000
AXNT20 KNHC 232345
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED JUL 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 04N42W TO 10N41W 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 THE NW
NEAR 18N51W SE TO THE LOCATION OF THE WAVE AXIS NEAR 04N42W. THE
WAVE REMAINS SOUTH OF A LOWER TO MIDDLE LEVEL EASTERLY JET N OF
10N 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
WITHIN 150 NM EITHER SIDE OF THE WAVE AXIS.

TROPICAL WAVE EXTENDS FROM 10N58W TO 18N56W MOVING W AT 15-20
KT. THE WAVE CONTAINS REMNANTS OF TROPICAL DEPRESSION TWO AND
HAS INCORPORATED THE NORTHERN POTENTIAL VORTICITY MAXIMUM OF A
700 MB TROUGH EXTENDING FROM 18N51W TO 04N42W. ISOLATED MODERATE
CONVECTION IS OCCURRING FROM 13N-15N BETWEEN 55W-62W...INCLUDING
THE WINDWARD ISLANDS. A LARGE AREA OF SAHARAN DUST FOLLOWS IN
WAKE OF THE WAVE WITH THE LEADING EDGE NOTED E OF 53W THIS
EVENING.

TROPICAL WAVE EXTENDS FROM 10N91W TO 20N93W MOVING W AT 15 KT.
ISOLATED MODERATE CONVECTION IS OCCURRING ACROSS INLAND PORTIONS
OF SOUTHERN MEXICO BETWEEN 91W-96W THIS EVENING.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 20N16W TO
13N20W TO 10N26W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 10N26W TO 09N35W TO 03N46W TO 03N51W. ASIDE FROM
CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...ISOLATED
MODERATE CONVECTION IS FROM 11N-15N BETWEEN 15W-18W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM OVER TENNESSEE
S-SW TO OVER THE MEXICO COAST NEAR 24N98W AND INTO AN UPPER
LEVEL LOW CENTERED NEAR 18N102W. MID-LEVEL ENERGY IS FOCUSED
OVER THE MISSISSIPPI RIVER DELTA REGION AND COASTAL LOUISIANA
THAT SUPPORTS A WEAK 1017 MB SURFACE LOW CENTERED NEAR 29N91W. A
STATIONARY FRONT MEANDERS FROM THE FLORIDA PANHANDLE INTO THE
LOW CENTER AND WEST TO THE TEXAS/LOUISIANA BORDER NEAR 30N94W.
AMPLE LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH THE MIDDLE TO
UPPER LEVEL LIFTING DYNAMICS IS GENERATING ISOLATED SHOWERS AND
TSTMS ACROSS THE NORTH-CENTRAL AND NW GULF THIS EVENING N OF 25N
BETWEEN 88W-95W. FARTHER SE...MIDDLE TO UPPER LEVEL DIFFLUENCE
IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS IN A
120 NM WIDE LINE FROM THE NORTHERN FLORIDA PENINSULA NEAR 30N82W
S-SW TO WESTERN CUBA NEAR 22N84W. ISOLATED SHOWERS ARE ALSO
OCCURRING FROM 23N-27N BETWEEN 84W-88W. LOOKING AHEAD...THE
OVERALL SYNOPTIC PATTERN WILL REMAIN A 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...THAT GRADUALLY SHIFTS NORTHWARD AND ANCHORS
ALONG 27N THROUGH THE REMAINDER OF THE WEEK INTO THE WEEKEND.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN NEAR 20N83W
THAT CONTINUES TO GENERATE ISOLATED SHOWERS AND TSTMS ACROSS
CUBA AND THE ADJACENT COASTAL WATERS AS WELL AS ACTIVITY IN THE
VICINITY OF 19N85W. WHILE MOST OF THE MIDDLE TO UPPER LEVEL
MOISTURE REMAINS OVER THE WESTERN CARIBBEAN...FARTHER EAST...AN
UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 17N68W. 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
ISOLATED SHOWERS AND TSTMS OCCURRING FROM 12N-15N BETWEEN 57W-
72W. MOST OF THIS MOISTURE IS A WESTWARD EXTENSION OF THE
REMNANTS OF TROPICAL DEPRESSION TWO WHICH IS NOTED AS A TROPICAL
WAVE ALONG 57W THIS EVENING. THE WAVE IS EXPECTED TO MOVE WEST
AND BRING INCREASED PRECIPITATION PROBABILITIES TO THE LESSER
ANTILLES DURING THE NEXT 24 TO 36 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 A FEW ISOLATED SHOWERS ARE OCCURRING ACROSS THE
ISLAND...HOWEVER OVERALL CONDITIONS REMAIN FAIR THIS EVENING DUE
TO MODERATELY DRY AIR ALOFT ON THE WESTERN PERIPHERY OF AN UPPER
LEVEL ANTICYCLONE CENTERED NEAR 17N68W. MOSTLY FAIR CONDITIONS
LIE TO THE EAST OF THE ISLAND AS A WEAK RIDGE PRECEDES 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 30N75W THAT IS SUPPORTIVE OF A SURFACE RIDGE
AXIS EXTENDING FROM 30N68W TO THE SOUTHERN FLORIDA PENINSULA
NEAR 27N80W. MOSTLY FAIR SKIES AND CONDITIONS PREVAIL THIS
EVENING S OF 30N WITH ONLY A FEW ISOLATED SHOWERS AND TSTMS
OCCURRING ACROSS THE WESTERN BAHAMAS AND ADJACENT COASTAL
WATERS. MOST MOISTURE AND CLOUDINESS REMAINS N OF 30N ON THE
NORTHERN PERIPHERY OF THE UPPER LEVEL RIDGE WITH LOW-LEVEL
MOISTURE CONVERGENCE AND AMPLE UPPER LEVEL DIFFLUENCE GENERATING
ISOLATED SHOWERS AND TSTMS N OF 30N W OF 67W. FARTHER EAST
ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...THE
SURFACE RIDGE PREVIOUSLY MENTIONED FOR THE SW NORTH ATLC ALONG
30N IS ANCHORED BY A PAIR OF 1025 MB HIGH CENTERED NEAR 31N33W
AND 30N39W. THE HIGH IS FORECAST TO SLIDE WESTWARD INTO THE
CENTRAL ATLC DURING THE NEXT 24 HOURS AND MAINTAIN MOSTLY CLEAR
SKIES AND FAIR CONDITIONS. FINAL ITEM OF NOTE IS 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 53W.

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

$$
HUFFMAN