000 AXNT20 KNHC 180553 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE APR 18 2006 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...WEATHER OBSERVATIONS... RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...ITCZ... ITCZ 7N10W 5N20W 2N30W 2N40W TO THE EQUATOR AT 52W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS WITHIN 90 NM ON EITHER SIDE OF AXIS EAST OF 30W...AND WITHIN 200 NM ON EITHER SIDE OF AXIS WEST OF 30W. ...DISCUSSION... THE GULF OF MEXICO... THE GULF IS ON THE N/NW PERIPHERY OF A STRONG UPPER HIGH IN THE SW CARIBBEAN. MODERATE SUBSIDENCE LIES ACROSS THE ENTIRE AREA ONLY ALLOWING SOME SCATTERED SCATTERED CLOUDS TO DEVELOP. SURFACE S/SW FLOW WARMED THE TEMPERATURES TO WELL ABOVE NORMAL VALUES...IN FACT OVER 100 DEGREE F TEMPS WERE FOUND IN PARTS OF MEXICO AND TEXAS YESTERDAY. FAIR AND WARM/HOT WEATHER IS EXPECTED ACROSS THE WESTERN AND CENTRAL GULF LATER TODAY. A COLD FRONT...CURRENTLY IN THE CAROLINAS...IS EXPECTED TO MOVE SOUTHWARD AS A BACK-DOOR FRONT AND BE MAINLY IN THE ATLC. THE TAIL END OF THE FRONT MAY EXTEND ACROSS FLORIDA AND THE EASTERN GULF. THE GFS 24-HOUR POSITION DRAPES THE FRONT NORTH OF THE BAHAMAS INTO CENTRAL FLORIDA. THEREAFTER THE FRONT IS LIKELY TO SAG A BIT MORE TO THE SOUTH BEFORE DISSIPATING BY WEDNESDAY NIGH AND THURSDAY. THE CARIBBEAN SEA... A WELL DEFINED UPPER LEVEL ANTICYCLONE IS CENTERED OFF THE COAST OF NICARAGUA NEAR 12N81W. MODERATE TO STRONG SUBSIDENCE LIES OVER MOST OF THE AREA EXCEPT FOR A NARROW PLUME OF UPPER LEVEL MOISTURE STREAMING NWD ON THE RETURN FLOW OF THE UPPER HIGH FROM THE EPAC ACROSS PANAMA AND NICARAGUA. THIS MOISTURE DRIES UP VERY QUICKLY AS IT APPROACHES JAMAICA. ENHANCED SUBSIDENCE... SUPPORTED BY UPPER LEVEL CONFLUENCE...LIES ACROSS THE EASTERN CARIBBEAN...NAMELY FROM 14N-22N BETWEEN 50W-73W. SCATTERED MODERATE CONVECTION CONTINUES TO FIRE OVER COLUMBIA AND VENEZUELA. WEAK SFC RIDGING LIES ACROSS THE AREA KEEPING THE TRADES FAIRLY LIGHT. SIMILAR WEATHER IS EXPECTED OVER THE NEXT FEW DAYS. TRADE WINDS SHOULD REMAIN LIGHT THRU THU UNTIL A SLIGHTLY STRONGER SFC HIGH DEVELOPS N OF THE AREA. WESTERN ATLANTIC OCEAN/CENTRAL ATLANTIC OCEAN... WESTERLY UPPER LEVEL FLOW IS WIDESPREAD ACROSS THIS AREA. UPPER LEVEL ANTICYCLONES ARE CENTERED SOUTH OF THE W/CNTRL ATLANTIC WITH A DEEP-LAYERED OCCLUDED LOW WELL TO THE N OF THE AREA SOUTHEAST OF NOVA SCOTIA. DRY/STABLE AIR ALOFT IS WIDESPREAD ACROSS THIS REGION. IN THE CENTRAL ATLANTIC...A STATIONARY FRONT PASSES 32N40W TO A 1016 MB LOW NEAR 26N47W...AND CONTINUES TO 19N54W. GFS/NOGAPS SUGGEST THAT THIS UNSETTLED WEATHER MAY LINGER FOR ANOTHER THE ATLANTIC OCEAN... FAIRLY ZONAL UPPER LEVEL FLOW COVERS THE EASTERN ATLANTIC OCEAN NORTH OF 20N. A WEAK SHORTWAVE IS ALONG 18W/19W NORTH OF 26N PRODUCING ONLY A LITTLE ABOUT IT. A LARGE UPPER HIGH IS CENTERED IN THE TROPICAL ATLC NEAR 12N42W WITH RIDGING EXTENDING NEWD TO 22N28W. PLENTY OF DRY/STABLE AIR LIES FROM 10N-20N EAST OF 35W. UPPER LEVEL DIFFLUENT FLOW ENHANCING SHOWER ACTIVITY ALONG AND TO THE NORTH OF THE ITCZ W OF 40W. SURFACE RIDGING STRETCHES ACROSS THE E ATLC WITH A 1028 MB HIGH CENTER NEAR 38N21W. GENERALLY FAIR WEATHER PREVAILS ACROSS THE AREA EXCEPT FOR A FEW SHOWERS SPILLING EWD W OF 34W N OF 22N ASSOCIATED WITH THE CNTRL ATLANTIC STATIONARY FRONT AND UPPER LEVEL SHORTWAVE TROUGH. SAHARAN DUST IS WIDESPREAD E OF 30W BETWEEN 10N-20N. THE SFC RIDGE IS EXPECTED TO REMAIN IN PLACE ACROSS THE E ATLC AND BUILD WWD THRU MID-WEEK BEFORE RETREATING TO THE N BY THE END OF THE WEEK. $$ MT