000 AXNT20 KNHC 171053 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC... ...ITCZ... FROM THE CENTRAL COAST OF LIBERIA NEAR 6N10W...WESTWARD ALONG 4N20W 5N30W 3N40W EQ50W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM EITHER SIDE OF THE AXIS WEST OF 20W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL SHORTWAVE OVER THE NORTHERN TIP OF THE YUCATAN PENINSULA SUPPORTING A MID LEVEL LOW SPINNING NEAR 21N89W. THIS FEATURE IS PRODUCING DEEP CONVECTION AT SURFACE FROM 20N TO 24N BETWEEN 89W AND 92W. ALSO...THIS SYSTEM SUPPORTS A SURFACE TROUGH OVER THE YUCATAN CHANNEL ALONG 24N88W 22N86W INTO THE NORTHWEST CARIBBEAN BASIN. THIS TROUGH IS BRINGING MULTIPLE SCATTER MODERATE TO HEAVY SHOWERS TO WESTERN CUBA. AS THIS UPPER LEVEL FEATURE MOVES EASTWARD THROUGH THE WEEKEND...EXPECT A SURFACE LOW TO DEVELOP ALONG THE FRONTAL TROUGH OVER THE SOUTH AND SOUTHEAST GULF BRINGING ADDITIONAL CONVECTION TO THIS REGION OVER THE NEXT 24 HOURS. A 1020 MB HIGH OVER THE WESTERN ATLANTIC CONTINUES PUSH LOW LEVEL MOISTURE AND SHOWERS TO THE SOUTHERN FLORIDA PENINSULA. THE WESTERN ATLANTIC HIGH WILL CONTINUE TO MOVE EASTWARD OVER THE NEXT 24 HOURS...AS A WEAK FRONTAL BOUNDARY SKIRTS THE NORTHERN WATERS AND COASTAL PLAIN. CARIBBEAN SEA... AN UPPER LEVEL SHORTWAVE IS OVER THE NORTHERN TIP OF THE YUCATAN PENINSULA SUPPORTING A MID LEVEL LOW SPINNING NEAR 21N89W. A TROUGH ENTERS THE NORTHWEST BASIN THROUGH THE YUCATAN CHANNEL ALONG 24N88W 22N86W 20N86W 18N86W 16N87W. THIS FEATURE IS SUPPORTING NUMEROUS SHOWERS AND SCATTERED TSTMS OVER THE FAR NORTHWEST BASIN NORTH OF 15N WEST OF 80W. COMPUTER MODELS INDICATE THIS AREA OF CONVECTION WILL MOVE EASTWARD AFFECTING THE CUBA AND WESTERN CARIBBEAN SEA NORTH OF 14N WEST OF 76W. ELSEWHERE ACROSS THE CENTRAL AND EASTERN BASIN...NORTHEAST WINDS OVER THE NORTH-NORTHEAST BASIN 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 UNDER GENERALLY FAIR SKIES. ATLANTIC OCEAN... A 1021 MB SURFACE HIGH OVER THE FAR WESTERN ATLANTIC NEAR 27N66W CONTINUES TO BRING FAIR WEATHER WEST OF 62W. 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 JETSTREAM FLATTENS ACROSS THE ATLANTIC WITH CENTRAL AXIS ALONG 25N. WITHIN THIS UPPER LEVEL FEATURE LIES A STRONG JETSTREAK COVERING THE WESTERN AND CENTRAL ATLANTIC FROM 34W TO 68W ALONG THE SAME LATITUDE AXIS. THIS FEATURE IS ENHANCING AN OCCLUDED UPPER LEVEL LOW NEAR 35N43W. THE UPPER LEVEL LOW SUPPORTS A PAIR OF SURFACE LOW PRESSURE SYSTEMS NEAR 35N46W AND 39N45W. SURFACE BOUNDARIES FROM THESE TWO SURFACE LOWS EXTEND INTO THE DISCUSSION AREA. A COLD FRONT ENTERS NEAR 32N36W TO A WEAK 1011 MB LOW CENTERED NEAR 22N43W. THEN...IT CONTINUES TO NEAR 17N48W...WHERE IT BECOMES A SURFACE TROUGH THAT EXTENDS TO THE EASTERN COAST OF VENEZUELA NEAR 10N62W. 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 32N41W TO 25N51W. A SHEAR LINE CONTINUES WEST TO NEAR 25N62W. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE BOUNDARY. FARTHER EAST...A 1018 MB HIGH IS CENTERED NEAR 25N25W 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