000
AXNT20 KNHC 070953
TWDAT 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0915 UTC.

...SPECIAL FEATURES...                                         
AS OF 07/0900 UTC...A 1007 MB LOW IS CENTERED NEAR 31N78W WITH A 
SURFACE TROUGH AXIS EXTENDING FROM THE LOW CENTER TO 32N77W TO 
30N75W TO 28N75W TO 24N78W. THE LOW PRESSURE IS LARGELY 
SUPPORTED BY A NEGATIVELY TILTED MIDDLE TO UPPER LEVEL TROUGH 
WITH AXIS EXTENDING FROM OVER EASTERN GEORGIA NEAR 33N82W SE TO 
A BROAD BASE NEAR 26N77W. MOST OF THE MID-LEVEL VORTICITY IS 
TIGHTLY CLUSTERED IN GLOBAL MODEL GUIDANCE IN THE VICINITY OF 
31N78W COLLOCATED WITH 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-35N BETWEEN 76W-81W...WELL TO THE E-NE FROM 31N-36N 
BETWEEN 64W-74W...AND FROM 23N-29N BETWEEN 73W-76W. 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 
06N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
06N21W TO THE EQUATOR NEAR 35W. SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE AXIS 
BETWEEN 15W-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 MORNING. IN ADDITION...SURFACE 
RIDGING HOLDS ACROSS BASIN ANCHORED BY A 1019 MB HIGH CENTERED 
NEAR 30N86W WITH AXIS EXTENDING SOUTHWESTWARD TO THE MEXICO 
COAST NEAR TUXPAN. THE RIDGE IS 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 80W/81W. 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 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 WEEKEND AND GRADUALLY EXPAND IN 
AREAL COVERAGE BY EARLY NEXT WEEK.
 
...HISPANIOLA...                                        
CURRENTLY MOSTLY CLEAR SKIES ARE NOTED ON SATELLITE IMAGERY 
ACROSS THE ISLAND THIS MORNING. 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 1026 MB HIGH CENTERED NEAR 30N51W. FARTHER 
EAST...AN MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED IN THE 
VICINITY OF 39N18W WITH AN ASSOCIATED SURFACE TROUGH ANALYZED 
INTO THE DISCUSSION AREA NEAR 32N20W SW TO 25N32W. ISOLATED 
SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE BOUNDARY.
 
FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
HUFFMAN