Re: 大西洋Katrina颶風目前已達到五級了
簡單整理一下Katrina的動向
目前根據飛機觀測預估地面風速約140 kt
微波輻射儀(microwave radiometer)則顯示120-130 kt左右
最低氣壓904mb
(之前有出現902mb的 是墨西哥灣曾經出現的最低壓...)
IR衛星與飛機觀測都發現眼牆開始有些鬆動且往外擴張
預報猜測在登陸前強度可能略有減弱
但強度至少會有四級
而且強風區可能會因為眼牆擴張而增大
路徑預報也有大幅修正
目前Katrina以9kt往北北西移動
大概再過六小時會登陸
預測接下來會往北/北北東前進
目前最受關注的是紐澳良的情形
由於紐澳良海拔比海平面還要低約8英呎(2.5m)
所以Katrina可能帶來的20英呎高風浪
對這個從未經歷過四級以上颶風的城市有莫大威脅
(在此之前侵襲紐澳良最強的是1965年的三級颶風Betsy)
市長下令全城撤離
目前有一百萬人已離開
有約五萬人則進入地勢較高的路易斯安那球場避難
(但是球場最底層仍有可能進水)
但還有五萬人待在家中
巨大的損失應是難以避免
根據預估的風浪和雨量 之後可能要花三星期才能將城內積水抽乾
將會有上百萬人無家可歸 也可能有公共衛生問題
除了路易斯安那 佛羅里達 阿拉巴馬三州的海岸地區首當其衝
這幾個州的其他內陸區域也可能有龍捲風等劇烈天氣出現
NOAA Hurricane KATRINA Discussion
http://www.nhc.noaa.gov/text/refresh/MIATCDAT2+shtml/290249.shtml
000
WTNT42 KNHC 290249
TCDAT2
HURRICANE KATRINA DISCUSSION NUMBER 25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SUN AUG 28 2005
THERE ARE CONFLICTING SIGNALS REGARDING THE INTENSITY OF KATRINA.
THE NOAA AIRCRAFT NEAR 00Z REPORTED A PEAK FLIGHT LEVEL WIND OF 155
KT...WHICH WOULD NORMALLY CORRESPOND TO 140 KT AT THE SURFACE. THE
PRESSURE REMAINS EXTREMELY LOW...904 MB AT LAST REPORT. ON THE
OTHER HAND...THE STEPPED-FREQUENCY MICROWAVE RADIOMETER...OR
SFMR...SUGGESTED WINDS WERE IN THE 120-130 KT RANGE...AND LIMITED
DROPSONDE DATA ALSO SUGGESTED SOMETHING A LITTLE BELOW 140 KT.
THERE ARE ENOUGH QUESTIONS ABOUT THE PERFORMANCE OF THE SFMR AT
THESE SPEEDS FOR ME TO STICK WITH THE STANDARD 90 PERCENT
ADJUSTMENT FOR NOW.
THERE HAVE BEEN SOME MODEST CHANGES IN THE STRUCTURE OF KATRINA OVER
THE LAST SEVERAL HOURS. RECENT MICROWAVE PASSES SHOW THAT AN OUTER
EYEWALL IS IN THE FORMATIVE STAGES...AND THE LATEST IR IMAGES SHOW
A LESS WELL-DEFINED EYEWALL WITH MORE EVIDENCE OF OUTER BANDING.
THE NOAA HURRICANE HUNTERS ALSO REPORTED AN EROSION OF THE EYEWALL
IN THE SOUTHWEST QUADRANT. THESE OBSERVATIONS SUGGEST THAT THERE
COULD BE SOME WEAKENING OF KATRINA PRIOR TO LANDFALL. ALL THIS IS
RELATIVE...HOWEVER...AND KATRINA IS STILL EXPECTED TO BE OF AT
LEAST CATEGORY FOUR INTENSITY WHEN IT REACHES THE COAST. AN EYEWALL
REPLACEMENT AT THIS POINT IS NOT ALL GOOD NEWS...AS THEY ARE
GENERALLY ACCOMPANIED BY A BROADENING OF THE WIND FIELD...SO THAT
EVEN AS KATRINA WEAKENS THERE COULD BE AN INCREASE IN THE AREA THAT
EXPERIENCES MAJOR HURRICANE FORCE WINDS.
THERE HAS BEEN NO SIGNIFICANT CHANGE TO THE TRACK FORECAST. THE
INITIAL MOTION IS 335/9. KATRINA IS EXPECTED TO GRADUALLY TURN
NORTHWARD INTO A BREAK IN THE SUBTROPICAL RIDGE ASSOCIATED WITH A
LARGE MID-LATITUDE CYCLONE NEAR THE GREAT LAKES. MODEL GUIDANCE
REMAINS TIGHTLY CLUSTERED...WITH THE NOGAPS SHIFTING JUST A BIT
EAST OF ITS PREVIOUS TRACK. WHILE THERE IS GREAT SIGNIFICANCE FOR
THE CITY OF NEW ORLEANS IN THE DETAILS OF THE TRACK...TRACK
ANOMOLIES OF 30-50 MILES ARE STILL POSSIBLE EVEN 12-18 HOURS OUT.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 29/0300Z 27.6N 89.4W 140 KT
12HR VT 29/1200Z 29.2N 89.7W 135 KT
24HR VT 30/0000Z 31.8N 89.5W 85 KT...INLAND
36HR VT 30/1200Z 34.8N 88.1W 45 KT...INLAND
48HR VT 31/0000Z 37.7N 85.9W 30 KT...INLAND
72HR VT 01/0000Z 43.5N 78.5W 25 KT...INLAND
96HR VT 02/0000Z 50.0N 70.0W 25 KT...EXTRATROPICAL
120HR VT 03/0000Z...ABSORBED
CNN的報導
http://www.cnn.com/2005/WEATHER/08/29/hurricane.katrina/
USATODAY有關於NOAA飛機觀測Katrina的報導
http://www.usatoday.com/tech/science/2005-08-28-katrina-plane-lab_x.htm
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※ 編輯: Waitingchen 來自: 69.234.106.113 (08/29 14:58)
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