Tropical Weather Discussion
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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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