000 AXNT20 KNHC 080532 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST THU MAR 08 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 7N10W 4N18W 2N29W 1N41W EQ46W 1S51W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE AXIS BETWEEN 35W-41W. ISOLATED MODERATE IS WITHIN 120 NM S OF THE AXIS BETWEEN 18W-21W AND FROM 4S-2N BETWEEN 45W-51W. ...DISCUSSION... GULF OF MEXICO... QUIET WEATHER CONTINUES IN THE GULF THANKS TO A 1023 MB HIGH PRES SYSTEM CENTERED IN THE NE GULF NEAR 30N86W. SFC OBS AND NIGHT CHANNEL VIS IMAGES SHOW LIGHT MAINLY ELY WINDS AND ONLY SCATTERED PATCHES OF LOW-MID LEVEL CLOUDS IN THE WRN GULF. IN THE MID AND UPPER LEVELS...THE FLOW IS MAINLY FROM THE WNW FLOWING AROUND UPPER RIDGING IN THE TROPICAL EPAC EXTENDING NWD INTO THE BAY OF CAMPECHE. SWLY FLOW ON THE W PERIPHERY OF THE UPPER RIDGE IS SPREADING HIGH LEVEL MOISTURE FROM THE EPAC INTO CENTRAL MEXICO AND THE WRN GULF...W OF 93W FROM 22N-26N. MODESTLY DRY AIR EXISTS ELSEWHERE AIDING IN THE WIDESPREAD TRANQUIL WEATHER. OVER THE NEXT COUPLE OF DAYS...LITTLE PATTERN CHANGE BOTH AT THE SFC AND ALOFT IS ANTICIPATED KEEPING WINDS LIGHT AND THE WEATHER CONDITIONS FAIR ACROSS MOST OF THE AREA. GFS IS HINTING AT DEVELOPING A WEAK LOW-LEVEL TROUGH IN THE MID-GULF LATE FRI/SAT WHICH MAY ENHANCE SOME CLOUDS/SHOWERS. CARIBBEAN... A WEAK 1014 MB LOW IS DRIFTING W NOW LOCATED ALONG THE COAST OF BELIZE. THE MAIN EFFECT OF THIS WEAK SYSTEM IS AN AREA OF LOW TO MID LEVEL CLOUDS WHICH LIE ACROSS NRN CENTRAL AMERICA AND THE COASTAL WATERS FROM 14N-20N W OF 86W. THE MOIST ONSHORE FLOW IS RUNNING UPSLOPE SOME OF THE HIGH TERRAIN LIKELY PRODUCING SOME SHOWERS OVER HONDURAS...GUATEMALA AND PARTS OF THE YUCATAN PENINSULA. ELSEWHERE FAIRLY TYPICAL CONDITIONS EXIST WITH MODERATE TO STRONG ELY TRADES AND THIN PATCHES OF LOW-LEVEL MOISTURE STREAMING W ACROSS THE SEA. ALOFT...THE FLOW IS RATHER ZONAL WITH A LARGE AMOUNT OF DRY STABLE AIR COVERING THE REGION PREVENTING THE MOISTURE PATCHES FROM ACQUIRING MUCH VERTICAL DEPTH. THE WEAK LOW/SFC TROUGH IN THE NW CARIB WILL CONTINUE TO DRIFT W LIKELY DISSIPATING LATER TODAY...OTHERWISE LITTLE CHANGE IS EXPECTED OVER THE NEXT DAY OR TWO. WESTERN ATLANTIC... SLIGHT MID TO UPPER LEVEL TROUGHING COVERS THE MAJORITY OF THE ATLC W OF 50W EXTENDING SWD FROM A LARGE STRONG POLAR LOW. AN ASSOCIATED FRONTAL BOUNDARY IS LINGERING IN THE REGION ANALYZED STATIONARY ALONG 32N46W 25N62W ACROSS THE SE BAHAMAS. BROKEN TO OVERCAST LOW AND MID LEVEL CLOUDS WITH EMBEDDED SHOWERS ARE WITHIN 150 NM EITHER SIDE OF THE FRONT N OF 25N AND WITHIN 240 NM W OF THE FRONT S OF 25N. THE CLOUDS APPEAR THICKEST OVER THE CENTRAL BAHAMAS WHERE A WEAK FRONTAL WAVE MAY BE DEVELOPING. SE OF THE FRONT SKIES ARE MAINLY FAIR UNDER THE INFLUENCE OF SFC HIGH PRES RIDGING FROM THE NE AND DRY STABLE AIR ALOFT. LOOKING AHEAD A COUPLE OF DAYS...THE LARGE POLAR VORTEX WILL GRADUALLY PULL EWD BUT IT SHOULD BE CLOSE ENOUGH TO PROVIDE SOME SUPPORT FOR WEAK SFC TROUGHS/FRONTAL BOUNDARIES TO REMAIN IN THE AREA. THIS WILL LIKELY CONTINUE TO PRODUCE SOME UNSETTLED WEATHER FOR PORTIONS OF THE W ATLC. EASTERN ATLANTIC... A STRONG 1035 MB HIGH PRES SYSTEM LOCATED A COUPLE HUNDRED NM SW OF THE AZORES IS DOMINATING THE SFC PATTERN ACROSS THE ATLC E OF 45W. THIS HIGH IS PRODUCING MODERATE TO STRONG TRADE WINDS ACROSS A GOOD PORTION OF THE DISCUSSION AREA PARTICULARLY E OF 30W. THE ONCE VIGOROUS UPPER LOW HAS NOW OPENED INTO A TROUGH ALIGNED ALONG 34W. SWLY UPPER LEVEL FLOW AND DIFFLUENCE TO THE E OF THE TROUGH IS STILL GENERATING A FAIR AMOUNT OF MOISTURE FROM 10N TO BEYOND 32N BETWEEN 23W-35W. HOWEVER THIS MOISTURE PLUME IS CONSIDERABLY THINNER THAN IT WAS YESTERDAY AT THIS TIME AND THIS TREND IS EXPECTED TO CONTINUE AS THE TROUGH PULLS NWD AND DISSIPATES THRU FRI. FAIR WEATHER LOOKS TO BE THE THEME FOR MOST OF THE REGION THIS WEEKEND AS STRONG DEEP LAYER RIDGING BECOMES WELL ESTABLISHED. $$ CANGIALOSI