000
AGXX40 KNHC 210618
MIMATS

MARINE WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
130 AM EST FRI DEC 21 2007

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

MODERATE SHORTWAVE TROUGH IN SRN BRANCH OF WESTERLIES TONIGHT 
ALONG 85W MOVING E. TROUGH OUT OF PHASE WITH NRN BRANCH THUS NO 
COLD AIR AVAILABLE BEHIND TROUGH. ON THE SURFACE TONIGHT WEAK 
LOW PRES OVER FL PANHANDLE WITH SQUALL LINE OVER ERN GULF. 
QUIKSCAT AND SSMI SHOW S TO SW WINDS TO 25 KT AHEAD OF LINE. 
MODERATE ELY WINDS OVER ATLC E OF 50W AND S OF 16N BETWEEN 50W 
AND 60W. CARIB WINDS LIGHT TO MODERATE. 

LATER DAY 1 SHORTWAVE TROUGH MOVES OFF SE COAST. MID LEVEL RIDGE 
BEGINS TO BUILD ALONG 90W. ON THE SURFACE LATER DAY 1 LOW PRES 
DEEPENS A FEW MILLIBARS AS IT MOVES TO NEAR 30N78W. S TO SW 
WINDS 20 TO 25 KT OVER ATLC W OF 75W N OF 27N. NE GULF WINDS NLY 
15 TO 20 KT OTHERWISE LIGHT ELSEWHERE. LITTLE CHANGE ELSEWHERE.

FOR DAY 2 SHORTWAVE TROUGH MOVES E OT 70W AND BEGINS TO INTERACT 
WITH LARGER TROUGH OVER N ATLC E OF 60W. MID LEVEL RIDGING MOVES 
TO 80W. SWLY FLOW W OF 90W AS TROUGHS IN SRN AND NRN BRANCH 
PHASE TOGETHER OVER PLAINS. ON THE SURFACE DAY 2 LOW PRES OVER 
ATLC CONTINUES E TO NEAR 29N69W. GRADIENT N OF 29N STRONG ENOUGH 
FOR 20 TO 30 KT WINDS THANKS TO HIGH PRES FURTHER N. WINDS OVER 
GULF INCREASE TO 20 KT AS LOW PRES DEVELOPS ALONG 95W. CARIB AND 
TRPL ATLC LITTLE CHANGE.

OUTLOOK PERIOD... 

FOR DAY 3 MID LEVEL TROUGH MOVES SE TO NEAR 20N60W BUT WEAKENS. 
MID LEVEL RIDGE CENTER DEVELOPS OVER NW CARIB AND BAHAMAS. 
STRONG MID LEVEL TROUGH MOVES ENE OVER OH VALLEY SENDING A SHOT 
OF COLD AIR S OVER THE SRN PLAINS INTO THE NW GULF. ON THE 
SURFACE DAY 3 A 1030 MB HIGH MOVES TO SE TX BEHIND A COLD FRONT 
THAT MOVES RAPIDLY SE OVER THE GULF WITH NLY WINDS 20 TO 25 KT. 
ATLC LOW SHIFTS E AND GRADIENT N OF 28N BETWEEN 48W AND 70W 
SUPPORTS NE TO E WINDS 20 TO 30 KT. CARIB WINDS INCREASE TO 20 
KT OVER S CENTRAL PORTION. 

FOR DAY 4 SHORTWAVES PHASE TOGETHER OVER CENTRAL ATLC NEAR 
33N43W. MID LEVEL RIDGE HOLDS FIRM OVER CUBA/BAHAMAS WITH STRONG 
SWLY FLOW OVER NW GULF AT MID LEVELS. ON THE SURFACE DAY 4 HIGH 
PRES WEAKENS OVER SRN CONUS BUT ENOUGH FOR NE TO E WINDS TO 20 
KT OVER GULF. ATLC WINDS REMAINS STRONG N OF 23N BETWEEN 40W AND 
60W AS MODERATE HIGH PRES FOLLOWS A COLD FRONT THROUGH THE AREA. 
LITTLE CHANGE OVER CARIB.

FOR DAY 5..CHRISTMAS DAY..STRONG MID LEVEL TROUGH OVER MID ATLC 
ALONG 40W BEGINS LIFTING NE. MID LEVEL RIDGE OVER BAHAMAS 
WEAKENING SOME WITH MID LEVEL SWLY FLOW WORKING IT'S WAY OVER 
GULF. ON THE SURFACE DAY 5 ATLC WINDS DECREASE AS PRES GRADIENT 
RELAXES. WEAK FRONT OVER NW GULF BUT LITTLE PUSH TO MOVE IT IN 
SWLY FLOW ALOFT. CARIB WINDS MODERATE E OF 80W.   

WARNINGS...

ATLANTIC...
NONE.

CARIBBEAN...
NONE. 

GULF OF MEXICO...
NONE.

FORECASTER RRG