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frintezza|2012-1-15 22:56
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顯示全部樓層
93S已被升為MEDIUM
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 25.9S
45.5E, IS NOW LOCATED NEAR 27.4S 38.7E, APPROXIMATELY 690 NM
SOUTHWEST OF ANTANANARIVO, MADAGASCAR. RECENT ANIMATED MULTISPECTRAL
SATELLITE IMAGERY AND HIGH RESOLUTION VISUAL IMAGERY SHOWS DEEP
CONVECTION ON EITHER SIDE OF A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC). THE LLCC HAS SHOWN TIGHTER ORGANIZATION
OVER THE PAST 12 HOURS AND AGENCY DVORAK ESTIMATES HAVE RISEN TO 25
KNOTS. RECENT SCATTEROMETRY DATA REVEALS AN EXTENSIVE AREA OF GALE
FORCE WINDS BETWEEN THE LLCC AND A RIDGE OF HIGH PRESSURE TO THE
SOUTHEAST. WINDS ARE SUBSTANTIALLY LIGHTER OVER THE NORTHERN
SEMICIRCLE. THE 150000Z PGTW UPPER LEVEL STREAMLINE ANALYSIS DEPICTS
AN UPPER LOW OVER THE LLCC, AND ANIMATED WATER VAPOR IMAGERY DOES
NOT INDICATE GOOD OUTFLOW CONDITIONS. HOWEVER, VERTICAL WIND SHEAR
IS LESS THAN 10 KNOTS AND SEA SURFACE TEMPERATURES IN THE REGION ARE
28 DEGREES. ALTHOUGH THE SYSTEM IS TRACKING STEADILY WESTWARD
THROUGH WARM WATERS AND A LOW SHEAR ENVIRONMENT, TOTAL PRECIPITABLE
WATER LOOPS INDICATE THE PRESENCE OF DRY AIR ON BOTH SIDES OF THE
SYSTEM. THE OVERALL ENVIRONMENT FOR FURTHER INTENSIFICATION TO
CYCLONE STRENGTH IS MIXED, BUT THERE HAS BEEN A TREND TOWARDS
INTENSIFICATION OVER THE PAST 12 HOURS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO
MEDIUM.
現時已到達比較高的緯度了, 不過仍有增強跡象
現時風切頗低, 水溫夠高
但是高空低壓跟乾空氣可能阻礙進一步發展 |
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