000 AXNT20 KNHC 261748 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 26 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 34W/35W S OF 14N MOVING W 15 KT. A NARROW NW-SE STRETCHED MOISTURE SURGE AND ASSOCIATED AREA OF LOW-LEVEL TURNING IS APPARENT ON SATELLITE IMAGES AND THE MIMIC TPW ANIMATION. THERE ARE A FEW SHOWERS EMBEDDED IN THE CLOUD TURNING WITHIN 60 NM OF THE WAVE AXIS...BUT THIS ACTIVITY IS VERY WEAK. MODEL GUIDANCE INDICATES THAT SOME OF THE WAVE ENERGY MAY BE ABSORBED BY THE LARGE DEEP LAYER TROUGH TO THE NW OVER THE NEXT DAY OR TWO...AS WAS LIKELY THE CASE FOR THE WAVE BELOW. TROPICAL WAVE IS ALONG 47W S OF 13N MOVING W 10-15 KT. THE MIMIC TPW ANIMATION SHOWS SOME TROPICAL MOISTURE...LIKELY ASSOCIATED WITH THIS FEATURE...PRESSING TO THE N AND BECOMING ABSORBED BY THE EXTENSIVE DEEP LAYER SWLY FLOW TO THE N OF THE WAVE LAST NIGHT. SINCE THEN...THERE IS NOT MUCH EVIDENCE OF THE TROPICAL PORTION OF THE WAVE...SO JUST NUDGED IT W FOLLOWING CONTINUITY. THERE IS NO SIGNIFICANT SHOWER ACTIVITY IN ITS VICINITY. TROPICAL WAVE IS LOCATED IN THE CENTRAL WRN CARIB S OF JAMAICA ALONG 77W MOVING W 10-15 KT. THERE IS NO WAVE-LIKE SIGNATURE APPARENT IN ANY OF THE AVAILABLE DATA AT THE MOMENT. MOST OF THE SHOWER AND TSTM ACTIVITY...LOCATED TO THE E AND W OF THE WAVE...IS ASSOCIATED WITH OTHER SYNOPTIC SCALE SYSTEMS. FOR DETAILS SEE THE CARIBBEAN DISCUSSION BELOW. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 3N24W 2N35W 6N46W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN 35W-41W. SIMILAR CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 16W-18W. DISCUSSION... GULF OF MEXICO... THE FRONTAL BOUNDARY THAT CROSSED THE ENTIRE AREA OVER THE PAST SEVERAL DAYS IS NOW STARTING TO PUSH ITS WAY BACK TOWARD THE GULF AS A SLOW MOVING WARM FRONT. AS OF 15Z...THE FRONT WAS ANALYZED ALONG OR JUST E OF THE E COAST OF FLA INTO THE STRAITS AND THEN DISSIPATING ACROSS THE NW CARIB. ISENTROPIC LIFT IS PRODUCING A LARGE AREA OF SCATTERED SHOWERS AND TSTMS OVER S FLORIDA AND FARTHER N OVER THE CAROLINAS. THIS ACTIVITY IS MORE ISOLATED IN NATURE ACROSS N AND CENTRAL FLA AND THE GULF WATERS OUT TO 85W. A VERY WEAK STRETCHED SFC TROUGH LIES TO THE W OF THE FRONT ANALYZED ACROSS THE GULF FROM NE TO SW ALONG 29N85W 25N89W 22N93W. THERE IS NOT MUCH MORE THAN SCATTERED CLOUDINESS ALONG THIS BOUNDARY...SO THE PRIMARY INFLUENCE IS A WIND SHIFT. MOST OF THE GULF...W OF 86W...LIES UNDER A VERY SUBSIDENT ENVIRONMENT TO THE S OF A LARGE CUT OFF OVER THE MIDWEST. THIS STABLE ENVIRONMENT IS PROVIDING A NICE SEASONABLE DAY. LOOKING AHEAD INTO THE WEEKEND...MODEL GUIDANCE SHOWS THE FRONT CONTINUING ITS SLOW W PROGRESS AS IT BECOMES INCREASINGLY DIFFUSE. THE MOISTURE SWATH IS EXPECTED TO SHIFT W WITH THE BOUNDARY AND WEAKEN. MODELS ALSO SHOW NLY WINDS INCREASING AS THE GRADIENT TIGHTENS BETWEEN THIS LOW PRES AREA AND STRONG SWD SURGING CANADIAN HIGH PRES. CARIBBEAN SEA... A COUPLE OF LOW PRES AREAS ARE ANALYZED IN THE REGION THIS AFTERNOON. IN THE E CARIB...A WSW MOVING LOW IS CENTERED TO THE SW OF PUERTO RICO NEAR 17N68W...ANALYZED 1006 MB. THIS LOW HAS NOT BECOME ANY BETTER ORGANIZED TODAY AS THE LOW-LEVEL CIRCULATION IS WELL EXPOSED W OF THE DENSE CLOUDINESS. THE MOST ACTIVE AREA OF CONVECTION IS FAR TO THE E OVER THE LESSER ANTILLES FROM 13N-18N E OF 64W. THIS PRECIP IS BEING ENHANCED BY A SMALL UPPER LOW LOCATED NEAR THE VIRGIN ISLANDS. THE LOW IS EXPECTED TO CONTINUE MOVING ON A GENERAL WSW OR W TRACK AND TROPICAL CYCLONE FORMATION...IF ANY...IS NOT EXPECTED TO OCCUR UNTIL THE SYSTEM REACHES THE WESTERN CARIBBEAN SEA IN ABOUT TWO DAYS. SHOWERS AND SQUALLS ARE EXPECTED TO CONTINUE OVER PORTIONS OF THE VIRGIN ISLANDS...PUERTO RICO...AND HISPANIOLA. ANOTHER LOW PRES SYSTEM HAS FORMED NEAR THE TAIL END OF A DISSIPATING FRONT IN THE W CARIB CENTERED NEAR 18N83W...1009 MB. THIS DEEP LAYER BROAD AREA OF LOW PRES IS NOT VERY WELL ORGANIZED WITH LITTLE CONVECTION ON ITS S SIDE. CONVECTION HAS INCREASED TO THE N OF THE SYSTEM...HOWEVER...FROM 19N-22N BETWEEN 81W-84W. ADDITIONAL DEVELOPMENT...IF ANY...IS EXPECTED TO BE SLOW TO OCCUR AS IT STAYS QUASI-STATIONARY. ELSEWHERE ...SCATTERED MODERATE CONVECTION IS IN THE SW CARIB S OF 13N BETWEEN 74W-82W TRIGGERED BY AN E-W LOW-LEVEL TROUGH BETWEEN THE LOW PRES SYSTEMS DISCUSSED. ATLANTIC... SHOWERY WEATHER IS AFFECTING THE SE U.S. AND THE COASTAL WATERS. THIS ACTIVITY IS ASSOCIATED WITH A SLOW MOVING WARM FRONT. FOR DETAILS REFER TO THE GULF SECTION ABOVE. HIGH PRES CONTROLS MUCH OF THE SW ATLC E OF THE FRONT ANCHORED BY A 1027 MB HIGH 150 NM NW OF BERMUDA NEAR 34N66W. THE TIGHT PRES GRADIENT BETWEEN THIS HIGH AND LOW PRES IN THE E CARIB IS PRODUCING 20-30 KT E TO NE WINDS ACROSS THE AREA S OF 29N BETWEEN 58W AND 78W. FARTHER E...A LARGE DEEP LAYER LOW PRES TROUGH LIES OVER THE CENTRAL ATLC EXTENDING SSW FROM A DEEP LAYER LOW. THE SFC LOW IS LOCATED TO THE SW OF THE UPPER SYSTEM CENTERED NEAR 30N47W...1009 MB. DIFFLUENCE ALOFT TO THE S AND E OF THE BROAD ELONGATED TROUGH IS SPREADING DEBRIS CLOUDINESS FROM THE E CARIB ACROSS THE TROPICAL ATLC WITHIN 240 NM S OF A LINE ALONG 18N63W 18N49W AND THEN NEWD WHERE THE MOISTURE DEEPENS SOME WITHIN 360 NM E OF A LINE ALONG 18N49W 31N37W. THE E ATLC IS RATHER TRANQUIL UNDER THE INFLUENCE OF SFC RIDGING EXTENDING SWD FROM HIGH PRES N OF THE AZORES AND A WELL DEFINED UPPER ANTICYCLONE CENTERED NEAR 15N30W. $$ CANGIALOSI