000 AXNT20 KNHC 220459 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED MAR 22 2006 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...WEATHER OBSERVATIONS... RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0500 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N10W 4N20W 1N30W EQ36W 1S46W. CLUSTERS OF MODERATE CONVECTION IS MOSTLY WITHIN 175 NM ON EITHER SIDE OF THE AXIS BETWEEN 19W-28W AND 38W-44W. A SMALL PATCH OF MODERATE WEAKENING CONVECTION IS FROM 3N-4N BETWEEN 13W-15W. ELSEWHERE...SCATTERED SHOWERS AND ISOLATED EMBEDDED TSTMS ARE WITHIN 250 NM OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... A BROAD FLAT MID-UPPER RIDGE COVERS THE EASTERN GULF AND W ATLANTIC WITH THE UPPER AXIS ALONG 77W/78W. THIS RIDGE HAS BECOME CONSIDERABLY LESS AMPLIFIED THAN IT WAS OVER THE PAST FEW DAYS. A WEAKENED SUB-TROPICAL JET EXTENDS FROM THE EPAC ACROSS MEXICO TO NORTH/CENTRAL FLORIDA. THE JET IS ADVECTING CONSIDERABLE MOISTURE INTO THE GULF OF MEXICO NW OF A LINE FROM 20N96W 26N87W 27N80W. SE OF THIS LINE...MODERATE SUBSIDENCE DOMINATES. AT THE SURFACE...A WEAK COLD FRONT EXTENDS FROM DAYTONA BEACH TO S MEXICO ALONG 29N81W 24N88W 19N96W...THEN BECOMES STATIONARY ALONG THE E SLOPES OF THE SIERRA MADRE MOUNTAINS TO 25N100W. ONLY THIN BANDS OF MULTILAYER CLOUDS AND ISOLATED SHOWERS EXTEND WITHIN 150 NM OF THE BOUNDARY. THICK LOW CLOUDS ARE BANKED UP AGAINST THE SOUTHERN PORTION OF THE SIERRA MADRE MOUNTAINS. SURFACE WINDS ARE SWLY FROM 15-20 KT AHEAD OF THE FRONT WITH STRONGER N/NW WINDS BEHIND THE BOUNDARY. THE COLD FRONT WILL CONTINUE SEWARD AND BECOME MORE HORIZONTAL ORIENTED TO A POSITION FROM THE STRAITS OF FLORIDA TO THE BAY OF CAMPECHE LATE THIS AFTERNOON BRINGING AN INCREASE IN THE CHANCE OF SHOWERS TO THE SOUTHERN GULF. THE FRONT WILL THEN BECOME STATIONARY AND DISSIPATE. A STRONGER COLD FRONT WILL FORM AND CROSS THE ENTIRE AREA ON FRIDAY BRINGING A NOTICEABLE COOLER AND DRIER AIRMASS. GALE CONDITIONS ARE EXPECTED LATE IN THE WEEK WITH THE PASSAGE OF THIS FRONT. CARIBBEAN... A STRONG MID-UPPER LEVEL HIGH IS CENTERED NEAR 8N57W WITH ITS WIDE ENVELOPE OF ANTICYCLONIC FLOW DOMINATING THE CARIBBEAN E OF 75W. CONSIDERABLE MID-UPPER LEVEL MOISTURE OVER S AMERICA IS FLOWING AROUND THE UPPER HIGH INTO THE CARIBBEAN SEA. THIS MOISTURE IS BREAKING UP AS IT TRAVELS EASTWARD AND STAYING MAINLY S OF 18N. ANOTHER MID-UPPER HIGH IS LOCATED IN THE EPAC NEAR 8N95W PRODUCING ANTICYCLONIC FLOW OVER CENTRAL AMERICA. STRONG SUBSIDENCE DOMINATES THE CARIBBEAN W OF 75W. AT THE SURFACE... PATCHES OF LOW CLOUDS ARE DRIVEN WESTWARD BY MODERATE EASTERLY TRADES. THE SURFACE FLOW BECOME SELY W OF 80W. PATCHY CLOUDS AND ISOLATED SHOWERS ARE OVER THE VIRGIN ISLANDS...PUERTO RICO AND HISPANIOLA ASSOCIATED WITH A DISSIPATING COLD FRONT TO THE NE OF THE AREA AND ENHANCED BY THE LOCAL OROGRAPHY. MODERATE TRADES ARE EXPECTED TO CONTINUE THROUGH THURSDAY AS THE ATLANTIC SURFACE RIDGE REMAINS IN PLACE. ATLANTIC... A RATHER ZONAL RIDGE/TROUGH/RIDGE PATTERN COVERS THE ATLANTIC. A A FLATTENING MID TO UPPER RIDGE IS OVER THE GULF OF MEXICO AND W ATLANTIC W OF 60W. AT THE SURFACE...A 1019 MB HIGH IS LOCATED NEAR 26N62W. MAINLY FAIR WEATHER EXISTS UNDER THE INFLUENCE OF THE RIDGE. A DEEP LAYER TROUGH COVERS THE CENTRAL ATLANTIC BETWEEN 30W-60W. AT THE SURFACE...A COMPLEX SERIES OF CYCLONES AND FRONTAL BOUNDARIES HAVE DEVELOPED IN THIS AREA...MOST OF THEM ARE NORTH OF 32N...HOWEVER TWO COLD FRONTS ARE IN THE DISCUSSION AREA. THE WESTERN-MOST FRONT IS DRAPED FROM A 985 MB LOW NEAR 40N44W ALONG 32N44W 30N55W 30N58W. LOW-MID LEVEL CLOUDS AND ISOLATED SHOWERS ARE WITHIN 100 NM AHEAD OF THIS BOUNDARY WITH WIDESPREAD STRATOCUMULUS CLOUDS BUILDING IN BEHIND THE FRONT. ANOTHER COLD FRONT IS LOCATED ABOUT 350-400 NM SE OF THE WESTERN-MOST FRONT AND ENTERS THE AREA ALONG 32N32W 24N46W THEN AS A DISSIPATING COLD FRONT TO 19N62W. A BROKEN LINE OF MULTILAYER CLOUDS AND ISOLATED SHOWERS...MAINLY N OF 28N...STRETCH 100 NM AHEAD OF THIS FRONT. A BROAD AMPLIFIED MID-UPPER RIDGE COVERS THE REMAINDER OF THE ATLANTIC E OF 30W. STRONG SUBSIDENCE IS EVIDENT ON WATER VAPOR IMAGERY FROM 15N-25N E OF 40W. AT THE SURFACE...A 1023 MB HIGH IS LOCATED NEAR 28N23W PRODUCING MAINLY FAIR WEATHER ACROSS THE EAST ATLANTIC. $$ CANGIALOSI