Course Summary:

Course Goals:

1. To gain practical experience combining weather maps, models, and theory.
2. To gain experience in how to interpret imperfect guidance.
3. To gain familiarity with tools available to weather forecasters.
4. To understand the atmosphere a bit better

Instructor:

Prof. R. Grotjahn

rm 231 Hoagland Hall, Phone: 752-2246, E-mail: grotjahn'at'ucdavis.edu

Meetings:

Course meeting times & location:

• discussion: 4:10-5:00 pm T,Th; rm 124 Hoagland Hall
• lab: 5:00-5:30 pm T,Th; rm 124 Hoagland Hall

Course Description:

• Students work together to prepare 12-60 hr forecasts for three locations: Davis, the Pacific coast (SFO), and the mountains (BLU).
• Prior to the class meetings students gather the necessary maps, charts, and textual data. Including:
  • AVN (or MRF) and NGM MOS products (on board)
  • NWS forecasts (on board)
  • current conditions at the forecast stations
  • persistence values (last night's low, estimates of others)
• The past, current, and forecast information is reviewed.
• The previous forecast by the class is reviewed with the intent of identifying what (if anything) went wrong and why.
  • The prior forecast and its error for us, the relevant NWS office, and persistence is written on the board
  • The gross error (Brier score) and bias are tabulated (see below) for the whole course.
• The forecast products are then discussed by the group and everyone participates.
  • Maps for the AVN are reviewed first (since the preferred MOS is used later, modifications to the MOS guidance we make can be drawn from differences we expect between the AVN and the model guidance we prefer.
  • It is useful to track a gross difference: thickness over KSAC at the forecast times from each model consulted
  • Typical order of maps:
    • Satellite loop -- (McIdas) to see current patterns and their recent trend(s)
    • 500mb with vorticity -- to see upper level flow, PVA & NVA, & large scale features
    • SLP/thickness -- to see low level flow, WAA & CAA, & tracks predicted of lows.
    • Precipitation -- (if not already on a map above) to see coverage & amounts forecast.
    • Other levels: 850mb for flows & T in Sierra mountains
• The specific forecast values are decided upon by the group.
• The final product is typed up during the lab session and placed on a web page for all to see.

Please see the instructor or check out the following web page for more details about the course procedures .

NOTES.

• This course is an excellent complement to the material given in ATM 111.
• This course is offered during fall quarter.
• A notebook on how to forecast is available in the bookstore and is consulted as is useful.
• The course may be repeated for credit.

Printed Materials:

Textbook used: None

Photocopied materials in the bookstore (see links below):

• A guide to preparing and presenting forecasts known as the Forecast Notebook. I have a web page showing the cover and table of contents. required
• An appendix for the forecast notebook known as the North American Radiosonde observing stations information and codes for tabulated data. recommended
• These two items are also required for ATM 111

Grading Policies

grading: P/NP. A passing grade is based on completion of the tasks. These tasks include the web page preparation and the oral presentations. Failure to meet a responsibility may lead to a No Pass grade. The forecasts themselves are not graded.

Miscellaneous:

• Access Dr. Grotjahn's weather links
• Items related to the Forecast notebook selected figures

• See the EXCEL files for the
  • 1999 forecast evaluation
  • 2000 forecast evaluation
  • 2002 forecast evaluation

• See the
  most recent forecast web page.

• Davis climatology almanac

Busted forecasts
• The December 2000 big freeze that wasn't
  • Now you see it: Forecasts made Tuesday afternoon (2000_12_6_00)
  • Now you don't: Forecasts made Friday morning (2000_12_8_12)