Weather forecasting skew t and human forecast

AFD

Forecasters thought process

AFF updates

2 times a day

CAM means

Convective allowing Models

PWAT means

Quantitative precipitation forecast

PWAT updates every

6 hours

Medium range forecast include

7 days out, temp and rain and location of front

Moisture advection

Southly flow ahead of front

Sounding

How the atmosphere varies vertically

Skew T was invented in

1947

Skew t rises

1,000 ft per min for 45 minutes

Pressure decreases

Logarithmically

CAPE indicates

How much energy and updraft strengths

90 mph keep hail up or down

Hail up

Air mass t storms

Precipitation makes downdraft cuts off updraft

Parcel temperature on right side of environment if

Warmer

Fast rising air just before EL

Gains momentum

More low level moisture during

Summer

2 things for strong CAPE

Low level moisture and steep lapse rate

What are the 4 main objectives of the WPC

Provide QPF’s, provide medium range forecast, numerical model discussion and surface analysis

Number 1 purpose

Accurately depict evolution of weather systems that affect US

East coast ridge is

Dry

West coast trough is

Wet

How many surface maps are produced every 3 hours

8

WPC prognosis charts are

Instantaneous

POPs stands for

Probability of precipitation

Adiabate

No energy added or released

Cool =

Expansion

Warm =

Compress

LCL

Where parcel becomes saturated

LFC

Parcel temp becomes warmer than surrounding

EL

Temperature of parcel and surrounding area equal

Rate for DALR

10 per km

Rate for MALR

6 per km

Hydrolapse

Rapid decrease in dewpoint

CAPE

Widely used predictor for t storm potential and severe weather risk

What percent of T storms = tornado

2%

What percent of supercells = tornado

30%

Moisture advection is in front of

Cold front

Snow Skew T/ Sounding

Temperature never above freezing

Numerical weather prediction

Science predicting future state of atmosphere using physical equations