Atm 509                                  Atmospheric Precipitation Processes                       Fall 2008

Course Information and Outline

Course Focus:

    The emphasis will be on: (1) application of fundamental dynamical and thermodynamical processes to understanding precipitation mechanisms, (2) application of remote sensing technologies (radar/satellite) to precipitation measurement and water vapor transport, (3) documenting atmospheric conditions favorable for heavy precipitation, (4) illustrating dangerous flooding situations through representative case studies, and (5) forecasting heavy precipitation and flooding events.

Instructor:                  Lance F. Bosart, ES-227; 518-442-4564; bosart@atmos.albany.edu

Credits:                       3

Class hours:               Tu/Th 2:45 pm to 4:05 pm in ES-232

Course requirements:

1.   Two exams: Tuesday 23 September 2008 (25%) and Tuesday 11 November 2008 (35%).

2.   Semester Project (30%): 2000 words (maximum) due Thursday 4 December 2008.

3.   Homework and QPF Exercise (last six classes) (10%).

4.   Final exam: None (oral presentation of class projects instead).

Texts:                         a) Martin, J., Mid-latitude Atmospheric Dynamics:  A First Course (2006; 
    paperback)

                                    b) Bluestein, H., Synoptic-Dynamic Meteorology in Midlatitudes, Volumes I
    (1992) and II (1993).

Class Materials:        Refereed journal articles and web-based information.

Course Outline:

1.   Forecast Verification:

a) Verification measures
b) State-of-the QPF art

2.   A Brief Review of QG Principles:

a) Lifting (and "uplifting") mechanisms.

b) Trough/ridge propagation mechanisms.

c) PV critters.

3.   The "Big Three":  Lift, Instability and Moisture:

a) Isallobaric processes.

b) Jet-induced vertical circulations.

c) Impact of atmospheric stability on vertical motion.

d) A stability tendency equation.

e) Some "raining" paradigms of water vapor transport.

f) Precipitable water and the water vapor budget.

4.   Satellite and Radar Interpretation:

a) Satellite physics.

b) Radar physics.

c) Applications.

5.   Heavy Precipitation (Stratiform):

a) Major winter storms.

b) Weak and moderate winter storms.

c) Banded precipitation events.

d) Orographic events.

e) Jet-mountain interaction storms.

6.   Heavy Precipitation (Convective):

a) MCCs/MCSs.

b) MCVs and bow echoes.

c) Landfalling and transitioning TCs.

d) Training storms with slow-moving fronts and boundaries.

e) Large-amplitude inertia-gravity waves.

7.   Case Studies of Flooding:

a) Synoptic-scale floods.

b) Mesoscale/local floods.

c) Mountain-induced floods.

d) Desert floods.

e) Rapid snowmelt floods.

f) Landfalling and transitioning TC floods.

8.   Qunatitative Precipitation Forecasting Exercise:

Three weeks on the hot seat....

    A "dry" sense of humor that "whets" your appetite for more is the focus of the following "raining" paradigms (tips) for forecast "success":

    A word to the wise about low-level northwesterly flow in New England: Although the rain in Spain falls mainly on the plane, the rain in Maine is planely on the wane.

    When the autumn winds blow persistently off the Rockies and well eastward onto the Plains, remember that out of the gray gloom of a cold early November late afternoon ride the Four Horsemen of the Apocalypse.  You know them well: Death, famine, pestilence, and....subsidence.

    Beware of spurious convective-vorticity feedbacks that can lead to excessive precipitation bullseyes in some model forecasts or you will surely have that "sinking" feeling later.  Failure to let the model wallow in its misery in these situations is a bit like rearranging the deck chairs on the Titantic: The model will still suck and the ship will still "sink".