000 AXNT20 KNHC 201742 TWDAT TROPICAL WEATHER DISCUSSION... NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN APR 20 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. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 4N23W 3N30W 1N40W TO THE EQUATOR AT 50W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 4N-7N BETWEEN 13W-16W. SCATTERED MODERATE CONVECTION IS WITHIN 210 NM N OF THE AXIS W OF 33W AND WITHIN 90 NM N OF THE AXIS BETWEEN 25W-27W. ...DISCUSSION... GULF OF MEXICO... A MID TO UPPER LEVEL RIDGE IS BUILDING E ACROSS THE GULF ...CURRENTLY CENTERED ALONG 93W...OVERTAKING TROUGHING OVER THE NE WATERS AND FLORIDA. THIS TROUGHING...ASSOCIATED WITH A CUT OFF LOW OVER THE OHIO VALLEY...IS PROVIDING LIMITED SUPPORT FOR A NEARLY STATIONARY FRONT FROM CENTRAL FLORIDA TO 26N90W. THE FRONT IS ONLY MARKED BY A VERY NARROW LINE OF LOW CLOUDS WITH EMBEDDED SCATTERED SHOWERS AS INDICATED ON DOPPLER RADAR. A WEAK 1018 MB HIGH HAS BUILT BEHIND THE FRONT CENTERED OVER THE N CENTRAL WATERS NEAR 29N89W. MAINLY FAIR WEATHER DOMINATES THE MAJORITY OF THE REGION SUPPORTED BY A SUBSIDENT ENVIRONMENT...ESPECIALLY OVER THE SW PORTION. THE FRONT IS EXPECTED TO CONTINUE TO WEAKEN AND SHIFT SE ALLOWING FAIR WEATHER TO CONTINUE INTO THE BEGINNING OF THE WORK WEEK. CARIBBEAN SEA... A BROAD UPPER TROUGH LIES OVER THE CARIBBEAN SEA AND FLAT RIDGING COVERS MUCH OF THE TROPICAL ATLC AND SOUTH AMERICA. THIS LARGE SCALE PATTERN IS PRODUCING A MODERATE TO STRONGLY SUBSIDENT ENVIRONMENT N OF 14N. S OF 14N...THE ATMOSPHERE IS BEING SOMEWHAT MOISTENED ALOFT BY BROKEN HIGH LEVEL CLOUDS. IN THE LOWER LEVELS...A 1034 Z QSCAT PASS SUGGESTS 25-30 KT NE WINDS NEAR THE COAST OF COLOMBIA AND MODERATE TRADES ELSEWHERE. THE TYPICAL LOW-LEVEL CLOUD PATCHES APPEAR SUBDUED TODAY WITH THE ONLY ORGANIZED PATCH OVER THE NRN LEEWARD ISLANDS. THE TRADE WIND FLOW IS EXPECTED TO WEAKEN TOMORROW AS TROUGHING BECOMES BETTER ESTABLISHED OVER THE W ATLC. OTHERWISE...LITTLE SIGNIFICANT CHANGE IS EXPECTED OVER THE NEXT DAY OR SO. ATLANTIC OCEAN... A LARGE SCALE TROUGH...WITH A FEW EMBEDDED SHORTWAVES...COVERS MUCH OF THE W ATLC. ONE OF THE SHORTWAVES IS SUPPORTING A COLD FRONT FROM THE NORTH CAROLINA COAST TO NE FLORIDA. A PRE-FRONTAL TROUGH LIES AHEAD OF IT FROM 32N78W TO 27N79W. DOPPLER RADAR AND LIGHTNING DATA IS SHOWING QUITE A BIT OF TSTM ACTIVITY ALONG THESE BOUNDARIES BUT MOST OF IT IS N OF 31N/32N. SCATTERED SHOWERS AND TSTMS ARE ALSO LOCATED N OF HISPANIOLA AND PUERTO RICO FROM 21N-24N BETWEEN 61W-72W. THIS ACTIVITY IS ASSOCIATED WITH BASE OF THE UPPER TROUGH (VORTICITY MAX) AND LOW-LEVEL CONVERGENCE ALONG A PAIR OF SFC TROUGHS. DEBRIS MID-HIGH LEVEL CLOUDS COMBINED WITH LOW LEVEL CLOUDS TRIGGERED BY A LINGERING SFC TROUGH FROM 31N54W TO 25N61W IS PRODUCING A FAIR AMOUNT OF CLOUD COVER AND ISOLATED SHOWERS WITHIN 120 NM OF THE SFC TROUGH LINE. THE CENTRAL AND EASTERN ATLC IS DOMINATED BY A QUASI-STATIONARY 1025 MB HIGH NEAR 31N35W. THIS HIGH IS PRODUCING A LARGE AREA OF 15-20 KT NE/E WINDS ACROSS THE TROPICAL BELT. IN THE MID AND UPPER LEVELS...A RIDGE AXIS EXTENDS FROM 20N40W THRU 32N35W...A WEAK SMALL UPPER LOW IS NEAR 19N30W AND UPPER TROUGHING LIES OVER THE FAR NE PORTION. THIS OVERALL PATTERN IS PRODUCING LITTLE SENSIBLE WEATHER BESIDES FOR AN AREA OF POSSIBLE SHOWERS/TSTMS FROM 8N-10N BETWEEN 33W-40W. $$ CANGIALOSI