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Atlantic Tropical Weather Discussion (Text)

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 
WWW.HURRICANES.GOV/MARINE

$$
HUFFMAN