000
AGXX40 KNHC 221658
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
100 PM EDT SAT SEP 22 2007

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

GULF OF MEXICO...REMNANTS OF TD 10 INLAND SW MS...BUT A SERIES 
OF LOW LEVEL TROUGHS STILL EXTEND S OVER THE GULF WATERS BETWEEN 
85W AND 91W. ALL EXPECTED TO DISSIPATE TONIGHT AS WEAK SURFACE 
HIGH PRES BUILDS SE OVER THE NW WATERS. A SECOND...INVERTED 
TROUGH IS ANALYZED S OF 23N ALONG 87W AND IS EXPECTED TO MOVE W 
TONIGHT AND SUN WITH SOME MODELS SUGGESTING LOW PRES DEVELOPMENT 
ALONG THE TROUGH AXIS. AN UPPER CYCLONE NEAR 27N94W IS MOVING W 
ACCOMPANIED BY PLENTY OF UPPER DIFFLUENCE WELL E OF ITS CENTER. 
SO I WILL PROG WEAK SURFACE LOW PRES SUN NEAR 24N90W AND MOVE IT 
NW TO TX/LA COASTAL PLAINS LATE MON NIGHT/TUE MORNING...BUT
CONTINUE A BROAD LOW LEVEL TROUGH OVER THE W GULF...WITH MEAN 
AXIS EXTENDING N-S ALONG 93W...THROUGH EXTENDED PERIOD. GFS MOST 
AGGRESSIVE MODEL...SO WILL GO GFS GUIDANCE ON STRENGTH OF 
WINDS...AND THUS THE ASSOCIATED SEAS...EXPECTING TIGHTEST 
GRADIENT ROUGHLY WITHIN 240 NM E SEMICIRCLE OF THE SURFACE 
LOW.     

SW ATLC...A WEAK TROUGH OVER THE EXTREME NW ATLC S WILL GET A 
LITTLE REINFORCEMENT BY UPPER SHORTWAVE DIPPING TO SE OF 
REMNANTS OF TD 10 LATE TONIGHT. SO WILL MOVE A WEAK COLD FRONT 
MOVING SE TO PSN 31N70W 27N80W LATE SUN...THEN WEAK REMNANTS OF 
BOUNDARY WILL MOVE BACK W AS ATLC RIDGE...WITH ITS AXIS N OF 
AREA...SETS UP ELY FLOW THROUGH REMAINDER OF PERIOD. ONLY 
EXCEPTION IS A LOW LEVEL TROUGH OVER THE NW PORTION OF TROPICAL 
ATLC WILL ALSO MOVE W-NW AND MAY SEE A SLIGHT NE TO E WIND SHIFT 
OVER EXTREME SE WATERS E OF BAHAMAS SUN NIGHT INTO TUE.    

TROPICAL ATLC...A FRONTAL TROUGH EXTENDS ALONG 22N55W 16N61W 
WITH CONVECTION FLARING E OF TROUGH. QSCAT AND SHIPS REPORTING 
10-15 KT EITHER SIDE OF TROUGH. EXPECT REMNANTS TO DRIFT NW OF 
AREA MON NIGHT...SEE ABOVE PARAGRAPH. NEXT TROPICAL WAVE MOVES W 
TO ALONG 55W AT SUNRISE MON AND MOVES W OF 65W AROUND SUNRISE 
WED. ASSOCIATED CONVECTION IS REMAINING S OF 14N CURRENTLY DUE 
TO STRONG SW UPPER WINDS. EXPECTING A NE-SE 15-20 KT WIND SHIFT 
ALONG WAVE AXIS. DUST PRECEDES WAVE WITH W EDGE ALONG 60W ATTM.  
    
CARIBBEAN...AN INVERTED TROUGH ANALYZED OVER NW WATERS...ROUGHLY 
TO THE N OF 17N ALONG 87W...AND IS EXPECTED TO MOVE W OF AREA 
SUN. GRADIENT E OF TROUGH SUPPORTED SE WINDS 20-30 KT PER BUOY 
42056 WHICH HAS BEEN IN CONVECTION SINCE SUNRISE THIS 
MORNING....LATEST OBS ARE SE 15 KT. SHIPS NEAR YUCATAN CHANNEL 
REPORTING 7-9 FT SEAS...BUT BUOY ONLY REPORTING 4-6 FT PAST FEW 
HOURS. EXPECT WINDS TO DIMINISH TO 10-15 KT SUN NIGHT AS TROUGH 
MOVES TO CENTRAL GULF OF MEXICO. SSMI DATA SUPPORTS FORECAST OF 
15-20 KT SEAS 4-7 FT S CENTRAL CARIBBEAN WATERS...AND GFS 
FLUCTUATES WINDS IN THAT SAME RANGE...OR A LITTLE LESS...THROUGH 
MIDDLE OF NEXT WEEK. 

WARNINGS...
ATLANTIC...
NONE.

CARIBBEAN...
NONE.

GULF OF MEXICO... 
NONE.

FORECASTER NELSON