000 AXNT20 KNHC 092346 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI MAR 09 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N10W 4N20W 3N35W EQ44W TO THE NE COAST OF BRAZIL NEAR 2S46W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 80 NM ON EITHER SIDE OF THE AXIS BETWEEN 32W-42W...AND WITHIN 150 NM S OF THE AXIS E OF 15W. SIMILAR CONVECTION IS OVER NE BRAZIL. ...DISCUSSION... GULF OF MEXICO... WEAK PRES PATTERN CHARACTERIZED BY WEAK RIDGING AND A VERY WEAK SFC TROUGH DOMINATES THE GULF. THE TROUGH IS OVER THE CENTRAL GULF ALONG 88/89W FROM 23N-28N. THIS FEATURE IS GENERATING AN AREA OF LOW AND MID CLOUDS WITH POSSIBLE SHOWERS WITHIN 60-80 NM OF THE AXIS. ELY WINDS ACROSS THE REGION ARE ADVECTING SOME LOW LEVEL MOISTURE ACROSS THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. A BROAD UPPER LEVEL RIDGE DOMINATES THE ENTIRE GULF AND THE SOUTH-CENTRAL PORTIONS OF MEXICO....INCLUDING THE YUCATAN PENINSULA. SWLY FLOW ON THE WRN PERIPHERY OF THE RIDGE IS ADVECTING HIGH LEVEL MOISTURE FROM THE EPAC ACROSS CENTRAL MEXICO AND INTO THE GULF MAINLY S OF 27N. MODERATE DRY AIR EXISTS N OF THE UPPER MOISTURE PLUME. THE WEAK PATTERN IS FORECAST TO PERSIST DURING THE UPCOMING WEEKEND WITH FAIRLY LIGHT WINDS AND SEAS. CARIBBEAN... QUIET WEATHER PERSISTS ACROSS MUCH OF THE BASIN THIS EVENING WITH PLENTY OF DRY STABLE AIR ALOFT IN PLACE. UPPER RIDGING GENERALLY DOMINATES THE REGION W OF 70W WITH A SHORTWAVE TROUGH FROM THE ATLC TO THE E CARIBBEAN. CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION HAVE DEVELOPED OVER N COLOMBIA AND W VENEZUELA NEAR LAKE MARACAIBO PROBABLY ASSOCIATED WITH THE CLIMATOLOGICAL LOW PRES THAT SITS OVER THE AREA. LOW AND MID CLOUDS ARE SEEN OVER THE YUCATAN PENINSULA...THE NW CARIBBEAN AND A GOOD PORTION OF CUBA ASSOCIATED WITH THE REMNANTS OF A WEAK SFC TROUGH. TYPICAL TRADE WIND SHOWERS ARE MOVING WWD ACROSS THE REGION. TRANQUIL WEATHER IS EXPECTED TO CONTINUE THROUGH THE WEEKEND WITH CONDITIONS DOMINATED BY MODERATE TRADE WINDS. WESTERN ATLANTIC... SFC LOW PRES PREDICTED BY THE REGIONAL GLOBAL MODELS DURING THE PAST FEW DAYS IS LOCATED JUST E OF THE BAHAMAS NEAR 25N74W AT 21Z. A TROUGH EXTENDS FROM THIS LOW TO THE WINDWARD PASSAGE WHILE ANOTHER TROUGH GOES MAINLY EWD FROM THE LOW TO 26N65W. A COLD FRONT IS ALSO IN THE AREA WITHIN 90-100 NM N OF THE SECOND TROUGH MENTIONED ABOVE. MULTILAYERED CLOUDS WITH EMBEDDED NUMEROUS SHOWERS AND SCATTERED TSTMS ARE ASSOCIATED WITH ALL THESE FEATURES. SAT IMAGERY ALSO SHOWS THE CLOUD PATTERN EXHIBITING CYCLONIC CIRCULATION DUE TO THE PRESENCE OF THE LOW PRES. THE PRES GRADIENT RESULTING BETWEEN STRONG HIGH PRES N OF THE AREA AND THE SFC LOW HAS TIGHTENED PRODUCING NE TO E WINDS OF 20 TO 30 KT N OF 27N E OF 75W. ACCORDING TO THE GFS MODEL...THE SFC LOW JUST E OF THE BAHAMAS WILL MOVE NE ACROSS THE OCEAN INTENSIFYING INTO A STRONG EXTRATROPICAL WITH A TRAILING FRONTAL TROUGH. EASTERN ATLANTIC... A STRONG 1039 MB HIGH PRES SYSTEM LOCATED ABOUT 300 NM W OF PORTUGAL 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 TO THE W COAST OF AFRICA WHERE THE TIGHTEST PRES GRAD EXISTS. FAIRLY DRY AIR ALOFT DOMINATES THE REGION PROVIDING STABLE CONDITIONS. THE STRONG SFC HIGH IS FORECAST TO RETREAT NE ALLOWING THE TRADES TO RELAX SLIGHTLY THIS WEEKEND IN THE E ATLC. HOWEVER THEY ARE SET TO PICK UP AGAIN SUN AND INTO NEXT WEEK AS STRONG HIGH PRES REBUILDS E ACROSS THE ATLC OCEAN. $$ GR