Guest baseball25 Posted June 27, 2010 Report Posted June 27, 2010 WTNT41 KNHC 272035TCDAT1TROPICAL DEPRESSION ALEX DISCUSSION NUMBER 9NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010400 PM CDT SUN JUN 27 2010SATELLITE IMAGES SHOW THAT ALEX CONTINUES TO HAVE A LARGE ANDWELL-DEFINED CIRCULATION WITH PLENTY OF BANDING FEATURES. NEAR THECENTER...HOWEVER...CONVECTION HAS DECREASED...PROBABLY DUE TO THEINFLUENCE OF LAND. THE MEXICAN NAVY SURFACE STATION AT ISLA PEREZRECENTLY REPORTED 30 KT WINDS...SO THE INITIAL WIND SPEED IS KEPTAT 30 KT. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT ISSCHEDULED TO INVESTIGATE ALEX THIS EVENING AFTER THE CENTER MOVESOFFSHORE. THE INITIAL MOTION OF ALEX IS A LITTLE SLOWER...WITH A 12-HR AVERAGEYIELDING AN ESTIMATE OF 300/8. THE PIVOTAL QUESTION FOR THELONG-TERM FORECAST TRACK OF THE TROPICAL CYCLONE APPEARS TO HINGEON THE STRENGTH OF MID-LEVEL RIDGING OVER THE NORTHERN GULF COAST. THE MODELS THAT SHOW A WEAKER RIDGE...SUCH AS THE CMC/GFS/HWRF...ALLOW THE TROPICAL CYCLONE TO TURN TOWARD THE NORTH-NORTHWEST ANDNORTH AND APPROACH THE NORTHWESTERN GULF COAST IN SEVERAL DAYS. OTHER MODELS...SUCH AS THE ECMWF/UKMET/NOGAPS...HAVE A STRONGERRIDGE AND KEEP ALEX MOVING TO THE NORTHWEST OR WEST-NORTHWEST INTOMEXICO. OVERALL THE MODEL GUIDANCE HAS SHIFTED SLIGHTLY TO THENORTH...AND THE OFFICIAL FORECAST IS A LITTLE TO THE RIGHT OF THEPREVIOUS ONE. SINCE THERE IS CONSIDERABLE MODEL SPREAD...THIS TRACKFORECAST IS THOUGHT TO BE OF BELOW-AVERAGE CONFIDENCE.WHILE THERE IS A LARGE DISAGREEMENT ON THE TRACK OF ALEX...THEGLOBAL MODELS ARE IN MUCH BETTER AGREEMENT WITH THE LARGE-SCALEENVIRONMENT. THESE MODELS SHOW AN UPPER-RIDGE AXIS SITTING VERYNEAR THE TROPICAL CYCLONE FOR THE NEXT SEVERAL DAYS...IN AFAVORABLE POSITION FOR INTENSIFICATION. COMBINED WITH THE WARMWATERS OF THE GULF OF MEXICO...STRENGTHENING IS LIKELY...ESPECIALLYAFTER ALEX MOVES FARTHER AWAY FROM THE YUCATAN PENINSULA. GIVEN THEOVERALL ENVIRONMENTAL CONDITIONS...IT IS SURPRISING THAT THEGFDL/HWRF DO NOT SHOW MORE INTENSIFICATION...LEAVING THE SYSTEM ASA TROPICAL STORM FOR MANY DAYS. THE STATISTICAL GUIDANCE SEEMS MOREREASONABLE AND THE NHC FORECAST IS CLOSE TO THE SHIPS MODEL...ANDIS NOT TOO DISSIMILAR FROM THE PREVIOUS FORECAST.
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