000 AXNT20 KNHC 180602 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED SEP 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM HUMBERTO AT 18/0300 UTC IS NEAR 30.8N 43.3W OR ABOUT 915 NM W-SW OF THE AZORES. ITS PRESENT MOVEMENT IS N-NW AT 6 KNOTS AND THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 35 KNOTS WITH GUSTS TO 45 KNOTS. PLEASE READ THE PUBLIC ADVISORIES ABOUT HUMBERTO THAT ARE ISSUED UNDER WMO HEADER WTNT34 KNHC AND UNDER AWIPS HEADER MIATCPAT4... AND THE FORECAST/ADVISORIES THAT ARE ISSUED UNDER WMO HEADER WTNT24 KNHC AND UNDER AWIPS HEADER MIATCMAT4. WIDELY SCATTERED MODERATE CONVECTION IS FROM 28N-36N BETWEEN 39W-46W. A 1006 MB LOW PRESSURE CENTER IS JUST N OF BELIZE NEAR 18N88W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND IN THE YUCATAN PENINSULA...BELIZE...GUATEMALA AND HONDURAS AS WELL AS THE YUCATAN CHANNEL AND THE NW CARIBBEAN SEA S OF 20N W OF 86W. NUMEROUS MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE NW CARIBBEAN SEA N OF 18N BETWEEN 80W-85W. ENVIRONMENTAL CONDITIONS ARE LIKELY TO BE CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM OVER THE BAY OF CAMPECHE DURING THE NEXT COUPLE OF DAYS AFTER THE LOW MOVES INTO THE REGION ON WEDNESDAY. THIS SYSTEM HAS A HIGH CHANCE...60 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. REGARDLESS OF TROPICAL CYCLONE FORMATION...THIS DISTURBANCE WILL LIKELY SPREAD HEAVY RAINS OVER EASTERN MEXICO. THESE RAINS COULD CAUSE LIFE-THREATENING FLOODS AND MUDSLIDES OVER AREAS ALREADY IMPACTED BY THE TORRENTIAL RAINS ASSOCIATED WITH INGRID AND MANUEL. ...TROPICAL WAVES... THE AXIS OF A TROPICAL WAVE IS WEST OF THE CAPE VERDE ISLANDS ALONG 19N23W...ACROSS THE MONSOON TROUGH TO 10N28W AND IS MOVING W NEAR 5 KNOTS. METEOSAT SATELLITE IMAGERY CONTINUE TO SHOW DRY AIR INTRUSION NORTH AND WEST OF THE WAVE AXIS WHICH IS HINDERING CONVECTION IN THIS SECTOR OF THE WAVE ENVIRONMENT. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE NE OF THE WAVE AXIS FROM 17N-20N...COINCIDING WITH A SMALL REGION OF MODERATE TO HIGH MOISTURE AS DEPICTED IN TOTAL PRECIPITABLE WATER IMAGERY. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SENEGAL NEAR 14N17W TO 14N26W TO 09N32W. THE ITCZ CONTINUES FROM 09N32W TO 10N40W TO 11N50W. SCATTERED MODERATE CONVECTION IS FROM 06N-09N BETWEEN 18W-47W...AS WELL AS WITHIN 150 NM EITHER SIDE OF THE MONSOON TROUGH AXIS BETWEEN 23W-31W. ...DISCUSSION... THE GULF OF MEXICO... SCATTERED SHOWERS...REMNANTS OF INGRID ARE OVER THE W-NW GULF WEST OF 92W. AN UPPER-LEVEL SHORTWAVE TROUGH OVER THE NE GULF CONTINUE TO SUPPORT A STATIONARY FRONT THAT EXTENDS ACROSS NORTH- CENTRAL FLORIDA TO 29N83W TO 30N85W TO SOUTHERN ALABAMA NEAR 30N87W. RAINSHOWERS ASSOCIATED WITH THIS FRONTAL BOUNDARY ARE OVER THE FLORIDA PANHANDLE AND EXTENDS OFFSHORE WITHIN 70 NM BETWEEN 84W-87W. A BROAD UPPER-LEVEL RIDGE COVERING THE WESTERN CARIBBEAN BASIN EXTENDS TO THE FLORIDA STRAITS. JUST WEST OF THIS RIDGE...AN INVERTED TROUGH IS GENERATING DIFFLUENT FLOW ALOFT TO SUPPORT SCATTERED MODERATE CONVECTION OVER THE SE GULF S OF 24N BETWEEN 80W-88W. FAIR WEATHER IS ELSEWHERE IN THE BASIN BEING SUPPORTED BY A TONGUE OF VERY DRY AIR PRESENT IN WATER VAPOR IMAGERY. A DISTURBANCE CURRENTLY MOVING ACROSS NORTH CENTRAL AMERICA AND THE YUCATAN PENINSULA IS EXPECTED TO ENTER THE BAY OF CAMPECHE LATER THIS MORNING. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE IN THE NEXT 48 HOURS. SEE THE SPECIAL FEATURES ABOVE. THE CARIBBEAN SEA... A BROAD UPPER-LEVEL RIDGE COVERS THE WESTERN CARIBBEAN BASIN WHICH EXTENDS TO THE FLORIDA STRAITS. JUST WEST OF THIS RIDGE...AN INVERTED TROUGH IS ACROSS THE NORTHERN CENTRAL AMERICA AND THE YUCATAN PENINSULA THUS GENERATING DIFFLUENT FLOW ALOFT TO SUPPORT NUMEROUS MODERATE/ISOLATED STRONG CONVECTION AND TSTMS FROM 19N-22N BETWEEN 82W-85W. SCATTERED MODERATE CONVECTION AND TSTMS ARE ELSEWHERE IN THE NW CARIBBEAN N OF 18N W OF 79W...INCLUDING WESTERN CUBA. THE MONSOON TROUGH AXIS EXTENDS FROM E PANAMA TO TO N NICARAGUA THUS SUPPORTING SCATTERED MODERATE CONVECTION AND TSTMS IN THE SOUTHERN CARIBBEAN SW OF A LINE FROM 16N82W TO 10N75W. AN UPPER-LEVEL RIDGE IS CENTERED E OF THE LESSER ANTILLES BUT EXTENDS TO THE EASTERN CARIBBEAN E OF 65W. DIFFLUENT FLOW ALOFT GENERATED BY NEARLY EASTERLY UPPER-LEVEL FLOW OVER NORTHERN SOUTH AMERICA IS SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 12N-16N E OF 65W...INCLUDING THE WINDWARD ISLANDS. THE DISTURBANCE CURRENTLY MOVING ACROSS NORTH CENTRAL AMERICA AND THE YUCATAN PENINSULA IS EXPECTED TO MOVE WEST-NORTHWESTWARD AND EMERGE OVER THE BAY OF CAMPECHE LATER TODAY...WHERE ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE CONDUCIVE FOR THE FORMATION OF A TROPICAL DEPRESSION OVER THE NEXT DAY OR TWO. CONVECTIVE ACTIVITY OVER THE NW BASIN IS EXPECTED TO CONTINUE THROUGH LATE WED NIGHT. HISPANIOLA... CURRENTLY DRY STABLE AIR IS ACROSS MOST OF THE ISLAND THIS MORNING WHICH IS FAVORING FAIR WEATHER. AN UPPER-LEVEL TROUGH MOVES ACROSS THE DOMINICAN REPUBLIC AND PUERTO RICO WHILE THE RIDGE OVER THE WESTERN CARIBBEAN EXTENDS TO HAITI. THIS IS CAUSING DIFFLUENCE ALOFT TO SUPPORT ISOLATED SHOWERS AND TSTMS IN HAITI AND THE WINDWARD PASSAGE. EXPECT RAINSHOWERS TO DEVELOP DURING THE AFTERNOON AND EVENING HOURS TODAY THOROUGH THURSDAY. THE ATLANTIC OCEAN... THE MAIN FEATURE IN THE ATLC IS TROPICAL STORM HUMBERTO WHICH INFORMATION IS PROVIDED IN THE SPECIAL FEATURES SECTION. AN UPPER-LEVEL TROUGH IN THE W ATLC SUPPORTS A FRONTAL SYSTEM THAT ENTERS THE DISCUSSION AREA AS A COLD FRONT FROM 30N67W TO 29N76W TO THE EASTERN COAST OF FLORIDA NEAR 29N80W WHERE IT TRANSITIONS TO A STATIONARY FRONT. DIFFLUENT FLOW ALOFT FROM THE UPPER-LEVEL TROUGH AND THE RIDGE COVERING THE BAHAMAS AND THE WESTERN CARIBBEAN SUPPORTS SCATTERED SHOWERS FROM 24N-29N BETWEEN 70W- 77W. REMNANT CONVECTION FROM A SURFACE TROUGH IS FROM 23N-27N BETWEEN 63W-67W. MIDDLE-LEVEL DIFFLUENCE SUPPORTS SCATTERED MODERATE CONVECTION N OF 28N BETWEEN 59W-62W. FURTHER EAST...A 1017 MB HIGH PRESSURE CENTER IS STARTING TO MOVE SOUTH TOWARDS THE AREA OF DISCUSSION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS