[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 282349
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT MAY 28 2011

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 IS FROM 06N TO 13N ALONG 57W MOVING W AT 10-15 KT.
VISIBLE SATELLITE IMAGERY SHOWS AN INVERTED-V STRUCTURE WITH
CYCLONIC FLOW ABOUT THE AXIS IN THE LOW-LEVEL CLOUD PATTERN.
TOTAL PRECIPITABLE WATER IMAGERY ALSO INDICATES A POLEWARD
EXTENSION OF LOW-LEVEL MOISTURE TO 13N IN THE VICINITY OF THE
WAVE AXIS. HOWEVER...DRY NW FLOW IN THE MIDDLE TO UPPER LEVELS
ABOVE THE LOW-LEVEL WAVE SIGNATURE IS INHIBITING ANY SIGNIFICANT
CONVECTION WITH THE WAVE THIS EVENING.

TROPICAL WAVE IS FROM 06N TO 14N ALONG 69W MOVING W AT 10-15 KT.
WHILE MOST OF THE WAVE AXIS REMAINS OVER NORTHWESTERN
VENEZUELA...CYCLONIC FLOW ACROSS THE NORTHERN EXTENT OF THE WAVE
AXIS IS NOTED IN THE LOW-LEVEL CLOUDS ON VISIBLE SATELLITE
IMAGERY. WESTERLY UPPER LEVEL FLOW ACROSS THE CARIBBEAN SEA
WATERS IN THE VICINITY OF THE WAVE IS SHEARING ANY POTENTIAL
CONVECTION N OF 12N...HOWEVER WIDELY SCATTERED MODERATE
CONVECTION IS OCCURRING INLAND OVER PORTIONS OF NW VENEZUELA
FROM 06N-11N BETWEEN 67W-70W.

...ITCZ...

ITCZ AXIS IS ALONG 09N13W 04N29W 05N40W 02N50W. WIDELY SCATTERED
MODERATE CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE AXIS
BETWEEN 19W AND 39W...AND BETWEEN 41W AND 48W.

...DISCUSSION...

GULF OF MEXICO...
AN AMPLIFIED UPPER LEVEL RIDGE IS LOCATED ALOFT OVER THE WESTERN
GULF AND WATER VAPOR IMAGERY INDICATES VERY DRY AIR AND STRONG
SUBSIDENCE. MOSTLY NW FLOW ALOFT COVERS THE ENTIRE GULF AS THE
UPPER LEVEL RIDGE AXIS EXTENDS FROM THE TENNESSEE RIVER VALLEY
SOUTHWESTWARD TO NE MEXICO. AT THE SURFACE...A RIDGE EXTENDS
ACROSS THE NORTHERN FLORIDA PENINSULA THROUGH THE BIG BEND
REGION OF FLORIDA W-SW TO 26N96W AND REMAINS ANCHORED BY A 1015
MB HIGH CENTERED NEAR 29N84W. E TO SE WINDS IN THE RANGE OF 10
TO 20 KT ARE NOTED IN RECENT SHIP AND BUOY OBSERVATIONS...WITH
THE EXCEPTION OF THE FAR NE GULF NEAR THE HIGH CENTER. SKIES
REMAIN REMARKABLY CLEAR THIS EVENING WITH THE LACK OF ABUNDANT
SYNOPTIC-SCALE MOISTURE TO WORK WITH...HOWEVER...VISIBLE IMAGERY
CONTINUES TO INDICATE A HAZY ATMOSPHERE W OF 92W DUE TO THE
ADVECTION OF SMOKE FROM SOUTHERN MEXICO WILDFIRES. A SELECT FEW
OFFSHORE OIL RIGS...AND LAND-BASED AIRFIELD METARS ACROSS SE
COASTAL TEXAS ARE REPORTING VISIBILITIES BELOW 10 STATUTE
MILES...OR 8.7 NM THIS EVENING.

CARIBBEAN SEA...
WEST-SOUTHWESTERLY FLOW ALOFT IS NOTED ACROSS MUCH OF THE
CARIBBEAN SEA THIS EVENING AS MOSTLY DRY AIR IS EVIDENT ON WATER
VAPOR IMAGERY N OF 18N W OF 78W. FAIR CONDITIONS AND RELATIVELY
CLEAR SKIES PREVAIL OVER MUCH OF THE NW CARIBBEAN WHILE ISOLATED
SHOWERS AND TSTMS IN ASSOCIATION WITH PEAK DAYTIME HEATING AND
INSTABILITY CONTINUE ACROSS INTERIOR PORTIONS OF CUBA AND
HISPANIOLA. THIS ACTIVITY IS EXPECTED TO DIMINISH OVER THE NEXT
FEW HOURS. ELSEWHERE...CONVERGENT TRADEWIND FLOW IS NOTED IN THE
SW CARIBBEAN FOCUSED ALONG A SURFACE TROUGH ANALYZED FROM
NORTHERN COLOMBIA NEAR 11N73W TO EASTERN COSTA RICA NEAR 10N83W.
THIS SURFACE FEATURE ALONG WITH UPPER LEVEL DIFFLUENCE EAST OF
UPPER LEVEL TROUGHING ACROSS THE SW NORTH ATLC IS GENERATING
WIDELY SCATTERED SHOWERS AND TSTMS OVER THE SW CARIBBEAN S OF
16N W OF 70W. AS THE TROPICAL WAVE ALONG 69W CONTINUES TO MOVE
WESTWARD...GLOBAL MODELS CONTINUE TO INDICATE ENERGY ASSOCIATED
WITH THE WAVE WILL COMBINE WITH ALREADY EXISTING BROAD CYCLONIC
FLOW ACROSS THE REGION. CYCLOGENESIS IN THE FORM OF A WEAK LOW
PRESSURE CENTER IS FORECAST TO OCCUR IN THE 36 TO 72 HOUR WINDOW
ACROSS THE SW CARIBBEAN SEA WATERS.

ATLANTIC OCEAN...
A SURFACE RIDGE COVERS THE WESTERN ATLC W OF 65W KEEPING
CONDITIONS MOSTLY FAIR THIS EVENING. HOWEVER...A FEW ISOLATED
SHOWERS AND TSTMS REMAIN OVER THE INTERIOR SOUTHERN FLORIDA
PENINSULA S OF 28N. FARTHER EAST...AN UPPER LEVEL LOW CONTINUES
TO SPIN NEAR 33N53W SUPPORTING A COMPLEX AREA OF LOW PRESSURE
CENTERED BY A 1013 MB LOW NEAR 28N55W. TWO OTHER 1013 MB LOWS
CIRCULATE ON THE PERIPHERY OF THE MEAN LOW...ONE CENTERED NEAR
29N59W AND THE OTHER CENTERED NEAR 24N50W. A SURFACE TROUGH
EXTENDS FROM THE EASTERNMOST LOW ALONG 21N54W TO 20N60W
SUPPORTING ISOLATED SHOWERS WITHIN 120 NM EITHER SIDE OF THE
SURFACE TROUGH AXIS. SCATTERED SHOWERS AND POSSIBLE ISOLATED
TSTMS COVER A WIDER AREA FROM 17N-32N BETWEEN 40W-52W DUE TO
LOW-LEVEL CONVERGENCE AND UPPER LEVEL DIFFLUENCE IN ASSOCIATION
WITH THE TROUGH AXIS ALOFT. THE REMAINDER OF THE EASTERN ATLC IS
UNDER THE INFLUENCE OF A SURFACE RIDGE EXTENDING SOUTHWARD INTO
THE DISCUSSION AREA ALONG 32W. THE RIDGE IS ANCHORED BY A 1032
MB HIGH CENTERED NW OF THE AZORES NEAR 41N35W.

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

$$
HUFFMAN




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