Home


000
AXNT20 KNHC 311756
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON AUG 31 2015

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... HURRICANE FRED IS CENTERED NEAR 16.9N 24.2W AT 31/1800 UTC OR ABOUT 20 NM NNE OF RIBEIRA BRAVA IN THE CAPE VERDE ISLANDS AND ABOUT 50 NM ESE OF RIBEIRA GRANDE IN THE CAPE VERDE ISLANDS MOVING NW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 986 MB. MAXIMUM SUSTAINED WIND SPEED IS 75 KT WITH GUSTS TO 90 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 14N- 18N BETWEEN 22W-25W. SCATTERED MODERATE IS ELSEWHERE FROM 17N- 21N BETWEEN 15W-20W...AND FROM 09N-14N BETWEEN 22W-28W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.


...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N60W TO 19N57W MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH RELATIVELY BROAD 700 MB TROUGHING BETWEEN 55W-63W...WITH A MAXIMUM IN 850 MB RELATIVE VORTICITY ALONG THE WAVE AXIS FROM 12N-17N. ISOLATED MODERATE CONVECTION IS FROM 18N-21N BETWEEN 54W-59W.

TROPICAL WAVE EXTENDS FROM 10N75W TO 19N75W MOVING W AT 25 KT. THE WAVE LIES WITHIN THE SOUTHWESTERN PERIPHERY OF THE LOW TO MID-LEVEL SUBTROPICAL RIDGE ANCHORED OVER THE SW NORTH ATLC NEAR 30N69W. ISOLATED MODERATE CONVECTION IS FROM 16N-19N BETWEEN 75W- 78W.


...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 12N28W TO A 1013 MB LOW NEAR 07N38W TO 08N45W. OUTSIDE OF CONVECTION ASSOCIATED WITH HURRICANE FRED...ISOLATED MODERATE CONVECTION IS FROM 05N-08N BETWEEN 40W-43W.


...DISCUSSION...

GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM OVER THE OHIO RIVER VALLEY SW TO OVER THE ARKLATEX REGION TO A BROAD BASE OVER THE RIO GRANDE RIVER VALLEY NEAR 26N100W. THE TROUGHING IS PROVIDING MUCH OF THE GULF WITH SOUTHWESTERLY FLOW ALOFT THIS AFTERNOON. NEAREST TO THE MID-LEVEL 500 MB RELATIVE VORTICITY MAXIMUM OVER SOUTHERN TEXAS AND NE MEXICO...MIDDLE TO UPPER LEVEL DIFFLUENCE IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS THE WESTERN GULF N OF 22N W OF 93W. FARTHER EAST...A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY MOVING OVER THE EAST-CENTRAL GULF WATERS NEAR 27N83W. THE SHORTWAVE SUPPORTS A WEAK 1014 MB LOW CENTERED NEAR 25N85W WITH SURFACE TROUGHING EXTENDING N-NE TO THE FLORIDA BIG BEND REGION NEAR 30N83W...AND SW FROM THE LOW TO NEAR THE NW CORNER OF THE YUCATAN PENINSULA NEAR 21N90W. GIVEN THE FAVORABLE UPPER LEVEL ENVIRONMENT ALOFT AND MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE ALONG AND EAST OF THE SURFACE TROUGHING...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 24N-27N BETWEEN 82W-84W...AND S OF 23N BETWEEN 83W-87W...INCLUDING THE APPROACHES TO THE YUCATAN CHANNEL. OTHERWISE...GENERALLY GENTLE TO MODERATE ANTICYCLONIC FLOW PERSISTS AS SURFACE HIGH PRESSURE REMAINS ANCHORED ACROSS A LARGE PORTION OF THE MID-ATLC AND SE CONUS THROUGH THURSDAY.

CARIBBEAN SEA... UPPER LEVEL RIDGING EXTENDS OVER THE YUCATAN CHANNEL REGION AND MUCH OF THE NW CARIBBEAN THIS AFTERNOON. GIVEN THE FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT...SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 19N BETWEEN 82W-88W...INCLUDING FAR WESTERN CUBA...AND THE FAR EASTERN YUCATAN PENINSULA. OTHERWISE...THE OTHER MAIN UPPER LEVEL FEATURE IMPACTING THE BASIN IS A BROAD UPPER LEVEL LOW CENTERED OVER THE WINDWARD PASSAGE REGION NEAR 18N75W. THE UPPER LEVEL LOW ALONG WITH A WEAK TROPICAL WAVE ALONG 76W IS GENERATING A FEW ISOLATED SHOWERS AND TSTMS IN THE VICINITY OF JAMAICA AND ACROSS AN AREA SOUTH OF HISPANIOLA IN THE VICINITY OF 16N72W. FINALLY...THE APPROACH OF ANOTHER TROPICAL WAVE...CURRENTLY ALONG 59W...IS EXPECTED TO INCREASE PRECIPITATION PROBABILITIES FOR THE LESSER ANTILLES THIS AFTERNOON THROUGH EARLY TUESDAY. ISOLATED SHOWERS AND POSSIBLE ISOLATED TSTMS ALONG WITH POSSIBLE GUSTY WINDS WILL ACCOMPANY THE WAVE AS IT ENTERS THE EASTERN CARIBBEAN BY TUESDAY AFTERNOON.


...HISPANIOLA... CURRENTLY...MOSTLY CLEAR SKIES ARE NOTED ON VISIBLE SATELLITE IMAGERY DUE LARGELY TO RELATIVELY DRY CONDITIONS ALOFT AND OVERALL STABILITY PROVIDED BY THE SUBTROPICAL RIDGE ANCHORED ACROSS THE SW NORTH ATLC REGION. LITTLE CHANGE IN SYNOPTIC CONDITIONS ARE EXPECTED THROUGH TUESDAY AFTERNOON WHEN A TROPICAL WAVE CURRENTLY ALONG 59W WILL APPROACH AND INCREASE PROBABILITY OF PRECIPITATION ACROSS THE ISLAND.

ATLANTIC OCEAN... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS ANCHORED OVER THE SW NORTH ATLC NEAR 29N71W WITH A RIDGE AXIS EXTENDING W TO 29N77W THEN SW OVER THE SOUTHERN FLORIDA PENINSULA. LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH MIDDLE TO UPPER LEVEL DIFFLUENCE ON THE PERIPHERY OF THE RIDGING IS GENERATING SCATTERED SHOWERS AND TSTMS N OF 30N BETWEEN 78W-80W. OTHERWISE...THE MAIN FEATURE INFLUENCING THE SW NORTH ATLC IS A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED NEAR 31N69W. FARTHER EAST...THE CENTRAL ATLC IS GENERALLY UNDER THE INFLUENCE OF A WEAKER SURFACE RIDGE ANCHORED BY A 1020 MB HIGH CENTERED NEAR 23N45W...HOWEVER TO THE NW A WEAK 1018 MB LOW IS CENTERED NEAR 33N56W WITH A SURFACE TROUGH EXTENDING SW TO 29N61W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 30N-33N BETWEEN 52W-56W. FINALLY...AS MENTIONED ABOVE...THE MAIN FOCUS FOR THE EASTERN ATLC IS HURRICANE FRED AS IT TRACKS ACROSS THE CAPE VERDE ISLANDS THIS AFTERNOON.

FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE

$$ HUFFMAN

Home