000 AXNT20 KNHC 201735 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE MAR 20 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 3N21W 2N38W TO THE EQ41W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM N OF THE AXIS BETWEEN 23W-30W. SIMILAR ACTIVITY IS WITHIN 90 NM N OF THE AXIS BETWEEN 31W-43W AND S OF 2N W OF 47W. ...DISCUSSION... GULF OF MEXICO... THE MAIN STORY IN THE GULF IS THE MODERATE TO STRONG E-SE WINDS PRODUCED BY A RATHER TIGHT PRES GRADIENT TO THE SE OF A STRONG BERMUDA HIGH. THE STRONG ELY WINDS ARE ADVECTING PATCHES OF SHALLOW MOISTURE ACROSS CENTRAL AND S FLA WHERE DOPPLER RADAR IS DETECTING SOME PRECIP ECHOES. IN THE MID AND UPPER LEVELS...A HIGHLY AMPLIFIED RIDGE IS MOSTLY N OF THE REGION WITH A WEAK SHORTWAVE EXTENDING S ACROSS FLORIDA AND THE W BAHAMAS. THIS PATTERN IS LEADING TO MODERATE DRY SINKING AIR ACROSS THE GULF...EXCEPT FOR THE NW PORTION WHERE THERE IS A THIN AREA OF HIGH CLOUDS. LITTLE CHANGE IS EXPECTED OVER THE NEXT COUPLE OF DAYS AS THIS AREA REMAINS ON THE WRN PERIPHERY OF A STRONG SFC HIGH PRES RIDGE. CARIBBEAN... IT'S A FAIRLY QUIET DAY ACROSS MOST OF THE CARIB UNDER MODERATE DRY AIR AND SW TO WLY FLOW ALOFT ON THE NW PERIPHERY OF A BROAD MID TO UPPER LEVEL RIDGE. THE TAIL END OF AN ATLC FRONTAL TROUGH EXTENDS INTO THE WINDWARD PASSAGE. WHILE MOST OF THE SHOWER AND TSTMS ARE N OF THE ISLANDS THERE IS SOME SCATTERED ACTIVITY OVER JAMAICA...HAITI AND IN THE PASSAGE ENHANCED BY LOW-LEVEL CONVERGENCE NEAR THE TROUGH. ELSEWHERE TYPICAL PATCHES OF LOW AND MID LEVEL CLOUDS ARE BEING DRIVEN ACROSS THE SEA BY MODERATE TO STRONG TRADES. THESE WINDS ARE POOLING SHALLOW MOISTURE OVER HONDURAS AND BELIZE. LOOKING AHEAD A FEW DAYS...THE TRADES WILL BEGIN TO SLACKEN WED NIGHT AS THE TROUGH IN THE ATLC WEAKENS. WESTERN ATLANTIC... THE MAIN AREA OF PRECIP IN THE ATLC BASIN IS ASSOCIATED WITH A STALLED FRONTAL BOUNDARY ENTERING THE AREA NEAR 32N52W AND STRETCHING SW ALONG 27N61W 22N69W. THE BOUNDARY CONTINUES SW FROM THERE AS A SFC TROUGH TO THE WINDWARD PASSAGE. AN UPPER LEVEL DIFFLUENT PATTERN ALONG WITH LOW-LEVEL CONVERGENT FLOW IS PRODUCING A SWATH OF SHOWERS AND TSTMS WITHIN 180 NM EITHER SIDE OF THE FRONT AND MORE ISOLATED ACTIVITY WITHIN 90 NM OF THE TROUGH. MODELS SHOWS THIS BOUNDARY BECOMING FURTHER STRETCHED INTO THE RIDGE TO ITS W AND WEAKENING OVER THE NEXT COUPLE DAYS. SOME OF THE COMPUTER MODELS ARE HINTING AT A PIECE OF THE ENERGY BREAKING OFF LATER THIS WEEK POSSIBLY BRINGING SOME UNSETTLED WEATHER TO A SIMILAR REGION AS TODAY. ELSEWHERE HIGH PRES IS THE THEME. THE RATHER TIGHT GRADIENT BETWEEN THE FRONT A 1033 MB HIGH NEAR BERMUDA IS PRODUCING MODERATE TO STRONG E-NELY WINDS ACROSS MUCH OF THE SW ATLC W OF THE FRONTAL TROUGH. THESE WINDS ARE STEERING PATCHES OF SHALLOW MOISTURE ACROSS THE BAHAMAS AND CENTRAL/SOUTH FLA. QUITE WINDY CONDITIONS AND ISOLATED SHOWERS ARE LIKELY TO CONTINUE MUCH OF THE WEEK AS THE PRES GRAD REMAINS TIGHT. EASTERN ATLANTIC... STRONG SFC HIGH PRES RIDGING IS ALSO THE THEME HERE SUPPORTED BY A 1040 MB HIGH N OF THE AZORES. A VERY WEAK COMPACT 1014 MB LOW IS LOCATED NEAR 24N20W. ONLY ISOLATED SHOWERS ARE NOTED WITHIN 90 NM N OF THIS OTHERWISE LOW-LEVEL CLOUD SWIRL. THE MAIN STORY...SIMILAR TO THE WRN-MOST ATLC...IS THE STRONG NE-ELY WINDS WHICH COVER A LARGE PORTION OF THE DISCUSSION AREA N OF 20N. IN THE MID AND UPPER LEVELS...A LARGE TROUGH HAS BEEN CARVED OVER JUST ABOUT THE ENTIRE E ATLC WITH THE MAIN UPPER LOW CENTERED JUST NW OF THE CANARY ISLANDS. THE ONLY WEATHER EFFECT OF THIS TROUGH IS ON THE SE SIDE ACROSS THE DEEP TROPICS WHERE A SWLY JET RACES FROM 14N32W ACROSS THE CAPE VERDE ISLANDS AND NRN AFRICA. PATCHY UPPER LEVEL MOISTURE LIES TO THE RIGHT OF THE JET AXIS WITH ENHANCED UPPER CONFLUENCE LEADING TO STRONG SINKING AIR LEFT OF THE AXIS. THE DIVERGENT PATTERN ALOFT TO THE E OF THE JET IS PROVIDING A FAVORABLE ENVIRONMENT FOR CONVECTION IN THE ITCZ. $$ CANGIALOSI