000
AXNT20 KNHC 232327
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI MAR 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N11W 4N21W 2N31W 1N45W EQ52W. 
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS 
WITHIN 240 NM S OF THE AXIS E OF 18W. ISOLATED SHOWERS AND TSTMS 
WITHIN 150 NM EITHER SIDE OF THE AXIS ELSEWHERE.

...DISCUSSION...

GULF OF MEXICO...
AN AMPLIFIED FAIRLY NARROW MID-UPPER LEVEL RIDGE IS PUSHING 
SLOWLY E WITH THE AXIS ALIGNED ALONG 91W. THIS RIDGE IS 
DOWNSTREAM OF A STRONG CUT OFF LOW OVER THE SW STATES. STRONG 
SWLY FLOW BETWEEN THE RIDGE AND TROUGH IS ADVECTING A PLUME OF 
MOISTURE ACROSS CENTRAL MEXICO AND INTO THE SOUTH CENTRAL U.S. 
SOME OF THIS MOISTURE...WHICH APPEARS TO BE MAINLY IN THE FORM 
OF MID-HIGH LEVEL CLOUDS...IS SPILLING INTO THE GULF CONTAINED W 
OF THE RIDGE AXIS. THE ERN HALF OF THE REGION IS VERY STABLE  
WITH WIDESPREAD STRONG SUBSIDENCE NOTED E OF 88W. THIS 
SUBSIDENCE IS BEING PRODUCED BY UPPER LEVEL CONFLUENCE BETWEEN 
THE DOWNWARD BRANCH OF THE RIDGE AND A SHARP UPPER TROUGH ACROSS 
THE BAHAMAS AND THE FL KEYS. AT THE SFC...IT'S THE SAME STORY AS 
THE AREA REMAINS ON THE SW PERIPHERY OF STRONG CENTRAL ATLC HIGH 
PRES. THIS IS KEEPING WINDS MODERATE OUT OF THE E-SE BLOWING IN 
ISOLATED SHOWERS ACROSS S FLA...BUT FAR FEWER THAN THERE WERE 
YESTERDAY AS THE UPPER DYNAMICS HAVE SHIFTED E. LOOKING AHEAD TO 
THE WEEKEND...MAINLY FAIR WEATHER IS EXPECTED TO CONTINUE WITH 
RIDGING BOTH AT THE SFC AND ALOFT CONTROLLING THE PATTERN.   

CARIBBEAN...
A SHARP UPPER LEVEL TROUGH EXTENDS FROM THE WRN BAHAMAS ACROSS 
CUBA TO HONDURAS WITH AN EMBEDDED UPPER LOW NEAR 18N83W. E OF 
THIS TROUGH AXIS...UPPER LEVEL DIFFLUENCE IS FUELING SCATTERED 
SHOWERS AND TSTMS WITHIN 150 NM EITHER SIDE OF A LINE ALONG 
16N84W 20N73W. SIMILAR ACTIVITY IS OCCURRING OVER THE ISLAND OF 
HISPANIOLA ENHANCED BY LOW-LEVEL CONVERGENCE NEAR THE TAIL END 
OF A PERSISTENT SFC TROUGH...MORE ON THIS FEATURE IN THE 
ATLANTIC SECTION. OUTSIDE OF THE REGION OUTLINED...RATHER 
TRANQUIL CONDITIONS PREVAIL WITH FAIR SKIES AND MODERATE TRADES. 
OVER THE NEXT COUPLE OF DAYS...THE AREA OF MOISTURE IS LIKELY TO 
PERSIST AND SHIFT SLIGHTLY TO THE E WITH THE UPPER LOW/TROUGH.  

ATLANTIC...
UNSETTLED WEATHER CONTINUES TO AFFECT PORTIONS OF THE WRN ATLC 
WITH A LARGE AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS...S OF 
29N BETWEEN 54W-74W. THIS ACTIVITY IS BEING PRODUCED BY TWO 
ELEMENTS. ONE OF THESE IS UPPER LEVEL DIFFLUENCE TO THE E OF A 
SHORTWAVE TROUGH AXIS WHICH RUNS FROM BERMUDA TO THE WRN 
BAHAMAS. THE OTHER IS LOW-LEVEL CONVERGENCE NEAR A SFC TROUGH 
WHICH EXTENDS FROM 27N62W TO HISPANIOLA. THIS MESSY WEATHER IS 
EXPECTED TO CONTINUE FOR THE NEXT FEW DAYS AS THE SFC BOUNDARY 
HANGS AROUND...POSSIBLY MERGING WITH A COLD FRONT EARLY NEXT 
WEEK... AND THE UPPER TROUGH MOVES VERY SLOWLY TO THE NE. 

THE UPPER LEVEL FLOW ACROSS THE REMAINDER OF THE ATLC IS FAIRLY 
ZONAL WITH PATCHES OF HIGH CLOUDS SANDWICHED BETWEEN A SERIES OF 
SHORTWAVES N OF THE AREA AND BROAD FLAT RIDGING ACROSS THE 
EQUATORIAL ATLC. THE SFC PATTERN IS DOMINATED BY A 1033 MB HIGH 
CENTERED NEAR 37N44W...PRODUCING A LARGE AREA OF MODERATE 
TRADES. THIS HIGH IS EXPECTED TO CONTINUE ON IT'S SE TRACK 
PROVIDING FAIR WEATHER FOR MUCH OF THE CENTRAL AND E ATLC THIS 
WEEKEND.
       
$$
CANGIALOSI