000 AXNT20 KNHC 201143 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT OCT 20 2012 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... A CARIBBEAN SEA TROPICAL WAVE IS ALONG 70W...FROM THE EASTERN HALF OF THE DOMINICAN REPUBLIC...TO THE NORTHWESTERN CORNER OF VENEZUELA. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG WITHIN 90 NM ON EITHER SIDE OF 12N66W...SCATTERED MODERATE TO ISOLATED STRONG BETWEEN 70W AND 75W AND FROM 15N TO 17N BETWEEN 76W AND 77W. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR GUADELOUPE FOR THE PERIOD ENDING AT 20/0000 UTC IS 0.69. ENVIRONMENTAL CONDITIONS ARE FORECAST TO BECOME MORE FAVORABLE FOR DEVELOPMENT DURING THE NEXT DAY OR TWO AS THE DISTURBANCE MOVES WESTWARD AND THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE POSITION HAS BEEN RE-LOCATED TO BE ALONG 44W FROM 10N TO 20N...BASED ON SATELLITE IMAGERY. RAINSHOWERS ARE POSSIBLE FROM 10N TO 20N BETWEEN 40W AND 47W. AN ATLANTIC OCEAN TROPICAL WAVE POSITION HAS BEEN RE-LOCATED TO BE 57W FROM 13N TO 25N...BASED ON SATELLITE IMAGERY. RAINSHOWERS ARE POSSIBLE FROM 17N TO 26N BETWEEN 56W AND 60W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL GUINEA-BISSAU NEAR 12N16W TO 10N20W...CURVING TO 9N30W. THE ITCZ CONTINUES FROM 9N30W TO 5N40W AND 5N50W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG FROM 5N TO 12N BETWEEN AFRICA AND 23W FROM 11N TO 12N BETWEEN 26W AND 30W FROM 7N TO 12N BETWEEN 31W AND 34W...WIDELY SCATTERED TO SCATTERED MODERATE AND ISOLATED STRONG ELSEWHERE FROM 6N TO 13N BETWEEN 37W AND 45W. ...DISCUSSION... FROM THE WESTERN ATLANTIC OCEAN INTO THE GULF OF MEXICO... AND THE REST OF THE GULF OF MEXICO... A DEEP LAYER TROUGH PASSES THROUGH THE GREAT LAKES REGION OF THE U.S.A....THROUGH THE SOUTHEASTERN U.S.A....INTO THE EAST CENTRAL AND SOUTHEASTERN GULF OF MEXICO. THE TROUGH SUPPORTS A SLOWLY- MOVING COLD FRONT THAT PASSES THROUGH 32N76W IN THE ATLANTIC OCEAN...TO 27N81W IN FLORIDA...TO 25N90W IN THE CENTRAL GULF OF MEXICO...TO 23N98W ALONG THE MEXICO COAST. COMPARATIVELY DRIER AIR IN SUBSIDENCE IN WATER VAPOR IMAGERY IS TO THE NORTH AND NORTHWEST OF THE LINE THAT PASSES THROUGH 32N77W...INTO THE SOUTH CENTRAL GULF OF MEXICO NEAR 23N90W...TO THE LOWER TEXAS GULF COAST. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE WITHIN 60 TO 90 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 28N80W TO 24N90W...AND IN THE WATERS THAT ARE FROM 22N TO 28N TO THE WEST OF 90W. OTHER BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION ARE IN THE WATERS THAT ARE TO THE SOUTH OF 22N TO THE WEST OF 90W. CONVECTIVE PRECIPITATION THAT IS TO THE EAST OF THE COLD FRONT AND THE DEEP LAYER TROUGH...SCATTERED MODERATE TO STRONG TO THE NORTH OF 29N BETWEEN 70W AND 76W...ISOLATED MODERATE TO LOCALLY STRONG ELSEWHERE THE NORTH OF 20N TO THE WEST OF 65W. THE CARIBBEAN SEA... MIDDLE LEVEL TO UPPER LEVEL WIND FLOW MOVES FROM THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO...ACROSS THE YUCATAN PENINSULA...INTO THE NORTHWESTERN CORNER OF THE AREA. THE DIRECTIONAL COMPONENT OF THE WIND EVENTUALLY CHANGES SLIGHTLY TO WESTERLY AND SOUTHWESTERLY AS THE WIND MOVES FROM THE YUCATAN PENINSULA THROUGH THE WINDWARD PASSAGE. THE SOUTHWESTERLY WIND FLOW THAT MOVES THROUGH THE WINDWARD PASSAGE EVENTUALLY MERGES INTO THE LONGER WAVE LARGER-SCALE TROUGH THAT SUPPORTS THE GULF OF MEXICO COLD FRONT. THE WIND FLOW THAT DOES NOT MERGE INTO THE TROUGH AREA BECOMES PART OF AN AREA OF MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW WITH A MEAN CENTER NEAR 16N70W. PART OF THE WIND THAT IS TO THE EAST OF 67W EVENTUALLY MERGES INTO CYCLONIC FLOW THAT IS MOVING AROUND AN ATLANTIC OCEAN 18N52W CYCLONIC CIRCULATION CENTER AND A RELATED TROUGH. THE MIDDLE LEVEL TO UPPER LEVEL WIND FLOW THAT IS IN THE SOUTHWESTERN CORNER OF THE AREA IS LARGELY EASTERLY-TO-NORTHEASTERLY. A TROPICAL WAVE IS ALONG 70W...FROM THE EASTERN HALF OF THE DOMINICAN REPUBLIC...TO THE NORTHWESTERN CORNER OF VENEZUELA. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG WITHIN 90 NM ON EITHER SIDE OF 12N66W...SCATTERED MODERATE TO ISOLATED STRONG BETWEEN 70W AND 75W AND FROM 15N TO 17N BETWEEN 76W AND 77W. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR GUADELOUPE FOR THE PERIOD ENDING AT 20/0000 UTC IS 0.69. A SURFACE TROUGH IS ALONG 82W/83W FROM 11N TO 20N. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS FROM 14N TO 16N BETWEEN 79W AND 83W...AND IN THE NORTHWESTERN CORNER OF THE AREA FROM 16N AT THE HONDURAS COAST TO 21N NEAR CUBA BETWEEN 79W AND 86W. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR TEGUCIGALPA HONDURAS FOR THE PERIOD ENDING AT 20/0000 UTC IS 0.31. THE REST OF THE ATLANTIC OCEAN... AN UPPER LEVEL SHEAR AXIS PASSES THROUGH 32N43W TO 25N50W... CURVING TO AN 18N52W ATLANTIC OCEAN MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER. THE TROUGH CONTINUES FROM 18N52W TO 13N52W AND 8N59W ALONG THE COAST OF GUYANA. MIDDLE LEVEL TO UPPER LEVEL NORTHERLY WIND FLOW THAT IS IN THE ATLANTIC OCEAN BETWEEN THE SHEAR AXIS AND 61W EVENTUALLY FEEDS INTO THE LARGER-SCALE CYCLONIC WIND FLOW AROUND THE WHOLE SYSTEM. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 20N TO 22N BETWEEN 43W AND 46W...WARMING CLOUD TOP TEMPERATURES AND WEAKENING/DISSIPATING BUT POSSIBLY STILL LINGERING CONVECTIVE PRECIPITATION IS FROM 22N TO 24N BETWEEN 49W AND 51W. A 1016 MB LOW PRESSURE CENTER IS NEAR 31N56W. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO 27N58W. ISOLATED TO WIDELY SCATTERED MODERATE CONVECTIVE PRECIPITATION IS FROM 27N TO 32N BETWEEN 53W AND 57W. RAINSHOWERS ARE POSSIBLE FROM 25N TO 28N BETWEEN 61W AND 63W. THIS AREA IS ON THE EASTERN SIDE OF AN UPPER LEVEL RIDGE... TO THE SOUTHWEST OF THE 31N56W 27N58W SURFACE TROUGH. AN UPPER LEVEL TROUGH EXTENDS FROM A WESTERN SAHARA CYCLONIC CIRCULATION CENTER THAT IS NEAR 24N13W TO 21N19W AND 13N20W. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS ASSOCIATED WITH THE TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT