[MTHOLLYSVRWX] Tropical Weather Discussion : AT@ 6/18/2006 1:47:14 PM

[n2qae at arrl.net]

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


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