVER SE U.S.. DRY AIR ALOFT COVERS A
GOOD PORTION OF THE AREA. A SQUALL LINE IS MOVING THROUGH
LOUISIANA AND THE TEXAS COAST AND ADJACENT COASTAL WATERS. THE
AFOREMENTIONED TROUGH IS SUPPORTING THIS CONVECTIVE ACTIVITY. AT
THE SURFACE...A RIDGE DOMINATES THE GULF. SE WINDS OF 10-15 KT
BLOW OVER THE WESTERN GULF WHILE E-SE WINDS DOMINATES THE
REMAINDER OF THE AREA. THE RIDGE ALONG THE NORTHERN GULF COAST
WILL REMAIN STATIONARY THROUGH MON.

CARIBBEAN SEA...
THE CARIBBEAN IS DOMINATED BY TWO UPPER HIGHS...THE ONE OVER THE
GULF OF MEXICO AND THE SECOND OVER THE W TROPICAL ATLC. BROAD
UPPER TROUGH OVER THE W ATLC DIPS INTO THE CENTRAL CARIBBEAN N
OF 16N FROM 70W-80W. SWLY WINDS AHEAD OF THE UPPER TROUGH ARE
FAVORING THE DEVELOPMENT OF SHOWERS AND TSTMS OVER THE NE
CARIBBEAN. SCATTERED SHOWERS ARE BETWEEN JAMAICA AND EASTERN
CUBA RELATED TO THE BASE OF THE UPPER TROUGH. DRY AIR ALOFT
DOMINATES THE BASIN WEST OF 70W AND S OF 15N. MODERATE TRADE
WINDS ARE OBSERVED OVER THE CARIBBEAN SEA. WINDS WILL INCREASE
TO 20-25 KT OFF THE NW COAST OF VENEZUELA AND COLOMBIA TONIGHT
TROUGH MONDAY.

ATLANTIC OCEAN...
THE ATLANTIC HAS A TROUGH/RIDGE/TROUGH PATTERN. BROAD DEEP
LAYERED TROUGH CONTINUES TO DIG S ACROSS THE W ATLC INTO THE N
CENTRAL CARIBBEAN FROM W OF 60W. THE ASSOCIATED SURFACE TROUGH
EXTENDS ALONG 31N64W 29N68W. SCATTERED SHOWERS ARE WITHIN AROUND
5O NM SE OF THE TROUGH AXIS. A RIDGE IS BETWEEN THE W ATLC
TROUGH AND A BROAD UPPER LOW CENTERED NEAR 30N35W WITH THE UPPER
TROUGH EXTENDING S TO 20N35W. THE DEEP TROPICS IS DOMINATED BY
AN UPPER HIGH OVER THE W TROPICAL ATLC NEAR 16N48W AND A SECOND
RIDGE EXTENDING OFF THE AFRICAN COAST TO THE CAPE VERDE ISLANDS.
DIFFLUENCE ON THE E SIDE OF THE W ATLC TROUGH IS GENERATING AN
AREA OF OVERCAST CLOUDINESS WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS FROM 19N-27N BETWEEN 55W-60W. AS IS TYPICAL FOR
THIS TIME OF THE YEAR...THE BERMUDA-AZORES HIGH WITH A 1036 MB
CENTER IN THE VICINITY OF 41N41W EXTENDS OVER MOST OF THE ATLC
OCEAN...WITH A RIDGE COVERING THE GULF OF MEXICO AND THE SE
PORTION OF THE U.S.. A SECONDARY HIGH PRESSURE CENTER OF 1026 MB
IS NEAR 35N-68W.

$$
GR


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