000 AXNT20 KNHC 261119 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SUN NOV 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1100 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 7N29W 8N47W 7N58W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM S OF THE AXIS BETWEEN 27W-36W. ISOLATED MODERATE IS FROM 4N-14N BETWEEN 26W-52W ENHANCED BY THE UPPER LOW E OF THE WINDWARD ISLANDS. ...DISCUSSION... THE GULF OF MEXICO... THE WEATHER ACROSS THE GULF IS FAIRLY UNEVENTFUL AS SFC HIGH PRES CONTINUES TO DOMINATE THE AREA. BREEZY 15-20 KT NE TO E WINDS IN THE ERN AND CNTRL GULF IS ADVECTING SOME LOW-LEVEL CLOUDS AND ISOLATED SHOWERS ACROSS CENTRAL AND SOUTH FLORIDA...MAINLY THE ERN HALF OF THE STATE...WITH SOME BROKEN CLOUDS PUSHING W ACROSS THE GULF WATERS. HOWEVER BECAUSE OF THE WIDESPREAD STRONG SUBSIDENCE ABOVE THE LOW-LAYER OF MOISTURE THERE IS LIMITED DEPTH TO THE CLOUDS. LIGHTER E TO SE WINDS EXIST IN THE WRN GULF. IN THE UPPER LEVELS...A RIDGE EXTENDS FROM THE EPAC ACROSS CENTRAL MEXICO INTO THE WESTERN HALF OF THE GULF. SLIGHT UPPER TROUGHING LIES ACROSS THE EASTERN HALF. GFS SHOWS THE TROUGH LIFTING OUT WITH THE RIDGE BUILDING ACROSS THE AREA. THIS SHOULD ALLOW TEMPS TO REMAIN NEAR OR SLIGHTLY ABOVE NORMAL OVER THE NEXT FEW DAYS. THE NEXT AIRMASS CHANGE IS ANTICIPATED TO AFFECT THE AREA LATE IN THE WEEK AS A POTENTIAL STRONG COLD FRONT APPROACHES. THE CARIBBEAN SEA... THE SFC LOW PRES SYSTEM IN THE SW CARIB HAS WEAKENED TO OPEN TROUGH...WHICH IS ANALYZED ALONG 78W FROM 9N-17N. DESPITE THE STRUCTURAL DECAY...SHOWER ACTIVITY HAS INCREASED SLIGHTLY THIS MORNING WITH SCATTERED MODERATE CONVECTION NOTED ON IR IMAGERY WITHIN 120 NM OF THE TROUGH AXIS S OF 15N. A SLOWLY WEAKENING STATIONARY FRONT EXTENDS FROM THE WINDWARD PASSAGE JUST W OF JAMAICA TO THE COAST OF HONDURAS. DEEP MOISTURE IS VERY LIMITED ALONG THE FRONT WITH ONLY ISOLATED SHOWERS WITHIN 150 NM OF THE SFC BOUNDARY. A VERY BROAD UPPER LEVEL RIDGE...CENTERED NEAR THE ABC ISLANDS...IS ADVECTING MOISTURE FROM THE ITCZ AND SPREADING IT ABOVE THE SFC FRONT INTO THE ATLC WITH CONSIDERABLE MID-HIGH LEVEL CLOUDINESS AND EMBEDDED SHOWERS NOTED BETWEEN 72W-82W. VERY DRY AIR/STRONG SUBSIDENCE LIES ABOVE THE ERN AND THE EXTREME WRN CARIB SUPPRESSING ANY DEEP CLOUDINESS. SCATTERED SHOWERS HAVE FORMED OVER THE PAST COUPLE OF HOURS JUST E OF THE LESSER ANTILLES...SOME OF THIS MAY MOVE ACROSS THE ISLANDS LATER THIS MORNING DRIVEN BY MODERATE TRADE WINDS. LITTLE CHANGE IS EXPECTED OVER THE NEXT FEW DAYS. LATE THIS WEEK...TRADES WILL LIKELY INCREASE AS STRONG HIGH PRES DEVELOPS TO THE N. THE ATLANTIC OCEAN... VERY DRY AIR ALOFT AND PATCHES OF LOW-LEVEL MOISTURE COVERS THE AREA W OF A WEAKENING STATIONARY FRONT THAT EXTENDS FROM E OF BERMUDA TO THE WINDWARD PASSAGE ALONG 32N59W 25N67W 20N74W. A WEAK AREA OF LOW PRES...ANALYZED AT 1014 MB...HAS DEVELOPED ALONG THE BOUNDARY NEAR 30N62W. MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS ARE ASSOCIATED WITH THE WEAK LOW/FRONTAL BOUNDARY AND EXTEND WITHIN 240 NM E OF THE FRONT N OF 25N AND WITHIN 150 NM EITHER SIDE S OF 25N. A NARROW UPPER TROUGH STRETCHES FROM 32N43W 22N52W TO AN UPPER LOW IN THE DEEP TROPICS NEAR 10N56W. UPPER LEVEL DIFFLUENCE BETWEEN THIS UPPER LOW AND AN AMPLIFIED RIDGE TO ITS E NEAR 9N39W IS ENHANCING SCATTERED SHOWERS AND TSTMS NEAR AND N OF THE ITCZ FROM 4N-14N BETWEEN 33W-52W. THIS AMPLIFIED MID/UPPER LEVEL RIDGE BECOMES HIGHLY ELONGATED AS THE NRN BRANCH OF THE SHORTWAVE TO ITS W IS IMPINGING ON IT. THE AXIS EXTENDS FROM THE HIGH CENTER IN THE TROPICS NORTHEASTWARD ALONG 23N33W 32N26W. AN AREA OF MID/UPPER LEVEL MOISTURE WITH EMBEDDED SCATTERED SHOWERS IS ALSO BEING PRODUCED BY UPPER DIFFLUENCE N OF 25N BETWEEN 31W-40W. AN UPPER LEVEL TROUGH CLIPS THE EXTREME ERN PORTION OF THE AREA EXTENDING FROM SPAIN ACROSS WRN AFRICA TO THE CAPE VERDE ISLANDS. PLENTY OF DRY STABLE AIR ALOFT IS LOCATED W OF THE TROUGH AXIS OUT TO 30W. AT THE SFC...MODERATE HIGH PRES RIDGING IS A GOOD PHRASE TO DESCRIBE THE PATTERN ACROSS THE SUBTROPICAL ATLC SUPPORTED BY A 1023 MB HIGH NEAR 30N27W AND A 1022 MB HIGH NEAR THE MADEIRA ISLANDS. THIS HIGH PRES IS INTERRUPTED BY THE FRONTAL BOUNDARY/WEAK LOW MENTIONED E OF BERMUDA. $$ CANGIALOSI