000
AXNT20 KNHC 061741
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
205 PM EDT THU MAY 06 2010

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...METEOROLOGICAL ANALYSIS...WEATHER 
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC...

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 34W FROM 1N-9N MOVING W AT 10-15 KT. 
UPPER-AIR TIME SECTION ANALYSES INDICATE THE WAVE PASSED DAKAR 
SENEGAL AROUND 02/1200 UTC. EXAMINING THE HOVMOLLER DIAGRAM OF 
METEOSAT-9 SATELLITE IMAGERY ACROSS THE EASTERN TROPICAL ATLC 
CONFIRMS PROPAGATION OF THE WAVE LARGELY EMBEDDED WITHIN THE 
ITCZ AXIS THAT HAS REMAINED LOW-LATITUDE SINCE EMERGING OFF OF 
WEST AFRICA A FEW DAYS AGO. AN EARLIER MORNING ASCAT PASS AROUND 
05/1210 UTC CAPTURED 15-20 KT RETRIEVALS N OF 4N IN THE VICINITY 
OF THE WAVE AXIS AND ALSO CONFIRMED THE APPROXIMATE POSITION OF 
THE WAVE. TOTAL PRECIPITABLE WATER VALUES NEAR THE WAVE ARE 
ELEVATED WITH SCATTERED MODERATE CONVECTION WITHIN 130 NM W OF 
THE WAVE AXIS FROM 5N-8N. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N12W 4N18W 3N33W 3N36W AND TO THE 
EQUATOR NEAR 50W. NUMEROUS MODERATE AND SCATTERED STRONG 
CONVECTION IS FROM 1N-9N BETWEEN 9W-19W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION COVERS THE REMAINDER OF THE AREA FROM 
THE EQUATOR TO 8N BETWEEN 4W-31W.

...DISCUSSION...

GULF OF MEXICO...
WEAK UPPER LEVEL TROUGHING IS EVIDENT ON WATER VAPOR IMAGERY 
OVER THE FLORIDA PENINSULA AND THE ADJACENT COASTAL WATERS OF 
THE W ATLC BETWEEN TWO UPPER LEVEL ANTICYCLONIC CIRCULATION 
CENTERS...ONE CENTERED IN THE W ATLC NEAR 22N58W AND THE OTHER 
CENTERED OVER CENTRAL MEXICO NEAR 18N99W. THE UPPER LEVEL 
TROUGHING SUPPORTS A FAIRLY DIFFUSE STATIONARY FRONT THAT 
CROSSES THE FLORIDA PENINSULA ALONG 29N AND INTO THE NE GULF TO 
28N86W THAT CONTINUES SW AS A SURFACE TROUGH TO 22N91W. ISOLATED 
SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE BOUNDARY E OF 90W. 
THE REMAINDER OF THE GULF W OF 90W IS EXPERIENCING LIGHT 
SOUTHERLY RETURN FLOW TO 15 KTS...WHILE THE UPPER LEVEL RIDGE 
AND RELATIVELY DRY AIR ALOFT...SUPPORT OVERALL STABILITY AND 
FAIR SKIES THIS AFTERNOON. AS THE FRONT DISSIPATES BY THE 
WEEKEND...A SURFACE RIDGE IS FORECAST TO REMAIN ACROSS MOST OF 
THE GULF WITH THE NEXT WEAK FRONTAL BOUNDARY EXPECTED TO EMERGE 
OFF THE SE TEXAS COAST EARLY SATURDAY.

CARIBBEAN SEA...
NARROW UPPER LEVEL TROUGHING EXTENDS OVER THE WESTERN CARIBBEAN 
SEA BETWEEN 75W-82W TO AN UPPER LEVEL LOW CENTERED NEAR 13N83W. 
MOIST SOUTHWESTERLY UPPER LEVEL FLOW CONTINUES TO ADVECT 
MOISTURE NORTHWARD FROM THE SE PACIFIC ACROSS PANAMA INTO THE SW 
CARIBBEAN GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER 
THE SW CARIBBEAN S OF 15N W OF 76W. ISOLATED SHOWERS STRETCH 
FARTHER NORTH TO EASTERN CUBA BETWEEN 76W-82W. FARTHER EAST...A 
SHEAR LINE IS ANALYZED FROM THE TROPICAL NORTH ATLC NEAR 16N60W 
TO SOUTHERN DOMINICA AND INTO THE CARIBBEAN ALONG 14N65W TO 
13N70W. CONVERGENT NE TO E TRADES ARE GENERATING ISOLATED 
SHOWERS WITHIN 90 NM OF THE SHEAR LINE AND OVER THE LEEWARD 
ISLANDS E OF 63W. THESE SHOWERS SHOW LITTLE VERTICAL EXTENT AND 
REMAIN SHALLOW IN NATURE DUE TO PLENTY OF DRY AIR ALOFT IN PLACE 
OVER THE EASTERN CARIBBEAN E OF 72W.

ATLANTIC OCEAN...
UPPER LEVEL TROUGHING IS ACROSS THE FLORIDA PENINSULA AND THE NW 
CORNER OF THE W ATLC THAT SUPPORTS A 1013 MB LOW CENTERED NEAR 
33N76W. A DISSIPATING STATIONARY FRONT EXTENDS FROM THE LOW TO 
SAINT AUGUSTINE FLORIDA AND INTO THE NE GULF OF MEXICO. 
SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 60 NM OF THE 
BOUNDARY AND N OF 29N BETWEEN 71W-77W. THE REMAINDER OF THE W 
ATLC IS UNDER THE INFLUENCE OF A 1021 MB HIGH CENTERED NEAR 
28N63W. MOSTLY ZONAL WESTERLY UPPER LEVEL FLOW IS ACROSS MUCH OF 
THE SUB-TROPICAL CENTRAL ATLC...HOWEVER A COLD FRONT ENTERS THE 
DISCUSSION AREA NEAR 32N46W TO 30N56W AND BECOMES STATIONARY TO 
BEYOND 32N65W NEAR BERMUDA. ISOLATED SHOWERS ARE WITHIN 60 NM 
EITHER SIDE OF THE FRONTAL BOUNDARY WITH STRONGER NW WINDS 15 TO 
25 KTS NORTH OF THE FRONT AS CAPTURED BY EARLIER MORNING WINDSAT 
AND ASCAT SCATTEROMETER PASSES. A PRE-FRONTAL SURFACE TROUGH IS 
ANALYZED FROM 32N40W TO 27N54W WITH POSSIBLE ISOLATED SHOWERS 
WITHIN 60 NM E OF THE WEAK BOUNDARY. FARTHER SOUTH...A SHEAR 
LINE EXTENDS ACROSS THE TROPICAL NORTH ATLC FROM 19N54W TO 
SOUTHERN DOMINICA NEAR 15N61W AND INTO THE EASTERN CARIBBEAN 
SEA. ISOLATED SHOWERS COVER THE AREA WITHIN 200 NM NW OF THE 
SHEAR LINE...INCLUDING THE LEEWARD ISLANDS. THE REMAINDER OF THE 
EASTERN ATLC IS DOMINATED BY A 1019 MB HIGH CENTERED NEAR 24N37W 
THAT CONTINUES TO PROVIDE MOSTLY FAIR WEATHER FROM 10N-30N E OF 
45W.

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

$$
HUFFMAN