000 AXNT20 KNHC 150600 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED AUG 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURE A CENTRAL ATLANTIC OCEAN SURFACE TROUGH IS ALONG 29N53W... TO A 1016 MB LOW PRESSURE CENTER THAT IS NEAR 26N53W...TO 20N58W. THIS TROUGH ORIGINATED AS THE NORTHERN PART OF THE CURRENT 60W TROPICAL WAVE. WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION COVERS THE ATLANTIC OCEAN FROM 25N TO 30N BETWEEN 52W AND 56W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE ELSEWHERE FROM 22N TO 32N BETWEEN 48W AND 58W. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES NORTH-NORTHWESTWARD 13 KNOTS TODAY...AND THEN IT TURNS NORTHEASTWARD BY THURSDAY. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N19W TO A 1013 MB LOW PRESSURE CENTER THAT IS NEAR 13N20W...IN THE MONSOON TROUGH. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE FROM 9N TO 24N BETWEEN 14W AND 26W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 19N40W 15N37W 12N32W. RAINSHOWERS ARE POSSIBLE FROM 10N TO 20N BETWEEN 30W AND 40W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18N59W 14N60W... TO 9N61W IN NORTHEASTERN COASTAL VENEZUELA. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS FROM 9N TO 22N BETWEEN 57W AND 63W. A MIDDLE LEVEL TO UPPER LEVEL ATLANTIC OCEAN INVERTED TROUGH IS ALONG 22N57W 16N58W...BEYOND 7N59W IN NORTHERN GUYANA. A TROPICAL WAVE IS ALONG 23N85W IN THE YUCATAN CHANNEL... TO 18N85W...CROSSING THE BORDER OF EASTERN HONDURAS AND NORTHEASTERN NICARAGUA...TO 12N82W. SCATTERED TO NUMEROUS STRONG CONVECTIVE PRECIPITATION IS IN EASTERN AND SOUTHWESTERN NICARAGUA...AND IT IS SPREADING ACROSS EL SALVADOR FROM EAST TO WEST. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS WITHIN 60 NM OF THE COAST FROM THE GULF OF HONDURAS NORTHWARD...INTO THE YUCATAN CHANNEL...TO 20N80W JUST TO THE SOUTH OF CUBA. BROKEN TO OVERCAST MULTILAYERED CLOUDS FROM EARLIER CONVECTIVE PRECIPITATION COVER THE CARIBBEAN SEA TO THE SOUTH OF 18N TO THE WEST OF 70W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL MAURITANIA NEAR 18N16W...TO 13N20W...TO A 1013 MB LOW PRESSURE CENTER THAT IS NEAR 11N30W...TO 8N38W. THE ITCZ CONTINUES FROM 8N38W TO 5N44W...INTO NORTHEASTERN BRAZIL NEAR 2N52W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE ELSEWHERE TO THE SOUTH OF 10N BETWEEN 29W AND 60W. A MIDDLE LEVEL TO UPPER LEVEL ATLANTIC OCEAN INVERTED TROUGH IS ALONG 22N57W 16N58W... BEYOND 7N59W IN NORTHERN GUYANA. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL TROUGH IS ALONG THE U.S.A. EAST COAST/IN THE COASTAL WATERS OF THE U.S.A. EAST COAST. THE TROUGH PASSES THROUGH SOUTHERN GEORGIA AND THE FLORIDA PANHANDLE INTO THE NORTHEASTERN GULF OF MEXICO NEAR 29N87W...TO A 25N89W CYCLONIC CIRCULATION CENTER...TO THE NORTHWESTERN CORNER OF THE YUCATAN PENINSULA. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS ELSEWHERE TO THE NORTH OF 22N TO THE EAST OF 94W. UPPER LEVEL ANTICYCLONIC WIND FLOW THAT IS ON TOP OF MEXICO IS PUSHING HIGH LEVEL MOISTURE INTO TEXAS TO THE SOUTH OF 32N ALONG 101W. THE ANTICYCLONIC WIND FLOW IS TO THE SOUTHWEST OF 32N101W 25N96W 19N93W. A 1016 MB HIGH PRESSURE CENTER IS NEAR 26N91W. BROAD SURFACE ANTICYCLONIC WIND FLOW MOVES AROUND THE CENTER. THE SURFACE PRESSURE GRADIENT IS COMPARATIVELY WEAK IN THE GULF OF MEXICO. FROM THE ATLANTIC OCEAN INTO THE NORTH CENTRAL CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL TROUGH/SHEAR AXIS EXTENDS FROM A 33N62W CYCLONIC CIRCULATION CENTER TO 24N62W...20N62W... CROSSING PUERTO RICO AND HISPANIOLA...TO A WEAKENING UPPER LEVEL CYCLONIC CIRCULATION CENTER THAT IS NEAR 19N76W BETWEEN JAMAICA AND HAITI. RAINSHOWERS ARE POSSIBLE WITHIN 60 TO 90 NM ON EITHER SIDE OF THE TROUGH/SHEAR AXIS...AND IN THE WATERS THAT ARE BETWEEN HAITI...CUBA...AND JAMAICA. THE REST OF THE CARIBBEAN SEA... A TROPICAL WAVE IS ALONG 23N85W IN THE YUCATAN CHANNEL... TO 18N85W...CROSSING THE BORDER OF EASTERN HONDURAS AND NORTHEASTERN NICARAGUA...TO 12N82W. SCATTERED TO NUMEROUS STRONG CONVECTIVE PRECIPITATION IS IN EASTERN AND SOUTHWESTERN NICARAGUA...AND IT IS SPREADING ACROSS EL SALVADOR FROM EAST TO WEST. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS WITHIN 60 NM OF THE COAST FROM THE GULF OF HONDURAS NORTHWARD...INTO THE YUCATAN CHANNEL...TO 20N80W JUST TO THE SOUTH OF CUBA. BROKEN TO OVERCAST MULTILAYERED CLOUDS FROM EARLIER CONVECTIVE PRECIPITATION COVER THE CARIBBEAN SEA TO THE SOUTH OF 18N TO THE WEST OF 70W. THE UPPER LEVEL INVERTED TROUGH THAT WAS IN THE SOUTHWESTERN CORNER OF THE AREA FOR THE LAST FEW DAYS HAS MOVED WESTWARD... AND NOW IT EXTENDS FROM THE GULF OF HONDURAS...ACROSS EL SALVADOR...INTO THE EASTERN PACIFIC OCEAN. SCATTERED TO NUMEROUS STRONG CONVECTIVE PRECIPITATION IS SPREADING ACROSS EL SALVADOR FROM EAST TO WEST. THE MONSOON TROUGH IS NOT DEFINED AT THE MOMENT. NUMEROUS STRONG CONVECTIVE PRECIPITATION WAS IN EXTREME NORTHWESTERN VENEZUELA AND EXTREME NORTHEASTERN COLOMBIA AT 15/0145 UTC. THE CLOUD TOP TEMPERATURES HAVE WARMED AND THE PRECIPITATION HAS WEAKENED AND DISSIPATED SINCE THEN. SCATTERED MODERATE TO STRONG CONVECTIVE PRECIPITATION IS ALONG THE PANAMA COAST WITHIN A 30 NM RADIUS OF 9N81W. SCATTERED STRONG CONVECTIVE PRECIPITATION IS IN THE COLOMBIA COASTAL WATERS IN THE EASTERN PACIFIC OCEAN FROM 3N TO 6N TO THE EAST OF 80W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE 20 TO 25 KNOT WINDS AND 8 TO 9 FOOT SEA HEIGHTS THAT ACCOMPANY THE TROPICAL WAVE/REMNANTS OF T.D. SEVEN THAT ARE ALONG 23N85W TO 12N82W. THE REST OF THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 22N57W 16N58W...BEYOND 7N59W IN NORTHERN GUYANA. UPPER LEVEL ANTICYCLONIC WIND FLOW IS ON TOP OF THE AREA OF THE 29N53W 20N58W SURFACE TROUGH. A SURFACE RIDGE EXTENDS FROM A 1022 MB HIGH PRESSURE CENTER THAT IS NEAR 33N35W TO A 1026 MB HIGH PRESSURE CENTER THAT IS NEAR 33N47W...TO 30N61W...SOUTHWESTWARD PASSING ON TOP OF THE NORTHERN BAHAMAS TO 26N80W NEAR THE EXTREME SOUTHEASTERN COAST OF FLORIDA. AN UPPER LEVEL TROUGH PASSES THROUGH 32N15W TO 28N18W... BECOMING A SHEAR AXIS FROM 28N18W TO 23N26W AND 22N35W. THE TROUGH SUPPORTS A DISSIPATING COLD FRONT THAT PASSES THROUGH 32N19W 31N25W 31N32W. BROKEN MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE WITHIN 30 TO 60 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 32N18W TO 30N25W TO 32N34W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR DETAILS ABOUT THE 20 TO 25 KNOT WINDS AND 8 FOOT SEA HEIGHTS THAT ARE RELATED TO THE CENTRAL ATLANTIC OCEAN 29N53W 20N58W SURFACE TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT