From: Subject: Monday Weather Topic in Greater Depth Date: Sun, 20 Sep 2009 10:56:25 -0700 MIME-Version: 1.0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.ametsoc.org/amsedu/dstreme/last_week/m_sup.html X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 Monday Weather Topic in Greater Depth

SUPPLEMENTAL INFORMATION...IN GREATER DEPTH

To complement the Daily Weather Summary for Monday, = 31 August=20 2009

TOURING THE DATASTREME ATMOSPHERE WEBSITE

Welcome to DataStreme Atmosphere! You are launching on a study of the = earth's=20 atmosphere, focusing upon a variety of physical processes in the Earth = system=20 that we commonly associate with weather. This unique teacher enhancement = course=20 focuses on current weather events as a vehicle for understanding = processes such=20 as the flow and transformations of energy and water substance into and = out of=20 the atmosphere. Throughout this learning experience, you will be using = the=20 DataStreme Atmosphere website to access and interpret a variety = of=20 environmental information, including recent observational data. This=20 Supplemental Information provides a brief tour of the features of = this=20 DS Atmosphere website.

The first section of this home page is titled Learning Files, = which=20 contains the Daily Weather Summary, the Supplemental = Information=20 and Weekly Weather and Climate News. The Daily Weather Summary = is=20 posted each weekday morning during the semester and contains a = description of=20 the current and recent weather features across the United States, Puerto = Rico,=20 and the Virgin Islands. Reference is given to features on the previous = evening's=20 weather maps, permitting you to inspect the map features as you read the = summary. On Tuesday and Thursday , a "Concept of the Day" is included = that=20 develops some weather topic in detail. Supplemental Information = files,=20 posted several times per week as appropriate, are files that contain = interesting=20 weather-related features, such as the occurrence of a White Christmas, = or=20 lengthier descriptions of how to decipher a surface weather map. The = Weekly=20 Weather and Climate News includes links to various current news = items that=20 pertain to weather and climate issues or to events that occur around the = world=20 that are not typically associated with events covered in the Daily = Weather=20 Summary.

The last part of the Learning Files section is the Current Weather = Studies, which contains links to the two electronic files that are = delivered=20 each week. CWS A is posted on Monday of each week, while CWS B is placed = online=20 on Wednesday. As many as three images may accompany each of these weekly = Investigations. Click the appropriate links to download and print these=20 electronic components of the investigations as well as your Chapter = Progress and=20 Investigations Response forms.

The body of the DS Atmosphere website provides links to a = variety of=20 current weather maps, weather data in text format and a selection of = radar and=20 satellite images. Extra information, such as blank maps and a key to = weather map=20 symbols, are also available. Let's take a quick tour to become more = familiar=20 with the DS Atmosphere website.

Since we live on the Earth's surface, we are most interested in the = weather=20 that is occurring within a short vertical distance from the surface, = typically=20 no more than 10 meters (30 feet). Under Surface, click on = Isobars,=20 Fronts, Radar and Data. This image is a current weather map is a = depiction=20 of the weather across the continental US, with weather data plotted for = a few=20 selected locations, isobars (which represent lines of equal air = pressure),=20 fronts and areal coverage of precipitation and its intensity from = weather radar.=20 You can retrieve a variety of other depictions of the surface weather. = Within=20 the next two weeks, several Supplemental Information files will be made=20 available that will help in your interpretation of the weather map.

We often find it informative to monitor the extent, intensity and = progress of=20 precipitation as it moves across the nation. Weather radar is a tool = that=20 permits us to detect this precipitation. Under Radar, click on = Latest=20 Radar Animation. A 12-hour loop of radar images can be run, showing = the=20 movement of areas of precipitation as detected by the National Weather = Service=20 radar units across the country.

Likewise we can track the motion of clouds from the perspective of a=20 satellite platform located in a geosynchronous orbit that is located=20 approximately 35,000 km above the earth's equator, which is at a = distance where=20 the forward motion of the satellite is synchronous with Earth and so = appears=20 stationary with respect to a point on the earth's surface. Under=20 Satellite, click on Latest IR Animation to access a loop = of images=20 collected from infrared radiation sensors on geosynchronous satellites = that show=20 the evolution and movement of cloud patterns across the country.

Although we obtain much information from weather observations made at = the=20 earth's surface, meteorologists have been using instrumented weather = balloons to=20 obtain a three dimensional picture of the atmosphere up to altitudes = exceeding=20 20 km. Under Upper Air, click on 500 mb - Contours, Isotherms = &=20 Data. The accompanying chart portrays the temperature, humidity and = wind=20 conditions that the weather balloons collected within the last 12 hours = at an=20 altitude where the air pressure (500 millibars or mb) is approximately = one-half=20 that at sea level (approximately 1000 mb), or at an altitude of = approximately=20 5.5 km. Later in the semester, we will take time to explain this chart, = along=20 with those at 850 mb (or an altitude of approximately 1.5 km), 700 mb (3 = km) and=20 300 mb (10 km).

"The National Weather Service (NWS) provides weather, hydrologic, and = climate=20 forecasts and warnings for the United States, its territories, adjacent = waters=20 and ocean areas, for the protection of life and property and the = enhancement of=20 the national economy [from NWS Mission Statement]." To fulfill this=20 responsibility, NWS generates and issues weather forecasts from several=20 numerical weather prediction models interpreted by highly trained and=20 experienced Meteorologists. When necessary, the NWS will issue weather=20 advisories, watches or warnings to alert the public of a possible or = occurring=20 weather event that could be harmful or even deadly. Under Watches, = Warnings,=20 Advisories and Forecasts, click on Current NWS Weather Watches = and=20 Warnings, which will launch the official NWS page that has an = interactive=20 map of the continental US with site specific displays of active watch, = warnings,=20 advisories and short term forecasts. By th e end of this course, you = will become=20 sufficiently familiar with the terminology that is used to alert the = public of=20 adverse weather.

Weather represents a snapshot of the current state of the atmosphere, = while=20 climate represents a perspective of the longer term state of the = atmosphere,=20 extending from months to decades, or longer. Climate typically involves=20 interaction between the earth's atmosphere and the underlying surface, = including=20 both continent and ocean. As we will see during the sixth week of this = course,=20 the water or hydrologic cycle is an important factor that keeps our = planet=20 habitable. Unfortunately, variations in the hydrologic cycle over a = region can=20 result in disastrous flooding or drought. Under the Climate = heading,=20 click on Drought Monitor, which displays a map of the current drought = conditions=20 across the nation as prepared by the National Drought Mitigation = Center.

Extras include a variety of information that should be of use = to you=20 for a better understanding of the content of this course as well as for = your use=20 in the classroom. Click on Weather Map Symbols to see the variety = of=20 symbols that appear on the surface weather map.

Take a few minutes when you have time to browse the other data and=20 information sources available via the DS Atmosphere website. You = should=20 "bookmark" ("favorites") this page on your computer. Return frequently = to learn=20 more about the current weather resources available through DataStreme=20 Atmosphere.

Return to the Monda= y Daily=20 Summary

Prepared by Edward J. Hopkins, Ph.D., email mailto:hopkins@meteor.wisc.edu
=A9=20 Copyright, 2009, The American Meteorological Society. =