颶風古斯塔夫 - 第二十六報 - 颱風討論

現在正值勞動節假期,故可能會稍晚

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WTNT42 KNHC 310308
TCDAT2
HURRICANE GUSTAV DISCUSSION NUMBER 26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008
1100 PM EDT SAT AUG 30 2008

THE EYE OF GUSTAV CROSSED WESTERN CUBA DURING THE PAST SEVERAL
HOURS AND IS NOW OVER THE SOUTHEASTERN GULF OF MEXICO. THE
HURRICANE WEAKENED DURING PASSAGE OVER LAND...WITH THE EYE BECOMING
CLOUD FILLED AND THE EYEWALL CONVECTION BECOME LESS IMPRESSIVE IN
BOTH SATELLITE AND RADAR DATA. IT IS ESTIMATED THAT THE INITIAL
INTENSITY HAS DECREASED TO 120 KT. AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT WILL ARRIVE IN THE STORM ABOUT 06Z TO DETERMINE THE
ACTUAL INTENSITY.

過去幾小時來古斯塔夫的風眼通過了古巴西部,現在位於墨西哥灣東南部.颶風在通過陸地
時
減弱...包含風眼被雲填充以及眼牆對流在衛星和雷達資料中變成不怎麼明顯. 推估起始
強度已降低到一二零節. 空軍備役颶風獵人機將會約零六時抵達風暴進行測量確實強度.

THE MOTION HAS BEEN WOBBLING BETWEEN 315 AND 320 DEGREES AT 13
KT...WITH 320/13 USED IN THIS PACKAGE. THERE IS NO CHANGE IN THE
SYNOPTIC REASONING...WITH GUSTAV BEING STEERED NORTHWESTWARD BY A
MID-LEVEL RIDGE OVER THE SOUTHEASTERN UNITED STATES...AND THEN BY
AN AMPLIFYING MID-LEVEL RIDGE OVER THE EASTERN UNITED STATES. THE
TRACK GUIDANCE IS TIGHTLY CLUSTERED THROUGH 72 HR...CALLING FOR
GUSTAV TO TRACK ACROSS THE GULF OF MEXICO AND MAKE LANDFALL IN
SOUTHEASTERN OR SOUTH CENTRAL LOUISIANA. THE NEW FORECAST TRACK
FOLLOWS THIS SCENARIO IS LIES JUST TO THE EAST OF THE PREVIOUS
TRACK. AFTER LANDFALL...THE DYNAMICAL MODELS DISAGREE ON HOW MUCH
MID-LEVEL RIDGING WILL DEVELOP NORTH AND WEST OF GUSTAV...WITH A
CONSIDERABLE SPREAD IN THE GUIDANCE. THE TRACK FORECAST AT THAT
TIME CALLS FOR A SLOW WESTWARD MOTION. IT SHOULD BE NOTED THAT THE
12Z UKMET FORECASTS GUSTAV TO TURN SOUTHWESTWARD AS IT REACHES THE
LOUISIANA COAST...WHICH APPEARS UNLIKELY AT THIS TIME.

運動在以十三節,三一五和三二零度之間晃動... 含三二零度/十三節作為此PACKAGE.
此處未對SYNOPTIC REASONING做出改變... 古斯塔夫正被位於美國東南部的中層脊
導引走西北向路徑... 然後由位於美國東部增強的脊導引. 路徑指引在七十二小時中
密集地群集一起... 報出古斯塔夫通過墨西哥灣然後在路易斯安納東南部或中部以南登陸
.
新的預報路徑跟隨著此情節,只是在前次路徑的東邊. 登陸之後... 動態模型對中層脊將
會
在古斯塔夫北邊與西邊如何發展不一致...在指引中出現滿多的分歧. 路徑預報在此時報
出一個向西緩慢的移動. 這必須注意的是在十二時UKMET預報古斯塔夫當接近
路易斯安納海岸時向西南西轉向... 這個在此時不太會出現.

THE INTENSITY FORECAST REMAINS PROBLEMATIC. ANALYSES FROM CIMSS AT
THE UNIVERSITY OF WISCONSIN SUGGEST THAT THE INTENSIFICATION
OCCURRED DESPITE ABOUT 20 KT OF SOUTHERLY VERTICAL SHEAR CAUSED BY
AN UPPER-LEVEL TROUGH OVER THE GULF OF MEXICO. THE PRESENCE OF
THIS SHEAR IS SUPPORTED BY RADAR DATA FROM THE KEY WEST WSR-88D...
WHICH CURRENTLY SHOWS A WEAK SOUTHERN EYEWALL AND LITTLE
PRECIPITATION SOUTH OF THE EYEWALL. THE SHIPS MODEL SUGGESTS THE
SHEAR SHOULD DIMINISH SOME DURING THE NEXT 18 HR...THEN INCREASE
AGAIN AS GUSTAV MOVES BETWEEN THE TROUGH AND AN UPPER-LEVEL
ANTICYCLONE TO THE SOUTHEAST. ON THE OCEAN SIDE...GUSTAV IS
FORECAST TO PASS OVER THE LOOP CURRENT DURING THE NEXT 24 HOURS...
THEN POSSIBLY PASS OVER A COUPLE OF COLD EDDIES NORTH OF 26N. ALL
GUIDANCE FORECAST RE-INTENSIFICATION DURING THE NEXT 24 HR...SO THE
INTENSITY FORECAST WILL CALL FOR A PEAK INTENSITY OF 135 KT IN 24
HR...FOLLOWED BY SLIGHT WEAKENING BEFORE LANDFALL DUE TO SHEAR AND
LOWER HEAT CONTENT...THEN FASTER WEAKENING OVER LAND. DUE TO THE
VARIOUS FACTORS...THIS IS A LOW CONFIDENCE INTENSITY FORECAST.

強度預報依然問題重重. 從威斯康辛大學的CIMSS分析推測增強已發生,儘管有一個
位於墨西哥灣的高層槽產生的約二十節的南向垂直風切. 此風切的存在由佛羅里達
西嶼的WSR-88D雷達證實...現在顯示出一個南側的弱眼牆,以及眼牆南部少許的降雨.
SHIPS模型推測風切應該在接下十八小時間縮減... 然後當古斯塔夫移動到槽和高槽反氣
旋
之間時對東南增強. 在海洋方面...預報古斯塔夫在接下來二十四小時通過套流...然後
有可能通過北緯二十六度的一對冷渦流. 所有的指引預報在接下來二十四小時間重新
再增強...所以強度預報將會二十四小時報一個一三五節的巔峰強度...接著登陸前因
風切和低海洋比熱造成許些減弱...然後在陸地快速減弱.根據以上各種因素...
這是個低可性度的強度預報

HURRICANE WARNINGS WILL LIKELY BE REQUIRED FOR PORTIONS FOR THE
NORTHERN GULF COAST ON THE NEXT ADVISORY.

颶風警報將會很可能必須在下個報告對灣區海岸北部發佈




(個人推測會至少以第三級颶風登陸)

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Geheimer Wetter- und Seeschlüssel der Kriegsmarine
Teil 2
Watterkurzschlüssel (3 Auflage)

Oberkommando de Kriegsmarine Berlin 1942


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