000 AXNT20 KNHC 220554 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN OCT 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 0515 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 46W S OF 22N MOVING W NEAR 10 KT. A 1012 MB LOW IS ALONG THE WAVE NEAR 14N. THIS WEAK SWIRL OF LOW LEVEL CLOUDS APPEARS TO HAVE OPENED UP AND WILL LIKELY BE REMOVED FROM THE MAP AT 06 Z. ASSOCIATED CONVECTION IS MINIMAL AND MAINLY WITHIN 360 NM E OF THE WAVE AXIS. THE GLOBAL MODELS...THAT HAVE THIS WAVE INITIALIZED...CONTINUE TO TRACK IT WNW AS AN OPEN WAVE. THE WEAK TROPICAL WAVE THAT WAS PREVIOUSLY ANALYZED NEAR THE LESSER ANTILLES HAS BEEN REMOVED FROM THE SFC ANALYSIS BECAUSE OF THE LACK EVIDENCE OF THIS FEATURE OVER THE PAST SEVERAL DAYS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 13N17W 6N30W 6N44W 7N58W. THE ERN PORTION OF THE AXIS IS ACTIVE WITH SCATTERED MODERATE CONVECTION E OF 17W FROM 6N-10N...WITHIN 240 NM N AND 120 NM S OF THE AXIS BETWEEN 21W-31W AND WITHIN 360 NM N OF THE AXIS BETWEEN 37W-44W. ...DISCUSSION... THE GULF OF MEXICO... QUIET WEATHER EXISTS ACROSS MUCH OF THE GULF OF MEXICO THIS EARLY MORNING THANKS TO DRY STABLE AIR ALOFT IN PLACE GENERATED BY AN ELONGATED UPPER RIDGE STRETCHED ACROSS THE AREA ORIGINATING FROM A HIGH CENTER IN THE SW GULF. A WEAK SFC FRONTAL BOUNDARY IS STATIONARY FROM CENTRAL FLORIDA TO 28N85W THEN LIFTING N AS A WARM FRONT TO THE MS/AL COASTLINE. SFC FLOW IS GENERALLY LIGHT FROM THE SE TO S PRODUCING TYPICAL EARLY FALL WARM AND HUMID CONDITIONS. HOWEVER A CHANGE IN AIRMASS IS IN STORE FOR THE AREA AS A STRONG COLD FRONT IS CURRENTLY MOVING OFF THE SE TEXAS COASTLINE. TEMPS HAVE FALLEN TO THE 40'S AND 50'S BEHIND THE BOUNDARY IN TEXAS WITH DEWPOINTS IN THE 30'S. A LINE OF SHOWERS AND TSTMS HAVE FORMED ALONG A PRE-FRONTAL TROUGH ANALYZED FROM THE SRN LOUISIANA TO 26N95W. THIS FRONTAL BOUNDARY WILL LIKELY CLEAR THE ENTIRE AREA LATE MON BRINGING MODIFIED COOLER AND MUCH DRIER AIR WITH IT. AN INCREASE IN NLY WINDS AND SEAS WILL FOLLOW THE BOUNDARY AS HIGH PRES BUILDS IN BEHIND THE FRONT. THE CARIBBEAN SEA... THE WEATHER IN THE CARIBBEAN HAS BECOME LESS ACTIVE THIS MORNING COMPARED TO THE PAST COUPLE OF DAYS. ONLY ISOLATED SHOWERS AND TSTMS ARE EMBEDDED IN A LARGE UPPER LEVEL MOISTURE PLUME E OF 72W. THIS MOISTURE IS MAINLY ASSOCIATED WITH DEBRIS TROPICAL MOISTURE ROTATING AROUND AN ANTICYCLONE CENTERED OVER THE LEEWARD ISLANDS. MORE IMPRESSIVE CONVECTION IS ON THE N SIDE OF THE RIDGE ASSOCIATED WITH A SFC LOW LOCATED ABOUT 300 NM NNE OF PUERTO RICO. THE CENTRAL AND WRN CARIBBEAN REMAIN QUIET WITH ONLY WIDELY SCATTERED SHOWERS. HOWEVER THE ATMOSPHERE ALOFT IS NOT AS STABLE AS IT WAS OVER THE PAST FEW DAYS DUE TO AN UPPER LOW...WHICH IS MOISTENING THE AIR SLIGHTLY...TRACKING WWD NOW CENTERED NEAR JAMAICA. A WEAK SFC TROUGH IS ANALYZED FROM HAITI SW TO NEAR THE NICARAGUA COAST. SFC WINDS ARE LIGHT AND VARIABLE NEAR THE TROUGH BUT APPEAR TO BE MORE TYPICAL EASTERLY ELSEWHERE. THESE WINDS ARE EXPECTED TO BECOME MORE UNIFORM FROM THE E AND INCREASE SLIGHTLY OVER THE NEXT DAY OR TWO. THE ATLANTIC OCEAN... IN THE WRN ATLC...AN UPPER HIGH IN THE SW GULF OF MEXICO HAS RIDGING THAT EXTENDS NE ACROSS THE NRN BAHAMAS. ANOTHER UPPER LEVEL RIDGE IS CENTERED OVER THE ERN CARIBBEAN AND CENTRAL ATLC WITH TWO HIGH CENTERS ONE NEAR 29N50W...WHICH IS GETTING PUSHED QUICKLY E...AND THE OTHER NEARLY STATIONARY OVER THE LEEWARD ISLANDS. A SLIGHT WEAKNESS IN THE RIDGE EXISTS OVER THE SRN BAHAMAS DUE TO THE UPPER LOW IN THE WRN CARIBBEAN. THIS PATTERN HAS PRODUCED PLENTY OF VERY DRY STABLE AIR N OF 25N W OF 45W. A THINNING MOISTURE PLUME EXISTS S OF 25N BETWEEN 55W AND 70W. MOST OF THE MOISTURE IN THIS REGION IS NOT DEEP IN NATURE EXCEPT FOR ONE CLUSTER OF CONVECTION THAT HAS BEEN INCREASING IN INTENSITY AND COVERAGE OVER THE PAST FEW HOURS FROM 21N TO 25N BETWEEN 61W AND 65W. CLOSER ANALYSIS IN THE REGION SUGGESTS THAT A SFC LOW PRES SYSTEM HAS FORMED NEAR 24N65W WITH A TROUGH EXTENDING FROM THIS LOW TO HAITI. THE SFC LOW IS EXPOSED LOCATED ABOUT 40-60 NM W OF THE EDGE OF THE DEEP CONVECTION. WLY UPPER LEVEL WINDS...ON THE N PERIPHERY OF THE ANTICYCLONE OVER THE LEEWARD ISLANDS...IS PROVIDING UNFAVORABLE CONDITIONS FOR THE CONVECTION TO WRAP AROUND THE SFC LOW. THE UPPER LEVEL ENVIRONMENT MAY BECOME SLIGHTLY LESS HOSTILE OVER THE NEXT DAY OR SO BEFORE BECOMING VERY UNFAVORABLE AS A LARGE TROUGH MOVES OFF THE U.S. COAST. THE TROPICAL ERN ATLC IS DOMINATED BY UPPER RIDGING WITH AN ANTICYCLONE CENTERED A COUPLE HUNDRED NM SSW OF THE CAPE VERDE ISLANDS. AN ELONGATED TROUGH STRETCHES FROM THE CANARY ISLANDS WSW ALONG 27N29W TO A DEVELOPING CUT OFF NEAR 24N35W. THE E ATLC SFC PATTERN IS DOMINATED BY E-W RIDGING IN THE SUBTROPICS FROM A 1020 MB NEAR 27N53W TO A 1020 MB HIGH NEAR 25N32W TO A 1017 MB HIGH OVER MOROCCO. THIS RIDGE IS BLEMISHED BY A BENIGN SFC TROUGH ALONG 32N40W 26N43W. $$ CANGIALOSI