AXNT20 KNHC 202355
TWDAT 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU NOV 20 2008

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 52W S OF 18N MOVING W AT 10 KT. WITH AXIS 
MAINLY EMBEDDED WITHIN THE ITCZ...ISOLATED MODERATE SHOWERS ARE 
FROM 10N-18N BETWEEN 46W-52W. AN UPPER RIDGE COVERS THE WRN 
TROPICAL ATLC AND IS SUPPORTING THESE SHOWERS WITH UPPER LEVEL 
DIFFLUENCE.

...THE ITCZ...
THE ITCZ AXIS IS ANALYZED ALONG 9N12W 7N30W 9N50W 10N54W 9N61W. 
SCATTERED MODERATE CONVECTION IS FROM 5N-8N BETWEEN 16W-21W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER LEVEL WESTERLY WIND FLOW COVERS THE ENTIRE GULF OF 
MEXICO. A 1023 MB SURFACE HIGH PRESSURE IS CENTERED NEAR NEW 
ORLEANS LOUISIANA AND COVERS THE FLORIDA PENINSULA AND GULF THIS 
EVENING KEEPING WINDS LIGHT THROUGHOUT THE REGION. POSSIBLE 
ISOLATED SHOWERS ARE ALONG THE ERN MEXICO COAST S OF 24N AND W 
OF 94W. ANOTHER REINFORCEMENT OF COLD AIR IS EXPECTED LATE 
TONIGHT AS A COLD FRONT CURRENTLY DRAPED ACROSS THE SRN US COAST 
STATES WILL ENTER THE FAR NRN GULF WITH 20-25 KT WINDS BEHIND 
THE FRONT.

CARIBBEAN SEA...
A COLD FRONT ENTERS THE CARIBBEAN THROUGH THE MONA PASSAGE AND 
EXTENDS SOUTH OF HISPANIOLA W-SW TO NEAR 16N78W WHERE IT TURNS 
STATIONARY AND EXTENDS SOUTHWARD TO A 1008 MB LOW CENTERED OVER 
CENTRAL PANAMA. THE WIND FORECAST FOR THE CARIBBEAN SEA WEST OF 
THE FRONTAL BOUNDARY IS NORTHERLY WINDS FROM 20 TO 30 KT AND SEA 
HEIGHTS RANGING FROM 8 TO 12 FT FOR THE NEXT 24 TO 48 HOURS. 
SCATTERED SHOWERS ARE WITHIN 50 NM OF THE COLD FRONT N OF 18N 
AND ACROSS HISPANIOLA AND PUERTO RICO. SCATTERED MODERATE 
CONVECTION IS ASSOCIATED WITH THE STATIONARY BOUNDARY IN THE SW 
CARIBBEAN FROM 9N-15N BETWEEN 77W-83W. ELSEWHERE...ACROSS THE  
ERN CARIBBEAN A SURFACE TROUGH EXTENDS NWD FROM THE GULF OF 
PARIA ACROSS MONTSERRAT AND BARBUDA GENERATING SCATTERED SHOWERS 
AND TSTMS FROM 12N-17N BETWEEN 60W-64W. IN THE UPPER LEVELS A 
BROAD UPPER LEVEL RIDGE COVERS MUCH OF THE CARIBBEAN SEA AND IS 
PROVIDING UPPER DIFFLUENCE FOR THE SCATTERED SHOWER AND TSTM 
ACTIVITY S OF 17N AND ACROSS NRN SOUTH AMERICA THIS EVENING.

ATLANTIC OCEAN...
BROAD UPPER LEVEL TROUGHING IS ACROSS THE WRN AND CENTRAL ATLC W 
OF 45W. THIS TROUGHING SUPPORTS A COLD FRONT THAT ENTERS THE 
DISCUSSION AREA NEAR 32N51W AND EXTENDS SW TO 22N60W AND INTO 
THE CARIBBEAN SEA THROUGH THE MONA PASSAGE. BROKEN TO OVERCAST 
STRATOCUMULUS CLOUDINESS COVERS THE AREA W OF THE FRONT WITH 
POSSIBLE ISOLATED SHOWERS ACROSS THE SE BAHAMAS...HISPANIOLA AND 
THE W ATLC. A SURFACE HIGH PRESSURE RIDGE EXTENDS FROM THE GULF 
OF MEXICO ACROSS THE FLORIDA PENINSULA TO NEAR 26N65W ACROSS THE 
W ATLC WATERS. A 1013 MB LOW PRESSURE CENTER IS NEAR 28N44W AND 
IS ALL THAT REMAINS OF THE DEEP LAYER CYCLONIC ENVELOPE THAT HAS 
PERSISTED IN THE CENTRAL ATLC OCEAN OVER THE PAST FEW DAYS. THE 
CYCLONIC SYSTEM IS BEING STRETCHED ALONG A E-W LINE ON WATER 
VAPOR IMAGERY...FROM SRN MOROCCO ACROSS THE CAPE VERDE ISLANDS 
TO NEAR 28N33W. SCATTERED MODERATE SHOWERS AND POSSIBLE TSTMS 
ARE FROM 24N-29N BETWEEN 27W-38W.

$$
HUFFMAN