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000
AXNT20 KNHC 070545
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU MAY 07 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC.


...SPECIAL FEATURES... AS OF 07/0300 UTC...A 1010 MB LOW IS CENTERED NEAR 31N78W WITH A SURFACE TROUGH AXIS EXTENDING NE FROM THE LOW CENTER TO 34N76W AND ANOTHER SURFACE TROUGH ANALYZED FROM THE LOW CENTER TO 30N77W TO 28N76W TO 25N78W. THE LOW PRESSURE IS LARGELY SUPPORTED BY A NEGATIVELY TILTED MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM OVER EASTERN GEORGIA NEAR 33N83W SE TO A BROAD BASE NEAR 25N76W. MOST OF THE MID-LEVEL VORTICITY IS TIGHTLY CLUSTERED IN GLOBAL MODEL GUIDANCE IN THE VICINITY OF 30N77W NEAR THE SURFACE LOW. CONVECTION OVERALL REMAINS LIMITED AS DRY AIR CONTINUES TO WRAP INTO THE SYSTEM ORIGINATING ON THE WESTERN PERIPHERY AND IMPACTING THE SOUTH AND SOUTHEAST QUADRANTS. SCATTERED MODERATE CONVECTION IS OCCURRING FROM 31N- 34N BETWEEN 76W-79W...WELL TO THE E-NE FROM 29N-35N BETWEEN 68W- 72W...AND FROM 22N-25N BETWEEN 74W-78W. REGARDLESS OF SUB- TROPICAL OR TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT 48 HOURS AS THE SYSTEM TRACKS NORTHWARD...HEAVY PRECIPITATION IS HIGHLY PROBABLE ACROSS PORTIONS OF THE COASTAL SE CONUS THROUGH SUNDAY.


...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 07N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N19W TO 03N30W TO THE EQUATOR NEAR 46W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 01N-10N BETWEEN 14W-22W...AND WITHIN 120 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 22W-36W.


...DISCUSSION...

GULF OF MEXICO... A MIDDLE TO UPPER RIDGE IS NOTED ON WATER VAPOR IMAGERY OVER THE WESTERN GULF WITH AXIS EXTENDING FROM OVER SOUTHERN MEXICO NEAR 19N96W TO OVER THE LOWER MISSISSIPPI RIVER VALLEY NEAR 32N91W. WEST-NORTHWESTERLY FLOW ALOFT INFLUENCES MOST OF THE BASIN WHICH REMAINS RELATIVELY DRY AND STABLE PROMOTING OVERALL FAIR WEATHER AND GENERALLY CLEAR SKIES THIS EVENING. IN ADDITION...SURFACE RIDGING HOLDS ACROSS BASIN WITH AXIS EXTENDING FROM THE NE GULF SOUTHWESTWARD TO THE MEXICO COAST NEAR TUXPAN PROVIDING GENTLE TO MODERATE E-SE WINDS. LOOKING AHEAD...THIS OVERALL SYNOPTIC PATTERN IS EXPECTED TO PERSIST THROUGH LATE FRIDAY INTO SATURDAY WITH SE WINDS ACROSS THE WESTERN GULF FORECAST TO INCREASE BY SUNDAY.

CARIBBEAN SEA... BROAD UPPER LEVEL TROUGHING IS NOTED OVER THE WESTERN AND CENTRAL CARIBBEAN WITH AXIS GENERALLY ALONG 81W/82W. WATER VAPOR IMAGERY INDICATES DRY AND STABLE AIR EMBEDDED WITHIN THE TROUGHING AND TO THE EAST AS SOUTHWESTERLY FLOW ALOFT PREVAILS. THE RESULT AT THE SURFACE IS THAT OF MOSTLY CLEAR SKIES AND FAIR CONDITIONS FOR THE OVERNIGHT PERIOD INTO THURSDAY. THE MAIN IMPACT WILL CONTINUE TO BE FRESH TO STRONG TRADES E OF 81W DUE TO A STRENGTHENED PRESSURE GRADIENT BETWEEN LOWER PRESSURE ACROSS NORTHERN SOUTH AMERICA AND SURFACE RIDGING EXTENDING FROM THE CENTRAL ATLC. THESE TRADES WILL PERSIST THROUGH THE END OF THE WEEK AND GRADUALLY EXPAND IN AREAL COVERAGE BY EARLY NEXT WEEK.


...HISPANIOLA... CURRENTLY MOSTLY CLEAR SKIES ARE NOTED ON SATELLITE IMAGERY ACROSS THE ISLAND THIS EVENING. WATER VAPOR IMAGERY INDICATES RELATIVELY DRY AND STABLE AIR REMAINS ALOFT OVER THE REGION PROMOTING THE OVERALL FAIR WEATHER. THESE SYNOPTIC CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE REMAINDER OF THE WEEK.

ATLANTIC OCEAN... ASIDE FROM THE SPECIAL FEATURES LOW PRESSURE SYSTEM IMPACTING THE SW NORTH ATLC REGION...THE REMAINDER OF THE SW NORTH ATLC E OF 65W AND CENTRAL ATLC ARE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 31N53W. FARTHER EAST...AN MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED IN THE VICINITY OF 43N19W WITH THE ASSOCIATED COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N20W TO 24N27W WHERE IT BECOMES A DISSIPATING COLD FRONT INTO THE AFOREMENTIONED RIDGING TO 20N40W TO 21N51W. VERY LITTLE SENSIBLE WEATHER IS OCCURRING WITH THE WEAKENING COLD FRONT.

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

$$ HUFFMAN

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