000
AXNT20 KNHC 240548
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU JUL 24 2014

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...
A STRENGTHENING PRESSURE GRADIENT ACROSS THE SW CARIBBEAN SEA
WATERS IS EXPECTED OVERNIGHT INTO EARLY THURSDAY RESULTING IN
MINIMAL GALE FORCE NE TO E WINDS FROM 11N-13.5N BETWEEN 73-77W.
SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS
MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 03N44W TO 12N43W MOVING W AT 15-20
KT. THE WAVE APPEARS TO BE A SOUTHERN POTENTIAL VORTICITY
MAXIMUM ALONG A BROADER 700 MB TROUGH AXIS EXTENDING FROM 18N54W
TO THE NW OF THE WAVE AXIS SE TO THE LOCATION OF THE WAVE AXIS
NEAR 04N44W. THE WAVE REMAINS SOUTH OF A LOWER TO MIDDLE LEVEL
EASTERLY JET N OF 09N THAT IS LARGELY EMBEDDED WITHIN THE
SAHARAN AIR LAYER ACROSS THE TROPICAL ATLC. AS A RESULT OF THE
SAL...CONVECTION REMAINS SUPPRESSED S OF 10N WITH ISOLATED
MODERATE CONVECTION OCCURRING FROM 06N-10N BETWEEN 40W-47W.

TROPICAL WAVE EXTENDS FROM 11N59W TO 19N56W MOVING W AT 15 KT.
THE WAVE CONTAINS THE REMNANTS OF TROPICAL DEPRESSION TWO AND
HAS INCORPORATED THE NORTHERN POTENTIAL VORTICITY MAXIMUM OF A
700 MB TROUGH EXTENDING FROM 18N54W TO 04N44W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 13N-16N BETWEEN 58W-63W...INCLUDING
A PORTION OF THE LESSER ANTILLES. A LARGE AREA OF SAHARAN DUST
FOLLOWS IN WAKE OF THE WAVE WITH THE LEADING EDGE NOTED E OF 55W.

TROPICAL WAVE EXTENDS FROM 09N93W TO 20N94W MOVING W AT 15 KT.
ISOLATED MODERATE CONVECTION IS FROM 15N-20N BETWEEN 90W-95W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 19N17W TO
11N23W TO 10N26W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 10N26W TO 09N35W TO 02N50W. ASIDE FROM CONVECTION
ASSOCIATED WITH THE TROPICAL WAVES...ISOLATED MODERATE
CONVECTION IS FROM 08N-14N BETWEEN 15W-21W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM OVER TENNESSEE
S-SW TO OVER THE MEXICO COAST NEAR 25N97W AND INTO AN UPPER
LEVEL LOW CENTERED NEAR 18N103W. MID-LEVEL ENERGY IS FOCUSED
OVER THE MISSISSIPPI RIVER DELTA REGION AND COASTAL LOUISIANA
THAT SUPPORTS A WEAK 1014 MB SURFACE LOW CENTERED NEAR 29N92W. A
DISSIPATING STATIONARY FRONT MEANDERS FROM THE LOW CENTER WEST
TO THE TEXAS COAST NEAR GALVESTON BAY. WEAK LOW-LEVEL MOISTURE
CONVERGENCE ALONG WITH THE MIDDLE TO UPPER LEVEL LIFTING
DYNAMICS IS GENERATING ISOLATED SHOWERS N OF 28N BETWEEN 89W-
92W. FARTHER SOUTH...A SURFACE RIDGE EXTENDS FROM THE CENTRAL
FLORIDA PENINSULA W-SW TO 25N90W TO THE EAST-CENTRAL MEXICO
COAST NEAR 22N98W. A FEW ISOLATED SHOWERS AND TSTMS ARE
OCCURRING JUST NORTH OF THE RIDGE AXIS WITHIN 45 NM EITHER SIDE
OF A LINE FROM 28N82W TO 25N94W. LOOKING AHEAD...THE OVERALL
SYNOPTIC PATTERN WILL RETAIN THE SURFACE RIDGE AXIS EXTENDING
FROM THE SW NORTH ATLC ACROSS THE SOUTHERN FLORIDA PENINSULA TO
THE EAST-CENTRAL MEXICO COAST THROUGH THE OVERNIGHT INTO
THURSDAY. THE RIDGE WILL GRADUALLY SHIFT NORTHWARD AND ANCHOR
ALONG 27N THROUGH THE REMAINDER OF THE WEEK INTO THE WEEKEND.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN NEAR 21N84W
THAT CONTINUES TO GENERATE A FEW ISOLATED SHOWERS ACROSS CUBA
AND ACTIVITY IN THE VICINITY OF 19N84W. WHILE MOST OF THE MIDDLE
TO UPPER LEVEL MOISTURE REMAINS OVER THE WESTERN CARIBBEAN...
FARTHER EAST...AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR
18N71W. WATER VAPOR IMAGERY INDICATES THIS UPPER LEVEL FEATURE
REMAINS VERY DRY AND SUBSIDENT PROVIDING MOSTLY FAIR CONDITIONS
ACROSS THE NE CARIBBEAN...HISPANIOLA...PUERTO RICO...AND THE
LEEWARD ISLANDS. ON THE SOUTHERN PERIPHERY OF THIS RIDGING...A
STREAM OF LOW TO MIDDLE LEVEL MOISTURE IS ADVECTING WESTWARD
WITH EMBEDDED WIDELY SCATTERED SHOWERS AND TSTMS OCCURRING FROM
12N-16N BETWEEN 58W-68W. MOST OF THIS MOISTURE IS A WESTWARD
EXTENSION OF THE REMNANTS OF TROPICAL DEPRESSION TWO WHICH IS
NOTED AS A TROPICAL WAVE ALONG 58W THIS EVENING. THE WAVE IS
EXPECTED TO MOVE WEST AND BRING INCREASED PRECIPITATION
PROBABILITIES TO THE LESSER ANTILLES DURING THE NEXT 12 TO 24
HOURS. FINALLY...FRESH TO STRONG TRADES ARE EXPECTED TO PERSIST
ACROSS MUCH OF THE CARIBBEAN S OF 17N THROUGH THE REMAINDER OF
THE WEEK.

...HISPANIOLA...
CURRENTLY OVERALL CONDITIONS REMAIN FAIR THIS EVENING DUE TO
MODERATELY DRY AIR ALOFT AS AN UPPER LEVEL ANTICYCLONE IS
CENTERED OVER THE ISLAND NEAR 18N71W. MOSTLY FAIR CONDITIONS LIE
TO THE EAST OF THE ISLAND AS WELL WITH A WEAK RIDGE PRECEDING A
TROPICAL WAVE EXPECTED TO IMPACT HISPANIOLA WITH PRECIPITATION
BY LATE THURSDAY INTO EARLY FRIDAY.

ATLANTIC OCEAN...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE SW
NORTH ATLC NEAR 30N76W THAT IS SUPPORTIVE OF A SURFACE RIDGE
AXIS EXTENDING FROM 28N57W TO THE SOUTHERN FLORIDA PENINSULA
NEAR 27N80W. MOSTLY FAIR SKIES AND CONDITIONS PREVAIL THIS
EVENING S OF 28N. MOST MOISTURE AND CLOUDINESS REMAINS N OF 28N
ON THE NORTHERN PERIPHERY OF THE UPPER LEVEL RIDGE WITH LOW-
LEVEL MOISTURE CONVERGENCE AND AMPLE UPPER LEVEL DIFFLUENCE
GENERATING ISOLATED SHOWERS N OF 28N BETWEEN 63W-77W. FARTHER
EAST ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...THE
SURFACE RIDGE PREVIOUSLY MENTIONED FOR THE SW NORTH ATLC ALONG
28N IS ANCHORED BY A 1025 MB HIGH CENTERED NEAR 31N31W AND A
1024 MB HIGH CENTERED NEAR 28N57W. FINALLY...A LARGE AREA OF THE
CENTRAL AND EASTERN TROPICAL ATLC IS UNDER THE INFLUENCE OF THE
SAHARAN DUST STRETCHING REMAINING MOSTLY NORTH OF 10N AND EAST
OF 55W.

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

$$
HUFFMAN