000 AXNT20 KNHC 070528 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED MAR 07 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 3N20W 1N31W EQ42W 2S48W. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM EITHER SIDE OF THE AXIS E OF 20W AND WITHIN 240 NM N OF THE AXIS BETWEEN 35W-44W. SCATTERED MODERATE IS FROM THE EQ TO 3S BETWEEN 30W-38W. ...DISCUSSION... GULF OF MEXICO... A 1026 MB SFC HIGH PRES SYSTEM REMAINS ESTABLISHED ACROSS THE AREA CENTERED OVER CENTRAL ALABAMA. LATEST QSCAT DATA AND SFC OBS SHOW LIGHT TO MODERATE NE-E WINDS ACROSS THE E AND MIDDLE GULF VEERING TO THE S IN THE W GULF ON THE W PERIPHERY OF THE RIDGE. IN THE MID AND UPPER LEVELS...THE FLOW IS MAINLY WNW BETWEEN EXTENSIVE ZONAL FLOW IN THE CARIB AND WELL DEFINED TROUGHING OVER THE ERN U.S. ASSOCIATED WITH A LARGE POLAR VORTEX. BROKEN MID AND HIGH CLOUDINESS IS LOCATED N OF 28N ESPECIALLY IN THE NE GULF CLOSER TO THE BASE OF THE DEEP TROUGH. ABUNDANT DRY SINKING AIR EXISTS ELSEWHERE KEEPING SKIES FAIR TO MOSTLY CLEAR. OVER THE NEXT COUPLE OF DAYS...LITTLE CHANGE IN THE SFC PATTERN IS EXPECTED SO THE WINDS SHOULD REMAIN LIGHT TO MODERATE. THE MID AND UPPER PATTERN SHOULD ALSO REMAIN ZONAL BUT MAY INCREASE IN MAGNITUDE AS SMALL IMPULSES/VORT MAXES MOVE ACROSS THE SRN U.S. CARIBBEAN... REMNANT PATCHES OF LOW TO MID LEVEL CLOUDS...LEFT OVER FROM THE DISSIPATED TROUGH/FRONT...ARE STILL LINGERING IN THE NW CARIB STEERED BY MODERATE TO STRONG NELY FLOW. THIS FLOW IS POOLING MOISTURE ACROSS HONDURAS...BELIZE...GUATEMALA AND S MEXICO ENHANCED BY OROGRAPHIC LIFT NEAR/OVER THE HIGH TERRAIN LIKELY PRODUCING ISOLATED SHOWERS. A SIMILAR SETUP EXISTS OVER THE HIGH TERRAIN OF HISPANIOLA. ELSEWHERE MODERATE ELY TRADES ARE BLOWING WITH ONLY A FEW PATCHES OF LOW-LEVEL MOISTURE. ALOFT...THE FLOW IS RATHER ZONAL WITH A LARGE AMOUNT OF DRY STABLE AIR ...ESPECIALLY E OF 77W...KEEPING MOST OF THE MOISTURE PATCHES SHALLOW. NO BIG PATTERN CHANGES APPEAR LIKELY IN THE DAY OR TWO SO SIMILAR TRADES AND WEATHER CONDITIONS ARE LIKELY TO CONTINUE. WESTERN ATLANTIC... DEEP LAYER TROUGHING COVERS THE MAJORITY OF THE ATLC W OF 55W EXTENDING SWD FROM A LARGE POLAR LOW. TWO FRONTAL BOUNDARIES ARE ASSOCIATED WITH THE TROUGH. ONE OF THESE HAS BEEN IN THE AREA FOR QUITE SOMETIME AND IS ANALYZED STATIONARY ALONG 32N55W 26N66W ACROSS THE ERN BAHAMAS. BROKEN LOW AND MID LEVEL CLOUDS AND LIKELY EMBEDDED SHOWERS ARE WITHIN 120 NM W OF THE BOUNDARY. THE OTHER FRONT IS PROGRESSIVE ENTERING THE AREA NEAR 32N59W EXTENDING WSW TO 29N75W. THIS FRONT IS CLEARLY MARKED BY A THIN ROPE LINE ON NIGHT CHANNEL VIS BUT BECAUSE OF THE STABLE ENVIRONMENT BEHIND THE FIRST FRONT...INDICATED BY COLD AIR STRATOCUMULUS CLOUDS...LIMITED MOISTURE IS ASSOCIATED WITH THIS ONE. HOWEVER WV IMAGES DO SHOW A PATCH OF MID-HIGH LEVEL CLOUDS N OF 28N W OF 68W ASSOCIATED WITH A CLIPPER SYSTEM EMBEDDED IN THE DEEP LAYER TROUGH. NWP MODELS SHOW THE TROUGH HOLDING ON FOR THE NEXT DAY OR TWO BEFORE PULLING NE TOWARD THE END OF THE WEEK SO SOME UNSETTLED WEATHER IS EXPECTED IN THE REGION. EASTERN ATLANTIC... A 1035 MB HIGH PRES SYSTEM LOCATED A FEW HUNDRED NM S OF THE AZORES NEAR 33N24W IS DOMINATING THE SFC PATTERN ACROSS THE ATLC E OF 55W. THIS HIGH IS PRODUCING MODERATE TO STRONG TRADES ACROSS A GOOD PORTION OF THE DISCUSSION ZONE. THE MAIN FEATURE IN THIS AREA IS IN THE UPPER LEVELS WHERE A FAIRLY VIGOROUS 300 MB LOW IS LOCATED NEAR 25N42W. THIS LOW IS EMBEDDED AND CUTTING OFF A LARGE UPPER RIDGE THAT COVERS MOST OF THE REGION. SWLY UPPER LEVEL FLOW AND DIFFLUENCE TO THE E OF THE UPPER LOW IS ADVECTING AND GENERATING A FAIR AMOUNT OF MOISTURE/SCATTERED SHOWERS FROM 11N-30N BETWEEN 24W-41W. MODELS SHOW THE UPPER LOW MOVING NWD AND OPENING INTO A TROUGH LATER TODAY OR TOMORROW. THIS WILL LIKELY REDUCE THE FETCH OF MOISTURE ACROSS THE REGION AS THE UPPER RIDGE GAINS CONTROL. $$ CANGIALOSI