000 AXNT20 KNHC 131028 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT OCT 13 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 72W S OF 18N MOVING W 10-15 KT. WEAK SATELLITE SIGNATURE WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM HISPANIOLA TO INLAND OVER SOUTH AMERICA BETWEEN 66W-76W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N10W 8N16W 9N35W 10N56W 10N62W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 4N-8N BETWEEN 11W-16W...FROM 7N-12N BETWEEN 37W-42W...AND FROM 7N-10N BETWEEN 42W-47W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 7N14N BETWEEN 17W-25W AND FROM 7N-11N BETWEEN 47W-63W. DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH COVERS MOST OF THE GULF ANCHORED BY A LARGE UPPER LOW N OF THE GREAT LAKES AND EXTENDS INTO THE W ATLC WITH THE ASSOCIATED FRONTAL BOUNDARY IN W ATLC. A SURFACE TROUGH IS OVER THE W GULF FROM 21N91W TO OFF THE TEXAS COAST NEAR BROWNSVILLE WITH ISOLATED SHOWERS FROM 23N-26N BETWEEN 90W-96W. BROAD UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN COVERING THE FAR SE GULF PROVIDING UPPER DIFFLUENCE FROM THE YUCATAN CHANNEL THROUGH THE FLORIDA STRAITS TO GENERATING HEAVY SHOWERS/ THUNDERSTORMS S OF THE FLORIDA KEYS E OF 83W. SMALL AREA OF THUNDERSTORMS ARE OFF THE W COAST OF FLORIDA NEAR FT. MYERS WITHIN 30/45 NM OF RADIUS OF 26.5N83W. OTHERWISE THE REMAINDER OF THE GULF IS UNDER DRY STABLE AIR THUS CLEAR SKIES. CARIBBEAN SEA... A PERSISTENT 1005 MB LOW IN THE NW CARIBBEAN ALONG THE COAST OF THE YUCATAN JUST N OF BELIZE NEAR 19N87W WITH A SURFACE TROUGH EXTENDING NE ACROSS CENTRAL CUBA INTO THE W ATLC. SCATTERED SHOWERS/THUNDERSTORMS ARE NW OF A LINE FROM HONDURAS NEAR 16N85W ACROSS CUBA NEAR 20N77W BUT DOES NOT INCLUDE THE YUCATAN CHANNEL. AN UPPER HIGH IS SITUATED BETWEEN E CUBA AND JAMAICA NEAR 19N78W EXTENDING A RIDGE AXIS NE INTO THE W ATLC AND SW TO THE COAST OF HONDURAS ENHANCING THE ACTIVITY ABOVE. LOW LEVEL AND UPPER LEVEL CONVERGENCE IS GENERATING SOME SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ACROSS THE SW CARIBBEAN S OF 12N. ATLANTIC OCEAN... THE DEEP LAYERED TROUGH OVER THE E US AND THE GULF OF MEXICO EXTENDS OVER THE W ATLC W OF A LINE FROM CENTRAL CUBA TO E OF BERMUDA BEYOND 32N63W WITH THE ASSOCIATED COLD FRONT EXTENDING THROUGH 32N64W TO A 1010 MB LOW NEAR 30N66W BECOMING STATIONARY TO OVER THE N BAHAMA ISLANDS. DUE TO DRY CONTINENTAL AIR FILTERING E OFF THE COAST OF THE US SHOWER ACTIVITY IS SEVERELY LIMITED IN ASSOCIATION WITH THE FRONTAL BOUNDARY. A SURFACE TROUGH EXTENDS FROM THE 1005 MB LOW IN THE W CARIBBEAN ACROSS CENTRAL CUBA NEAR 22N79W TO 26N68W. THE UPPER RIDGE IS ANCHORED IN THE N CARIBBEAN EXTENDS A RIDGE AXIS THROUGH THE WINDWARD PASSAGE WELL E OF BERMUDA TO BEYOND 32N56W WITH ENOUGH DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 26N FROM 68W-80W AND THROUGH THE FLORIDA STRAITS AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 28N-33N BETWEEN 60W-65W. WEAKENING ELONGATED UPPER LOW IS CENTERED NEAR 23N56W. THE REMNANTS OF T.D. FIFTEEN IS ANALYZED AS A 1013 MB SURFACE LOW NEAR 31N50W AND CHARACTERIZED AS A SMALL LOW LEVEL SWIRL. AN UPPER TROUGH COVERS THE REMAINDER OF THE ATLC EXTENDING FROM AN UPPER LOW OFF THE S COAST OF PORTUGAL ACROSS THE WESTERN MOST CANARY ISLANDS INTO THE E TROPICAL ATLC TO NEAR 17N40W. A WEAKENING 1011 MB SURFACE LOW REMAINS CENTERED JUST S OF THE CANARY ISLANDS NEAR 27N17W BUT DUE TO DRY STABLE AIR IT IS NOT ABLE TO SUPPORT ANY SHOWER ACTIVITY. $$ WALLACE