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Neil's WikiProject Homepage

Summary of Featured Articles and Good Articles

In order to become a featured article, you must obtain the little bronze star that would be placed in the upper right corner of the article page. When that bronze star is observed on the top right corner, then you know that it is a featured article. A featured article is one that shows the best that Wikipedia has to offer in that it is the end result (or polished as they call it) of a collaborative effort to create an article that gives the best information that is possible by the users that helped to contribute. It showcases what Wikipedia is all about and can be seen as an example for the rest of the articles.

As far as I can tell, on the WikiProject-Meteorlogy homepage, there is a scale in which the articles are being rated. With FA being the highest, A, then GA, B, Start, Stub, Current, and needed. By looking at the number of articles in each quality category, it looks like this project is really struggling with A and FA rated articles with most lying in the start and stub regions of quality.


WikiProject: Proposal

Currently I am considering doing my wiki project on the mesoscale phenomena of microburst winds. I have been fascinated with the way in which microburst winds have caused severe damage in a relatively small area. I am also intrigued by the outflow which has pure divergence characteristics that is also seen with some microbursts. Upon digging around Wikipedia, I found that there is an article that is written on microbursts, but it is not a large article and could have more information posted to it. Another alternative is to focus primarily on dry microbursts, an event which can be seen here in Utah and is one of the reasons I have interest in this subject. The internet has many sources of information relating to the subject and can be a valuable source of information. Seen below are just a couple of links in which I felt were reliable sources of information that I can pull from in order to contribute to the Microburst article found on Wikipedia. My contribution would focus on the why part of microbursts and not so much the what part. I would try to explain using the knowledge gained from my meteorology classes and especially my mesoscale/radar meteorology class to help explain what is happening and why it is happening when a microburst occurs. Microbursts can be extremely dangerous and have proven deadly in the past and I feel it is important that as much information as possible can be obtained on these powerful wind events.

Microburst
Microburst Handbook
University of Illinois
NCAR
NOAA

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WikiProject: Microbursts

The curl phase soon after an intense microburst impacted the surface

Definition
A microburst is an intense windshear. A small, very intense downdraft that descends to the ground resulting in a strong wind divergence (outflow of winds equal in all directions upon impact). The size of the event is typically less than 4 kilometers (2.5 miles) across. Microbursts are capable of producing tornado-strength winds with gusts as high as 75 m/s (168 MPH) causing significant damage. The life span of a microburst wind event is around 5-15 minutes.

Dry Microburst
When rain falls below cloud base or is mixed with dry air, it begins to evaporate and this evaporation process cools the air. The cool air descends and accelerates as it approaches the ground. When the cool air approaches the ground, it spreads out in all directions and this divergence of the wind is the signature of the microburst.
Dry microbursts, produced by high based thunderstorms that generate little surface rainfall, occur in environments characterized by a thermodynamic profile exhibiting an inverted-V at thermal and moisture profile, as viewed on a Skew-T log-P thermodynamic diagram. Wakimoto (1985) developed a conceptual model (over the High Plains) of a dry microburst environment that comprised of three important variables: mid-level moisture, a deep and dry adiabatic lapse rate in the sub-cloud layer, and low surface relative humidity.

Wet Microburst
Wet microbursts are downbursts accompanied by significant precipitation at the surface (Fujita, 1985) which are warmer than their environment (Wakimoto, 1998). These downbursts rely more on the drag of precipitation for downward acceleration of parcels than negative buoyancy which tend to drive "dry" microbursts. As a result, higher mixing ratios are necessary for these downbursts to form (hence the name "wet" microbursts). Melting of ice, particularly hail, appears to play an important role in downburst formation (Wakimoto and Bringi, 1988), especially in the lowest one kilometer above ground level (Proctor, 1989). These factors, among others, make forecasting wet microbursts a difficult task.


Characteristic Dry Microburst Wet Microburst
Location of Highest Probability Midwest/West Southeast
Precipitation Little or none Moderate or heavy
Cloud Bases As high as 500 mb Usually below 850 mb
Features below Cloud Base Virga Shafts of strong precipitation reaching the ground
Primary Catalyst Evaporative cooling Downward transport of higher momentum
Environment below Cloud Base Deep dry layer/low relative humidity/dry adiabiatic lapse rate Shallow dry layer/high relative humidity/moist adiabatic lapse rate
Surface Outflow Pattern Omni-directional Gusts of the direction of the mid-level wind




File:Ulogo10.gif University of Utah -- Department of Meteorology


This user is a member of WikiProject Meteorology.