Download Lab 1: Weather discussion and internet resources

MET 3502(L) – Synoptic Meteorology Lab
Lab Assignment #1: Weather Discussion and Internet Resources
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What is a Lab and how is it different from a Lecture?
Lectures require the student to primarily listen to material presented by the professor, while labs require students to
actively participate and to perform specified tasks during the lab time. Lab attendance is required and attendance will
be taken at every lab. The bulk of the lab is hands-on work which you are responsible for completing in a timely manner.
In most labs, you do the experimental portion in the lab itself and then take home and complete the writeups to be
turned in the following week. In the synoptics lab we won't be doing experiments per se, as in a physics or chemistry
lab, but we will be learning how to use practical tools and procedures that are used by meteorologists every day. We
will have hands-on experience in understanding in real time characteristics of the atmosphere, now to analyze them,
and how these are used in weather forecasting.
Active participation is required in a lab. You may be working with other students in the lab for some assignments.
Part of this first lab will be an overview of what is expected and the lab procedures, but in future please read the lab
writeup before lab begins. The updated lab materials will be posted by the morning before the lab. Sometimes it can be
a bit of a scramble to finish a lab in the alloted time and you generally do not have extra time if you don't finish. So it is
helpful to read the lab instructions and be prepared when the lab begins.
You will need to provide your FIU email at the first lab. The later lab assignments (IDV) will be turned in via email.
Lab Materials and Grading
Typically the labs will have a portion of work that is expected to be completed during the lab time, and some portion
that will need to be completed later by the student and turned in at the next lab. Grades for Synoptic Lab are letter
grades (A, B,…) and for Weather Discussion Lab are pass/fail, and will be based on lab attendance, lab participation,
percentage of the lab that is completed during lab time, correctness of the completed labs and timely submission of
the completed labs the week following the lab.
Note: in our lab there are computers which are available if we need them in order to perform the lab tasks, and
sometimes to print material. Logging on to personal or FIU email or perusing the internet or social media is
prohibited during the lab time. Use of personal devices such as phones or tablets for these purposes as well should
be avoided during the lab time, which is to focus on the lab tasks. Students will be expected to either participate in
group discussions or to work individually on the lab assignments during the lab time.
Lab #1 Objectives
The material in the first three labs for Synoptic Lab and Weather Forecast Discussion Lab will overlap. After that,
Synoptic Labs will have specific assignments, while the Weather Forecast Discussion Labs will focus on student
presentations of the Forecast Discussions (these are also called Map Discussions). A schedule for the forecast
discussions will be provided during this lab. The first labs will be group discussions in order to make sure that everyone
understands the methods. After the group discussions, the Weather Forecast Discussion Labs will consist of two tenminute student presentations each lab, followed by a positive critique from the lab TA.
This lab #1 will introduce you to using current atmospheric analyses processed by an atmospheric model, based on
current observations from ground stations and rawindsondes (weather balloon) sounding data and a great deal of
satellite data. Because we are based in Miami, some weeks we will look at the Atlantic basin, and other weeks we will
review CONUS (Continental U.S.), which will be our primary focus. We will review current ATL tropical cyclones, but in
the specific context of understanding synoptic features that are factored into the track and intensity forecasts.
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Lab Assignment #1: Weather Discussion and Internet Resources
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We will look at specific levels in the atmosphere: 200/300 mb, 500 mb, 700 mb, 850 mb, and surface observations. We
will learn to relate the model views with the actual satellite imagery in near-real-time.
These levels of the atmosphere are used in the "forecast funnel," a technique that is used to drill down in the
atmosphere in order to do surface weather forecasting such as forecasting tomorrow's temperature and precipitation.
In the forecast funnel, the highest level (200/300 mb) is referred to as the planetary scale, and the surface observations,
the lowest level, provide data on a local scale. Hence the idea that you are drilling down to a smaller and smaller
footprint as you work your way down through the atmospheric levels.
Today we will examine the Atlantic basin using the NCEP GFS, using a 4-panel analysis, the NHC ATL Tropical Weather
Discussion (TWDAT) product, the unified surface analysis, and associated satellite imagery. The reason to approach this
first lab from this perspective is that there is no longer a Satellite Interpretation Message (SIM) product for CONUS, but
the TWDAT identifies features on the satellite imagery. Therefore we can learn to recognize and link the features on the
satellite imagery in tandem with the model analysis, as a discussion of the pertinent features is provided in the TWDAT.
Model runs are done four times daily, at "synoptic times" which are in UTC (Universal time, sometimes called Zulu time),
which are 00Z, 06Z, 12Z, and 18Z. Weather balloons (rawindsondes) are released at 00Z and 12Z, providing a richer data
set for those two synoptic times.
On days when we analyze CONUS, we will use the GFS and MM5 models, using a 4-panel analysis, and relate it to
satellite imagery. The students will be responsible for writing a basic satellite interpretation message similar to the
TWDAT identifying atmospheric features, which will be prepared by the student in advance, and the student will be
responsible for presenting this in the Weather Discussion Labs. Alternatively a student may present the criteria they
used in the Forecast Funnel, going through each criteria and how it is applied, when discussing the different levels of the
atmosphere on the 4-panel maps, and ending with a temperature and precipitation forecast for a specific city (if a
student is enrolled in the Weather Forecast Challenge, this presentation may coincide with the work done for the
forecast challenge).
Students should use completed available model analyses from 12Z or 00Z time previous to the time of the class
discussion, and these will have to be from the previous day. The 12Z runs are usually completed by noontime. So either
the 12Z run can be analyzed by the student the day before, or the 00Z run analyzed the morning before the lab. It is
recommended that the 12Z run be used in order to complete the analysis prior to 11am of class/lab time, as the student
may run out of time if analyzing last night's 00Z run the following morning, but if you are sure you can complete it you
can use the 00Z model run.
The following material from the previous year synoptic lab will help you learn how to do the weather discussion using
internet resources.
The Forecast Funnel
The forecast funnel visualizes the analysis and forecast process as a "funnel" that drills down from the high-level
planetary scale to smaller and smaller scales. The concept was developed by Len Snellman, a National Weather Service
Meteorologist (Snellman 1982). Any good synoptic meteorologist will use this to method to do a weather forecast. The
idea is as shown in the figure: Always understand the planetary scale (waves) background first, then go to synoptic scale
(such as frontal cyclones), then mesoscale (such as MCC, MCS, sea breeze), and finally local scale (such as super cells,
tornadoes).
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Lab Assignment #1: Weather Discussion and Internet Resources
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Resources for preparing for a weather discussion
Putting together a weather discussion can be an intimidating process. Assembling figures and graphics loops can
consume much of your preparation time, allowing little time to think about the weather.
Here are two alternative websites to NCEP/GFS that are commonly used:
University of Wisconsin-Madison MM5: http://sol.aos.wisc.edu/
(Click current run on the left, and choose 00hr for each level, this is for current observation.)
DuPage site: http://weather.cod.edu/forecast/
(Click one of the models on top: RAP/NAM/GFS, then choose the level and select the parameter you're interested in on
the left. 00hr shows you the current observation.)
You can find more details on how to interpret weather maps in different levels in Lecture 14
(http://faculty.fiu.edu/~hajian/MET3502/Interpreting_Weather_Maps.pdf ).
Here are some suggestions to help you be as prepared as possible for the discussion.
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Go to the computer lab the day before your discussion and gain a good understanding of the features on the
various size scales, using the 4-panel maps. Then determine what you will want to focus on for tomorrow's
discussion.
Use model runs to gain an understanding of the past, present, and future weather. Pick two or three major
issues to discuss. Critical to this process is developing an intuition for (1) recognizing the social and/or scientific
significance of weather events and (2) identifying the major forecast problem(s) of the day. Developing such
intuition can only be done by making every effort to understand and predict the weather on a daily basis.
Prepare a manual surface analysis on the morning of your briefing, or review one online. This can take awhile,
but it is essential for understanding of the weather and is complemented by numerical analyses and forecasts.
During your briefing use the forecast funnel method. Always start with the large scale and descend down to
smaller scales. For example, if discussing the development of monsoonal convection over Arizona, first use
satelite imagery and synoptic analyses to define the evolution of the large scale before jumping to radar imagery
and mesonet analyses.
A good outline to follow is below.
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The recent (last 2-5 days) large-scale upper-level flow evolution based on Northern Hemisphere 300-mb
heights/vorticity or dynamic tropopause analyses.
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Check WPC (previously HPC) North American Surface Analysis:
http://www.hpc.ncep.noaa.gov/html/sfc2.shtml
MET 3502(L) – Synoptic Meteorology Lab
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Lab Assignment #1: Weather Discussion and Internet Resources
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CONUS-scale weather using WV, IR, and VIS satelite imagery, which can be obtained from
http://weather.unisys.com/index.html or http://www.meteo.psu.edu/~gadomski/ewall.html.
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Regional-scale weather: look above items in regional scale, for example:
http://www.nhc.noaa.gov/satellite.shtml.
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Soundings (KMFL and possibly elsewhere in the region) using http://www.rap.ucar.edu/weather/upper/
or http://weather.uwyo.edu/upperair/sounding.html.
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AMX (Miami) radar imagery using http://www.weather.gov/radar_tab.php.
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Surface observations for Southern Florida using http://www.rap.ucar.edu/weather/surface/ or IDV.
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Your nowcast for the afternoon (16-04Z) maximum temperature and 16-22Z precipitation amount.
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NAM synoptic and (possibly) convective loops obtained from http://weather.utah.edu/.
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GFS synoptic and (possibly) convective loops obtained from http://weather.utah.edu/.
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The SREF short-range forecast at http://w1.spc.woc.noaa.gov/exper/sref/.
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Your forecast for the overnight (22-16Z) minimum temperature, next day (10-04Z) maximum
temperature, and 22-22Z (daily) precipitation amount.
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The GFS medium range forecast: http://weather.unisys.com/index.html.
Keep it simple and specific. Stay focused on the 2-3 issues. Describe what you know, raise questions about what
you don't. Don't handwave, and don't try to use new techniques you've just learned in class if you haven't had a
chance to absorb and understand them.
Spend more time discussing observations and less time discussing model forecasts. There are 6 questions that
need to be answered when forecasting (Bosart 2003), and the first four are: What happened, why did it
happen, what is happening, and why is it happening? Answer these questions before moving on to the NWP
guidance. The final two questions are what is going to happen and why is it going to happen. Total reliance
upon NWP guidance to answer these questions should be avoided.
Other On-line Resources (also will be in class web site)
Jeff Haby's website
http://www.theweatherprediction.com/
GOES Satellite Imagery at NASA/MSFC
http://weather.msfc.nasa.gov/GOES/
WPC Surface Analysis
http://www.wpc.ncep.noaa.gov/html/sfc2.shtml
Miami Weather Forecast Office
http://www.srh.weather.gov/mfl/
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Miami WSR-88D Radar Base Reflectivity
http://radar.weather.gov/ridge/radar.php?rid=amx&product=N0R&overlay=11101111&loop=no
Miami WSR-88D Radar Loop
http://radar.weather.gov/ridge/radar.php?rid=AMX&product=N0R&overlay=11101111&loop=yes
National Radar Mosaic
http://radar.weather.gov/ridge/Conus/
National Hurricane Center (NHC)
http://www.nhc.noaa.gov
NHC Satellite Links
http://www.nhc.noaa.gov/satellite.php
NESDIS Tropical Satellite links:
http://www.ssd.noaa.gov/PS/TROP/text_index.html
Storm Prediction Center (SPC)
http://www.spc.noaa.gov/
SPC Soundings
http://www.spc.noaa.gov/exper/soundings/
NCAR/RAP Upper-Air Site
http://www.rap.ucar.edu/weather/upper/
NCEP Analyses and Forecasts
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis
NCEP Home
http://www.ncep.noaa.gov/
NCEP Models
http://www.emc.ncep.noaa.gov/modelinfo/index.html
NRL Satellite Imagery Site
http://www.nrlmry.navy.mil/sat_products.html
JETSTREAM (NWS Southern Region Online Weather School)
http://www.srh.weather.gov/jetstream/synoptic/synoptic_intro.htm
Canadian Weather Office Analyses:
http://www.weatheroffice.gc.ca/analysis/index_e.html
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Tools for Synoptic Map Discussion
Model Analyses:
NCEP Model Analyses and Guidance web page:
Main page:
mag.ncep.noaa.gov
Select model guidance:
mag.ncep.noaa.gov/model-guidance-model-area.php
Select ATLANTIC, then GFS.
Select model cycle:
(usually 12UTC)
Select 200_wnd_ht.
Select 000 and save image.
(upper level winds)
Go back, select 500_vort_ht.
Select 000 and save image.
(vorticity)
Go back, select 700_rh_ht.
Select 000 and save image.
(precip and humidity)
Go back, select 850_temp_ht. (temperature advection)
Select 000 and save image.
Alternative model run websites:
University of Wisconsin-Madison MM5: http://sol.aos.wisc.edu/
(Click current run on the left, and choose 00hr for each level for current observation)
DuPage site: http://weather.cod.edu/forecast/
(Click one of the models on top: RAP/NAM/GFS, then choose the level and select the
parameter you're interested in on the left. 00hr shows the current observation)
Tools for Tropical Atlantic Discussion
NHC home page:
nhc.noaa.gov
Select Atlantic Tropical Weather Discussion, underneath the map of the Atlantic basin on RH side.
Save the text of the discussion in a file.
Select 0600 UTC Surface Analysis link and save the image.
Select satellite imagery link.
Select Single Image With Lat/Lon RGB and save image.
Do the same with Visible, Water Vapor, None, and AVN images. If nighttime imagery also save Shortwave IR.
MET 3502(L) – Synoptic Meteorology Lab
Lab Assignment #1: Weather Discussion and Internet Resources
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Developing a Synoptic Glossary of Meteorological Terms
In addition to the lab assignments, every week each of you will add to a glossary that you will update every week by
adding the assigned meteorological terms. You will maintain this in an MS Word document which you will add to during
the lab time every week. Please maintain this in alphabetical order.
Most of the terms are defined in the AMS Glossary and for those cut and paste the AMS definition into your personal
glossary. Other terms may be pulled from the class lecture. If a term does not exist in the AMS Glossary you can Google
the term to find an appropriate definition. Also helpful in this regard is Jeff Haby's website "The Weather Prediction."
At times I may email you the definition.
We may also review the previous week's terms in the lab, so please be prepared to respond to questions.
Use the following format – underline the term and below it place the definition:
jet stream
Relatively strong winds concentrated within a narrow stream in the atmosphere.
While this term may be applied to any such stream regardless of direction (including vertical), it is coming more and
more to mean only a quasi-horizontal jet stream of maximum winds embedded in the midlatitude westerlies, and
concentrated in the high troposphere. The question of the maintenance of the jet stream is a cardinal problem of
theoretical meteorology. Two such jet streams are sometimes distinguished. The predominant one, the polar-front jet
stream, is associated with the polar front of middle and upper-middle latitudes. Very loosely, it may be said to extend
around the hemisphere, but, like the polar front, it is discontinuous and varies greatly from day to day. A subtropical jet
stream is found, at some longitudes, between 20° and 30° latitude and is strongest off the Asian coast. Currently, in
the analysis of upper-level charts, a jet stream is indicated wherever it is reliably determined that the wind speed equals
or exceeds 50 knots.
The terms for this first week are below:
weather forecast
synoptic scale (also include definition of cyclonic scale)
jet stream
synoptic chart
upper-air chart
constant-pressure chart
constant-height chart
thickness chart
long wave
short wave
cyclonic circulation
upper-level low (upper-level cyclone)
anticyclonic circulation
upper-level high (upper-level anticyclone)
cut-off low
blocking high
front