000 AXNT20 KNHC 172322 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON APR 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 4N20W 2N30W 3N40W 2N52W. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM OF THE AXIS BETWEEN 14W-18W AND 23W-34W. A CLUSTER OF WEAKENING MODERATE CONVECTION IS ALONG THE AXIS FROM THE EQ TO 3N BETWEEN 47W-50W. ELSEWHERE...ISOLATED/SCATTERED SHOWERS ARE WITHIN 250 NM OF THE AXIS. ...DISCUSSION... 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 IS WARMING THE TEMPS TO WELL ABOVE NORMAL VALUES...IN FACT OVER 100 DEGREE F TEMPS ARE OBSERVED OVER PARTS OF MEXICO AND TEXAS. FAIR AND WARM/HOT WEATHER IS EXPECTED TO PREVAIL ACROSS THE W/CNTRL GULF TOMORROW. A COLD FRONT...CURRENTLY ACROSS THE CAROLINAS IS EXPECTED TO MOVE SWD AS A BACK-DOOR FRONT AND BE MAINLY IN THE ATLC...HOWEVER THE TAIL END OF THE FRONT MAY EXTEND ACROSS FL AND THE E GULF. THE GFS 24-H POSITION DRAPES THE FRONT N OF THE BAHAMAS INTO CENTRAL FLORIDA. THEREAFTER THE FRONT IS LIKELY TO SAG A BIT FURTHER S BEFORE DISSIPATING BY WED NIGHT/THU. CARIBBEAN... 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 THE E 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. TRADE WIND SHOWERS ARE SCATTERED ACROSS THE SEA BUT MORE CONCENTRATED ACROSS THE LAND AREAS OF THE VIRGIN ISLANDS...PUERTO RICO...HAITI AND JAMAICA. SEA BREEZE CONVERGENCE AND LOCAL TOPOGRAPHIC LIFT IS ENHANCING SOME OF THESE SHOWERS. A FEW SHOWERS ARE ALSO OCCURRING ACROSS THE LESSER ANTILLES. 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. WEST/CENTRAL ATLANTIC... WESTERLY UPPER LEVEL FLOW IS WIDESPREAD ACROSS THIS AREA. UPPER LEVEL ANTICYCLONES ARE CENTERED S OF THE W/CNTRL ATLANTIC WITH A DEEP-LAYERED OCCLUDED LOW WELL TO THE N OF THE AREA SE OF NOVA SCOTIA. DRY/STABLE AIR ALOFT IS WIDESPREAD ACROSS THIS REGION. IN THE CENTRAL ATLANTIC...A 1015 MB LOW NEAR 26N47W SITS ON A DISSIPATING STATIONARY FRONT WHICH ENTERS THE AREA ALONG 32N41 26N47W 19N58W. BROKEN CLOUDS AND SCATTERED SHOWERS ARE WITHIN 125 NM OF THE BOUNDARY AND WITHIN 150 NM OF THE LOW CENTER. A WEAK SFC TROUGH MARKED BY A LINE OF CLOUDS AND POSSIBLE SHOWERS IS E OF THE LOW ALONG 41W FROM 18N-22N. A WEAK SHORTWAVE IS ENHANCING SHOWERS AND EMBEDDED TSTMS S OF THE LOW ALONG AND TO THE E OF THE STATIONARY FRONT. GFS/NOGAPS SUGGEST THAT THIS UNSETTLED WEATHER MAY LINGER FOR ANOTHER 24 HOURS OR SO...BEFORE AN E ATLC SFC RIDGE STRETCHES WWD. EAST ATLANTIC... FAIRLY ZONAL UPPER LEVEL FLOW COVERS THE E ATLC N OF 20N. A WEAK SHORTWAVE IS ALONG 20W N OF 26N PRODUCING VERY LITTLE WEATHER. 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 E OF 35W. UPPER LEVEL DIVERGENCE IS ENHANCING SHOWER ACTIVITY ALONG AND TO THE N 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. $$ CANGIALOSI