000 AXNT20 KNHC 131822 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON AUG 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... TROPICAL DEPRESSION FOUR FORMED NEAR 12.0N 31.6W AT 13/1500 UTC MOVING WEST 18 KT. THE MINIMUM CENTRAL PRESSURE WAS 1005 MB. THE MAXIMUM SUSTAINED WIND SPEEDS WERE 30 KT WITH GUSTS TO 40 KT. PLEASE REFER TO THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 11N TO 12N BETWEEN 33W AND 35W. ISOLATED MODERATE SHOWERS AND THUNDERSTORMS ARE FROM 8N TO 10N BETWEEN 30W AND 34W. A 1011 MB SURFACE LOW PRESSURE CENTER FORMED AT 13/1500 UTC NEAR 22N86.5W IN THE YUCATAN CHANNEL. UPPER LEVEL WINDS ARE BECOMING MORE FAVORABLE FOR DEVELOPMENT OF THIS SYSTEM...AND IT IS POSSIBLE THAT A TROPICAL DEPRESSION MAY FORM LATER TODAY OR TOMORROW AS THE LOW MOVES TO THE WEST-NORTHWEST AT 10 TO 15 MPH. RESIDENTS IN THE WESTERN GULF OF MEXICO SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. AN AIR FORCE RESERVE RECONNAISSANCE PLANE IS SCHEDULED TO INVESTIGATE THIS SYSTEM TOMORROW IF NECESSARY. THIS LOW CENTER FORMED ALONG A TROPICAL WAVE ALONG 86W/87W SOUTH OF 26N. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE SOUTH OF 27N BETWEEN 82W AND 88W. UPPER LEVEL DIFFLUENT WIND FLOW HAS BEEN CREATED IN THE WESTERN CARIBBEAN SEA DUE TO THE CYCLONIC FLOW AROUND THE CENTRAL GULF OF MEXICO MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER...AND THE NORTHEAST-TO-SOUTHWEST ORIENTED CARIBBEAN SEA MIDDLE TO UPPER LEVEL TROUGH. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ALSO ARE NORTH OF 14N WEST OF 78W. THE SCATTERED MODERATE TO ISOLATED STRONG SHOWERS AND THUNDERSTORMS SOUTH OF 12N BETWEEN 78W AND 79W ARE PROBABLY MORE RELATED TO THE MIDDLE TO UPPER LEVEL TROUGH THAT STRETCHES FROM THE NORTHEASTERN CARIBBEAN SEA TO THE SOUTHWESTERN CARIBBEAN SEA. ...TROPICAL WAVES... A 1012 MB LOW PRESSURE CENTER WAS NEAR 16N19W MOVING WEST 10 TO 15 KT. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS FROM 12N TO 22N BETWEEN 14W AND 25W. THE TROPICAL WAVE ALONG 38W AT 13/0600 UTC WAS DROPPED FROM THE SURFACE MAP ANALYSIS BECAUSE OF THE LACK OF DATA IN ORDER TO SUPPORT ITS EXISTENCE. THE TROPICAL WAVES ALONG 82W AND 91W/92W WERE DROPPED FROM THE SURFACE MAP BECAUSE OF THE LACK OF DATA IN ORDER TO SUPPORT THEIR EXISTENCE. ...THE ITCZ... 14N21W 12N28W 10N35W 9N44W 8N47W 7N59W. ISOLATED MODERATE SHOWERS FROM 5N TO 8N BETWEEN 21W AND 33W. SCATTERED TO BROKEN MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION FROM 3N TO 10N BETWEEN 40W AND 53W. DISCUSSION... THE GULF OF MEXICO... A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN THE CENTRAL GULF OF MEXICO. ISOLATED MODERATE SHOWERS ARE SOUTH OF 28N BETWEEN 86W AND 94W IN THE CYCLONIC FLOW AROUND THIS FEATURE. THE TROPICAL WAVE IS ALONG 86W/87W WITH THE DEVELOPING 1011 MB LOW PRESSURE CENTER. A SURFACE TROUGH IS ALONG 30N91W 26N94W 20N95W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 21N TO 23N BETWEEN 92W AND 96W. SOME OF THIS PRECIPITATION ALSO IS INLAND MOVING ACROSS AND SLIGHTLY TO THE WEST OF THE ISTHMUS OF TEHUANTEPEC. THE CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL TROUGH CUTS INTO THE CARIBBEAN SEA FROM THE NORTHEASTERN CORNER OF THE AREA TO 14N73W 12N77W AND 10N80W. THIS TROUGH IS SURROUNDED BY MIDDLE TO UPPER LEVEL DRY AIR WITH VIRTUALLY NO DEEP LAYER PRECIPITATION. THE 86W/87W TROPICAL WAVE AND THE UPPER LEVEL TROUGH ARE HELPING TO CREATE THE ENVIRONMENT FOR CONTINUED AND/OR ENHANCED DEEP CONVECTIVE PRECIPITATION. THE ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM A 30N50W CYCLONIC CIRCULATION CENTER TO 25N51W TO 22N56W TO A SECOND CYCLONIC CENTER IN THE CARIBBEAN SEA NEAR 18N65W NEAR PUERTO RICO AND THE VIRGIN ISLANDS. UPPER LEVEL ANTICYCLONIC FLOW COVERS THE ATLANTIC OCEAN NORTH OF 10N BETWEEN 26W AND THE 30N50W 18N65W TROUGH...AND AWAY FROM THE AREA OF TROPICAL DEPRESSION FOUR. AN EASTERN ATLANTIC OCEAN TROUGH EXTENDS FROM A SMALL CYCLONIC CIRCULATION CENTER NEAR 30N19W TO 26N22W TO 23N24W. $$ MT