000 AXNT20 KNHC 072341 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON MAY 07 2007 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 3N24W 2N35W EQ46W EQ51W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 18W-28W. SIMILAR ACTIVITY IS WITHIN 60 NM OF THE AXIS W OF 37W. ...DISCUSSION... GULF OF MEXICO... A BACK DOOR COLD FRONT ASSOCIATED WITH A LARGE OCCLUDED LOW PRES SYSTEM IN THE W ATLC CONTINUES TO SLOWLY PUSH SW IN THE GULF ANALYZED FROM WRN CUBA TO SRN LOUISIANA...MARKED BY PATCHES OF LOW LEVEL CLOUDS. BEHIND THE FRONT...15-20 KT E/NE WINDS ARE USHERING IN FAIRLY COMFORTABLE TEMPS AND A NOTICEABLE DROP IN HUMIDITY. ABUNDANT SUBSIDENCE IS KEEPING SKIES FAIR TO MAINLY CLEAR IN THIS REGION. W OF THE FRONT...THE AIRMASS IS MORE HUMID BUT OTHERWISE THE WEATHER CONDITIONS ARE SIMILAR WITH FAIR SKIES AND BRISK E TO SE WINDS. MORE ACTIVE WEATHER IS OCCURRING OVER NRN MEXICO INTO THE S CENTRAL U.S. ASSOCIATED WITH A STALLED FRONT AND E OF THE REGION OVER THE WRN ATLC WATERS...MORE ON THIS FEATURE BELOW. MOSTLY FAIR WEATHER IS EXPECTED TO PREVAIL OVER THE NEXT COUPLE OF DAYS. CARIBBEAN SEA... THE LARGE LOW PRES SYSTEM IN THE WRN ATLC IS RESULTING IN A WEAK PRESSURE PATTERN ACROSS THE CARIB WHICH IS KEEPING E/NE TRADES FAIRLY LIGHT...MOSTLY IN THE 10-15 KT RANGE EXCEPT TO 20 KT IN THE SE PORTION. THE BACK DOOR COLD FRONT ASSOCIATED WITH THE LARGE WRN ATLC LOW IS PUSHING SLOWLY SWD ACROSS THE CENTRAL BAHAMAS AND THE NRN SHORE OF CUBA. THERE ARE POSSIBLE ISOLATED SHOWERS ALONG THIS BOUNDARY. MORE IMPRESSIVE MOISTURE...IN THE FORM OF SCATTERED MODERATE CONVECTION...LIES OVER THE SRN COUNTRIES OF CENTRAL AMERICA AND NRN SOUTH AMERICA ASSOCIATED WITH THE ITCZ AND ENHANCED IN AN UPPER DIFFLUENT ZONE. DEBRIS MID-HIGH LEVEL CLOUDS AND EMBEDDED SCATTERED SHOWERS ARE BEING TRANSPORTED NE FROM THIS CONVECTIVE AREA TO THE LEEWARD ISLANDS BY STRONG SWLY UPPER FLOW. THIS SWLY WIND REGIME LIES BETWEEN EXTENSIVE ZONAL FLOW IN THE CENTRAL AND W CARIB AND AMPLIFIED RIDGING IN THE TROPICAL ATLC. LOOKING AHEAD A COUPLE DAYS...ELY TRADES WILL LIKELY INCREASE IN THE CENTRAL AND E CARIB AS HIGH PRES RIDGING BUILDS CLOSER. ALSO...SOME MODELS ARE SHOWING A MOISTURE SWATH DEVELOPING IN THE CENTRAL CARIB AS THE UPPER PATTERN BECOMES MORE DIFFLUENT. WESTERN ATLANTIC... THE HIGHLIGHT CONTINUES TO BE A LARGE OCCLUDED LOW PRES SYSTEM CENTERED OFF THE SE U.S. NEAR 31N75W...ANALYZED 998 MB. A TRAILING/BACK DOOR COLD FRONT EXTENDS FROM A TRIPLE POINT NEAR 32N67W ACROSS THE CENTRAL BAHAMAS...NRN CUBA AND THEN INTO THE GULF OF MEXICO. A STATIONARY FRONT RUNS FROM THE TRIPLE POINT TO 52W ALONG 32N WITH TWO WEAK FRONTAL WAVES. THIS LOW PRES SYSTEM HAS AN IMPRESSIVELY LARGE CIRCULATION BUT NOT MUCH DEEP MOISTURE...ESPECIALLY ON ITS S SIDE. ISOLATED SHOWERS ARE WITHIN 180 NM E OF THE FRONT AND BASICALLY ANYWHERE BETWEEN 50W AND THE FRONT ENHANCED BY UPPER SWLY FLOW. HOWEVER...WHAT IT IS PRODUCING IS VERY STRONG WINDS AS A VERY TIGHT PRES GRADIENT HAS SET UP BETWEEN THE LOW AND A STRONG HIGH PRES RIDGE OVER AND OFF THE NE U.S. COASTLINE. THIS PRES GRADIENT IS PRODUCING HURRICANE FORCE WINDS N OF THE AREA E OF THE CAROLINA COASTLINE AND STORM FORCE CONDITIONS IN OUR AREA N OF 28N W OF 74W. SEVERAL ADVISORIES AND WARNINGS HAVE BEEN POSTED ALONG THE COAST FROM SOUTH FLORIDA TO BEYOND THE CAROLINAS WHERE ROUGH SURF AND VERY DANGEROUS RIP CURRENTS ARE LIKELY OCCURRING. GLOBAL MODELS ARE IN GOOD AGREEMENT TRACKING THE LOW WWD TOWARD THE SE COAST BUT THERE ARE DIFFERENCES IN SPEED/TIMING. THE CURRENT FORECAST CALLS FOR WINDS TO BEGIN SLOWLY SUBSIDING...AS THE GRADIENT SLACKENS... FALLING BELOW GALE FORCE IN ABOUT 36 HOURS. CENTRAL AND EASTERN ATLANTIC... HEALTHY 1032 MB AZORES HIGH IS IN CONTROL OF THE PATTERN ACROSS THE ATLC E OF 50W. THIS HIGH IS PRODUCING A LARGE AREA OF MODERATE TO FRESH TRADES...STRONGEST E OF 25W WHERE THE PRES GRADIENT IS TIGHTENED DUE TO LOWER PRES OVER AFRICA. SCATTERED STRATOCUMULUS COVER MUCH OF THE REGION...EXCEPT S OF 20N E OF 35W WHERE THIS LOW-LEVEL CLOUD DECK IS ERODED BY SAHARAN DUST. IN THE UPPER LEVELS...THE MAIN FEATURE IS AN UPPER LOW ABOUT 180 NM WNW OF THE CANARY ISLANDS AND ASSOCIATED TROUGHING STRETCHING SWD ALONG 25W. THIS UPPER SYSTEM IS ONLY GENERATING SCATTERED PATCHES OF CIRRUS. $$ CANGIALOSI