[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 222340
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON JUN 22 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...
A STRONG PRESSURE GRADIENT EXISTS ACROSS THE SW CARIBBEAN SEA
DUE TO A MODEST 1027 MB HIGH CENTERED IN THE CENTRAL ATLC NEAR
28N48W AND LOWER PRESSURE ANALYZED ACROSS NORTHERN COLOMBIA.
CURRENTLY STRONG TO NEAR GALE FORCE TRADES ARE NOTED S OF 15N
BETWEEN 70W-79W PER EARLIER ASCAT PASSES AROUND 22/1352 UTC...
22/1440 UTC...AND 22/1534 UTC. THE HIGH IS FORECAST TO SHIFT
WEST SLIGHTLY THROUGH TUESDAY AND INCREASE THE WIND FIELD OFF
THE COAST OF COLOMBIA INTO A RANGE OF NEAR GALE TO GALE FORCE BY
23/0000 UTC. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO
HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 08N32W TO 19N30W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH AN AMPLIFIED GLOBAL MODEL INDICATED
700 MB TROUGH BETWEEN 25W-36W. 850 MB RELATIVELY VORTICITY IS
ALSO MAXIMIZED ALONG THE WAVE AXIS NEAR 13N. DUE TO THE PRESENCE
OF THE SAHARAN AIR LAYER...NO SIGNIFICANT CONVECTION IS
ASSOCIATED WITH THE WAVE AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 07N49W TO 15N50W MOVING W AT 15 KT.
POSITION IS BASED LARGELY ON CONTINUITY AND VERY SUBTLE 700 MB
TROUGHING BETWEEN 47W-54W. A 700 MB LOW-LEVEL JET MAXIMUM LIES
TO THE EAST OF THE WAVE FROM 08N-14N STRETCHING EASTWARD TO THE
TROPICAL WAVE ALONG 31W MENTIONED ABOVE. NO SIGNIFICANT
CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME DUE TO THE
PRESENCE OF THE SAHARAN AIR LAYER.

TROPICAL WAVE EXTENDS FROM 09N68W TO 17N65W MOVING W AT 15 KT.
VERY SUBTLE 700 MB TROUGHING IS NOTED OVER THE EASTERN CARIBBEAN
SEA AS THE WAVE INTERACTS WITH AN UPPER LEVEL CENTERED NORTH OF
THE MONA PASSAGE NEAR 21N68W. LOW-LEVEL MOISTURE CONVERGENCE
ALONG WITH MIDDLE TO UPPER LEVEL DIFFLUENCE DUE TO THE UPPER
LEVEL LOW IS GENERATING WIDELY SCATTERED MODERATE CONVECTION
FROM 14N-22N BETWEEN 60W-68W...INCLUDING THE LEEWARD ISLANDS...
PUERTO RICO...AND THE US/UK VIRGIN ISLANDS.

TROPICAL WAVE EXTENDS FROM 08N87W TO 16N87W MOVING W AT 10-15
KT. WHILE MOST OF THE WAVE IS LOCATED IN THE EASTERN PACIFIC
REGION...A PORTION OF THE WAVE CONTINUES TO MOVE ACROSS HONDURAS
AND EL SALVADOR. A MAXIMUM IN 850 MB RELATIVE VORTICITY IS NOTED
IN GLOBAL MODEL DATA OVER THE GULF ON HONDURAS. THESE AMPLE
DYNAMICS ALOFT ARE GENERATING ISOLATED TO WIDELY SCATTERED
MODERATE CONVECTION FROM 17N-21N BETWEEN 81W-90W ACROSS THE NW
CARIBBEAN AND PORTIONS OF THE YUCATAN PENINSULA.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO
09N25W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
09N25W TO 06N34W TO 04N51W. SCATTERED MODERATE AND ISOLATED
STRONG CONVECTION IS FROM 07N-12N BETWEEN 11W-18W.

...DISCUSSION...

GULF OF MEXICO...
THE BASIN IN UNDER THE INFLUENCE OF TWO UPPER LEVEL FEATURES
THIS EVENING...THE FIRST AN UPPER LEVEL RIDGE CENTERED IN THE
EASTERN PACIFIC REGION WITH AXIS EXTENDING OVER CENTRAL MEXICO
TO OVER THE LOUISIANA COAST NEAR 30N93W. THE OTHER FEATURE IS A
BROAD UPPER LEVEL LOW CENTERED OVER BELIZE AND GUATEMALA NEAR
18N89W. BETWEEN THESE FEATURES...UPPER LEVEL NORTHERLY FLOW
REMAINS RELATIVELY DRY AND STABLE ACROSS THE NORTH-CENTRAL GULF
AND SW GULF WATERS. OVER THE NW GULF...MIDDLE TO UPPER LEVEL
MOISTURE INCREASES DUE TO DIFFLUENCE ALOFT GENERATING MOSTLY
CLOUDY SKIES THIS EVENING. ON THE NORTHERN PERIPHERY OF THE
UPPER LEVEL LOW...SCATTERED SHOWERS AND TSTMS CONTINUE TO
BLOSSOM ACROSS THE SE GULF WATERS S OF 24N AND ACROSS PORTIONS
OF THE YUCATAN PENINSULA FUELED BY PEAK DAYTIME HEATING AND
INSTABILITIES. ELSEWHERE AT THE SURFACE ACROSS THE BASIN...A
1021 MB HIGH REMAINS ANCHORED ACROSS THE NORTHERN HALF OF THE
GULF PROVIDING GENERALLY GENTLE TO MODERATE EASTERLY FLOW FROM
THE FLORIDA PENINSULA TO THE TEXAS AND MEXICO COAST. THE RIDGE
IS ANTICIPATED TO REMAIN RELATIVELY STATIONARY AND WEAKEN
SLIGHTLY BY LATE WEDNESDAY INTO THURSDAY. WINDS ACROSS THE
WESTERN GULF ARE EXPECTED TO HAVE MORE OF A SOUTHERLY COMPONENT
FOR THE LATTER PART OF THE WEEK.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED OVER BELIZE AND GUATEMALA NEAR
18N89W WHICH IS PROVIDING THE NW CARIBBEAN WITH SOUTH-
SOUTHWESTERLY WINDS ALOFT ADVECTING MOISTURE AND MIDDLE TO UPPER
LEVEL CLOUDINESS NORTHWARD TOWARD CUBA. THIS OVERALL DIFFLUENT
ENVIRONMENT ALOFT IS GENERATING A FEW SCATTERED SHOWERS AND
ISOLATED TSTMS IN THE VICINITY OF 16N85W OFF THE COAST OF
HONDURAS AND A FEW SCATTERED SHOWERS AND ISOLATED TSTMS N OF 18N
W OF 76W. CONVECTION COVERAGE AND INTENSITY INCREASES SLIGHTLY
ACROSS MUCH OF CUBA AND PORTIONS OF THE YUCATAN PENINSULA DUE TO
DIFFERENTIAL HEATING AND PEAK DAYTIME INSTABILITY. THE
SOUTHWESTERLY FLOW ALOFT ALSO EXTENDS OVER PORTIONS OF THE SW
CARIBBEAN WATERS GENERATING A FEW ISOLATED SHOWERS AND TSTMS S
OF 13N W OF 80W INCLUDING INLAND PORTIONS OF COSTA RICA AND SE
NICARAGUA. FINALLY...INTERACTION BETWEEN A TROPICAL WAVE ALONG
67W AND AN UPPER LEVEL LOW CENTERED NORTH OF THE MONA PASSAGE
NEAR 21N68W IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS THE
NE CARIBBEAN N OF 14N BETWEEN 60W-69W...INCLUDING THE LEEWARD
ISLANDS...PUERTO RICO...AND THE US/UK VIRGIN ISLANDS. THE WAVE
IS FORECAST TO MOVE WESTWARD AND IMPACT THE EASTERN GREATER
ANTILLES THROUGH WEDNESDAY.

...HISPANIOLA...
CURRENTLY A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING ACROSS
THE DOMINICAN REPUBLIC THIS EVENING AS A TROPICAL WAVE
APPROACHES FROM THE EAST. AN UPPER LEVEL LOW IS ALSO NOTED ON
WATER VAPOR IMAGERY CENTERED NORTH OF THE ISLAND NEAR 21N68W
THAT CONTINUES TO PROVIDE RELATIVELY DRY AND STABLE AIR DUE TO
NORTH-NORTHWESTERLY FLOW ON THE WESTERN PERIPHERY OF THE UPPER
LEVEL LOW. WHILE THE UPPER LEVEL LOW IS FORECAST TO MOVE VERY
LITTLE OVER THE NEXT FEW DAYS...LOW-LEVEL MOISTURE IS EXPECTED
TO INCREASE ACROSS HISPANIOLA THROUGH THURSDAY BRINGING
INCREASED PROBABILITY OF PRECIPITATION FOR THE WEEK DUE TO THE
PASSING OF THE TROPICAL WAVE TO THE SOUTH.

ATLANTIC OCEAN...
ASIDE FROM THE A FEW ISOLATED SHOWERS ACROSS THE WESTERN BAHAMAS
AND FLORIDA STRAITS THIS EVENING...AND THE PRECIPITATION AND
CONVECTION OCCURRING IN ASSOCIATION WITH AN UPPER LEVEL LOW
CENTERED NEAR 21N68W...THE SW NORTH ATLC IS UNDER THE INFLUENCE
OF A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED IN THE
CENTRAL ATLC NEAR 28N48W. THE RIDGE AXIS EXTENDS WESTWARD TO THE
FLORIDA PENINSULA ALONG 28N WITH MOSTLY CLEAR SKIES AND FAIR
CONDITIONS EXPECTED. ON THE EASTERN PERIPHERY OF THIS
RIDGE...THE RIDGE AXIS EXTENDS ALONG 28N TO 25W THEN NE TO THE
MADEIRA ISLANDS NEAR 33N17W.

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

$$
HUFFMAN
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