000 AXNT20 KNHC 130519 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 71W S OF 18N MOVING W NEAR 15 KT. WEAK SATELLITE SIGNATURE WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS BETWEEN PUERTO RIC/HISPANIOLA AND SOUTH AMERICA FROM 67W-74W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N11W 7N25W 8N46W 10N62W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 180 NM N OF THE ITCZ AXIS FROM 37W-41W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 3N-11N BETWEEN 10W-37W AND FROM 7N-11N BETWEEN 43W-62W. DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH COVERS MOST OF THE GULF ANCHORED BY A LARGE UPPER LOW OVER CANADA AND EXTENDS INTO THE W ATLC WITH THE ASSOCIATED COLD FRONT IN W ATLC. REMNANT ISOLATED SHOWERS REMAIN OVER THE CENTRAL GULF FROM 22N-26N BETWEEN 88W-96W. BROAD UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN COVERING THE FAR SE GULF PROVIDING UPPER DIFFLUENCE FROM THE YUCATAN CHANNEL AND OVER THE FLORIDA STRAITS TO GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 24N E OF 85W INCLUDING THE FLORIDA KEYS. OTHERWISE THE REMAINDER OF THE GULF IS UNDER MOSTLY DRY STABLE AIR THUS CLEAR SKIES. CARIBBEAN SEA... A PERSISTENT 1005 MB LOW IN THE NW CARIBBEAN ALONG THE COAST OF N BELIZE NEAR 28N87W 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 JAMAICA TO THE WINDWARD PASSAGE COVERING THE N PORTION OF CENTRAL AMERICA/ YUCATAN PENINSULA AND ALL OF CUBA INCLUDING THE YUCATAN CHANNEL. AN UPPER HIGH IS SITUATED BETWEEN E CUBA AND JAMAICA EXTENDING A RIDGE AXIS NE INTO THE W ATLC AND SW TO OVER NICARAGUA/HONDURAS ENHANCING THE ACTIVITY ABOVE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 13N E OF 66W ACROSS TRINIDAD AND TOBAGO AND ARE ASSOCIATED WITH THE ITCZ. 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 BEYOND BERMUDA WITH THE ASSOCIATED COLD FRONT EXTENDING THROUGH 32N66W TO 30N70W WHERE IT BECOMES STATIONARY TO THE E COAST OF NEAR PALM BEACH. 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 A 1005 MB LOW IN THE W CARIBBEAN ACROSS CENTRAL CUBA NEAR 22N78W ALONG 24N69W TO 30N65W. THE UPPER RIDGE IS ANCHORED IN THE N CARIBBEAN EXTENDS A RIDGE AXIS THROUGH THE WINDWARD PASSAGE WELL E OF BERMUDA TO BEYOND 32N58W WITH ENOUGH DIFFLUENCE TO GENERATE SCATTERED SHOWERS/THUNDERSTORMS S OF 25N W OF 67W THROUGH THE FLORIDA STRAITS AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150 NM OF LINE FROM 25N68W TO BEYOND 32N61W. AN UPPER TROUGH IN THE W/CENTRAL ATLC EXTENDING FROM 31N48W THROUGH AN UPPER LOW NEAR 24N53W TO 20N56W. THE REMNANTS OF T.D. FIFTEEN IS UNDER THE N END OF THIS UPPER TROUGH ANALYZED AS A 1014 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 THE COAST OF PORTUGAL ACROSS THE WESTERN MOST CANARY ISLANDS INTO THE E TROPICAL ATLC TO NEAR 16N43W. A SMALL SURFACE 1010 MB LOW REMAINS CENTERED JUST SW OF THE CANARY ISLANDS NEAR 27N18W BUT DUE TO DRY STABLE AIR IT IS NOT ABLE TO SUPPORT ANY SHOWER ACTIVITY. A WEAK 1019 MB HIGH IS CENTERED BETWEEN THE TWO SURFACE LOWS NEAR 26N36W. $$ WALLACE