000
AXNT20 KNHC 051730
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON MAR 05 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 
SECTIONS OF SOUTH AMERICA...AND THE 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...THE ITCZ...
AXIS IS ALONG 8N12W 3N22W 1N31W EQ41W EQ52W. SCATTERED SHOWERS 
AND TSTMS ARE WITHIN 240 NM EITHER SIDE OF THE AXIS W OF 20W.

...DISCUSSION...

THE GULF OF MEXICO...
A STRONG SFC HIGH PRES RIDGE STRETCHED ACROSS THE CENTRAL AND 
WESTERN GULF COAST IS SUPPLYING THE REGION WITH FAIR AND RATHER 
COOL WEATHER ADVECTED BY STRONG NLY WINDS. THE LATEST QSCAT DATA 
AND SFC OBS SHOW THE STRONGEST WINDS GENERALLY 20-30 KT IN THE 
BAY OF CAMPECHE AND MAINLY S OF 28N E OF 90W. ALOFT...A 
MID/UPPER LEVEL TROUGH COVERS MUCH OF THE AREA WITH THE AXIS 
RUNNING FROM THE FL PANHANDLE TO NEAR 24N94W. THIS TROUGH IS 
ONLY GENERATING A VERY NARROW LINE OF HIGH LEVEL MOISTURE ACROSS 
THE E GULF AND CENTRAL FL. ELSEWHERE ABUNDANT DRY SUBSIDENT FLOW 
EXISTS ENHANCED BY UPPER CONFLUENCE BETWEEN THIS TROUGH AND 
STRONG RIDGE ALIGNED OVER MEXICO AND THE WRN U.S. ALONG 104W.

LOOKING AHEAD A DAY OR TWO...THE SFC RIDGE IS ANTICIPATED TO 
SLIDE E. THIS WILL ALLOW THE WINDS TO VEER ELY AND SLACKEN FROM 
W TO E. THE MID/UPPER TROUGH WILL ALSO PUSH EWD WITH THE FLOW 
BECOMING MORE ZONAL. THESE ELEMENTS WILL BRING ABOUT A MODIFIED 
MORE NORMAL AIRMASS.

THE CARIBBEAN SEA...
THE TAIL END OF A STRONG ATLC COLD FRONT LIES ACROSS CENTRAL 
CUBA TO NEAR 18N86W CONTINUING AS A SFC TROUGH INTO HONDURAS. W 
OF THE FRONT...THERE ARE PATCHES OF LOW TO MID LEVEL CLOUDS 
DRIVEN SWD BY STRONG NLY WINDS. SOME OF THIS MOISTURE IS 
OROGRAPHICALLY LIFTED OVER THE HIGH TERRAIN IN NRN CENTRAL 
AMERICA POSSIBLY PRODUCING A FEW SHOWERS. E OF THE 
BOUNDARY...THE WEATHER IS MORE TYPICAL WITH MODERATE ELY TRADES 
AND POCKETS OF LOW AND MID LEVEL CLOUDS STREAMING ACROSS THE 
SEA. IN THE MID AND UPPER LEVELS...A HIGH IS CENTERED OVER THE 
LEEWARD ISLANDS WITH AN EXTENSIVE AMOUNT OF DRY STABLE AIR E OF 
82W. THIS SINKING AIR IS KEEPING MOST OF THE MOISTURE PATCHES 
SHALLOW PROVIDING FAIR WEATHER ACROSS THE BULK OF THE REGION.

THE COLD FRONT WILL GRADUALLY BECOME DIFFUSE. AS IT DOES 
SO...THE SFC FLOW WILL BECOME MORE UNIFORM ELY ACROSS THE CARIB. 
OTHERWISE LITTLE CHANGE IS EXPECTED OVER THE NEXT COUPLE OF 
DAYS. 

WESTERN ATLANTIC...
BROAD DEEP LAYERED TROUGHING EXTENDS ACROSS MUCH OF THE AREA 
WITH TWO ASSOCIATED FRONTAL BOUNDARIES. THE MAIN ONE ENTERS 
THE AREA NEAR 32N58W CONTINUING SW ACROSS THE CENTRAL BAHAMAS 
AND INTO THE CARIB SEA. THIS FRONT IS CLEARLY DEFINED BY A ROPE 
CLOUD ON VIS IMAGERY AND A SWATH OF LOW TO MID LEVEL MOISTURE 
BEHIND IT WITHIN 120 NM. THE OTHER FRONT IS MORE OF A 
REINFORCEMENT EXTENDING FROM 32N62W TO 26N70W. W OF THE 
FRONTS...MODERATE TO STRONG N-NWLY WINDS ARE ADVECTING IN COOL 
AIR WITH PATCHES OF STRATOCUMULUS SEEN ON SAT 
IMAGERY...INDICATING THE COOL STABLE LOW-LEVELS.

LATEST SAT IMAGERY SHOWS THE FRONTS BEGINNING TO MERGE. GFS 
FORECASTS THE MAIN FRONT TO INCREASE IN STRENGTH LATE TUE INTO 
WED AS IT GAINS UPPER SUPPORT. AS THE FRONT PUSHES E...STRONG 
SFC HIGH PRES...CURRENTLY IN THE GULF...WITH BUILD OVERHEAD IN 
ITS WAKE.

CENTRAL AND EASTERN ATLANTIC...
STRONG SFC HIGH PRES DOMINATES THE ENTIRE AREA ANCHORED BY A 
1029 MB HIGH CENTERED NEAR 30N32W. THIS HIGH IS PRODUCING 
MODERATE TO STRONG TRADES ACROSS A GOOD PORTION OF THE REGION. 
THE MID TO UPPER LEVEL PATTERN IS MORE COMPLEX WITH A LARGE 
STRONG RIDGE EXTENDING ACROSS THE SUBTROPICS BEING CUT OFF OR 
ERODED BY A LARGE WELL DEFINED UPPER LEVEL LOW CENTERED NEAR 
19N44W. EXTENSIVE SWLY WINDS ALOFT...BETWEEN THE UPPER LOW AND 
AN RIDGE CENTERED NEAR 5N19W IS PRODUCING AN ABUNDANT AMOUNT OF 
MOISTURE FROM 12N-23N E OF 41W. BASED ON IR IMAGERY...THERE IS 
LIKELY SCATTERED SHOWERS FOUND IN THAT AREA. 

THE UPPER LOW IS ANTICIPATED TO MOVE N AND SLOWLY WEAKEN OVER 
THE NEXT COUPLE OF DAYS. THE SFC RIDGE WILL PRESS NE BUT SHOULD 
REMAIN IN CONTROL. 

$$
CANGIALOSI