000 AXNT20 KNHC 021735 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI MAR 02 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N10W 4N20W EQ35W 3S47W. WIDELY SCATTERED MODERATE CONVECTION S OF 3N BETWEEN 24W-52W... PRIMARILY EXTENDING TO THE BRAZILIAN COAST. ...DISCUSSION... GULF OF MEXICO... A CUT-OFF MID/UPPER LOW MEANDERING NEAR THE WESTERN GREAT LAKES IS PRODUCING MOSTLY CYCLONIC FLOW ACROSS A MAJORITY OF THE CONTINENTAL US...WHICH IS IN TURN CAUSING NEARLY ZONAL FLOW ACROSS THE GULF WATERS. AN UPPER LEVEL JET...PARTLY RESPONSIBLE FOR YESTERDAY'S DEADLY TORNADO OUTBREAK...IS SCREAMING ACROSS THE DEEP SOUTH WITH MAXIMUM CORE SPEEDS UP TO 180 KT REPORTED AT SHREVEPORT LA AND MARFA TX AT 250 MB. A FRONTAL BOUNDARY ASSOCIATED WITH THIS SYSTEM NOW STRETCHES FROM NORTH FLORIDA SW TO 25N90W AS A SLOW-MOVING COLD FRONT...THEN AS A STATIONARY FRONT INTO THE FAR SW GULF. CONVECTION HAS REALLY DIED OFF NEAR THE FRONT WITH NOW ONLY A BROKEN LINE OF SCATTERED SHOWERS/ISOLATED TSTMS EXTENDING FROM APALACHEE BAY NE ACROSS GAINESVILLE AND JACKSONVILLE FL TO OFF THE CAROLINA COAST. WEAK HIGH PRES HAS BUILT IN BEHIND THE FRONT CENTERED OVER TEXAS AND THE MEXICAN COAST...BUT THE FRONT WILL REMAIN STALLED OVER THE AREA THROUGH MIDDAY SAT UNTIL A SECOND SHORTWAVE NOW OVER ARIZONA GIVES THE BOUNDARY A SECOND PUSH. THE FRONT IS EXPECTED TO MOVE SE OF THE GULF WATERS BY SUN EVENING WITH AN INCREASE IN WINDS TO GALE FORCE OVER THE SW GULF THROUGH THE WEEKEND. CARIBBEAN... A MID-LEVEL HIGH IS CENTERED OVER THE NW CARIBBEAN WITH AN ASSOCIATED RIDGE AXIS ALONG 19N STRETCHING ACROSS THE GREATER ANTILLES TO EXTREME SE MEXICO. IN ADDITION...THERE IS AN UPPER LEVEL TROUGH/SHEAR AXIS EXTENDING FROM THE VIRGIN ISLANDS SW TO JUST OFF THE COAST OF COLOMBIA...THEN SW ACROSS PANAMA. BOTH OF THESE FEATURES ARE PRODUCING MODERATE/STRONG SUBSIDENCE OVER THE REGION...THE STRONGEST AREA BEING JUST N OF ARUBA. LOW-LEVEL MOISTURE IS FAIRLY SCARCE...ALTHOUGH THERE IS JUST ENOUGH TO PRODUCE A FEW TRADE WIND SHOWERS ACROSS THE LEEWARD ISLANDS EXTENDING NW TOWARDS PUERTO RICO AND THE DOMINICAN REPUBLIC. ATLANTIC... A COLD FRONT HAS MOVED OFF THE GEORGIA/N FLORIDA COAST WITH SCATTERED SHOWERS/ISOLATED TSTMS EXTENDING UP TO 120 NM OFFSHORE N OF 29N. THIS AREA IS COVERED BY AN AREA OF UPPER DIFFLUENCE TRANSITIONING INTO A SHORTWAVE RIDGE ALONG 63W...WITH HIGH CLOUDS SPILLING EWD FROM FLORIDA TO 70W. FARTHER DOWNSTREAM...MID/UPPER TROUGH LIES FROM 32N50W TO 20N58W AND THE DIFFLUENCE E OF IT IS PRODUCING AN AREA OF DEVELOPING SCATTERED MODERATE CONVECTION N OF 26N BETWEEN 43W-53W. THIS ACTIVITY LIES NEAR A WEAKENING STATIONARY FRONT LYING ALONG 32N39W 29N50W 27N64W. TO THE S...A SURFACE TROUGH IS EMBEDDED WITHIN THE TRADES ALONG 51W S OF 20N...MAINLY AS A PRESSURE PERTURBATION BUT ALSO SHOWING SOME SIGNS OF SLIGHT TURNING IN THE CUMULUS FIELD. OVER THE E ATLC...A SURFACE RIDGE IS IN CONTROL WITH A 1027 MB HIGH CENTERED NEAR MADEIRA ISLAND AND THE AXIS STRETCHING SW TO 26N46W. A REX BLOCK APPEARS TO HAVE DEVELOPED IN THE UPPER LEVEL PATTERN WITH AN EXTENDED RIDGE AXIS EXTENDING FROM 15N43W IN THE TROPICS NE TO MADEIRA ISLAND THEN EWD INTO MOROCCO...LYING ON TOP OF A TROUGH FROM CENTRAL ALGERIA TO THE CANARY ISLANDS TO 10N30W SW OF THE CAPE VERDES. THIS PATTERN IS OBSTRUCTIVE TO PROGRESSIVE FLOW SO THINGS WILL REMAIN STAGNANT FOR ANOTHER 24 HRS OR SO. THERE IS VERY LITTLE MOISTURE TO WORK WITH... HOWEVER...SO THERE IS NO SIGNIFICANT PRECIPITATION FALLING ACROSS W AFRICA OR THE E ATLC WATERS...EXCEPT FOR THE SEA BREEZE OVER LIBERIA AND IVORY COAST. $$ BERG