000 AXNT20 KNHC 270601 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI OCT 27 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 0545 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 36W S OF 13N MOVING W NEAR 10 KT. SOME CYCLONIC TURNING IS APPARENT IN THE LOW TO MID CLOUD FIELD VIA SHORTWAVE IR IMAGERY...THOUGH HIGH CLOUDS MOVING AROUND THE UPPER LOW JUST TO THE N OF THE WAVE ARE MASKING THE SIGNAL A BIT. SCATTERED MODERATE CONVECTION FROM 2N-8N BETWEEN 32W-40W. A TROPICAL WAVE ABOUT 390 NM E OF THE WINDWARD ISLANDS IS ALONG 53W S OF 20N MOVING W 10 TO 15 KT. A 1010 MB LOW IS ALONG THE WAVE NEAR 13N. PATCHES OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION NOTED FROM 11N-17N BETWEEN 48W-58W...THOUGH THE SHOWERS/TSTMS ARE POORLY ORGANIZED AND SIGNIFICANT DEVELOPMENT OF THIS SYSTEM IS NOT ANTICIPATED AT THIS TIME. TROPICAL WAVE IS ALONG 69W S OF 19N...0R BETWEEN ERN HISPANIOLA AND VENEZUELA...MOVING W 10 TO 15 KT. THIS WAVE IS BECOMING DIFFICULT TO LOCATE WITH JUST A HINT OF CYCLONIC TURNING NOTED S OF ERN DOMINICAN REPUBLIC AND THE MONA PASSAGE. THE WAVE IS EMBEDDED IN A DRY ENVIRONMENT JUST SE OF THE STRONG ATLC FRONTAL BOUNDARY...PRODUCING ONLY ISOLATED SHOWERS. ...THE ITCZ... ITCZ AXIS IS ALONG 10N14W 7N30W 6N45W 10N52W TO NEAR TRINIDAD NEAR 10N61W. A NARROW BAND OF SCATTERED MODERATE CONVECTION NOTED FROM 7N-9N BETWEEN 18W-32W. SCATTERED MODERATE ALSO SEEN FROM 4N-8N BETWEEN 40W-47W. ...DISCUSSION... THE GULF OF MEXICO... SURFACE HIGH PRESSURE HAS SLID NE OF THE AREA...NOW NEAR CAPE FEAR NORTH CAROLINA AT 1024 MB...AS THE NEXT FRONTAL SYSTEM GETS ITS ACT TOGETHER OVER THE SRN STATES. ASSOCIATED DEEP SLY FLOW OBSERVED IN THE 15-25 KT RANGE ACROSS THE GULF. NEARLY THE ENTIRE GULF OF MEXICO IS RAIN-FREE WITH MID TO UPPER RIDGING EXTENDING NNE FROM THE GULF UP THE EAST COAST. OVERALL UPPER FLOW IS MOSTLY ZONAL...WITH ABUNDANT DRY AIR ALOFT. TWO UNSETTLED WEATHER AREAS CONTINUE TO CLIP THE BORDER OF THE GULF...THE FIRST IS THE CLUSTER OF MODERATE TO STRONG CONVECTION IN THE YUCATAN CHANNEL AND THE SECOND IS THE CONVECTION HUGGING THE CENTRAL GULF COAST. THE FORMER IS ASSOCIATED WITH SFC TROUGHING AT THE TAIL END OF THE STRONG ATLC COLD FRONT. THE LATTER IS ASSOCIATED WITH THE NEXT FRONTAL SYSTEM THAT WILL ENTER THE NW PORTION OF THE REGION BY THIS MORNING. THIS FRONT WILL BRING AN INCREASE IN MOISTURE AHEAD OF IT AND COOLER/DRIER AIR BEHIND IT. NLY WINDS WILL INCREASE WITH GUSTS TO GALE FORCE BUILDING STEEP...SHORT PERIOD WIND WAVES AS STRONG SFC RIDGING BUILDS IN BEHIND THE FRONT. THE CARIBBEAN SEA... THE TAIL END OF A STRONG ATLC FRONTAL BOUNDARY EXTENDS THROUGH THE NW CARIBBEAN AS A TROUGH FROM HISPANIOLA TO THE NE PART OF THE YUCATAN PENINSULA. A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ASSOCIATED WITH THIS BOUNDARY NOTED FAR NW PORTION FROM 19N-23N BETWEEN 84W-87W. AN UPPER LOW IS SEEN IN WV IMAGERY BETWEEN HONDURAS AND CUBA NEAR 18N83W. A FEW ISOLATED SHOWERS/TSTMS SEEN ROTATING AROUND THIS UPPER LOW FROM 16N-20N BETWEEN 80W-85W. THE SW CARIBBEAN DOMINATED BY BROKEN TO OVERCAST HIGH CLOUDS ROTATING ANTICYCLONICALLY AROUND AN UPPER HIGH E OF NICARAGUA NEAR 13N79W. THE ERN CARIBBEAN IS MAINLY DRY...WITH MODERATE DRY AIR ALOFT AND NLY UPPER FLOW BETWEEN THE UPPER HIGH E OF NICARAGUA AND A BROAD UPPER LOW NEAR TRINIDAD. THIS FLOW IS ADVECTING SOME MOISTURE S OF HISPANIOLA AND PUERTO RICO THOUGH...FROM THE LITTLE LEFTOVER CONVECTION FROM THE ATLC COLD FRONT. MOISTURE WILL LIKELY BE ON THE INCREASE IN THE ERN CARIB THIS WEEKEND AS A TROPICAL WAVE AND WEAK AREA OF LOW PRES...CURRENTLY 390 NM E OF THE WINDWARD ISLANDS...MOVES INTO THE AREA. THE ATLANTIC OCEAN... A HIGHLY AMPLIFIED PATTERN IS ESTABLISHED ACROSS THE ATLC. HIGH PRES RIDGING EXISTS ACROSS THE ERN U.S. AND A PORTION OF THE WRN ATLC W OF 67W. A LARGE STRONG TROUGH LIES TO THE E OF THE RIDGE. THE ASSOCIATED COLD FRONT REMAINS WELL DEFINED ALONG 32N48W 24N60W TO THE DOMINICAN REPUBLIC. SCATTERED SHOWERS AND TSTMS ARE WITHIN 250NM E OF THE FRONT. BEHIND THE FRONT...A DRIER AND COOLER AIRMASS EXISTS WITH STRATOCUMULUS AND NW FLOW. THE ASSOCIATED NW SWELL WILL CONTINUE TO SPREAD E THROUGH THE CARIBBEAN THROUGH THE WEEKEND AND SUBSIDE EARLY NEXT WEEK. A LARGE STRONG MID/UPPER LEVEL RIDGE IS LOCATED E OF THE TROUGH CENTERED IN THE SUBTROPICS NEAR 29N31W. THIS RIDGE COVERS THE REMAINDER OF THE ATLC E OF 45W AND N OF 19N WITH DRY STABLE AIR ALOFT WIDESPREAD IN THE REGION. SFC HIGH PRES IS ALSO ANALYZED UNDERNEATH THE MID/UPPER RIDGE WITH A 1022 MB HIGH NEAR 25N39W AND A 1024 MB HIGH NEAR 32N27W. AN UPPER LOW...WHICH CUT OFF FROM THE STRONG TROUGH THAT WAS IN THE E ATLC EARLIER THIS WEEK...IS TRACKING WSW CENTERED NEAR 14N37W. W OF THIS UPPER LOW THERE IS AN UPPER HIGH NEAR 14N51W. UPPER DIFFLUENCE NEAR THIS HIGH IS HELPING SUPPORT THE CONVECTION AROUND THE TROPICAL WAVE ALONG 53W. $$ WILLIS/CANGIALOSI