[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 232344
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE JUN 23 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 1026 MB HIGH CENTERED IN THE CENTRAL ATLC NEAR
27N48W AND LOWER PRESSURE ANALYZED ACROSS NORTHERN COLOMBIA.
CURRENTLY STRONG TO NEAR GALE FORCE TRADES ARE NOTED S OF 17N
BETWEEN 66W-82W PER EARLIER ASCAT PASSES AROUND 23/1418 UTC...
AND 23/1514 UTC. THE HIGH IS FORECAST TO SHIFT WEST SLIGHTLY
THROUGH WEDNESDAY AND INCREASE THE WIND FIELD OFF THE COAST OF
COLOMBIA OVERNIGHT INTO A RANGE OF NEAR GALE TO GALE FORCE BY
THIS EVENING. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO
HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 07N40W TO 18N37W MOVING W AT 20 KT.
THE WAVE COINCIDES WITH AN AMPLIFIED GLOBAL MODEL INDICATED 700
MB TROUGH BETWEEN 34W-44W. 850 MB RELATIVELY VORTICITY IS ALSO
MAXIMIZED ALONG THE WAVE AXIS NEAR 10N. DUE TO THE PRESENCE OF
THE SAHARAN AIR LAYER...NO SIGNIFICANT CONVECTION IS ASSOCIATED
WITH THE WAVE AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 07N61W TO 16N59W MOVING W AT 20 KT.
POSITION IS BASED LARGELY ON CONTINUITY AND VERY SUBTLE 700 MB
TROUGHING BETWEEN 56W-61W. A 700 MB LOW-LEVEL JET MAXIMUM LIES
TO THE EAST OF THE WAVE FROM 07N-16N STRETCHING EASTWARD TO THE
TROPICAL WAVE ALONG 39W MENTIONED ABOVE. ISOLATED MODERATE
CONVECTION IS FROM 08N-11N BETWEEN 58W-63W.

TROPICAL WAVE EXTENDS FROM 09N75W TO 19N73W 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
HISPANIOLA NEAR 21N70W. LOW-LEVEL MOISTURE CONVERGENCE ALONG
WITH MIDDLE TO UPPER LEVEL DIFFLUENCE DUE TO THE UPPER LEVEL LOW
IS GENERATING A BROAD AREA OF ISOLATED MODERATE CONVECTION FROM
18N-26N BETWEEN 61W-73W...INCLUDING PUERTO RICO AND PORTIONS OF
HISPANIOLA...THE CONVECTION IS MOST LIKELY ASSOCIATED WITH THE
UPPER LEVEL LOW AND NOT THE TROPICAL WAVE.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 18N16W TO
11N20W TO 08N27W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 08N27W TO 07N36W TO 05N44W TO 04N51W. SCATTERED
MODERATE AND ISOLATED STRONG CONVECTION IS FROM 10N-14N BETWEEN
12W-16W.

...DISCUSSION...

GULF OF MEXICO...
THE BASIN IN UNDER THE INFLUENCE OF TWO UPPER LEVEL FEATURES
THIS EVENING...THE FIRST AN UPPER LEVEL RIDGE CENTERED OVER
NORTHERN FLORIDA NEAR 30N82W AND THE OTHER A BROAD UPPER LEVEL
LOW CENTERED OVER THE SOUTHERN YUCATAN PENINSULA NEAR 20N88W.
BETWEEN THESE FEATURES...UPPER LEVEL SOUTHEASTERLY FLOW PREVAILS
OVER THE GULF WITH DIFFLUENCE OCCURRING OVER THE GULF COASTAL
PLAIN AND FLORIDA PENINSULA. THIS DIFFLUENCE ALOFT ALONG WITH
PEAK DAYTIME HEATING AND INSTABILITY IS GENERATING SCATTERED
SHOWERS AND TSTMS ACROSS INLAND PORTIONS OF THE GULF COAST FROM
SE LOUISIANA EASTWARD TO JACKSONVILLE FLORIDA AND THEN SOUTHWEST
TO THE TAMPA BAY REGION AND SOUTH TO NAPLES FLORIDA. THE UPPER
LEVEL LOW IS ALSO GENERATING ISOLATED SHOWERS ACROSS CENTRAL
PORTIONS OF THE GULF FROM THE SE GULF WATERS OFF THE COAST OF
WESTERN CUBA NEAR 23N84W TO ALONG THE TEXAS COAST. STRONGER
CONVECTION IS ALSO NOTED ACROSS THE YUCATAN PENINSULA AND THE
ADJACENT COASTAL WATERS OF THE SW GULF FROM 17N-22N BETWEEN 88W-
92W. AT THE SURFACE...A 1021 MB HIGH REMAINS ANCHORED ACROSS THE
NORTHERN HALF OF THE GULF WITH AXIS ALONG 29N 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 THE SOUTHERN YUCATAN
PENINSULA NEAR 20N88W WHICH IS PROVIDING THE NW CARIBBEAN WITH
SOUTH-SOUTHWESTERLY WINDS ALOFT ADVECTING MOISTURE AND MIDDLE TO
UPPER LEVEL CLOUDINESS NORTHWARD. THIS OVERALL DIFFLUENT
ENVIRONMENT ALOFT IS GENERATING A FEW SCATTERED SHOWERS AND
WIDELY SCATTERED TSTMS N OF 18N W OF 83W THIS EVENING.
CONVECTION COVERAGE AND INTENSITY INCREASES SLIGHTLY ACROSS
PORTIONS OF EASTERN CUBA DUE TO THE PRESENCE OF A SURFACE TROUGH
THAT EXTENDS FROM THE SW NORTH ATLC REGION NEAR 26N69W TO
19N78W. THIS SURFACE TROUGH IS LARGELY THE REFLECTION OF AN
UPPER LEVEL LOW CENTERED NORTH OF HISPANIOLA NEAR 21N70W. THE
SOUTHWESTERLY FLOW ALOFT ALSO EXTENDS OVER PORTIONS OF THE SW
CARIBBEAN WATERS GENERATING SCATTERED SHOWERS AND TSTMS S OF 16N
W OF 80W INCLUDING INLAND PORTIONS OF EASTERN NICARAGUA.
FINALLY...A PAIR OF TROPICAL WAVES ARE ANALYZED ONE ALONG 74W
AND THE OTHER ALONG 60W. BOTH WAVES REMAIN RELATIVELY INACTIVE
CONVECTIVELY WITH ONLY A FEW ISOLATED SHOWERS NOTED ACROSS THE
SOUTHERN WINDWARD ISLANDS...TRINIDAD AND TOBAGO...AND NE
VENEZUELA THIS EVENING. THE PRIMARY IMPACT ACROSS THE BASIN AS
THE WAVES CONTINUE WESTWARD IS THE STRONG PRESSURE GRADIENT
PRODUCING STRONG TRADE WINDS AND NEAR GALE TO GALE FORCE WINDS
IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. THESE STRONG TRADES
ARE FORECAST TO PERSIST THROUGH MUCH OF THE NEXT WEEK AHEAD.

...HISPANIOLA...
CURRENTLY A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING ACROSS
HISPANIOLA THIS EVENING AS A TROPICAL WAVE BEGINS TO MOVE AWAY
SOUTHWEST OF THE ISLAND. AN UPPER LEVEL LOW IS MORE THE PRIMARY
WEATHER PRODUCER AS WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL
LOW CENTERED NORTH OF THE ISLAND NEAR 21N70W. WITH THE UPPER
LEVEL LOW CENTERED TO THE NORTH OF THE ISLAND...LIFTING DYNAMICS
REMAIN MARGINAL WITH MOST OF THE PRECIPITATION AND CONVECTION
ASSOCIATED WITH THE UPPER LEVEL LOW REMAINING TO THE NORTH OF
THE ISLAND HOWEVER AS THE LOW MOVES NORTHWARD DURING THE NEXT 24
TO 36 HOURS...CONDITIONS ARE EXPECTED TO IMPROVE.

ATLANTIC OCEAN...
ASIDE FROM THE A FEW ISOLATED SHOWERS ACROSS THE NORTHWESTERN
PORTION OF THE SW NORTH ATLC THIS EVENING...AND THE
PRECIPITATION AND CONVECTION OCCURRING IN ASSOCIATION WITH AN
UPPER LEVEL LOW CENTERED NEAR 21N70W FROM 18N-27N BETWEEN 58W-
72W...THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE
RIDGE ANCHORED BY A 1026 MB HIGH CENTERED IN THE CENTRAL ATLC
NEAR 27N48W. THE RIDGE AXIS EXTENDS WESTWARD TO THE FLORIDA
PENINSULA ALONG 27N/28N. ON THE EASTERN PERIPHERY OF THIS
RIDGE...THE RIDGE AXIS EXTENDS ALONG 27N TO THE CANARY ISLANDS
NEAR 28N16W.

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

$$
HUFFMAN
This weather bulletin was brought to you by:
www.nashvilleweather.net