000 AXNT20 KNHC 181101 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU OCT 18 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 1045 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 42W/43W SOUTH OF 17N MOVING WEST 10 TO 15 KT. CYCLONIC TURNING IN THE OVERNIGHT IR-IMAGERY HELPED IN ORDER TO PLACE THIS WAVE...WHICH ACTUALLY IS A BIT TO THE EAST OF THE 18/0000 UTC POSITION. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS SOUTHWEST FROM A 24N34W CYCLONIC CIRCULATION CENTER TO 17N40W TO 13N46W. AN UPPER LEVEL RIDGE IS JUST TO THE EAST OF THIS TROUGH...ALONG 12N30W 24N30W BEYOND 32N29W. NO DEEP CONVECTIVE PRECIPITATION IS DIRECTLY RELATED TO THIS WAVE. AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 63W/64W SOUTH OF 16N MOVING WEST 10 TO 15 KT. NO DEEP CONVECTIVE PRECIPITATION ACCOMPANIES THIS WAVE. A TROPICAL WAVE IS MOVING THROUGH THE ISTHMUS OF TEHUANTEPEC OF MEXICO SOUTH OF 20N AND ULTIMATELY INTO THE EASTERN PACIFIC OCEAN...ALONG 95W...MOVING WEST 10 TO 15 KT. THE STRONG CONVECTIVE PRECIPITATION IN GUATEMALA AND THE CELL IN THE ISTHMUS OF TEHUANTEPEC FROM 6 HOURS AGO HAVE DISSIPATED. ONE CELL OF SHOWERS IS WITHIN ABOUT A 15 NM RADIUS OF 15.5N94W. ...THE ITCZ... 10N15W 8N30W 7N41W 7N50W 8N59W. STRONG SHOWERS AND THUNDERSTORMS FROM 7N TO 9.5N BETWEEN 31W AND 35W...FROM 7.5N TO 8.5N WITHIN 15 NM ON EITHER SIDE OF 42W...AND FROM 11N TO 12N BETWEEN 47W AND 49W. ISOLATED MODERATE SHOWERS ARE WITHIN 100 NM ON EITHER SIDE OF 7N12W 2N25W...WITHIN 120 TO 150 NM ON EITHER SIDE OF 6N28W 11N42W...AND WITHIN 120 NM ON EITHER SIDE OF 9N45W 11N61W. DISCUSSION... THE GULF OF MEXICO... MIDDLE TO UPPER LEVEL WIND FLOW MOVES ACROSS MEXICO NORTH OF 20N INTO TEXAS AND THE NORTHWESTERN GULF OF MEXICO WATERS. THE MIDDLE TO UPPER LEVEL FLOW FANS OUT TO BECOME ANTICYCLONIC ACROSS THE REST OF THE GULF WATERS. MIDDLE TO UPPER LEVEL CYCLONIC FLOW STARTS TO REACH CUBA AND THE YUCATAN CHANNEL... FROM A CYCLONIC CIRCULATION CENTER IN THE NORTHWESTERN CARIBBEAN SEA. MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE IS NORTHWEST OF 30N88W 25N92W 20N97W. ISOLATED MODERATE SHOWERS ARE ABOUT 140 NM OFFSHORE BETWEEN 85W AND 87W SOUTH OF THE FLORIDA PANHANDLE. THE CARIBBEAN SEA... THE 63W/64W TROPICAL WAVE IS NOT ACCOMPANIED BY ANY DEEP CONVECTIVE PRECIPITATION. THE SURFACE PRESSURE GRADIENT IS COMPARATIVELY WEAK. ONLY THE 1012 MB ISOBAR IS LOCATED IN THE CENTER OF THE AREA...FROM THE SOUTHEASTERN CORNER TO WESTERN CUBA AND BEYOND. A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER REMAINS IN THE NORTHWESTERN CORNER OF THE AREA. AN UPPER LEVEL RIDGE IS IN THE MIDDLE OF THE CARIBBEAN SEA. A BROAD AND NOT-SHARPLY-DEFINED EAST-WEST ORIENTED MIDDLE TO UPPER LEVEL TROUGH MOVES INTO THE SOUTHEASTERN CORNER OF THE AREA SOUTH OF 14N EAST OF 67W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS HAVE BEEN DEVELOPING DURING THE LAST FEW HOURS UNDER THE RIDGE WITH UPPER LEVEL DIFFLUENT FLOW. THE ATLANTIC OCEAN... AN ATLANTIC OCEAN SURFACE TROUGH IS ALONG 30N78W TO A 1012 MB LOW PRESSURE CENTER NEAR 29N80W TO 29N82W INLAND. ISOLATED MODERATE SHOWERS FROM 29N TO 30N BETWEEN 77W AND 79W. A FEW OTHER SHOWERS ARE FROM 24N TO 30N BETWEEN 70W AND 80W. BROAD SYNOPTIC SCALE UPPER LEVEL ANTICYCLONIC FLOW MOVES FROM NORTHERN FLORIDA AND IT CURVES ANTICYCLONICALLY TO 24N60W. ONE MIDDLE TO UPPER LEVEL TROUGH IS ALONG 62W FROM 24N NORTHWARD. A SECOND TROUGH IS IN THE CENTRAL ATLANTIC OCEAN ALONG 24N46W BEYOND 32N42W. THE SECOND TROUGH SUPPORTS A CENTRAL ATLANTIC OCEAN COLD FRONT THAT PASSES THROUGH 32N40W TO 27N50W TO 26N56W TO 30N70W. A SURFACE TROUGH IS WITHIN 200 TO 240 NM SOUTHEAST OF THE COLD FRONT BETWEEN 33W AND 45W...AND WITHIN 120 NM SOUTH OF THE COLD FRONT BETWEEN 45W AND 63W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 42W/43W. CYCLONIC TURNING IN THE OVERNIGHT IR-IMAGERY HELPED IN ORDER TO PLACE THIS WAVE...WHICH ACTUALLY IS A BIT TO THE EAST OF THE 18/0000 UTC POSITION. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS SOUTHWEST FROM A 24N34W CYCLONIC CIRCULATION CENTER TO 17N40W TO 13N46W. AN UPPER LEVEL RIDGE IS JUST TO THE EAST OF THIS TROUGH...ALONG 12N30W 24N30W BEYOND 32N29W. NO DEEP CONVECTIVE PRECIPITATION IS DIRECTLY RELATED TO THIS WAVE. A MIDDLE TO UPPER LEVEL TROUGH PASSES FROM A CYCLONIC CIRCULATION CENTER IN NORTHERN MOROCCO/WESTERN ALGERIA NEAR 31N4W TO 15N18W JUST OFF THE SENEGAL COAST. $$ MT