000 AXNT20 KNHC 181753 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN APR 18 2010 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 7N11W 3N19W 2N30W 2N40W AND INTO NE BRAZIL NEAR THE EQUATOR AND 49W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 2N-7N BETWEEN 06W-16W. SIMILAR CONVECTION IS FROM THE EQUATOR TO 6N BETWEEN 21W-36W. ...DISCUSSION... GULF OF MEXICO... AN AMPLIFIED UPPER LEVEL TROUGH IS LOCATED ACROSS THE GULF OF MEXICO WITH AXIS EXTENDING ALONG 90W. THIS PARTICULAR UPPER LEVEL TROUGH AXIS EXTENDS FROM SE LOUISIANA FAR SOUTH CROSSING PORTIONS OF NORTHERN CENTRAL AMERICA INTO THE E PACIFIC REGION TO 05N. THIS UPPER LEVEL FEATURE IS SUPPORTING A 1008 MB LOW CENTERED IN THE SE GULF NEAR 25N85W WITH A DEVELOPING WARM FRONT EXTENDING EASTWARD FROM THE LOW INTO THE STRAITS OF FLORIDA AND ACROSS THE CENTRAL BAHAMAS IN THE W ATLC. ALSO...A SURFACE TROUGH IS ANALYZED FROM THE LOW TO THE YUCATAN PENINSULA NEAR 21N88W AND INTO THE EASTERN BAY OF CAMPECHE NEAR 19N92W. LOW-LEVEL CONVERGENCE IN THE VICINITY OF THE LOW COUPLED WITH MIDDLE TO UPPER LEVEL LIFTING DYNAMICS ASSOCIATED WITH THE UPPER LEVEL TROUGH AXIS ARE GENERATING NUMEROUS SHOWERS AND SCATTERED TSTMS FROM 24N-29N E OF 86W TO INLAND OVER THE FLORIDA PENINSULA. MEANWHILE...AN UPPER LEVEL SHORTWAVE TROUGH EMBEDDED WITHIN THE MEAN TROUGH PREVIOUSLY MENTIONED IS LOCATED OVER SE TEXAS AND SUPPORTS A COLD FRONT THAT ENTERS THE NW GULF WATERS NEAR SAN ANTONIO BAY AND INLAND ONCE AGAIN NEAR BAFFIN BAY. MOSAIC DOPPLER RADAR INDICATES SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 60 NM EAST OF THE FRONT. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM JUST NORTH OF BROWNSVILLE TEXAS INTO THE SW GULF TO 21N94W. ISOLATED SHOWERS ARE OVER THE WESTERN GULF S OF 26N W OF 94W. GLOBAL MODEL GUIDANCE INDICATES THE SURFACE LOW OVER THE SE GULF IS FORECAST TO DRIFT NE OVER THE NEXT 24 HOURS BRINGING AMPLE MOISTURE ACROSS THE FLORIDA PENINSULA AND STRAITS OF FLORIDA. THIS LOW IS EXPECTED TO BE ABSORBED INTO A FRONTAL TROUGH THROUGH LATE MONDAY AS A WEAK FRONTAL BOUNDARY LINGERS ACROSS THE W ATLC AND NORTHERN FLORIDA ALONG 30N. CARIBBEAN SEA... AN UPPER LEVEL TROUGH IS ALONG 90W IN THE GULF OF MEXICO AND CONTINUES TO PROVIDE THE NW CARIBBEAN WITH PRONOUNCED MOIST SOUTHWESTERLY UPPER LEVEL FLOW W OF 70W. LOW-LEVEL CONVERGENCE OF E-SE SURFACE FLOW OVER THE WESTERN CARIBBEAN AND UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE APPROACHING UPPER LEVEL TROUGH ARE GENERATING SCATTERED SHOWERS ISOLATED TSTMS WITHIN 120 NM EITHER SIDE OF A LINE FROM EASTERN CUBA NEAR 20N75W TO JAMAICA THEN SW TO OFFSHORE OF NORTHEASTERN NICARAGUA NEAR 13N83W. OF NOTE WITH THIS PERSISTENT RAINFALL OVER JAMAICA...2.80 INCHES OF PRECIPITATION HAD BEEN RECORDED AT KINGSTON OVER THE LAST 24 HOURS. AS A FRONTAL TROUGH DEVELOPS NORTH OF THE CARIBBEAN SEA...EASTERLY TRADES AND NORTHERLY WINDS FILTERING INTO THE NW CARIBBEAN WILL PROVIDE FOR CONTINUED SCATTERED SHOWERS OVER THE CENTRAL CARIBBEAN...INCLUDING HISPANIOLA...JAMAICA...EASTERN CUBA...AND THE WINDWARD PASSAGE. ELSEWHERE ACROSS THE EASTERN CARIBBEAN...THE TAIL END OF A REMNANT FRONT...ANALYZED NOW AS A SHEARLINE...EXTENDS FROM THE TROPICAL NORTH ATLC ACROSS BARBADOS AND THE GRENADINES TO 13N64W. THE SHEARLINE CONTINUES TO PROVIDE FOCUS FOR LOW-LEVEL MOISTURE GENERATING ISOLATED SHOWERS OVER THE EASTERN CARIBBEAN E OF 66W. ATLANTIC OCEAN... WATER VAPOR IMAGERY SHOWS UPPER LEVEL DIFFLUENCE OCCURRING OVER A LARGE PORTION OF THE W ATLC WEST OF 70W AHEAD OF AN UPPER LEVEL TROUGH POSITIONED OVER THE CENTRAL GULF OF MEXICO. MOISTURE CONTINUES TO ADVECT FROM THE FAR EASTERN PACIFIC REGION AND WESTERN CARIBBEAN NORTHEASTWARD OVER THE FLORIDA PENINSULA AND W ATLC...SUPPORTING SCATTERED TO NUMEROUS SHOWERS W OF 77W. WITH A SURFACE LOW CONTINUING TO DEVELOP IN THE SE GULF OF MEXICO...A WARM FRONT EXTENDS FROM THE LOW CENTERED NEAR 25N85W THROUGH THE FLORIDA STRAITS TO 23N73W. ISOLATED SHOWERS ARE OCCURRING FROM 20N-31N BETWEEN 66W-77W MAINLY NORTH OF THIS FRONTAL BOUNDARY. ELSEWHERE ACROSS THE REMAINDER OF THE WESTERN AND CENTRAL ATLC...A 1021 MB HIGH IS CENTERED NEAR 27N59W AND SUPPORTS MOSTLY FAIR WEATHER N OF 18N BETWEEN 40W-67W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 40N37W THAT EXTENDS A TROUGH AXIS ALONG 35W TO 20N. THIS UPPER LEVEL FEATURE SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N27W AND CONTINUES SW ALONG 27N30W 17N44W BECOMING STATIONARY TO 13N52W AND THEN ANALYZED AS A SHEARLINE TO BARBADOS AND THE GRENADINES NEAR 13N61W. SCATTERED SHOWERS AND POSSIBLE ISOLATED TSTMS ARE WITHIN 150 NM EAST OF THE COLD FRONT N OF 22N...WHILE ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE REMAINDER OF THE BOUNDARY S OF 22N. ELSEWHERE OVER THE EASTERN ATLC...A 1018 MB SURFACE HIGH IS CENTERED OVER THE SW CANARY ISLANDS AND CONTINUES TO EXTENDS A RIDGE AXIS S-SW TO THE CAPE VERDE ISLANDS PROVIDING GENERALLY FAIR WEATHER AND CLEAR SKIES THIS AFTERNOON. 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