000 AXNT20 KNHC 221712 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED NOV 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1700 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 6N24W 4N35W 4N47W 3N53W. SCATTERED SHOWERS AND TSTMS ARE WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 28W-40W. SOME OF THIS ACTIVITY MIGHT BE ASSOCIATED WITH A WEAK LOW AMPLITUDE TROPICAL WAVE ALONG 37W/38W. HOWEVER...BECAUSE OF ITS VERY WEAK NATURE AND DUE TO THE HOSTILE UPPER LEVEL ENVIRONMENT THIS WEAK FEATURE WAS NOT ADDED TO THE MAP. ...DISCUSSION... THE GULF OF MEXICO... A STRONG VERTICALLY STACKED OCCLUDED LOW PRES SYSTEM HAS BEEN SLOWLY DRIFTING NE OFF THE SE U.S. COASTLINE. THE GULF LIES TO THE W...DRY SIDE...OF THIS SYSTEM WITH STRONG NLY MID-UPPER LEVEL FLOW AND STRONG SUBSIDENCE NOTED ACROSS NEARLY THE ENTIRE AREA. AN UPPER LEVEL RIDGE IS BUILDING EASTWARD ACROSS THE WRN GULF WEAKENING THE UPPER LEVEL WINDS THERE. AT THE SFC...HIGH PRES CONTINUES TO DOMINATE ANCHORED BY A 1027 MB HIGH IN THE NW GULF NEAR 27N94W. THIS HIGH PRES RIDGING IS FURTHER S AND WEAKER THAN THE PAST FEW DAYS ALLOWING WINDS TO SUBSIDE SUBSTANTIALLY IN THE WRN GULF. STRONGER WINDS...15-20 KT WITH ONE OR TWO BUOYS REPORTING SLIGHTLY HIGHER...STILL EXIST IN THE CNTRL AND ERN GULF. THESE WINDS CONTINUE TO ADVECT COLD AIR INTO THE REGION. THIS MORNING TEMPS WERE IN THE VERY UNSEASONABLE 30'S AND 40'S ACROSS FLORIDA WITH EVEN SOME WET SNOW FLAKES MIXED IN WITH LIGHT RAIN/DRIZZLE ACROSS THE CNTRL AND NRN PART OF THE STATE LATE LAST NIGHT. THINNING STRATO-CU CLOUDS STILL EXIST IN THE SRN GULF. THE STACKED LOW OFF THE SE COAST WILL PULL NE AT A FASTER RATE AS THE UPPER RIDGE IN THE WRN GULF BUILDS E. THIS UPPER LEVEL PATTERN ALONG WITH THE CONTINUED WEAKENING PRES GRAD AT THE SFC WILL ALLOW THE AIRMASS TO MODIFY GRADUALLY RETURNING TEMPS TO NORMAL VALUES. THE CARIBBEAN SEA... A SHARP AIRMASS DIFFERENCE CONTINUES TO BE VERY EVIDENT IN THE CARIB. THE DIVIDER IS A STRONG FRONT WHICH EXTENDS FROM THE ATLC ACROSS WRN HAITI THEN STATIONARY VERY FAR S TO PANAMA NEAR 10N79W. BEHIND THE FRONT...NOTABLE COOL AND DRY AIR IS STILL BE ADVECTED INTO THE REGION ON STRONG NLY WINDS. THESE WINDS HAVE DECREASED THIS MORNING ALLOWING THE GALE WARNING TO EXPIRE BUT THEY ARE STILL RATHER STRONG JUST BELOW GALE FORCE. CLUSTERS OF SCATTERED MODERATE CONVECTION IS LOCATED WITHIN 120 NM EITHER SIDE OF THE STALLED FRONT. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE BETWEEN A HIGHLY AMPLIFIED STRETCHED UPPER RIDGE AND THE STRONG TROUGH ACROSS THE SW ATLC AND NW CARIB. GFS HAS DONE A PRETTY GOOD JOB IN SHOWING THE MOISTURE SWATH THINNING SLIGHTLY AND SHRINKING IN WIDTH OVER THE PAST FEW DAYS. THE MODEL CONTINUES TO SHOW THAT TREND WITH IT GETTING PUSHED BACK TO THE W BY THE TRADES. THE ERN ATLC IS QUIET WITH UPPER LEVEL CONFLUENCE ...BETWEEN A BROAD UPPER LEVEL LOW OVER VENEZUELA AND UPPER RIDGING IN THE CNTRL ATLC...PRODUCING PLENTY OF DRY STABLE AIR ALOFT E OF 70W. TRADE WINDS E OF THE FRONT ARE LIGHT TO MODERATE SPREADING TYPICAL ISOLATED SHALLOW SHOWERS ACROSS THE SEA. A PATCH OF SOMEWHAT DEEPER MOISTURE...ASSOCIATED WITH THE MOIST FLOW OF THE UPPER LOW OVER VENEZUELA...IS LOCATED JUST E OF THE LESSER ANTILLES. SOME OF THIS MAY MOVE ACROSS THE ISLANDS TONIGHT OR TOMORROW. THE ATLANTIC OCEAN... A PRONOUNCED TROUGH/RIDGE/TROUGH PATTERN EXISTS ACROSS THE SUBTROPICAL AND TROPICAL ATLC. A STRONG COMPLEX OCCLUDED LOW PRES SYSTEM WITH SEVERAL EMBEDDED LOW CENTERS OFF THE SE COASTLINE IS MOVING TO THE NE. DOPPLER RADAR CONTINUES TO SHOW BANDS OF NUMEROUS SHOWERS AND TSTMS ON THE COLD BACK SIDE OF THE LOW AFFECTING MUCH OF THE CAROLINAS. THE STRONG TRAILING COLD FRONT EXTENDS FROM THE ERN MOST LOW ALONG 32N68W 26N70W ACROSS THE SE BAHAMAS AND DEEP INTO THE CARIB WHERE IT HAS STALLED. THIS SFC BOUNDARY ALONG WITH UPPER DIFFLUENCE IS GENERATING A CONSIDERABLE AMOUNT OF MOISTURE BETWEEN 66W-73W. W OF THE FRONT...MUCH COLDER AIR IS ADVECTED BY STRONG W-NWLY WINDS. A STRONG MID-UPPER LEVEL RIDGE LIES TO THE E OF THE COMPLEX WEATHER PATTERN CENTERED IN THE SUBTROPICS NEAR 30N59W. A HIGHLY ELONGATED TROUGH IS LOCATED E OF THE RIDGE WITH SEVERAL UPPER LEVEL LOWS EMBEDDED FROM A LARGE CUT OFF NEAR 26N25W TO A SMALL UPPER LOW NEAR 24N47W EXTENDING DEEP INTO THE TROPICS TO A BROAD UPPER LOW OVER VENEZUELA. PLENTY OF DRY AIR ALOFT EXISTS ACROSS MOST OF THE AREA BETWEEN 32W-66W N OF 20N. S OF 20N E OF THE CARIBBEAN...THERE IS A CONSIDERABLE AMOUNT OF MOISTURE ADVECTED FROM THE ITCZ BY SWLY UPPER LEVEL FLOW AND DRIVEN EASTWARD BY A WLY JET. THIS MOISTURE DOES NOT APPEAR TO BE VERY CONVECTIVE...BASED ON IR IMAGERY...ALTHOUGH SCATTERED SHOWERS ARE LIKELY OVER A LARGE AREA BETWEEN 23W-60W MOSTLY S OF 18N. AT THE SFC...HIGH PRES IS THE RULE E OF THE WRN ATLC FRONTAL BOUNDARY ANCHORED BY A 1030 MB HIGH NEAR 34N47W AND A 1029 MB HIGH S OF THE AZORES NEAR 35N24W. THIS STRONG RIDGING IS INTERRUPTED A BIT BY A WEAK 1018 MB LOW NEAR 23N34W...WHICH IS ASSOCIATED WITH THE LARGE CUT OFF UPPER SYSTEM MENTIONED. THE LOW IS ONLY A SWIRL OF LOW CLOUDS WITH SCATTERED SHOWERS WELL NE OF THE CENTER FROM 23N-27N BETWEEN 26W-29W. $$ CANGIALOSI