Tropical Weather Discussion
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000
AXNT20 KNHC 040547
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON MAY 04 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.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO
03N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
03N19W TO 04N27W TO 03N34W TO 04N40W TO THE EQUATOR NEAR 49W.
SCATTERED MODERATE TO STRONG CONVECTION IS FROM 04N-11N BETWEEN
THE PRIME MERIDIAN AND 07W. SCATTERED MODERATE CONVECTION IS
FROM 01N-03N BETWEEN 10W-14W...FROM 05N-08N BETWEEN 12W-17W...
AND FROM THE EQUATOR TO 05N BETWEEN 39W-48W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE EASTERN GULF WITH
AXIS EXTENDING FROM 30N87W TO OVER WESTERN CUBA AND INTO THE NW
CARIBBEAN SEA. THE TROUGHING SUPPORTS A WEAK SURFACE TROUGH
EXTENDING FROM MOBILE BAY NEAR 30N88W TO 26N87W TO 22N85W. WHILE
THE SURFACE TROUGH CONTINUES TO DRIFT WESTWARD AND MOVE WITHIN
THE BACK SIDE AND NW FLOW OF THE UPPER LEVEL TROUGH...CONVECTION
IS LIMITED...HOWEVER A FEW ISOLATED SHOWERS ARE POSSIBLE WITHIN
90 NM EITHER SIDE OF THE TROUGH AXIS. OTHERWISE...THE REMAINDER
OF THE GULF IS UNDER THE INFLUENCE OF SURFACE RIDGING WITH AXIS
EXTENDING FROM NORTHERN FLORIDA W-SW TO THE EAST-CENTRAL COAST
OF MEXICO NEAR TUXPAN. GENERALLY MODERATE TO FRESH E-SE WINDS
PREVAIL WITH THE STRONGEST WINDS NOTED ACROSS THE FLORIDA
STRAITS AND SE GULF AND E OF 85W TO THE FLORIDA PENINSULA. THIS
OVERALL SYNOPTIC PATTERN IS EXPECTED TO PERSIST THROUGH LATE
WEDNESDAY.

CARIBBEAN SEA...
AN UPPER LEVEL TROUGH EXTENDS OVER THE EASTERN GULF OF MEXICO
AND INTO THE NW CARIBBEAN WITH AXIS FROM OVER WESTERN CUBA NEAR
22N85W TO A BASE OVER THE SW CARIBBEAN NEAR 13N80W. THE
TROUGHING SUPPORTS A PAIR OF BOUNDARIES ACROSS PORTIONS OF THE
NW CARIBBEAN. THE EASTERN BOUNDARY IS A STATIONARY FRONT
EXTENDING FROM FAR EASTERN CUBA NEAR 20N74W SW TO 16N83W. THE
SECOND BOUNDARY IS A SURFACE TROUGH ANALYZED FROM 22N82W TO
16N85W. BOTH BOUNDARIES ARE PROMOTING LOW-LEVEL MOISTURE
CONVERGENCE...AND WITH THE PRESENCE OF AMPLE UPPER LEVEL
DIFFLUENCE TO THE EAST OF THE UPPER LEVEL TROUGH AXIS...
SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WEST OF A
LINE FROM THE WINDWARD PASSAGE NEAR 20N73W SW TO THE TAIL END OF
THE STATIONARY FRONT NEAR 16N84W. OTHERWISE...THE REMAINDER OF
THE CARIBBEAN REMAINS UNDER MOSTLY CLEAR SKIES AND FAIR
CONDITIONS AS WATER VAPOR IMAGERY INDICATES DRY AND STABLE AIR
ALOFT E OF 73W. ONE EXCEPTION IS A FEW ISOLATED SHOWERS AND
TSTMS OCCURRING S OF 10N ACROSS THE SW CARIBBEAN...INCLUDING
PORTIONS OF PANAMA WHICH REMAINS IN CLOSE PROXIMITY TO THE
MONSOON TROUGH AXIS ALONG 05N. LOOKING AHEAD...THE FRONT AND
SURFACE TROUGH IS EXPECTED TO BECOME DIFFUSE BY TUESDAY WITH
FRESH TO STRONG TRADES EXPANDING MONDAY INTO TUESDAY ACROSS THE
CENTRAL AND EASTERN CARIBBEAN AS THE PRESSURE GRADIENT
STRENGTHENS.

...HISPANIOLA...
A STATIONARY FRONT IS ANALYZED TO THE NORTHWEST OF THE ISLAND
FROM 23N70W TO 20N75W TO 19N80W AND IS PROVIDING FOCUS FOR LOW-
LEVEL MOISTURE CONVERGENCE AND ISOLATED SHOWERS N OF 19N W OF
71W FOR THE OVERNIGHT PERIOD. THE FRONT IS EXPECTED TO LINGER TO
THE NW OF THE ISLAND THROUGH MONDAY BECOMING DIFFUSE BY LATE
MONDAY INTO EARLY TUESDAY. WITH CLOSE PROXIMITY OF A SURFACE
BOUNDARY IN THE REGION AND UPPER LEVEL DIFFLUENCE MAXIMIZED OVER
THE WINDWARD PASSAGE AREA DUE TO AN UPPER LEVEL TROUGH AXIS
EXTENDING OVER THE NW CARIBBEAN SEA...SCATTERED SHOWERS AND
TSTMS WILL REMAIN POSSIBLE DURING PEAK DAYTIME HEATING ON
MONDAY.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR
IMAGERY IN THE VICINITY OF 40N51W WITH AXIS EXTENDING SW TO NEAR
31N69W. THIS TROUGHING SUPPORTS A 1006 MB LOW CENTERED NEAR
39N53W WITH THE ASSOCIATED COLD FRONT ENTERING THE DISCUSSION
AREA NEAR 32N52W WHICH QUICKLY BECOMES STATIONARY NEAR 31N54W
AND EXTENDS SW TO THE FAR EASTERN TIP OF CUBA NEAR 20N74W.
POSSIBLE ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE
OF THE FRONT...HOWEVER W OF 65W...MOISTURE INCREASES ON THE
EASTERN PERIPHERY OF ANOTHER UPPER LEVEL TROUGH OVER THE EASTERN
GULF OF MEXICO AND NW CARIBBEAN SEA. SCATTERED SHOWERS AND
ISOLATED TSTMS ASSOCIATED WITH TROUGH REMAIN FROM 20N-27N
BETWEEN 65W-82W. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC
IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1024 MB
HIGH CENTERED OFFSHORE OF THE CAROLINAS NEAR 33N76W. FARTHER
EAST...THE CENTRAL ATLC IS ALSO UNDER THE INFLUENCE OF A SURFACE
RIDGE ANCHORED BY A 1022 MB HIGH CENTERED NEAR 26N47W.
FINALLY...ANOTHER MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS
NOTED ON WATER VAPOR IMAGERY NEAR 40N18W THAT SUPPORTS A COLD
FRONT ANALYZED FROM 32N18W SW TO 29N23W TO 26N36W. ISOLATED
SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE FRONT AS IT
CONTINUES DRIFTING SOUTHEASTWARD AND GRADUALLY WEAKENING.

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

$$
HUFFMAN



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