000 AXNT20 KNHC 200001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU SEP 19 2013 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION HUMBERTO IS CENTERED NEAR 33.6N 42.0W AT 19/2100 UTC OR ABOUT 778 NM W-SW OF THE AZORES MOVING E AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. PLEASE SEE LATEST PUBLIC ADVISORIES UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 AND THE FULL FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/ WTNT24 FOR MORE DETAILS. ISOLATED MODERATE CONVECTION IS E OF THE CENTER FROM 29N-34N BETWEEN 38W-43W. A 1004 MB LOW IS CENTERED OVER THE SW GULF OF MEXICO NEAR 21N95W. CONDITIONS APPEAR CONDUCIVE FOR THE FORMATION OF A TROPICAL DEPRESSION DURING THE NEXT DAY OR TWO WHILE THE SYSTEM MOVES TOWARD THE WEST-NORTHWEST TO NORTHWESTWARD AT 5-10 KT. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A MEDIUM CHANCE...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. THIS DISTURBANCE COULD SPREAD LOCALLY HEAVY RAINS OVER PORTIONS OF EASTERN AND SOUTHERN MEXICO DURING THE NEXT FEW DAYS. SCATTERED MODERATE CONVECTION IS FROM 24N-27N BETWEEN 92W-95W. ...TROPICAL WAVES... TROPICAL WAVE IS W OF THE CAPE VERDE ISLANDS EXTENDING FROM 23N31W TO 12N31W MOVING W 5-10 KT. WAVE IS ALONG THE LEADING EDGE OF SURGE OF DEEP MOISTURE WITH A SLOT OF DRIER AIR UNDERCUTTING THE N PORTION OF THE WAVE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS E OF THE WAVE AXIS FROM 15N-18N BETWEEN 26W-28W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 11N16W AND CONTINUES TO 11N31W TO 8N40W WHERE THE ITCZ BEGINS AND CONTINUES TO 10N46W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 9N-15N BETWEEN 12W-17W. ISOLATED MODERATE CONVECTION IS FROM 6N-13N BETWEEN 22W-44W. A SURFACE TROUGH W OF THE LESSER ANTILLES EXTENDS FROM 17N53W TO 10N55W WITH CLUSTERS OF SCATTERED MODERATE CONVECTION FROM 9N- 16N BETWEEN 47W-60W. ...DISCUSSION... GULF OF MEXICO... A 1004 MB SURFACE LOW IS CENTERED OVER THE SW GULF OF MEXICO NEAR 21N95W AND HAS THE POTENTIAL FOR FURTHER DEEPENING OVER THE NEXT 24 HOURS. 20-25 NM CYCLONIC WINDS ARE WITHIN 180 NM OF THE CENTER. SEE ABOVE. A 1022 MB HIGH IS CENTERED OVER SOUTH CAROLINA NEAR 35N82W PRODUCING SURFACE RIDGING OVER THE NE GULF. ISOLATED MODERATE CONVECTION IS ALONG THE COAST OF LOUISIANA... AND INLAND OVER S FLORIDA S OF 27N. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER N MEXICO NEAR 24N100W PRODUCING NORTHERLY UPPER LEVEL WINDS OVER THE W GULF W OF 88W. AN UPPER LEVEL TROUGH IS OVER THE NE GULF PRODUCING MORE NORTHERLY WINDS. EXPECT THE SURFACE LOW TO BE JUST NE OF TAMPICO MEXICO NEAR 22N97W IN 24 HOURS WITH CONVECTION. CARIBBEAN SEA... 10-20 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST WINDS OVER THE NW CARIBBEAN. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION DOTS THE CENTRAL AND W CARIBBEAN W OF 70W TO INCLUDE HISPANIOLA...JAMAICA...AND E CUBA. A MONSOON TROUGH EXTENDS INLAND FROM E PANAMA TO GUATEMALA. AGAIN CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION DOTS CENTRAL AMERICA. IN THE UPPER LEVELS...UPPER LEVEL RIDGING IS OVER THE WESTERN AND CENTRAL CARIBBEAN W OF 70W. UPPER LEVEL DIFFLUENCE IS ESPECIALLY NOTED OVER HISPANIOLA ENHANCING CONVECTION. AN UPPER LEVEL LOW IS CENTERED OVER THE E CARIBBEAN NEAR 13N68W. UPPER LEVEL DIFLUENCE E OF THIS CENTER IS PRODUCING SCATTERED SHOWERS OVER THE E CARIBBEAN E OF 65W. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. HISPANIOLA... SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS PRESENTLY OVER HISPANIOLA. THIS CONVECTION IS DUE TO BOTH AFTERNOON HEATING AND UPPER LEVEL DIFFLUENCE. EXPECT CONTINUED CONVECTION OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... ISOLATED MODERATE CONVECTION IS OVER THE BAHAMAS FROM 21N-26N BETWEEN 71W-80W. A SURFACE TROUGH IS FURTHER E FROM 29N70W TO 21N70W. A COLD FRONT IS ALSO OVER THE CENTRAL ATLANTIC FROM 32N51W TO 30N54W TO 29N58W. A STATIONARY FRONT CONTINUES TO 29N70W. CLUSTERS OF SCATTERED MODERATE CONVECTION IS FROM 22N- 29N BETWEEN 59W-70W. T.D. HUMBERTO IS ALSO OVER THE CENTRAL ATLANTIC NEAR 33.6N 42.0W. SEE ABOVE. EXPECT A 1010 MB LOW TO FORM SHORTLY E OF THE BAHAMAS NEAR 25N70W WITH CONVECTION. ALSO EXPECT THE FRONTAL SYSTEM TO DISSIPATE OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA