000 AXNT20 KNHC 101740 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU APR 10 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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 3N24W 1N33W 1N50W. SCATTERED MODERATE AND EMBEDDED ISOLATED STRONG CONVECTION IS WITHIN 180 NM N AND 60 NM S OF THE AXIS BETWEEN 14W-17W. SCATTERED MODERATE CONVECTION IS WITHIN 210 NM S OF THE AXIS BETWEEN 37W-43W. ...DISCUSSION... GULF OF MEXICO... A LARGE MID TO UPPER RIDGE LIES OVER THE REGION PRODUCING WIDESPREAD DRY AIR ALOFT ESPECIALLY S OF 24N...CLOSER TO THE HIGH CENTER. PRONOUNCED MID-UPPER TROUGHING IS OVER THE ROCKIES EXTENDING S TO MEXICO. THIS TROUGH IS PROVIDING SUPPORT FOR A COMPLEX 992 MB LOW PRES SYSTEM OVER THE S CENTRAL PLAINS WITH AN ASSOCIATED COLD FRONT EXTENDING THROUGH S TEXAS AND INTO N MEXICO. THE TIGHT PRESS GRADIENT BETWEEN THE FRONT AND 1024 MB HIGH PRES N OF BERMUDA IS PRODUCING 20-30 KT S TO SE WINDS W OF 84W...BUILDING SEAS TO 11 FT. BESIDES FOR ISOLATED QUICK MOVING SHALLOW SHOWERS...STEERED BY THE STRONG LOW-LEVEL FLOW...FAIR WEATHER DOMINATES THANKS TO THE SUBSIDENT MID-UPPER RIDGE. NWP MODELS SHOW THE AFOREMENTIONED MID-UPPER TROUGH DEEPENING AND PUSHING E DRIVING A COLD FRONT INTO THE NW WATERS TOMORROW. THIS FRONT APPEARS TO BE A STRONG ONE...LIKELY CLEARING THE ENTIRE AREA BY THE END OF THE WEEKEND. CARIBBEAN SEA... AN UPPER TROUGH EXTENDS THROUGH THE SE BAHAMAS...THE WINDWARD PASSAGE TO NE NICARAGUA. UPPER CONFLUENCE ALONG AND TO THE W OF THIS TROUGH AXIS IS SUBSTANTIALLY DRYING OUT THE MID AND UPPER LEVELS. E OF THE AXIS...BROKEN MID-HIGH LEVEL DEBRIS CLOUDINESS IS SPREADING NE FROM CONVECTIVE BLOW-UPS OVER THE TROPICAL EPAC JUST S OF PANAMA. AT THE SFC...THE TRADE WIND FLOW IS MODERATE TODAY WITH QSCAT DATA DEPICTING NE 20-25 KT WINDS NEAR COLOMBIA AND 15-20 KT ELSEWHERE E OF ABOUT 80W. SIMILAR MAGNITUDE E TO SE WINDS RESUME IN THE GULF OF HONDURAS...ENHANCED BY LOW PRES OVER THE S CENTRAL CONUS. THE LOW-LEVEL CLOUD STREAMERS APPEAR THINNER THAN USUAL WITH THE ONLY ORGANIZED PATCHES OVER THE SE CARIB FROM 12N-15N E OF 68W AND N OF 17N BETWEEN 71W-74W ...INCLUDING THE ISLAND OF HISPANIOLA. THE LATTER PATCH IS ENHANCED BY A WEAK SFC TROUGH N OF THE AREA. MOISTURE MAY INCREASE SLIGHTLY OVER THE NEXT FEW DAYS AS LOW-LEVEL TROUGHS IN THE TROPICAL ATLC PUSH W INTO THE E CARIB AND AS A COLD FRONT NEARS THE NW PORTION. ATLANTIC OCEAN W OF 40W... A COMPLEX HORIZONTALLY STRETCHED SFC LOW PRES TROUGH EXTENDS NEARLY ACROSS THE SUBTROPICAL BELT W OF 40W. THE MAIN LOW...1013 MB...IS LOCATED NEAR 29N47W WITH A WARM FRONT EXTENDING WITHIN 180 NM SE OF THE LOW. A WEAK FRONT IS DRAPED W THROUGH A 1014 MB LOW NEAR 29N58W TO AN ILL-DEFINED 1015 MB LOW NEAR 28N70W. A TROUGH EXTENDS BOTH TO THE NW AND SW OF THIS LOW. SCATTERED SHOWERS AND ISOLATED TSTMS ARE N OF 29N BETWEEN 41W-46W IN AN OVERRUNNING REGIME AND WIDELY SCATTERED SHOWERS ARE POSSIBLE ELSEWHERE N OF 24N E OF 72W. WINDS AROUND 20 KT ARE OCCURRING N OF THE FRONT E OF 70W. THE MAIN LOW...1013 MB...IS EXPECTED TO DEEPEN AND PUSH JUST NE OF THE AREA BY TOMORROW. THIS WILL LIKELY HELP DECREASE THE SHOWER ACTIVITY W OF 55W. FARTHER S...A LOW-LEVEL TROUGH IS PRESSING W ALONG 49W FROM 5N-11N AIDING IN THE WIDELY SCATTERED MODERATE CONVECTION FROM 6N-9N BETWEEN 47W-55W. ATLANTIC OCEAN E OF 40W... A MID-UPPER TROUGH IS RETREATING OVER THE NE PORTION OF THE DISCUSSION ZONE ALLOWING A COLD FRONT TO DISSIPATE FROM MOROCCO TO 25N16W CONTINUING TO 23N31W. A TROUGH HAS BROKEN OFF THE TAIL END OF THE FRONT AND IS NOW MOVING W ALONG 37W FROM 21N-26N. SCATTERED SHOWERS ARE WITHIN 180 NM E OF THE TROUGH AXIS AND ONLY ISOLATED ACTIVITY IS IN THE VICINITY OF THE DYING COLD FRONT. QUIETER WEATHER PREVAILS ELSEWHERE UNDER THE INFLUENCE OF NEARLY ZONAL FLOW ALOFT AND SFC RIDGING EXTENDING SWD FROM N OF THE AZORES. $$ CANGIALOSI