Tropical Weather Discussion
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000
AXNT20 KNHC 171043
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU JUL 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 11N17W TO 19N18W MOVING W AT 10-15
KT. A FAIRLY IMPRESSIVE AMOUNT OF CONVECTION IS ASSOCIATED WITH
THE WAVE THAT HAS MOVED OFF THE COAST OF WEST AFRICA THIS
MORNING IN AN AREA OF MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE TO
THE SOUTH AND EAST OF THE WAVE AXIS. SCATTERED MODERATE AND
STRONG CONVECTION IS FROM 06N-14N BETWEEN 12W-19W.

TROPICAL WAVE EXTENDS FROM 05N39W TO 13N37W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH WEAK 700 MB TROUGHING BETWEEN 34W-42W...
AND A BROAD AREA OF 850 MB RELATIVE VORTICITY FOCUSED ALONG THE
WAVE AXIS NEAR 09N. ISOLATED MODERATE CONVECTION IS FROM 05N-10N
BETWEEN 36W-43W.

TROPICAL WAVE EXTENDS FROM 07N52W TO 12N50W MOVING W AT 15 KT.
THE WAVE APPEARS AS PART OF A GREATER 700 MB TROUGH BETWEEN 50W-
60W...OF WHICH THE WEAKER 700 MB TROUGH IS S OF 12N ALONG 51W.
SCATTERED MODERATE CONVECTION IS FROM 08N-10N BETWEEN 50W-57W.

TROPICAL WAVE EXTENDS FROM 13N56W TO 20N53W MOVING W AT 10-15
KT. SIMILAR TO THE WAVE SE OF THIS WAVE...THE WAVE LIES WITHIN A
BROAD 700 MB TROUGH ALOFT BETWEEN 50W-60W. IT IS LIKELY ENERGY
FROM BOTH THESE WAVE WILL MERGE OVER THE NEXT SEVERAL DAYS. NO
SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS
TIME.

TROPICAL WAVE EXTENDS FROM 10N87W TO 19N87W MOVING W AT 10-15
KT. THE WAVE CONTINUES TO MOVE ON THE SOUTHWESTERN PERIPHERY OF
A MID-LEVEL RIDGE CENTERED OVER CUBA AND THE YUCATAN CHANNEL
REGION WITH MOST OF THE LOW-LEVEL ENERGY FOCUSED OVER CENTRAL
AMERICA AND AREAS OF THE EAST PACIFIC SOUTH OF NICARAGUA. NO
SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE COAST OF AFRICA NEAR 12N16W
TO 10N26W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
10N26W TO 10N33W TO 06N42W TO 06N55W. ASIDE FROM CONVECTION
ASSOCIATED WITH THE PREVIOUSLY MENTIONED TROPICAL WAVES...
ISOLATED MODERATE CONVECTION IS FROM 06N-12N BETWEEN 20W-28W.

...DISCUSSION...

GULF OF MEXICO...
A LONGWAVE MIDDLE TO UPPER LEVEL TROUGH COVERS MUCH OF THE
EASTERN CONUS WITH A TROUGH AXIS DIPPING SOUTHWARD OVER PORTIONS
OF THE NE GULF AND NORTHERN FLORIDA. THE TROUGHING SUPPORTS A
COLD FRONT EXTENDING FROM THE FLORIDA PANHANDLE NEAR 31N84W W-SW
TO THE MISSISSIPPI RIVER DELTA REGION NEAR 29N89W. FROM THERE
THE FRONT BECOMES STATIONARY ACROSS COASTAL LOUISIANA TO THE
TEXAS AND LOUISIANA BORDER. IN ADDITION...A PRE-FRONTAL SURFACE
TROUGH IS ANALYZED FROM NEAR JACKSONVILLE FLORIDA SW TO 28N88W
IN THE NE GULF WATERS. WHILE THERE IS RELATIVELY DRY CONDITIONS
ALONG THE FRONT...A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING
SOUTH OF THE PRE-FRONTAL TROUGH FROM 26N-29N EAST OF 87W. OTHER
ISOLATED SHOWERS ARE OCCURRING FROM 25N-27N EAST OF 84W.
OTHERWISE...A SURFACE RIDGE AXIS EXTENDS FROM ACROSS CUBA ALONG
22N INTO THE CENTRAL GULF THEN SW TO A 1017 MB HIGH ANCHORED
ALONG THE MEXICO COAST NEAR 20N97W. MOSTLY CLOUDY SKIES PREVAIL
IN ASSOCIATION WITH THE SURFACE RIDGE WHICH IS FORECAST TO SHIFT
EASTWARD THROUGH EARLY FRIDAY. BY FRIDAY...SOUTHERLY RETURN FLOW
WILL HAVE ESTABLISHED ITSELF ACROSS THE WESTERN GULF AS AN AREA
OF LOW PRESSURE DEVELOPS ACROSS THE INTERMOUNTAIN WEST.

CARIBBEAN SEA...
NORTHWESTERLY FLOW ALOFT PREVAILS OVER THE WESTERN CARIBBEAN W
OF 77W THIS MORNING PROVIDING MOSTLY STABLE CONDITIONS IN THE
UPPER LEVELS OF THE ATMOSPHERE. HOWEVER...A PORTION OF UPPER
LEVEL TROUGHING EXTENDS FROM THE SW NORTH ATLC OVER CUBA AND THE
WINDWARD PASSAGE REGION GENERATING AN AREA OF ISOLATED SHOWERS
AND TSTMS N OF 18N BETWEEN 73W-87W. FARTHER EAST...A BROAD UPPER
LEVEL TROUGH IS OVER THE CENTRAL CARIBBEAN BETWEEN 70W-77W THAT
REMAINS FAIRLY STABLE WITH WATER VAPOR IMAGERY INDICATING DRY
AIR ALOFT. WEST-SOUTHWESTERLY FLOW ALOFT RESUMES E OF 70W ON THE
SOUTHERN PERIPHERY OF THE UPPER LEVEL TROUGH WITH MOSTLY CLEAR
SKIES PREVAILING THIS MORNING ACROSS PUERTO RICO...THE US/UK
VIRGIN ISLANDS...AND THE REMAINDER OF THE LESSER ANTILLES.
MODERATE TO FRESH TRADES ARE EXPECTED TO PERSIST THROUGH
SATURDAY.

...HISPANIOLA...
CURRENTLY CONDITIONS REMAIN FAIRLY TRANQUIL WITH ONLY A FEW
MIDDLE TO UPPER LEVEL CONVECTIVE DEBRIS CLOUDS ON SATELLITE
IMAGERY THIS MORNING. UPPER LEVEL TROUGHING LIES TO THE WEST OF
THE ISLAND GENERATING SCATTERED SHOWERS AND TSTMS ACROSS EASTERN
CUBA AND THE WINDWARD PASSAGE REGION...HOWEVER MUCH OF THIS
ACTIVITY SHOULD REMAIN OFFSHORE THROUGH THE MORNING HOURS. GIVEN
LITTLE MOVEMENT OF THE UPPER LEVEL LOW AND ASSOCIATED TROUGH TO
THE NORTH OVER THE SW NORTH ATLC...AN UPPER LEVEL DIFFLUENT
ENVIRONMENT REMAINS ACROSS HISPANIOLA AND SCATTERED SHOWERS AND
TSTMS ARE EXPECTED THURSDAY AFTERNOON AND EVENING WITH PEAK
DAYTIME HEATING AND INSTABILITY.

ATLANTIC OCEAN...
A LONGWAVE MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR
IMAGERY OVER THE EASTERN CONUS THAT SUPPORTS A 1012 MB LOW
CENTERED ACROSS COASTAL GEORGIA NEAR 32N81W. THE FRONTAL
BOUNDARY ASSOCIATED WITH THE LOW REMAINS OFFSHORE OF THE
CAROLINAS AND INLAND ACROSS SOUTHERN GEORGIA AND THE FLORIDA
PANHANDLE...WITH MOSTLY SOUTHWESTERLY WINDS ALOFT AND AT THE
SURFACE ADVECTING MOISTURE AND CLOUDINESS NORTHWARD. SCATTERED
SHOWERS AND TSTMS ARE OCCURRING EAST OF THE FRONT N OF 27N
BETWEEN 74W-80W. FARTHER SOUTH...MOISTURE ON THE WESTERN
PERIPHERY OF AN ELONGATED UPPER LEVEL LOW CENTERED NEAR 26N72W
IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 18N-27N BETWEEN
72W-79W. ON THE EASTERN PERIPHERY OF THE UPPER LEVEL LOW...
SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 23N-30N BETWEEN
66W-72W. FARTHER EAST...THE REMAINDER OF THE CENTRAL AND EASTERN
ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A
1030 MB HIGH CENTERED NEAR 36N52W. THE ONLY WEAKNESS WITHIN THE
RIDGE IS LOCATED ON THE EASTERN PERIPHERY AS A DISSIPATING COLD
FRONT ENTERS THE DISCUSSION AREA NEAR 32N30W AND EXTENDS SW TO
28N42W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE
OF THE FRONT.

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

$$
HUFFMAN


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