000 AXNT20 KNHC 140002 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU SEP 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION HUMBERTO IS LOCATED NEAR 31.4N 92.6W AT 13/2100 UTC OR ABOUT 10 MILES...15 KM...NORTHWEST OF ALEXANDRIA LOUISIANA MOVING NORTHEAST AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. RAINFALL AMOUNTS OF 4 TO 6 INCHES ARE EXPECTED THROUGH FRIDAY NEAR THE TRACK OF HUMBERTO OVER PORTIONS OF MISSISSIPPI... ALABAMA...AND EASTERN LOUISIANA. ISOLATED MAXIMUM ACCUMULATIONS OF 8 INCHES ARE POSSIBLE. PRESENTLY...A RESIDUAL CONVECTIVE BAND IS OVER THE N GULF OF MEXICO FROM 27N-30N BETWEEN 88W-92W. TROPICAL DEPRESSION EIGHT IS LOCATED NEAR 14.2N 48.4W AT 13/2100 UTC OR ABOUT 865 MILES...1395 KM...EAST OF THE LESSER ANTILLES MOVING WEST-NORTHWEST AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. ALTHOUGH UPPER-LEVEL CONDITIONS HAVE BECOME LESS FAVORABLE FOR STRENGTHENING...THE DEPRESSION STILL HAS THE CHANCE TO BECOME A TROPICAL STORM DURING THE NEXT 12 TO 24 HOURS. A NOAA HURRICANE HUNTER PLANE IS SCHEDULED TO INVESTIGATE THE SYSTEM THIS EVENING. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 21W S OF 17N MOVING W 10-15 KT. A 1010 MB LOW IS ON THE WAVE AXIS NEAR 10N21W. THIS WAVE SHOWS AN AREA OF LOW CLOUDS FROM 6N-20N BETWEEN 15W-30W. SCATTERED SHOWERS ARE ALONG THE ITCZ FROM 5N-8N BETWEEN 18W-25W...AND W OF THE WAVE AXIS FROM 8N-13N BETWEEN 21W-26W. HIGH AMPLITUDE TROPICAL WAVE IS ALONG 39W/40W S OF 21N DRIFTING WWD. THE NRN PART OF THE WAVE IS BEGINNING TO FRACTURE BASED ON THE POLEWARD MOVEMENT OF MOISTURE SEEN ON SATELLITE AND THE UW CIMSS TPW ANIMATION. A TROUGH WAS ANALYZED TO REFLECT THIS ALONG 38W/39W FROM 22N-26N. THE GFS MODEL SUGGESTS THAT A SFC LOW MAY FORM ALONG THE TROUGH AXIS DURING THE NEXT 24 HOURS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 20N-26N BETWEEN 35W-40W. FURTHER S... ISOLATED MODERATE CONVECTION IS ALONG THE ITCZ FROM 2N-10N BETWEEN 34W-40W. TROPICAL WAVE IS IN THE W CARIBBEAN ALONG 80W/81W S OF 22N MOVING W 15 KT. THE WAVE IS INTERACTING WITH AN UPPER UPPER LOW LOCATED W OF THE CAYMAN ISLANDS. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE SW CARIBBEAN...PANAMA...AND N COLOMBIA FROM 5N-13N BETWEEN 73W-83W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER NICARAGUA AND HONDURAS FROM 12N-16N BETWEEN 82W-87W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N10W 11N20W 9N30W 15N45W 10N60W. BESIDES FOR THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES AND T.D. EIGHT...SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ALONG THE COAST OF W AFRICA FROM 7N-13N BETWEEN 12W-15W. SCATTERED MODERATE CONVECTION IS E OF TRINIDAD FROM 9N-11N BETWEEN 58W-60W. DISCUSSION... THE GULF OF MEXICO... T.D. HUMBERTO IS INLAND OVER LOUISIANA. SEE SPECIAL FEATURES FOR MORE DETAILS. SCATTERED MODERATE CONVECTION IS INLAND OVER THE YUCATAN PENINSULA FROM 17N-21N BETWEEN 88W-92W. SCATTERED MODERATE CONVECTION IS OVER S FLORIDA FROM 25N-28N BETWEEN 81W-83W. ISOLATED MODERATE CONVECTION IS INLAND OVER N FLORIDA FROM 30N-31N BETWEEN 81W-88W. IN THE UPPER LEVELS... FAIRLY GOOD OUTFLOW IS NOTED OVER HUMBERTO. AN UPPER UPPER LOW LOCATED W OF THE CAYMAN ISLANDS NEAR NEAR 21N83W IS PRODUCING CYCLONIC TURNING OVER THE SE GULF OF MEXICO. SIGNIFICANT UPPER LEVEL MOISTURE WITH BROKEN TO OVERCAST HIGH CLOUDS COVERS THE ENTIRE GULF OF MEXICO. EXPECT HUMBERTO TO MOVE TO ALABAMA AND EXTEND A SURFACE TROUGH TO THE NW GULF OF MEXICO WITH CONVECTION ALONG THE TROUGH WITHIN THE NEXT 24 HOURS. THE CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE W CARIBBEAN SEA. SEE ABOVE. LIGHT TO MODERATE TRADES ARE OVER THE REMAINDER OF THE SEA. A 1007 MB LOW IS CENTERED OVER N COLOMBIA NEAR 8N75W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...ISOLATED MODERATE CONVECTION IS OVER INLAND CUBA BETWEEN 76W-82W. IN THE UPPER LEVELS... AN UPPER UPPER LOW IS LOCATED W OF THE CAYMAN ISLANDS NEAR NEAR 21N83W. AN UPPER LEVEL HIGH IS CENTERED OVER N COLOMBIA NEAR 11N74W. SIGNIFICANT MOISTURE IS W OF 72W. STRONG SUBSIDENCE IS E OF 72W. EXPECT CONVECTION OVER THE WESTERN CARIBBEAN AND CENTRAL AMERICA W OF 80W DURING THE NEXT 24 HOURS MAINLY DUE TO THE TROPICAL WAVE. THE ATLANTIC OCEAN... A 1022 MB HIGH IS OVER THE W ATLANTIC NEAR 32N61W. A WEAK SURFACE TROUGH IS FURTHER S OVER THE TROPICS ALONG 26N65W 21N62W. ISOLATED MODERATE CONVECTION IS WITHIN 60 NM E OF THE TROUGH. A SURFACE RIDGE IS OVER THE E ATLANTIC N OF 25N E OF 30W. IN THE UPPER LEVELS... A RIDGE IS OVER THE W ATLANTIC N OF 22N W OF 70W. AN UPPER LEVEL LOW IS OVER THE W ATLANTIC NEAR 26N65W. A LARGE UPPER LEVEL HIGH IS OVER THE TROPICS NEAR T.D. EIGHT AT 14N48W. ANOTHER LARGE UPPER LEVEL HIGH IS OVER THE EASTERN TROPICAL ATLANTIC NEAR 18N28W. $$ FORMOSA