Meteorology Exam 4 - Mizzou

what is weather forecasting?

predicting how the present state of the atmosphere will change over a period of time

what timescale is nowcasting?

present to 6 hours

what timescale is short range?

1 to 3 days

what timescale is medium range?

3 to 5 days

what timescale is long range?

5 to 10 days

what timescale is extended?

up to 90 days

why is weather forecasting important?

tells you how to dress, helps you plan your day, and helps with ag. info

what is folklore forecasting?

stories or anecdotes that predict weather

are all folklore forecasts accurate?

no!

what is climate forecasting?

using averages of weather conditions to predict the weather for a given day

what is one example of a time where weather forecasting won’t work?

if you are seeing record setting weather

what is the trend method of forecasting?

assumes that the speed and direction of weather systems will not change

what is the analogue method of forecasting?

also known as “pattern mapping” where you find a date in the past where the weather looked exactly like it does now and using that

when does the analogue method work the best?

with severe/winter weather events

what is the numerical method of forecasting?

using numerical equations to calculate the future state of certain variables (pressure, temp, winds, humidity, clouds, and precipitation)

what is the equations in the numerical method based on?

newton’s 2nd law of motion

what do the equations within the numerical method consist of?

pressure variations, gravity, friction, how heat and moisture are transferred, and how water vapor changes state

how is the data in the numerical method modeled?

plot or fed into the computer model

what does a good numerical method model depend on?

giving the computer program the right information at the beginning

what does garbage in = garbage out mean?

if you feed the computer inaccurate observations, the forecast won’t be accurate

what are spaghetti model plots?

looks like spaghetti on the plot, each model spits out its on idea of what the atmosphere will be like for a given time frame in the future (all at once)

what is an ensemble forecast?

different iterations of one model adjusted for different scenarios/eqations

what can a forecast 5 - 8 days out tell you?

very little. might give suggestions on upcoming pattern changes but can be very inaccurate

what can a forecast 3 - 5 days out tell you?

confidence increases on the potential storm area but the “when, where, type, and how much” are still very uncertain

what can a forecast 1 - 3 days out tell you?

forecast clears up, storm is now expected but the specifics can still be hard to pinpoint

what can a forecast 12 - 24 hours out tell you?

very detailed information and the forecasts need only minor adjustments

what is the forecasting process?

observations —> analysis —> predictions —> post-processing

what is post-processing?

seeing how well you did or didn’t do and why that happened

what are some ways weather data is collected around the world?

land observatories, ship observatories, weather balloons, and buoys

what is the analysis process of forecasting?

figure out what storm systems are out there and ask yourself questions

what is the predictions part of forecasting?

taking all the data you have collected and sharing it (or not lol)

what is one way you can be conservative with your forecasting?

start small and work your way up (be vague and then detailed closer to the day)

what percentage of accuracy is generally considered pretty good?

70% or higher

what is a station model plot?

a “cluster” of current weather data for one particular weather reporting site

what does the first symbol in this image mean?

calm

what does the second?

1 - 2 knots

what does the third mean?

10 knots

what does the fourth?

15 knots

for the sake of simplicity, what does a knot equal?

mph

what does “,” mean in weather symbols?

drizzle

what does “.” mean in weather symbols?

rain

what does “*” mean in weather symbols?

snow

what does this symbol mean?

thunderstorm

what does “)(“ mean in weather symbols?

funnel cloud

can you mix and match weather symbols to depict the weather?

yes!

what are some signs of thunderstorms?

thunder and lightening, strong & gusty winds, hail (all sizes), precipitation (rain/snow), and may contain tornados

what are the 3 types of thunderstorms? (from least to most harmful)

ordinary, multicell, supercell

what are ordinary thunderstorms?

the most common type of thunderstorm

what areas do ordinary thunderstorms usually form in?

areas with weak wind shear

what is the timeframe for an ordinary thunderstorm?

usually last under an hour

what are the 3 stages of an ordinary thunderstorm?

growth stage, mature stage, and decaying stage

what is the beginning of the mature stage of a thunderstorm?

the downdraft

what weakens the storm during the decaying stage?

updrafts

what are multicell thunderstorms?

clusters of storms that form in different growth stages in one area

what are the main differences between ordinary and multicell thunderstorms?

winds (ordinary = weak, multicell = strong), and severe weather (multicell can last hours, ordinary usually don’t)

what are squall-line thunderstorms?

an organized line of thunderstorms

what is a bow echo?

a portion of the leading line edge that jumps out ahead of the rest of the line, likely to produce damaging winds

what is a supercell thunderstorm?

a thunderstorm with a rotating updraft

what is another word for a rotating updraft?

a mesocyclone

what is a typical lifetime for a supercell thunderstorm?

2 hours or longer

what does HP and LP mean?

high precipitation, low precipitation

why is a HP supercell thunderstorm more dangerous?

you can’t see what is in them (could be a tornado!)

what classifies severe weather?

1 of 3 (or all): winds (greater than 58 mph), hail (larger than 1”), and a tornado or possible rotation within the thunderstorm

true or false: all supercell thunderstorms are severe.

true!

what is the flanking line (on a thunderstorm)?

updraft/food supply for the mesocyclone (warm, moist air)

what is the rear-flanking downdraft?

rear portion of the mesocyclone’s downdraft (cold, dry air)

what is the inflow of a thunderstorm?

“suck zone” - influx of moisture rich air into a mesocyclone

what does MCS stand for?

mesoscale convection system

what is an MCS? (what is it not what does it stand for)

large grouping of multiple storms that move together and last for hours

what are the 2 types/shapes of MCS’s?

circular and linear

what does a circular MCS do?

covers many states, can produce severe weather, and generally produces heavy rain

what does a linear MCS do?

produces very strong winds and is generally isolated and can cause quick tornados

what is a gust front?

leading edge of cold air from a large, severe thunderstorm (aka “exhaling” air)

what is a microburst?

a very localized column of sinking air, producing damaging, and straight-line winds at the surface

where are microbursts usually located?

strong downdraft areas

what is a derechos?

a widespread and long-lived, violent windstorm that is associated with a fast-moving band of severe t-storms usually taking the form of a bow echo

when and where do derechos usually occur?

the summer, associated with buoyant, warm airmasses

what is lightening?

a discharge of electricity in a mature thunderstorm

what can lightening heat the air to?

over 50,000 F

what is thunder?

heating and expansion of the air creating a shock wave

how can you tell how far away the lightening is?

count the seconds between the flash and thunder (5 seconds = 1 mile)

what does the thunder sound like if the lightening is close-by?

a crack then a loud boom/bang

why does thunder “rumble” when it is far away?

because the sound bounces off various surfaces before reaching the

where are the negative charges found in the cloud?

near the cloud base

where are the positive charges found in the cloud?

up in the cloud and at the ground

what is the “stepped leader”?

initial spark of lightening that leaves the cloud base

what is the return stroke?

the upward flow of current that we see (as lightening)

what is the most common type of lightening?

cloud to ground

what is cloud to cloud lightening?

stays inside the cloud

what is sheet lightening?

lightening that is diffused by the reflection within the cloud

what is heat lightening?

distant lightening the illuminates the sky but is too far away for thunder to be heard, has nothing to do with “summer-time heat”

what is a tornado?

a rapidly rotating column of air whose rotation reached the ground

what are characteristics of a tornado?

diameter of 50-100+ yards, path length of 2-4 miles, lifespan of 5-10 minutes, wind speeds of 80-300 mph, and forward speed of about 30 mph

where was the largest tornado in the world located?

El Reno, OK in 2013

where is the “tornado capital of the world”?

the US

where was the strongest tornado located?

Greenfield, IA in 2024

what was the deadliest tornado in the world and how many people died?

the “tri-state tornado” (MO, IL, and IN) and it killed 695 people in 1925

when was the largest tornado outbreak in a single day?

April 27, 2011 (across 7 states)

what is the average amount of tornados per month?

~ 30

what is the average amount of people killed by tornados annually?

~ 60 (usually from debris)