000 AXNT20 KNHC 180528 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 42W. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS SOUTHWEST FROM A 21N37W CYCLONIC CIRCULATION CENTER TO 13N42W. AN UPPER LEVEL RIDGE IS JUST TO THE EAST OF THIS TROUGH...ALONG 30W/31W SOUTH OF 26N. ITCZ PRECIPITATION IS FROM 5N TO 12N BETWEEN 40W AND 50W. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 42W. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS SOUTHWEST FROM A 21N37W CYCLONIC CIRCULATION CENTER TO 13N42W. AN UPPER LEVEL RIDGE IS JUST TO THE EAST OF THIS TROUGH...ALONG 30W/31W SOUTH OF 26N. ITCZ PRECIPITATION IS FROM 5N TO 12N BETWEEN 40W AND 50W. AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 62W 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 93W/94W...MOVING WEST 10 TO 15 KT. SCATTERED STRONG SHOWERS AND THUNDERSTORMS COVER WESTERN GUATEMALA. AN ISOLATED THUNDERSTORM CELL IS ALONG 95W FROM 16N TO 17N INLAND. ...THE ITCZ... 12N16W 9N26W 9N35W 8N44W 9N56W 8N61W. ISOLATED TO WIDELY SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS FROM 5N TO 6N BETWEEN 17W AND 18W...AND WITHIN 45 NM ON EITHER SIDE OF 8N31W 10N36W. ISOLATED MODERATE SHOWERS ELSEWHERE FROM 2N TO 10N BETWEEN 10W AND 40W...FROM 5N TO 12N BETWEEN 40W AND 60W. 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 27N90W 21N97W. ISOLATED MODERATE SHOWERS ARE ABOUT 100 NM OFFSHORE BETWEEN 88W AND 89W SOUTH OF MISSISSIPPI AND LOUISIANA. THE CARIBBEAN SEA... THE 62W 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 SOUTHEAST TO AND BEYOND WESTERN CUBA. THE 1008 MB ISOBAR MOVES FROM THE EASTERN PACIFIC OCEAN...ACROSS NICARAGUA... AND CURVES NORTHWESTWARD ACROSS THE YUCATAN PENINSULA INTO THE CENTRAL GULF OF MEXICO. THE WEST-CENTRAL CARIBBEAN SEA MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER OF 24 HOURS AGO HAS MOVED INTO 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 HAVE BEEN DEVELOPING DURING THE LAST FEW HOURS UNDER THE RIDGE WITH UPPER LEVEL DIFFLUENT FLOW. THE ATLANTIC OCEAN... THE SOUTHERN END OF AN ATLANTIC OCEAN SURFACE TROUGH REACHES THE EAST-CENTRAL FLORIDA COAST. IT RAINED ALL DAY WEDNESDAY IN FLORIDA FROM LAKE OKEECHOBEE SOUTHWARD. BROAD SYNOPTIC SCALE UPPER LEVEL ANTICYCLONIC FLOW MOVES FROM NORTHERN FLORIDA AND IT CURVES ANTICYCLONICALLY TO 22N60W. ONE MIDDLE TO UPPER LEVEL TROUGH IS ALONG 63W...AND ANOTHER ONE IN THE CENTRAL ATLANTIC OCEAN IS ALONG 25N50W BEYOND 32N45W. THIS TROUGH SUPPORTS A CENTRAL ATLANTIC OCEAN COLD FRONT PASSES THROUGH 32N45W TO 29N50W TO 27N60W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 42W. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS SOUTHWEST FROM A 21N37W CYCLONIC CIRCULATION CENTER TO 13N42W. AN UPPER LEVEL RIDGE IS JUST TO THE EAST OF THIS TROUGH...ALONG 12N31W 24N30W BEYOND 32N29W. A MIDDLE TO UPPER LEVEL TROUGH PASSES FROM A CYCLONIC CIRCULATION CENTER NEAR NORTHERN MOROCCO THROUGH TO THE AFRICA COAST NEAR 13N17W. $$ MT