000 AXNT20 KNHC 170547 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT APR 17 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0550 UTC... ...ITCZ... FROM THE SOUTHERN COAST OF SIERRA LEONE NEAR 7N12W...WESTWARD ALONG 5N20W 4.5N30W 3N40W EQ50W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM EITHER SIDE OF THE AXIS BETWEEN 20W AND 40W. ...DISCUSSION... GULF OF MEXICO... A 1021 MB SURFACE HIGH OVER THE FAR WESTERN ATLANTIC CONTINUES TO INFLUENCE THE WEATHER OVER THE EASTERN GULF EAST OF 90W. FURTHERMORE...A 1020 MB HIGH IS ALSO CENTERED OVER THE FLORIDA PANHANDLE RESULTING IN EAST TO SOUTHEAST SURFACE FLOW OVER THE GULF NORTH OF 24N. THE HIGH OVER THE PANHANDLE IS FORECAST TO MERGE WITH THE WESTERN ATLANTIC HIGH AND CONTINUE TO MOVE EASTWARD BY LATE SATURDAY...AS A WEAK FRONTAL BOUNDARY SKIRTS THE NORTHERN WATERS AND COASTAL PLAIN. WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL SHORTWAVE OVER THE FAR SOUTHWEST BASIN SUPPORTING A MID LEVEL LOW SPINNING NEAR 20N92W. AT SURFACE NEAR THE SAME AREA...A SURFACE TROUGH IS ANALYZED OVER THE SOUTHWEST BASIN FROM 26N96W 21N95W 19N91W. THIS SYSTEM IS CREATING NUMEROUS SHOWERS AND SCATTERED TSTMS OVER THE AREA FROM 20N-25N BETWEEN 85W-95W. AS THIS UPPER LEVEL FEATURE MOVES EASTWARD THROUGH THE WEEKEND...EXPECT A WEAK LOW OR FRONTAL TROUGH TO DEVELOP OVER THE SE GULF AND WESTERN CUBA BY LATE SUNDAY. CARIBBEAN SEA... AN UPPER LEVEL SHORTWAVE IS NEAR THE WESTERN YUCATAN PENINSULA SUPPORTING A MID LEVEL LOW SPINNING NEAR 20N92W. THIS FEATURE IS SUPPORTING NUMEROUS SHOWERS AND SCATTERED TSTMS OVER THE FAR NORTHWEST NORTH OF 17N WEST OF 82W. COMPUTER MODELS INDICATE THIS AREA OF CONVECTION WILL MOVE EASTWARD AFFECTING THE WESTERN CARIBBEAN WEST OF 78W. ELSEWHERE ACROSS THE CENTRAL AND EASTERN BASIN...A SURFACE TROUGH ENTERS THE FAR SOUTHEAST CORNER OF THE BASIN NEAR SAINT VINCENT EXTENDING TO CUMANA VENEZUELA. SHOWERS ARE WITHIN 90 NM ON EITHER SIDE OF THE TROUGH. NORTHEAST WINDS OVER THE NORTH-NORTHEAST BASIN ARE CONTINUE TO FEED ATLANTIC MOISTURE AND ISOLATED SHOWERS OVER PUERTO RICO AND HISPANIOLA. THE REMAINDER OF THE BASIN IS EXPERIENCING TRADES IN THE 15 TO 20 KT RANGE THIS EVENING UNDER GENERALLY FAIR SKIES. ATLANTIC OCEAN... A 1021 MB SURFACE HIGH OVER THE FAR WESTERN ATLANTIC NEAR 29N73W CONTINUES TO BRING FAIR WEATHER WEST OF 64W. HOWEVER...A FEW ISOLATED SHOWERS EMBEDDED WITHIN EASTERLY FLOW CONTINUE TO IMPACT THE CENTRAL AND NORTHERN BAHAMAS AS WELL AS PORTIONS OF THE SOUTHERN FLORIDA PENINSULA. BROAD AND ELONGATED SUBTROPICAL JET STREAM FLATTENS ACROSS THE ATLANTIC WITH CENTRAL AXIS ALONG 26N. WITHIN THIS UPPER LEVEL FEATURE LIES A STRONG JETSTREAM COVERING THE WESTERN AND CENTRAL ATLANTIC FROM 34W TO 75W ALONG THE SAME LATITUDE AXIS. THIS FEATURE IS ENHANCING AN UPPER LEVEL LOW NEAR 35N45W. THE UPPER LEVEL LOW SUPPORTS A PAIR OF SURFACE LOW PRESSURE SYSTEMS NEAR 35N48W AND 38N44W. SURFACE BOUNDARIES FROM THESE TWO SURFACE LOWS EXTEND INTO THE DISCUSSION AREA. A COLD FRONT ENTERS NEAR 32N38W TO A WEAK 1010 MB LOW CENTERED NEAR 23N44W. THEN...IT CONTINUES TO NEAR 17N54W...WHERE IT BECOMES A SURFACE TROUGH THAT EXTENDS TO THE FAR SOUTHEAST CORNER OF THE CARIBBEAN SEA. SCATTERED SHOWERS ARE WITHIN 200 NM EAST OF THE COLD FRONT AND WITHIN 200 NM EITHER SIDE OF THE SURFACE TROUGH. A SECONDARY SURFACE TROUGH IS NW OF THE LEADING COLD FRONT AND EXTENDS FROM 30N44W TO 25N63W. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE BOUNDARY. FARTHER EAST...A 1018 MB HIGH IS CENTERED NEAR 25N27W AND EXTENDS SURFACE RIDGING AND GENERALLY FAIR WEATHER OVER THE REMAINDER OF THE EASTERN ATLC...INCLUDING THE CAPE VERDE ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA