Course 2 topics are below. After this topic list are links to each of the lessons posted. Weather School Topics: 1. Graphical Forecast Models 2. Instability 3. Wind Shear 4. Dynamic Lift 5. Severe Thunderstorm Cookbook 6. Bombogenesis 7. CAPE, HELICITY, EHI, MOISTURE/LI 8. Convective Wind Gusts 9. Hail 10. Tornadoes 11. Lifted Condensation Level 12. Total Totals, K Index values 13. L57 and SWEAT 14. Capping 15. Theta-E 16. LFC and EL 17. Wind Shear and Severe Storms 18. Some Unique Sounding Types 19. Forecasting Winter Precipitation 20. Heavy Rain 21. Temperature Forecasting 22. Precipitation Forecasting 23. Features on Weather Models 24. Severe Weather Indices Page 25. The Low Level Jet 26. Fog Forecasting 27. Mesoscale Weather Data 28. Busted Forecast 29. Wind 30. Significant Tornadoes and Hurricanes 31. The Hodograph, Wind Shear and Storm Character 32. Weather Changers 33. Storm Convective Lift 34. Overweight CAPE 35. Severe Thunderstorm Structure 36. Wet Bulbing and Forecasting 37. Optimum Snowfall Region 38. Elevated Convection 39. Disaster Weather 40. Precipitable Water Haby's Weather School METEOROLOGIST JEFF HABY Lesson 1 Topic: Graphical Forecast Models Welcome back to another semester of Haby’s weather school! This is the first of a 40 lesson course that will focus on weather forecasting, severe weather and thermodynamics. There will be a posting each Monday, Wednesday and Friday. Today’s lesson is a compilation of what to look for on the graphical forecast models on each significant pressure level and interpreting the model data. The lesson can be found at the link below: http://www.theweatherprediction.com/winterwx/shortrange/interpret/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 2 Topic: Instability One of the ingredients for severe thunderstorms is instability. This will commonly be referenced by the Lifted Index (LI) or CAPE (Convective Available Potential Energy) value. Instability can be referenced in several ways such as parcel (static) instability, latent instability and convective (potential) instability. Today’s lesson goes over defining these specific types of instability and their importance to severe weather forecasting. Today’s lesson can be found at the link below: http://www.theweatherprediction.com/severe/ingredients/instability/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 3 Topic: Wind Shear One of the ingredients for severe thunderstorms is wind shear. This is a change of wind speed and wind direction with height and its interaction with a storm. It can also be the change of wind speed and wind direction along a horizontal surface and its influence on the mesoscale environment. Today’s lesson can be found at the links below: Shear’s influence on a storm: http://www.theweatherprediction.com/habyhints2/669/ Convergence and Divergence produced by wind shear: http://www.theweatherprediction.com/habyhints2/628/ Defining vertical wind shear: http://www.theweatherprediction.com/severe/ingredients/windshear/ Shear and thunderstorm type: http://www.theweatherprediction.com/habyhints/275/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 4 Topic: Dynamic Lift This lesson defines dynamic lifting, explains several important meteorological processes that produce lift and explains its importance to weather forecasting. It is also important to define the differences between convective ascent and dynamic lift. Today’s lesson can be found at the links below: Dynamic lift: http://www.theweatherprediction.com/severe/ingredients/lifting/ Contrast with convective ascent: http://www.theweatherprediction.com/habyhints/336/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 5 Topic: Severe Thunderstorm Cookbook Today’s lesson compiles the concepts mentioned in the previous lessons into one. Instability, moisture, wind shear and lift are important ingredients for severe thunderstorms. Additional specific supports for severe weather including 500-mb vorticity, the jet stream, low level inflow and convective instability are also discussed. Today’s lesson is at the following link: http://www.theweatherprediction.com/severe/cookbook/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 6 Topic: Bombogenesis With the developing nor’easter in the eastern U.S., this is a good opportunity to go over the term “bombogenesis”. This lesson will also include information on “thundersnow” and Nor’easters. Today’s lesson is at the links below: Bombogenesis: http://www.theweatherprediction.com/habyhints/188/ Thundersnow: http://www.theweatherprediction.com/habyhints/334/ Nor’easter: http://www.theweatherprediction.com/habyhints3/793/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 7 Topic: CAPE, HELICITY, EHI, MOISTURE/LI Today’s lesson examines 4 index charts that are important for severe weather forecasting. The link below goes over the operational significance of each term (1) CAPE, (2) Helicity, (3) Energy Helicity Index, (4) Lifted Index/Low Level Moisture), the influence each term has on severe weather, and operational images for these index values: http://theweatherprediction.com/thermo/images/ Additional resources for these concepts are below: CAPE defined: http://www.theweatherprediction.com/habyhints/305/ MU CAPE: http://www.theweatherprediction.com/habyhints2/634/ More on Helicity: http://www.theweatherprediction.com/habyhints2/633/ Energy Helicity Index (EHI): http://www.theweatherprediction.com/habyhints/314/ More on Energy with Helicity: http://www.theweatherprediction.com/habyhints2/679/ LI (Lifted Index): http://www.theweatherprediction.com/habyhints/300/ RH PANEL: http://www.theweatherprediction.com/habyhints/105/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 8 Topic: Convective Wind Gusts One of the features of a storm that can cause severe weather is the storm wind called convective wind gusts. This lesson defines and explains the causes and results of convective wind gusts. Today’s lesson is at the following link: http://www.theweatherprediction.com/habyhints2/584/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 9 Topic: Hail One of the features of a storm that can cause severe weather is hail. This lesson defines and explains forecasting information that is relevant to hail analysis and prediction. Today’s lesson is at the following links: http://www.theweatherprediction.com/severe/hail/ http://www.theweatherprediction.com/habyhints2/585/ http://www.theweatherprediction.com/habyhints/166/ http://www.theweatherprediction.com/severe/gianthail/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 10 Topic: TORNADOES This lesson focuses on defining a tornado, the general set-up, ingredients that cause tornado formation, forecasting of tornadoes, and weather phenomena that are not tornadoes. The links below cover these concepts: Formation: http://www.theweatherprediction.com/habyhints2/417/ Ingredients: http://www.theweatherprediction.com/habyhints2/586/ Helicity with CAPE:http://www.theweatherprediction.com/habyhints2/679/ False Tornadoes: http://www.theweatherprediction.com/habyhints3/721/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 11 Topic: Lifted Condensation Level This lesson focuses on how the Lifted Condensation Level (LCL) is found on a Skew-T. Operational significance and differences from Convective Condensation Level (CCL) are also discussed. The lesson is at the links below: http://www.theweatherprediction.com/habyhints/299/ http://www.theweatherprediction.com/habyhints/307/ http://www.theweatherprediction.com/habyhints/160/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 12 Topic: Total Totals, K Index values Two index values that are used to assess convective potential are the Total Totals and K Index. This lesson looks at the terms that make up each equation and the operational significance of the value obtained. Pitfalls that can result are also discussed. The lesson is at the links below: Total Totals: http://www.theweatherprediction.com/habyhints/302/ K Index: http://www.theweatherprediction.com/habyhints/303/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 13 Topic: L57 and SWEAT This lesson looks at an index called L57 which is the temperature lapse rate between 700 and 500 millibars. How the value is calculated is covered along with the operational significance. This lesson also looks at the SWEAT index which stands for Severe Weather Threat Index. There are several variables that go into determining this value. Operational significance of values obtained from this index will be examined. The links to the lesson are below: L57: http://www.theweatherprediction.com/habyhints/298/ SWEAT: http://www.theweatherprediction.com/habyhints/304/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 14 Topic: Capping Today’s lesson is on capping. This occurs when heat and moisture are trapped from convectively lifting from the lower troposphere up into the upper troposphere. A cap can prevent storms from occurring but it can also help storms to be more severe in cases where the cap is broken when heat and moisture are maximized in the lower troposphere. This lesson defines capping, explains operational significance using two index values (Convective Inhibition, and cap), explains the physical processes that develop and weaken a cap, and explains in more detail the relationship between severe weather and capping. What creates a cap?: http://www.theweatherprediction.com/habyhints2/405/ Convective Inhibition (CINH) index: http://www.theweatherprediction.com/habyhints/306/ Cap index: http://www.theweatherprediction.com/habyhints/308/ Cap and CINH info: http://www.theweatherprediction.com/habyhints/163/ Erosion of cap: http://www.theweatherprediction.com/habyhints3/725/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 15 Topic: Theta-E Theta-E is an index used to help assess the contributions that moisture and temperature have together in order to help assess the instability environment. Two ways instability can increase are by increasing low level dewpoints and increasing low level temperature. Both these factors will increase Theta-E also. Moisture contains latent energy that is released when moisture condenses. Increasing temperature adds increasing thermal energy to the air. Since storms can be more prevalent when Theta-E is high and regions with the highest Theta-E can be the initial burst point for convection, forecasters examine Theta-E as a piece of the puzzle when putting together a storm forecast. Today’s lesson is found at the links below: http://www.theweatherprediction.com/habyhints/324/ http://www.theweatherprediction.com/habyhints/162/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 16 Topic: LFC and EL The topic for today covers Level of Free Convection (LFC) and Equilibrium Level (EL). The LFC is the base of the region of CAPE while the EL is the top of the region of CAPE. This lesson will cover defining these terms on a Skew-T along with forecasting implications (including tornadoes): LFC: http://www.theweatherprediction.com/habyhints/309/ EL: http://www.theweatherprediction.com/habyhints/310/ LFC and tornadoes: http://www.theweatherprediction.com/habyhints2/586/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 17 Topic: Wind Shear and Severe Storms This lesson looks at an important factor in severe weather formation: wind shear. Indices from the Skew-T diagram that directly or indirectly use wind shear information include: Sweat Index (SW), Helicity (HEL), Energy Helicity Index (EHI), Storm Motion (STM), Bulk Richardson Number (BRN), Storm Relative Directional Shear (SRDS), and 0-3 km Shear. Operational interpretation and significance of each of these index values are explained at the links below: SW: http://www.theweatherprediction.com/habyhints/304/ HEL: http://www.theweatherprediction.com/habyhints/313/ EHI: http://www.theweatherprediction.com/habyhints/314/ STM: http://www.theweatherprediction.com/habyhints/312/ BRN: http://www.theweatherprediction.com/habyhints/315/ SRDS: http://www.theweatherprediction.com/habyhints/316/ 0-3 km Shear: http://www.theweatherprediction.com/habyhints/322/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 18 Topic: Some Unique Sounding Types This lesson looks at a few unique sounding types. Each link for the sounding type includes important notes about the sounding and weather forecasting implications: Goalpost (Loaded Gun) Sounding: http://www.theweatherprediction.com/thermo/soundings/gun/ Inverted-V Sounding: http://www.theweatherprediction.com/thermo/soundings/invertedv/ Strong Morning Inversion: http://www.theweatherprediction.com/thermo/soundings/inversion/ Wet Microburst Sounding: http://www.theweatherprediction.com/thermo/soundings/wetmicro/ Front Sounding: http://www.theweatherprediction.com/thermo/soundings/front/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 19 Topic: Forecasting Winter Precipitation This lesson includes modules on forecasting winter precipitation. The topics of the winter weather modules include general forecasting, extended forecasting, short range forecasting, nowcasting, thickness criteria, lake effect snow forecasting, and determining precipitation type. The modules are available at the link below: http://www.theweatherprediction.com/winterwx/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 20 Topic: Heavy Rain This lesson marks the half way point of the course this semester! Today’s topic is on the ingredients for heavy rain and it is at the link below: http://www.theweatherprediction.com/heavyrain/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 21 Topic: Temperature Forecasting Temperature forecasting involves developing a forecast for the expected high temperature and low temperature for the next day and future days. It will also include temperature trends throughout the future especially when the temperature is expected to change abruptly such as with the passage of a front. An important temperature to forecast also includes whether the temperature will get below freezing and for how long. Record high and low temperatures as well as the normal high and low temperature can also be referenced to put the current weather into perspective. Today’s lesson goes over some of the tools used when developing a temperature forecast and the lesson is available at the link below: http://www.theweatherprediction.com/tempfx/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 22 Topic: Precipitation Forecasting Today’s lesson examines general precipitation forecasting. The important influences from each model panel and other data are discussed. The two basic ingredients for precipitation are adequate moisture and adequate lift (dynamic lift). The addition of instability makes thunder more likely when a precipitation event occurs. Today’s lesson is at the link below: http://www.theweatherprediction.com/precipfx/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 23 Topic: Features on Weather Models This lesson looks are various unique features, events and processes that can show up on the graphical weather forecast models. The lesson is located at the link below: http://www.theweatherprediction.com/modelwx/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 24 Topic: Severe Weather Indices Page Today’s lesson includes several indices that are used to forecast thunderstorms and severe weather along with the operational interpretation and notes. Indices are used together along with other weather data to develop an idea of the environment in which storms will form and the characteristics that storms will take: http://www.theweatherprediction.com/severe/indices/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 25 Topic: The Low Level Jet The low-level jet is a common experience for forecasters in the Great Plains and Eastern US. As the name implies, it is a fast moving ribbon of air in the low levels of the atmosphere. It can rapidly transport Gulf moisture and warmer temperatures to the North at speeds ranging from 25 to over 70 knots. There are two primary classifications of low-level jets. They are the nocturnal low level jet and the mid-latitude cyclone induced low level jet. Both are described in this lesson along with sketches characterizing their formation at the link below: http://www.theweatherprediction.com/severe/llj/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 26 Topic: Fog Forecasting Fog is a major nuisance to travelers. Whether driving or flying, fog results in travel delays and in some cases cancellations. Forecasting fog can be difficult, but its proper prediction is extremely important. The proper prediction of fog can have people better prepared to avoid delays and being late for work. The best preparation is to leave early for work or school. Leaving early will help avoid the larger traffic jams that can result in urban areas on those foggy mornings. The lesson at the following link explains the various factors that result in fog: http://www.theweatherprediction.com/fog/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 27 Topic: Mesoscale Weather Data The mesoscale analysis occurs at time and space scales that are shorter and smaller than the synoptic scale. A mesoscale weather analysis allows for more frequent updates over a more localized area. This introductory overview looks at mesoscale data including using models, radar, satellite, forecast soundings, interactive weather data and data overlays. The lesson can be found at the link below: http://www.theweatherprediction.com/mesoscale/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 28 Topic: Busted Forecast For this next lesson we focus on the causes of busted forecasts. A bust is a situation in which an anticipated weather event does not occur. This is especially true if there was a high probability of the weather event occurring. Winter weather and severe weather busts are two categories that are anticipated weather events. By anticipated it means that a large percentage of the general public is aware of the threat. This lesson looks at 10 reasons why a forecast can bust. The 10 part lesson is found at the link below: http://www.theweatherprediction.com/bustedfx/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 29 Topic: Wind Wind is the movement of air. To move the air, a force is required. The initiating factor that develops wind is due to horizontal temperatures differences in the troposphere. Air masses (and air with different temperature and moisture properties on smaller scales) will have different densities and these density differences cause pressure differences between the regions the air masses or smaller air regions meet. The force responsible for moving the air is the Pressure Gradient Force. There are other factors that influence the wind speed and direction (Coriolis, friction, centrifugal, etc.) but the Pressure Gradient Force starts it off. Since temperature differences occur on all scales (global, synoptic, mesoscale, and smaller), wind patterns are also on all of these scales. This lesson covers many of the various winds and terminology important to wind in meteorology at the links below: http://www.theweatherprediction.com/habyhints2/567/ http://www.theweatherprediction.com/wind/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 30 Topic: Significant Tornadoes and Hurricanes This lesson examines the ingredients for significant tornadoes and significant hurricanes. The lesson is at the following links below: http://www.theweatherprediction.com/habyhints2/586/ http://www.theweatherprediction.com/habyhints2/587/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 31 Topic: The Hodograph, Wind Shear and Storm Character The hodograph is used to assess the vertical wind profile of a location. The graph shows how the wind speed and direction changes with height. Part 1 of the lesson, which is an introduction to the hodograph, is at the link below: http://www.theweatherprediction.com/habyhints2/629/ Part 2 of the lesson discusses the hodograph and the thunderstorm type expected. The wind shear determines a storm’s movement and life span. Wind shear has two forms which are speed shear and directional shear. Speed shear is a change in wind speed with height while directional shear is a change in wind direction with height. The link below explains the wind shear environment on a hodograph and how it influences the characteristics that a storm will have: http://www.theweatherprediction.com/habyhints/275/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 32 Topic: Weather Changers This lesson looks at 20 dramatic changes in the weather that can take place. The lesson is found at the link below: http://www.theweatherprediction.com/wxchangers/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 33 Topic: Storm Convective Lift Convective uplift occurs quickly. These regions of rising air are termed updrafts. This rising air goes against the gravity that pulls objects toward the surface. The rising air results from density differences in the air. The updraft is less dense than the surrounding air (primarily created by warmer air within updraft). Like a helium balloon, the less dense updraft air accelerates upward. The speed of this updraft can be approximated by knowing the value of CAPE. This lesson looks at determining updrafts speeds within a storm. A very strong updraft speed increases the risk of severe weather including large hail, flash flooding rain and strong convective wind gusts. The lesson can be found at the link below: http://www.theweatherprediction.com/habyhints/319/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 34 Topic: Overweight CAPE CAPE is a measure of instability in the troposphere. Higher values of CAPE can lead to stronger updrafts. This lesson focuses on the ingredients that can lead to huge values of CAPE: http://www.theweatherprediction.com/habyhints2/636/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 35 Topic: Severe Thunderstorm Structure This lesson looks at several definitions as they relate to a severe thunderstorm. Definitions are provided for major cloud, precipitation, updraft and downdraft features of the storm at the link below: http://www.theweatherprediction.com/severe/structure/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 36 Topic: Wet Bulbing and Forecasting This lesson looks at the forecast implications that result from the wet bulbing process. The term is defined, the process is explained, and the importance it has for weather forecasting is discussed at the link below: http://www.theweatherprediction.com/habyhints2/619/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 37 Topic: Optimum Snowfall Region This lesson looks at several factors that are responsible for determining where the heaviest snowfall will occur in association with a mid-latitude cyclone: http://www.theweatherprediction.com/habyhints2/700/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 38 Topic: Elevated Convection Convection is a process in which air rises due to positive buoyancy (being less dense than surrounding air). In a typical thunderstorm situation, convection begins from near the Earth’s surface and rises throughout the troposphere. Elevated convection is convection that begins aloft such as from the 850 mb level. This can happen when the boundary layer at the surface has stable air but there is a layer of unstable air aloft such as warm and moist air advecting into the area aloft but not at the surface. The lesson at the link below examines elevated convection and forecast implications: http://www.theweatherprediction.com/habyhints2/624/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 39 Topic: Disaster Weather This lesson at the link below looks at several types of weather disasters and a perspective concerning the coverage each type of event receives. http://www.theweatherprediction.com/disasters/ Haby's Weather School METEOROLOGIST JEFF HABY Lesson 40 Topic: Precipitable Water This lesson, at the link below, looks at defining Precipitable Water and gives an explanation of various forecasting implications of using the Precipitable Water value and associated charts: http://www.theweatherprediction.com/habyhints/294/ |