000
AGXX40 KNHC 230520
MIMATS

MARINE WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
120 AM EDT THU OCT 23 2008

MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...
CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W.

UPPER LEVELS...
STRONG CYCLONIC CIRCULATION OVER THE UNITED STATES GREAT PLAINS 
WILL SLOWLY MOVE EAST AND BECOME PART OF A MAJOR LONGWAVE TROUGH 
THAT FORMS OVER THE EASTERN UNITED STATES THROUGH SATURDAY. THE 
TROUGH WILL CONTINUE THROUGH MONDAY. THE TROUGH AFFECTS THE GULF 
OF MEXICO AND THE ATLANTIC WEST OF 75W AND NORTH OF ABOUT 25N. A 
SHORTWAVE MOVING THROUGH THE TROUGH WILL MOVE OFF THE NORTHWEST 
GULF COAST LATE SATURDAY. ANOTHER SHORTWAVE WILL SHARPEN THE 
TROUGH MONDAY WITH THE TROUGH EXTENDING TO 22N MONDAY WITH AN 
AXIS ALONG 85W.

SURFACE...
COLD FRONT IN THE WEST GULF OF MEXICO WILL MOVE TO THE CENTRAL 
GULF TONIGHT. A STRONG RIDGE IS ALONG THE EAST UNITED STATES 
COAST AND A BROAD LOW IS OVER THE WESTERN CARIBBEAN. THE 
PRESSURE GRADIENT BETWEEN THE TWO IS CONCENTRATED OVER THE AREA 
NORTH OF 25N FROM ABOUT 75W TO 90W IN WHAT COULD BE CONSIDERED A 
DEVELOPING WARM FRONT. WINDS OF UP TO 30 KNOTS FROM THE EAST TO 
SOUTHEAST WILL BE NORTH OF THE WARM FRONT. THE STRONG RIDGE 
ALONG THE EAST COAST WILL MOVE EAST AND ACCOMPANYING EAST WINDS 
WILL COVER MOST OF THE ATLANTIC NORTH OF ABOUT 23N AS THIS 
SYSTEM MOVES EAST. IN THE GULF THE LACK OF A STRONG RIDGE BEHIND 
THE COLD FRONT KEEPS THE WINDS GENERALLY LESS THAN 20 KNOTS 
AFTER EARLY TONIGHT. A STRONG HIGH LATE IN THE PERIOD PUSHES 
ANOTHER COLD FRONT OFF THE NORTHWEST GULF COAST LATE SUNDAY WITH 
20 TO 30 KNOT NORTHERLY WINDS OVER MOST OF THE GULF BY LATE 
MONDAY. 

TROPICAL ATLANTIC TRADES WILL BE LESS THAN NORMAL THROUGHOUT THE 
PERIOD. CARIBBEAN TRADES WILL BE NEAR NORMAL THROUGH FRIDAY 
NIGHT THEN DIMINISH TO LESS THAN NORMAL SATURDAY AND CONTINUE 
LESS THAN NORMAL SUNDAY AND MONDAY.

ATLANTIC...
NONE.

CARIBBEAN...
NONE.

GULF OF MEXICO...
NONE.

FORECASTER LL. TROPICAL PREDICTION CENTER.