ATSC 5160 Synoptic Meteorology Spring 2003

Instructor: Dr. B. Geerts, [email protected], 6062 Eng Bldg, 766-2261.

Textbook: Bluestein, H., 1993: Synoptic-Dynamic Meteorology in Midlatitudes, Vol II. Oxford University Press, 594 pp.

Additional books: Palmen and Newton, 1969: Atmospheric circulation systems: their structure and physical interpretation. (QC 880 .P28) Newton, C., and E.O. Holopainen, Eds., 1990: Extratropical Cyclones, The Erik Palmen Memorial Volume.American Meteorological Society, Boston, 262 pp. Peixoto and Oort, 1992: Physics of Climate (QC981 .P434) Shapiro and Gronas, 1999: The life cycles of extratropical cyclones Houze, 1993: Cloud dynamics (QC921.6.D95 H68) Klemp, 1984: Dynamics of mesoscale weather systems.

Class meetings: Tue Thu 2:45-5:15 pm (150 min). In theory at least, the first hour (75 min really) should be class time, and the second hour lab time. In practice theory and applications are blended. There is no other scheduled lab time.

Website: http://weather.uwyo.edu/~geerts/atsc5160/ (includes the lecture slides)

What is ‘synoptic’ meteorology? - historical roots, scales of atmospheric motion, and scale interaction - connection to physical and dynamic meteorology: this course will continuously refer to atmospheric processes to understand real-world atmospheric behavior - from the general circulation to the mesoscale, today’s frontier of atmospheric research

Topics: The textbook covers 3 topics: the synoptic scale, the mesoscale, and the organization of precipitation. The course is organized around these three main topics, however we will add certain subtopics not covered in the book, and omit some that are covered in excessive detail in the book. Select book and journal articles will give you the reading for topics not covered, for instance, about tropical meteorology.

The list below contains more material than we can handle in a 4 cr course. Your input in the selection of topics is important: what general direction or specific topics are you most interested in?

A. Synoptic-scale

1) The formation of surface lows and highs a) quasi-geostrophic and hydrostatic principles (1.1-1.1.2) b) effect of surface friction and diabatic heating (heat low and cold high) (1.1.3- 1.1.4) c) potential vorticity conservation (1.1.5) d) CISK and air-sea interaction instability (1.1.7) e) Climatology of lows and highs (1.2.5) f) Climatology of cyclogenesis and anticyclogenesis (1.1.8) 2) The movement of lows and highs (1.2 – 1.2.2) 3) The formation of upper-level troughs and ridges (1.3) 4) The movement of upper-level troughs and ridges (1.4) a) Short waves and long waves (1.4.1) b) Group velocity (1.4.2) c) Blocking (1.4.3) d) Upper-level height climatology (1.4.4) 5) Classical midlatitude cyclone: lifecycle (1.6) a) QG analysis (1.6.1) b) Cloud and precipitation patterns (1.6.2) c) East coast cyclogenesis (1.6.3) d) Lee cyclogenesis (1.6.4) 6) Special cases a) Rapid cyclogenesis (1.5.4) b) Polar low (1.5.4) 7) IPV thinking (1.9) a) Definitions, approximations, and typical distributions (1.9.1-1.9.2) b) Surface PVAs and upper-level PVAs (1.9.3-1.9.4) c) Large-scale vertical motion and baroclinic instability from an IPV perspective (1.9.5) d) Motion of PVAs aloft and near the surface (1.9.7-1.9.8) e) Formation of PVAs aloft and near the surface (1.9.10-1.9.11) f) Applications: PV in bombs and lee cyclones 8) Synoptic-scale forcing in the Tropics (not covered in the textbook) a) Dynamical considerations b) (a)symmetric coherent tropical modes c) monsoons d) easterly waves e) tropical cyclones i) genesis: CISK and air-sea interaction theory ii) intensification, environmental influences iii) anatomy of a mature hurricane (IPV perspective) iv) hurricane track forecasting

B. Mesoscale: fronts and jets

1) Jets and jet streaks (2.7-2.8) a) Jet streaks and frontal circulations (2.7.1), characteristics (2.7.4), formation (2.8.1), and vertical motion (2.8.2), and vertical coupling (2.8.4) b) low-level jet, pre-frontal and orographical (2.7.3) 2) Fronts a) Cross-front scale, mesoscale structure of fronts (2.2) b) Frontogenesis: 2D (2.3.1) and (2.5.3-2.5.4) c) Special fronts: i) coastally-trapped wind reversals (2.5.6) ii) coastal front and cold-air damming (2.4.1) iii) drylines (2.4.1) iv) cold front aloft (2.4.2) v) gravity currents, undular bores, and solitary waves

C. The organization of precipitation

1) Non-convective precipitation systems (3.5) a) Rainbands (3.5.1) b) fronts and conditional symmetric instability: 2.5.2 (starting at p 339) and 3.5.2 and COMET c) other processes: i) Feeder-seeder process, potential instability (3.5.3) ii) Latent effects: evaporative cooling and the snowline iii) Ducted gravity waves (3.5.4) 2) Convective systems (3.4) a) Cumulus dynamics (3.4.1) b) Convective initiation (3.4.3) c) Anticipating convective storm structure: CAPE and shear d) Supercell dynamics e) Severe weather phenomena, tornadogenesis (3.4.8) f) Mesoscale organization of convection: squall lines (3.4.9) i) Bow echoes (derechoes) ii) mesoscale convective vortices, MCCs, and IPV thinking

Grading scale

A: >80% D: 50-60% B: 70-80% F: <50% C: 60-70%

Assessment

Homeworks: 5 homeworks, 4 % each 20% Project 1: COMET case study 12% Project 2: NWP (ETA) 20% Midterm: Thursday 27 March 22% Final exam: Friday May 16, 8-10 am 22% Class participation, effort, evidence of progress 4%

Homeworks: 1. handout: Thu 30 Jan; due: Tue 4 Feb 2. handout: Thu 13 Feb; due: Tue 18 Feb 3. handout: Thu 27 Feb; due: Tue 4 Mar 4. handout: Thu 13 Mar; due: Thu 27 Mar 5. handout: Thu 3 Apr; due: Tue 8 Apr

Project 1: COMET There are many COMET case studies (see http://www.comet.ucar.edu/resources/cases/index.htm for details). Check with Dr. Oolman about availability here, we should have most except the most recent ones. We have at least the ones listed below. But if you have a ‘favorite case’, make it yours (allow 2 weeks for ordering if we don’t have it here). case # date type name date 07 13-14 Mar ‘96 High Plains Snow Event 15 28 Apr ‘98 Southeast US Cyclogenesis 24 19-26 Jan ‘00 East Coast Explosive Cyclogenesis 05 4-5 Jan ‘95 Lake Effect Snow 20 14-18 Sept ‘99 Hurricane Floyd 19 3 May ‘99 Oklahoma City Tornado 26 23-26 Nov ‘99 Pacific Northwest Winter Storm

Timeline: 1. Thu Feb 13: pick a case and date (one case per student, first come first serve), and write a one- page summary of why you want to analyze the case, and what specifically you plan to focus on. 2. Present your case study. Available dates: March 4, 3/6, 3/11, 3/13, 3/27

Present an oral presentation of at most 30 minutes. Be prepared for difficult questions afterwards, for which you may want to have extra charts ready, or be ready to use GARP to make them. Your presentation should acquaint us with the development and evolution of the weather phenomenon in question. Don’t give a general synoptic weather briefing, but rather, focus on the topic of your case. For instance, for case #19, try to put yourself in the shoes of an Oklahoma forecaster (trained at graduate level). For case #5, assess the occurrence of Lake Effect snow, and then try to answer why. The challenge forecasters always face is what that synoptic picture will do locally to the weather. Try to apply the knowledge gained in this class, and in previous classes (dynamic meteorology, weather analysis ...) to shed insight into the weather event. Make every attempt possible to understand the dynamical processes leading to the observed structure and evolution.

Project 2: ETA run Objectives:  to become acquainted with NWP processes by running your own model and varying physics packages, boundary conditions, resolution, domain, etc  to better understand weather phenomena at the local level, down to the mesoscale  to use some non-traditional diagnostics to analyze your case

Method: To run your own ETA simulation, read the guidelines at http://www.comet.ucar.edu/strc/model/. The model binary code is installed on coyote. Usage details will follow. This is the main class project after spring break.

Topic: You can choose your own weather of interest. For instance a case of lee cyclogenesis, or cyclogenesis along the Gulf or East Coasts. A snow storm in New England or in the Pacific Northwest. Or a focus on frontogenesis. Or convective initiation in the Plains. Or the sea breeze circulation in Florida.

A note on Academic Integrity and Plagiarism

Academic integrity is the pursuit of scholarly activity in an open, honest and responsible manner. Academic integrity is a basic guiding principle for all academic activity at the University of Wyoming, and all students are expected to act in accordance with this principle. Consistent with this expectation, all students should act with personal integrity, respect other students' dignity, rights and property, and help create and maintain an environment in which all can succeed through the fruits of their efforts. Academic integrity includes a commitment not to engage in or tolerate acts of plagiarism, falsification, misrepresentation, or deception. Such acts of dishonesty violate the fundamental ethical principles of the academic community and compromise the worth of work completed by others. Evidence of plagiarism may result in expulsion from the course (with an F grade) as well as dismissal or suspension from the University of Wyoming (Unireg #030-1970).