این طوفان برفی، در اواخر فصل زمستان (دوم و سوم مارس، 12 و 13 اسفند 1388) سال 2010 اتفاق افتاده. بخش هایی از توضیحات مربوط به این طوفان برفی رو اینجا میذارم، برای دیدن متن کامل و بسیار جالب این مطلب به لینکی که در ادامه گذاشتم برید:
March 2-3, 2010 Winter Storm
Event Headlines
...This was an impressive event with localized snow totals of 6 to 8 inches in Randolph and Chatham Counties...
...This was a late season winter storm that featured a deepening surface low which followed a preferred track for winter storms in central North Carolina...
...Uncertainty in the amount of forecast precipitation along with surface temperatures at or just above freezing, warmer soil temperatures then typically associated with accumulating snow, and the late season nature of the storm made snow accumulation forecasts very difficult...
...Mesoscale features including frontogentical forcing and the resultant bands of heavier snow along with local conditions played a critical role in the snow accumulations and the highly variable accumulations...
...Winter Storm Warnings were issued for 20 counties with 12 warnings verified and 3 missed events. The average lead time for all of the Winter Storm Warnings was 8.6 hours with all warnings preceded by advisories. Winter Weather Advisories were issued for 31 counties with 26 advisories verified. The average lead time for all of the Winter Weather Advisories was 17.7 hours...
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Surface Analysis
A Java Loop of surface analysis imagery from 00 UTC March 01 through 21 UTC March 03, 2010 shows the surface low developing across the western Gulf of Mexico at 12 UTC on March 01 with a 1035 MB area of high pressure centered over Ontario. By 12 UTC on March 02, the surface low had deepened to 1000 MB and was located over northern Florida while the area of high pressure had weakened to around 1025 MB and was located just slightly southeastward from its location 24 hours earlier. The surface low deepened slowly during the afternoon and evening of March 02 as it moved northeastward along the Southeast coast.
At 00 UTC on March 03, the surface low was located near Cape Hatteras with a pressure of 996 mb. By 12 UTC, the pressure had fallen to 984 MB (a drop of 12 MB in 12 hours) and at 00 UTC on March 4, the pressure had fallen to 982 MB or a drop of 14 MB in 24 hours. While the pressure fall of 14 MB in 24 hours is impressive, it does not meet the generally accepted definition of a "Meteorogical bomb" as defined by Sanders and Gyakum (1980). This definition is the formation of an "extratropical area of low pressure in which the central barometric pressure drops at least 24 millibars in 24 hours. It must be noted that the 24 MB requirement is true for storms that are north of 60 degrees latitude. Sanders and Gyakum set the pressure fall needed to reach bomb status at 23 millibars in 24 hours at 55 degrees and 19 millibars in 24 hours at 45 degrees (map of the western Atlantic with lines of latitude and longitude).
While a strong flow of cold air into the region was lacking and the area of high pressure to the north and west of the storm system was relatively weak and not in a favored location, the track of the developing storm system and its deepening nature was consistent with a classic winter storm scenario for central North Carolina.
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Final Thoughts and Lessons Learned
Three to four days in advance of the event, HPC expressed higher than normal confidence in the ECMWF model, which depicted a coastal surface low just off the Carolina coast. The GFS forecast a surface low crossing the upper Florida peninsula and continuing just north of due east into the open Atlantic. HPC noted a higher than normal clustering of ECMWF ensemble members as reason for confidence. The Canadian relatively quickly joined the ECMWF, while the GFS only gradually adjusted its low track westward. A very similar scenario occurred earlier in the season in the Carolinas which boosted local confidence in HPC and the ECMWF.
Early model and HPC preferences of a climatologically preferred storm track for winter weather for portions of central NC was noted. It also became increasingly evident three to five days prior to the potential event that the storm would likely have to produce its own cold air to generate wintry precipitation since there would not be a strong cold high pressure system in a favorable location to support and sustain wintery precipitation in central NC. However, the favored surface low track from the Gulf of Mexico northeast, close to the SC/NC coast along with the deepening nature of the storm suggested a potential winter storm. This potential was also enhanced by the potential for the mid/upper level low to track very close to central or eastern NC, giving credence to the capability of the storm producing its own cold air.
On February 20th, an email was sent to various users including broadcasters highlighting the anticipated pattern change and potential for a late season winter storm. The hazardous weather outlook mentioned the potential for late season storm in the 400 AM EST February 26th issuance which corresponded to a 4 day lead time.
Uncertainty in the amount of forecast precipitation along with surface temperatures at or just above freezing, warmer soil temperatures then typically associated with accumulating snow, and the late season nature of the storm made snow accumulation forecasts very difficult. Mesoscale features including frontogentical forcing and the resultant bands of heavier snow along with local conditions played a critical role in the snow accumulations and the highly variable accumulations. In the future, highlighting broader regions in Watches, Warnings, and advisories should be considered
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اینم لینک برای مشاهده کل مطالب: http://www4.ncsu.edu/~nwsfo/storage/cases/20100302
و اما در این متن چند عکس و فیلم بسیار زیبا هم وجود داره:
عکس ها یک طرف، این فیلم هم یک طرف. حتما فیلم (حجم: 5.40MB) رو دانلود کنید و ببینید:
http://www4.ncsu.edu/~nwsfo/storage/cases/20100302/photo/20100303.gilchrist.1.mp4
عکس ها یک طرف، این فیلم هم یک طرف. حتما فیلم (حجم: 5.40MB) رو دانلود کنید و ببینید:
http://www4.ncsu.edu/~nwsfo/storage/cases/20100302/photo/20100303.gilchrist.1.mp4
متاسفانه GFS تو آبدیت جدیدش بارشای مشهد رو تضعیف کرده::ناراحت:
مطمئن باش بارش دورقمی میل در انتظارتونه !
Tuesday12 February | Wednesday13 February | Thursday14 February | Friday15 February | Saturday16 February | Sunday17 February | Monday18 February | Tuesday19 February | Wednesday20 February |
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11° | 10° | 4° | 3° | 5° | 10° | 10° | 2° | 5° |
0 mm precipitation per 24 hours | 11 mm precipitation per 24 hours | 5 mm precipitation per 24 hours | 0 mm precipitation per 24 hours | 0 mm precipitation per 24 hours | 0 mm precipitation per 24 hours | 3.4 mm precipitation per 24 hours | 1.3 mm precipitation per 24 hours | 1.9 mm precipitation per 24 hours |
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Tuesday12 February | Wednesday13 February | Thursday14 February | Friday15 February | Saturday16 February | Sunday17 February | Monday18 February | Tuesday19 February | Wednesday20 February |
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12° | 9° | 6° | 9° | 12° | 10° | 4° | 5° | 5° |
12 mm precipitation per 24 hours | 0.3 mm precipitation per 24 hours | 0 mm precipitation per 24 hours | 0 mm precipitation per 24 hours | 0 mm precipitation per 24 hours | 3.6 mm precipitation per 24 hours | 0.3 mm precipitation per 24 hours | 0.1 mm precipitation per 24 hours | 0.2 mm precipitation per 24 hours |
پس بگو چرا ecm چند روزی ناقص آپ میشد !
گویا بازه زمانی این مدل معتبر به 15 روز افزایش یافته ، هرچند فعلا همون 7 روز رو میاره !
:خنده1::خنده1::تعجب2::خنده1:
تهرانیها آماده برف و باران شدید باشند
دوشنبه ۲۳ بهمن ۱۳۹۱ ساعت ۰۸:۴۶
مدیرکل پیشبینی و هشدار سریع سازمان هواشناسی کشور از بارش برف و باران در تهران خبر داد.
عرش نیوز :
مهندس عبدالرضا امیدوار شهری در گفتوگو با خبرنگار «محیط زیست» ایسنا، افزود: بررسی نقشههای پیشیابی هواشناسی نشان میدهد تا روز دوشنبه در غالب مناطق کشور جوی آرام حاکم خواهد بود. از اواخر وقت همین روز یک سامانه بارشی از نوار غربی، وارد کشور خواهد شد که در پی آن، در استانهای غربی کشور بارش باران و وزش باد را خواهیم داشت.
وی افزود: در روز سهشنبه بتدریج دامنه این بارشها به نواحی مرکزی و در روز چهارشنبه به استانهای شرقی کشور نیز کشیده خواهد شد و از بعدازظهر سهشنبه با نفوذ جریانات سرد شمالی به سواحل دریای خزر به تدریج بارش باران و کاهش دما در این مناطق آغاز و در اواسط روز پنجشنبه از شمال شرق کشور خارج خواهد شد. همچنین از بعدازظهر روز دوشنبه تا اواسط سهشنبه خلیجفارس مواج پیشبینی میشود.
وی به وضع هوای تهران در روز دوشنبه اشاره کرد و گفت: بر این اساس در این روز آسمان پایتخت نیمه ابری تا ابری همراه با بارش پراکنده خواهد بود که حداقل و حداکثر دما در این روز به 7 و 15 درجه سانتیگراد بالای صفر میرسد. همچنین در روز سهشنبه آسمان تهران نیمه ابری تا ابری همراه با بارش باران و برف پیشبینی شده است که حداقل و حداکثر دما در این روز به 4 و 13 درجه سانتیگراد بالای صفر خواهد رسید.