000 AXNT20 KNHC 131741 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE SEP 13 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM MARIA IS CENTERED NEAR 22.2N 67.9W AT 13/1800 UTC OR ABOUT 280 NM E OF THE SOUTHEASTERN BAHAMAS AND ABOUT 630 NM S-SW OF BERMUDA MOVING N-NW AT 3 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE CONVECTION IS FROM 16N-24N BETWEEN 63W-69W. DOPPLER RADAR IMAGERY FROM SAN JUAN PUERTO RICO INDICATES THAT COPIOUS AMOUNTS OF HEAVY RAINFALL CONTINUES ACROSS MUCH OF THE ISLAND THIS AFTERNOON WITH SEVERAL FLOOD RELATED WATCHES AND WARNINGS CURRENTLY IN EFFECT. RAIN ACCUMULATIONS OF 4-8 INCHES WITH ISOLATED MAXIMUM AMOUNTS OF 15-20 INCHES ARE EXPECTED OVER THE HIGHER ELEVATIONS THROUGH EARLY WEDNESDAY. AS MARIA BEGINS TO MOVE FARTHER NORTH OVER THE NEXT 24 HOURS...AN ADDITIONAL 1-2 INCHES OF RAINFALL IS EXPECTED ACROSS THE US/UK VIRGIN ISLANDS. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 12N58W TO 23N57W MOVING W AT 15-20 KT. THE WAVE IS EMBEDDED WITHIN AN AREA OF MAXIMUM DEEP LAYER MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. VISIBLE SATELLITE IMAGERY ALSO SHOWS CYCLONIC TURNING OF THE LOW-LEVEL CLOUD FIELD IN THE VICINITY OF THE WAVE AXIS. FURTHERMORE...AN EARLIER MORNING ASCAT PASS 13/1306 UTC DEPICTED THOSE SURFACE CYCLONIC WINDS WITH WINDS IN THE 20-25 KT RANGE NEAR 20N57W. SCATTERED MODERATE CONVECTION IS FROM 16N-22N BETWEEN 55W-59W. TROPICAL WAVE IS ANALYZED FROM 13N86W TO 22N87W MOVING W-NW AT 5 KT. LOW TO MID-LEVEL CYCLONIC TURNING OF THE CLOUD FIELD IS NOTED ALONG THE WAVE AXIS AS IT MOVES BENEATH THE SOUTHEASTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER NE MEXICO NEAR 24N100W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 15N-18N BETWEEN 87W-91W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W ALONG 10N25W TO 07N45W. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF A LINE FROM 04N11W TO 15N27W...AND FROM 07N-10N BETWEEN 48W-53W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH IS SWINGING ACROSS THE FLORIDA PENINSULA AND FAR SOUTHEASTERN GULF WITH AXIS FROM 32N78W TO 22N85W. WHILE MOST OF THE MIDDLE TO UPPER LEVEL ENERGY IS FOUND OVER THE SW NORTH ATLC WATERS...WATER VAPOR IMAGERY INDICATES THAT VERY DRY AIR AND OVERALL SUBSIDENCE ASSOCIATED WITH NW FLOW ALOFT IS PROVIDING FOR CLEAR SKIES AND FAIR CONDITIONS ACROSS MUCH OF THE GULF THIS AFTERNOON. AT THE SURFACE...A 1019 MB HIGH IS CENTERED NEAR 28N90W WITH RIDGE AXIS EXTENDING NE ACROSS THE SE CONUS AND SW TO A 1020 MB HIGH CENTERED OVER EAST-CENTRAL MEXICO NEAR 21N98W. MOSTLY LIGHT ANTICYCLONIC WINDS PREVAIL AND ARE EXPECTED TO PERSIST THROUGH EARLY THURSDAY ACROSS MUCH OF THE GULF AS THE RIDGE REMAINS STATIONARY. CARIBBEAN SEA... TROPICAL STORM MARIA CONTINUES TO IMPACT PUERTO RICO AND THE ADJACENT COASTAL WATERS WITH NUMEROUS SHOWERS AND SCATTERED TSTMS N OF 16N BETWEEN 63W-69W. THIS AREA OF PRECIPITATION ASSOCIATED WITH MARIA IS ENHANCED DUE TO AN UPPER LEVEL RIDGE AXIS EXTENDING ALONG 19N FROM THE YUCATAN PENINSULA TO 62W...AND IS FORECAST TO TRACK NORTHWARD AS MARIA MOVES MORE NORTH OF THE BASIN OVER THE NEXT 24-36 HOURS. HOWEVER...A TROPICAL WAVE ALONG 58W IS FORECAST TO MOVE W-NW BRINGING ANOTHER ROUND OF SCATTERED SHOWERS AND TSTMS TO THE LESSER ANTILLES AND NE CARIBBEAN THROUGH THURSDAY. SURFACE TROUGHING EVIDENT WITHIN THE PRESSURE PATTERN ACROSS THE CENTRAL CARIBBEAN IS PROVIDING FOCUS FOR ISOLATED SHOWERS AND TSTMS WITHIN 120 NM EITHER SIDE OF A LINE FROM 17N68W TO EASTERN PANAMA NEAR 09N79W. FARTHER WEST...A TROPICAL WAVE OVER THE NW CARIBBEAN IS ANALYZED ALONG 87W AND WILL CONTINUE TO PRODUCE SCATTERED SHOWERS AND ISOLATED TSTMS FROM 15N-18N BETWEEN 87W-91W...INCLUDING THE GULF OF HONDURAS. AS THIS TROPICAL WAVE SLOWLY MOVES WESTWARD...RAINFALL IS EXPECTED TO CONTINUE ACROSS INTERIOR PORTIONS OF BELIZE... GUATEMALA...AND THE YUCATAN PENINSULA WITH THE POSSIBILITY OF LOCALIZED FLASH FLOODING AND MUDSLIDES. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS SWEEPING ACROSS THE FLORIDA PENINSULA WITH AXIS EXTENDING FROM 32N78W TO 22N85W. WHILE A SURFACE TROUGH EXTENDS FROM 31N78W TO 25N80W...WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING EAST OF THE SURFACE TROUGH BOUNDARY WITHIN 120 NM EITHER SIDE OF A LINE FROM 32N74W TO 27N79W AND ARE MORE CLOSELY ASSOCIATED WITH THE UPPER LEVEL DIFFLUENCE AND TROUGHING ALOFT. FARTHER TO THE SE...TROPICAL STORM MARIA IS FORECAST TO CONTINUE TRACKING IN A GENERAL NORTHWARD DIRECTION OVER THE NEXT FEW DAYS. A SHORT WAVE UPPER LEVEL TROUGH IN THE VICINITY OF 28N65W IS ADVECTING MIDDLE TO UPPER LEVEL MOISTURE OVER A LARGE PORTION OF THE W ATLC WITH WIDELY SCATTERED SHOWERS OCCURRING FROM 24N-32N BETWEEN 61W-67W. OTHERWISE THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH CENTERED NEAR 31N47W. INFRINGING ON THE DISCUSSION AREA E OF 35W IS A DISSIPATING STATIONARY FRONT ALONG 31N BETWEEN 28W-35W. ISOLATED SHOWERS ARE WITHIN 30 NM EITHER SIDE OF THE FRONT. OTHERWISE NE TO E TRADES AND GENERALLY FAIR WEATHER CONDITIONS PREVAIL N OF 17N E OF 55W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN