000 AXNT20 KNHC 180001 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT OCT 17 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE WAS ADDED TO THE MAP ANALYSIS AT 17/1800 UTC...ALONG 31W/32W TO THE SOUTH OF 14N. THIS WAVE SHOWED UP IN THE LAST VISIBLE IMAGES OF THE DAY. POSSIBLE SHOWERS FROM 10N TO 14N BETWEEN 30W AND 34W. IT IS NOT EASY TO KNOW EXACTLY IF THIS PRECIPITATION ONLY ACCOMPANIES THE WAVE. IT MAY BE PART OF THE LARGER AREA OF PRECIPITATION THAT IS WITH THE ITCZ. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 16N78W 10N80W BEYOND PANAMA. THIS WAVE IS MOVING THROUGH THE AREA OF STRONG CONVECTIVE PRECIPITATION FROM SIX HOURS AGO. UPPER LEVEL CYCLONIC FLOW MOVES FROM THE EASTERN PACIFIC OCEAN SIDE OF COLOMBIA TO PANAMA AND COSTA RICA. UPPER LEVEL ANTICYCLONIC FLOW IS ON TOP OF THE WAVE. IT IS NOT EASY TO FIND CONVECTIVE PRECIPITATION THAT ONLY ACCOMPANIES THIS TROPICAL WAVE. ...THE ITCZ... FROM AFRICA NEAR 13N17W TO 8N27W TO 9N34W 7N42W 8N50W TO 7N60W IN NORTHERN GUYANA. SCATTERED STRONG SHOWERS AND THUNDERSTORMS ARE FROM 7N TO 12N BETWEEN 19W AND 27W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE ELSEWHERE WITHIN 180 NM TO 240 NM ON EITHER SIDE OF 11N16W 9N23W 7N35W 8N56W. ...DISCUSSION... THE GULF OF MEXICO... THE EASTERN U.S.A. DEEP LAYER TROUGH IS SUPPORTING THE CURRENT COLD FRONT THAT PASSES THROUGH 26N80W ALONG THE FLORIDA COAST... ACROSS THE FLORIDA KEYS TO 22N90W IN THE SOUTH CENTRAL GULF OF MEXICO...INTO THE SOUTHWESTERN CORNER OF THE AREA NEAR 18N94W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE SHOWERS ARE TO THE SOUTH OF 28N83W 27N90W 26N97W. THE CARIBBEAN SEA... UPPER LEVEL CYCLONIC FLOW COVERS CENTRAL AMERICA FROM THE EASTERN PACIFIC OCEAN NEAR 10N TO 17N BETWEEN CENTRAL NICARAGUA ALONG 85W AND 93W IN MEXICO JUST TO THE WEST OF THE GUATEMALA BORDER. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE TO THE WEST OF THE LINE FROM THE EASTERN END OF CUBA TO EASTERN HONDURAS. A SMALLER AREA OF UPPER LEVEL CYCLONIC FLOW IS MOVING FROM COLOMBIA TOWARD PANAMA AND COSTA RICA. UPPER LEVEL ANTICYCLONIC OUTFLOW IS ON TOP OF AN AREA OF STRONG SHOWERS AND THUNDERSTORMS THAT WAS IN THE SOUTHWESTERN CORNER OF THE AREA SIX HOURS AGO. MUCH OF THAT COMPARATIVELY STRONGER CONVECTIVE PRECIPITATION HAS WEAKENED...GIVING WAY TO REMNANT SHOWERS FROM 12N TO 14N BETWEEN 79W AND THE EASTERN COAST OF NICARAGUA. OTHER SHOWERS AND POSSIBLE THUNDERSTORMS GO FROM 16N TO JAMAICA BETWEEN 76W AND 80W. A SURFACE TROUGH IS ALONG 70W/71W TO THE SOUTH OF 17N MOVING WEST 10 TO 15 KT. EARLIER SHOWERS AND THUNDERSTORMS FROM 16N TO HISPANIOLA BETWEEN 70W AND 73W HAVE DISSIPATED ALREADY. THE ATLANTIC OCEAN... A DEEP LAYER LONG WAVE TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N70W TO THE NORTHERN BAHAMAS BEYOND THE SOUTHERNMOST TIP OF FLORIDA AND THE FLORIDA KEYS...INTO THE GULF OF MEXICO. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE SHOWERS/POSSIBLE THUNDERSTORMS ARE TO THE NORTHWEST OF THE LINE FROM BERMUDA TO 24N80W IN THE STRAITS OF FLORIDA. ISOLATED MODERATE SHOWERS ALSO ARE FROM 23N TO 28W BETWEEN 66W AND THE BAHAMAS. A CENTRAL ATLANTIC OCEAN DEEP LAYER TROUGH PASSES THROUGH 32N34W TO A CYCLONIC CIRCULATION CENTER THAT IS NEAR 27N34W 22N37W TO 15N46W TO 10N49W. THIS TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 32N36W TO 30N37W TO 22N42W. SHOWERS ARE POSSIBLE TO THE NORTH OF 20N BETWEEN 30W AND 40W...AND FROM 15N TO 27N BETWEEN 40W AND 50W. AN EASTERN ATLANTIC OCEAN DEEP LAYER TROUGH PASSES THROUGH 32N19W TO 28N20W TO A CYCLONIC CIRCULATION CENTER THAT IS NEAR 24N22W. A SOLID MASS OF HIGH LEVEL CLOUDS THAT IS TO THE SOUTH OF 24N16W 20N25W 13N40W COMPLETELY COVERS THE AREA TO THE SOUTH OF THAT LINE AND BLOCKS ANY VIEW OF THE REST OF THE TROUGH THAT IS TO THE SOUTH OF 24N22W. A SURFACE TROUGH REMAINS ALONG 30N25W 27N28W 19N32W. POSSIBLE SHOWERS ARE FROM 29N TO 31N BETWEEN 20W AND 22W...AND WITHIN 15 NM TO 30 NM ON EITHER SIDE OF 28N24W 26N26W 20N37W. $$ MT