000 AXNT20 KNHC 031743 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAY 03 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 2N19W 1N36W EQ50W. THE ERN PORTION OF THE AXIS IS FAIRLY CONVECTIVE WITH SCATTERED MODERATE WITHIN 240 NM N AND 120 NM S OF THE AXIS BETWEEN 14W-19W. SIMILAR ACTIVITY IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 19W-26W AND E OF 14W. ...DISCUSSION... GULF OF MEXICO... A WELL DEFINED MID TO UPPER LOW IS SLIDING E ACROSS N TEXAS. UPPER LEVEL DIFFLUENCE TO THE E OF THIS LOW CENTER IS FUELING SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE NW GULF N OF 26N BETWEEN 92W-95W. THIS ACTIVITY HAS SHARPLY DECREASED IN INTENSITY OVER THE LAST FEW HOURS. SFC OBS AND THIS MORNING'S QSCAT PASS DEPICTED A SFC BOUNDARY EMBEDDED IN THE UNSETTLED WEATHER ANALYZED AS A TROUGH ON THE SFC MAP RUNNING FROM JUST NE OF BROWNSVILLE TEXAS TO SW LOUISIANA. AN UPPER TROUGH IS SLIDING ESE OVER THE ERN GULF ALIGNED FROM MISSISSIPPI ACROSS WRN CUBA AND INTO THE CARIB SEA. THIS UPPER FEATURE IS ONLY PRODUCING A BROKEN LAYER OF CIRRUS OVER THE ERN GULF WATERS. AT THE SFC...THE WRN PERIPHERY OF A STRONG AZORES HIGH EXTENDS INTO THE CENTRAL GULF. SFC WINDS ARE GENERALLY E/SE 10-15 KT ON THE PERIPHERY. STRONGER 15-20 KT SELY WINDS ARE OBSERVED IN THE WRN GULF WHERE THE PRES GRADIENT TIGHTENS DUE TO LOWER PRES OVER MEXICO AND THE S CENTRAL U.S. THE SE WINDS IN THE WRN GULF ARE ANTICIPATED TO REMAIN ON THE STRONG SIDE OVER THE NEXT COUPLE DAYS AS LOW PRES DEEPENS IN THE CENTRAL U.S. CARIBBEAN SEA... THE BIG PICTURE ON WV IMAGERY SHOWS AN UPPER TROUGH COVERING THE WRN CARIB EXTENDING SWD FROM THE E GULF TO NICARAGUA AND AN UPPER RIDGE ESTABLISHED ACROSS THE E CARIB WITH THE AXIS EXTENDING N-S ALONG 64W. UPPER DIFFLUENCE AND EXTENSIVE SWLY FLOW ALOFT IS GENERATING AND DRAWING A LARGE SWATH OF TROPICAL MOISTURE BETWEEN THESE UPPER FEATURES ROUGHLY BETWEEN 65W-80W. WHILE A GOOD PORTION OF THIS MOISTURE SWATH IS ONLY IN THE FORM OF BROKEN TO OVERCAST MID TO HIGH LEVEL CLOUDS AND EMBEDDED ISOLATED SHOWERS...A FEW SMALL CLUSTERS OF TSTMS HAVE DEVELOPED IN THE SW CARIB S OF 13W W OF 77W. AT THE SFC...THE STRONG AZORES HIGH IS PRODUCING 15-20 KT ELY TRADES ACROSS THE CENTRAL AND ERN CARIB. THESE WINDS SLACKEN SLIGHTLY IN THE WRN CARIB...10-15 KT...NEAR THE SW PERIPHERY OF THE RIDGE AND NEAR A SFC TROUGH IN THE SE BAHAMAS...MORE ON THIS FEATURE IN THE ATLANTIC SECTION. ATLANTIC... THE ONLY AREA OF ACTIVE WEATHER IN THE ATLC DISCUSSION AREA...OUTSIDE OF CONVECTION ASSOCIATED WITH THE ITCZ...IS ASSOCIATED WITH A SLOW MOVING SFC TROUGH ANALYZED FROM THE NW TIP OF HAITI TO 27N73W. LOW-LEVEL CONVERGENCE ALONG THIS BOUNDARY ALONG WITH UPPER DIFFLUENCE/SWLY SHEAR TO THE E OF AN UPPER TROUGH OFF THE SE CONUS IS GENERATING SCATTERED SHOWERS AND TSTMS WITHIN 180 NM E OF THE SFC BOUNDARY AND FROM 28N-30N BETWEEN 73W-75W. MOST OF THE MODEL GUIDANCE CONTINUES TO SHOW DEVELOPMENT OF THIS SYSTEM INTO A CLOSED LOW WITHIN THE NEXT 24 HOUR OR SO AS IT GAINS UPPER SUPPORT BY THE TROUGH TO ITS W. AS THIS HAPPENS...THE LOW WILL BE GIVEN A KICK BY THE UPPER STEERING ACCELERATING IT TO THE NE. THE ONLY OTHER SFC FEATURE IS A BACK-DOOR COLD FRONT THAT IS EXPECTED TO SAG INTO THE AREA TOMORROW. THE REMAINDER OF THE BASIN...E OF 65W...IS DOMINATED BY A 1029 MB HIGH CENTERED ABOUT 400 NM SSE OF THE AZORES NEAR 32N32W. THIS HIGH IS PRODUCING MODERATE TRADES AND PATCHES OF STRATOCUMULUS CLOUDS ACROSS THE BULK OF AREA...STRONGEST E OF 30W WHERE THE PRES GRAD IS TIGHTEST DUE TO THE INTERACTION WITH LOW PRES OVER AFRICA. SAHARAN DUST IS SPREADING W ACROSS THE ATLC WATERS...THICKEST FROM THE CAPE VERDE ISLANDS EWD AS DEPICTED BY AN EROSION OF THE STRATOCUMULUS DECK AND A HAZY LOOK ON VISIBLE SATELLITE IMAGES. AN UPPER LOW IS CENTERED NEAR 27N43W WITH A JET BRANCH ON ITS S SIDE. THIS ENERGY IS PRODUCING HIGH LEVEL MOISTURE FROM 18N-32N BETWEEN 35W-45W. ELSEWHERE BOTH E AND W OF THE UPPER LOW...THE FLOW IS FAIRLY ZONAL AIDING IN THE TRANQUIL CONDITIONS. THE EXCEPTION IS THE UPPER SLY FLOW S OF 13N E OF 28W...ON THE W PERIPHERY OF AN UPPER RIDGE OVER AFRICA...WHICH IS FAVORING CONVECTION IN THE ITCZ. $$ CANGIALOSI