000
AXNT20 KNHC 241744
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
205 PM EDT WED APR 24 2013

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...ITCZ/MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO 
THE EQUATOR NEAR 22W. SCATTERED MODERATE CONVECTION IS FROM THE 
EQUATOR TO 07N BETWEEN THE PRIME MERIDIAN AND 23W. ISOLATED 
MODERATE CONVECTION IS FROM 01N-07N BETWEEN 26W-39W.

...DISCUSSION...

GULF OF MEXICO...                                               
A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS PROGRESSING E-NE 
OVER THE GREAT LAKES REGION THAT SUPPORTS A COLD FRONT ANALYZED 
ACROSS THE OHIO AND TENNESSEE RIVER VALLEYS INTO THE LOWER 
MISSISSIPPI RIVER VALLEY AND ACROSS THE NW GULF FROM 30N93W TO 
NEAR BROWNSVILLE TEXAS NEAR 26N97W. MOSAIC DOPPLER RADAR AND 
LIGHTNING DATA INDICATE SCATTERED SHOWERS AND TSTMS ARE 
OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT. THE FRONT 
CONTINUES TO ERODE AWAY SURFACE RIDGING WHICH REMAINS ANCHORED 
IN THE SW NORTH ATLC. THE RIDGING IS PROVIDING MUCH OF THE GULF 
EAST OF THE FRONT WITH SOUTH-SOUTHEAST WINDS IN THE RANGE OF 10 
TO 20 KT. NW OF THE FRONT...STRONG N-NE WINDS ARE OCCURRING IN 
THE RANGE OF 20 TO 25 KT UNDER OVERCAST SKIES THIS AFTERNOON. 
THE NORTHERN PORTION OF THE FRONT WILL CONTINUE SLIDING EASTWARD 
ALONG THE GULF COAST AND SE CONUS THROUGH LATE THURSDAY WHILE 
SOUTHERN PORTIONS BEGIN TO GRADUALLY WEAKEN AND DISSIPATE AS 
HIGH PRESSURE ONCE AGAIN BUILDS IN ACROSS THE SE CONUS AND GULF 
BY FRIDAY.
 
CARIBBEAN SEA...                                          
OVERALL DRY AND STABLE AIR IN WEST-NORTHWESTERLY FLOW ALOFT 
DOMINATES OVER MUCH OF THE CARIBBEAN THIS AFTERNOON KEEPING 
CONDITIONS ACROSS THE BASIN FAIRLY TRANQUIL. SATELLITE AND TOTAL 
PRECIPITABLE WATER IMAGERY INDICATE INCREASED LOW-LEVEL MOISTURE 
AND ISOLATED SHOWERS OCCURRING OVER THE SE CARIBBEAN S OF 16N E 
OF 68W. OTHERWISE...TRADE WINDS REMAIN IN THE RANGE OF 10 TO 20 
KT AND ARE EXPECTED TO PERSIST IN THAT RANGE THROUGH LATE 
THURSDAY.
 
ATLANTIC OCEAN...                                               
A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE SW NORTH ATLC WITH 
AXIS ALONG 68W THAT SUPPORTS A COLD FRONT ANALYZED INTO THE 
DISCUSSION AREA NEAR 32N68W AND EXTENDS S-SW TO 25N74W. A 
SURFACE TROUGH IS FOUND S-SE OF THE COLD FRONT FROM 26N71W TO 
THE NORTHERN COAST OF HISPANIOLA NEAR 20N72W. WITHIN THE AREA OF 
MAXIMUM MIDDLE TO UPPER LEVEL DIFFLUENCE EAST OF THE TROUGH AXIS 
AND WITHIN CLOSE PROXIMITY TO THE COLD FRONT...WIDELY SCATTERED 
SHOWERS AND ISOLATED TSTMS ARE OCCURRING N OF 20N BETWEEN 60W-
69W AND WITHIN 60 NM EITHER SIDE OF THE COLD FRONT. THE 
REMAINDER OF THE SW NORTH ATLC WEST OF THE FRONT IS UNDER THE 
INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED 
OFF THE CAROLINA COAST NEAR 34N76W. FARTHER EAST OVER THE 
CENTRAL ATLC...AN UPPER LEVEL RIDGE AXIS IS ALONG 54W AND 
EXTENDS FAR NORTH OF THE AREA AS THE CURRENT PATTERN OVER THE 
NORTHERN ATLC CONTINUES TO AMPLIFY. THE RIDGING ALOFT SUPPORTS A 
SURFACE RIDGE BETWEEN 40W-60W ANCHORED BY A STRONG 1042 MB HIGH 
CENTERED OFF THE NEWFOUNDLAND COAST NEAR 46N49W. THE REMAINDER 
OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF DEEP LAYERED LOW 
CENTERED NEAR 34N34W. THE LOW REFLECTS AS A 998 MB SURFACE LOW 
CENTERED NEAR 38N31W WITH THE ASSOCIATED COLD FRONT ENTERING THE 
DISCUSSION AREA NEAR 32N28W. THE FRONT EXTENDS SW ALONG 27N30W 
TO 24N33W TO 22N41W. POSSIBLE ISOLATED SHOWERS ARE NOTED ON 
SATELLITE IMAGERY EAST OF THE COLD FRONT FROM 20N-32N BETWEEN 
17W-25W.

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

$$
HUFFMAN