Weather Alert in Pennsylvania
Extreme Heat Warning issued June 21 at 3:02AM EDT until June 25 at 8:00PM EDT by NWS State College PA
AREAS AFFECTED: Franklin; Perry; Dauphin; Lebanon; Cumberland; Adams; York; Lancaster
DESCRIPTION: * WHAT...Dangerously hot conditions with heat index values over 105 expected for the Lower Susquehanna Valley. * WHERE...Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN...From 11 AM Sunday to 8 PM EDT Wednesday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS...Heat index values and the associated risk of heat-related impacts will be highest on Monday and Tuesday.
INSTRUCTION: Drink plenty of fluids, stay out of the sun, and stay in an air-conditioned room. Check up on relatives and neighbors, and provide pets with adequate water and shelter from the sun. Extreme Heat can be life-threatening among at-risk populations, such as children, the elderly, and those with pre-existing health conditions. In addition to the daytime heat, overnight low temperatures will also be very warm and oppressively muggy.
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Weather Topic: What are Shelf Clouds?
Home - Education - Cloud Types - Shelf Clouds
Next Topic: Sleet
A shelf cloud is similar to a wall cloud, but forms at the front
of a storm cloud, instead of at the rear, where wall clouds form.
A shelf cloud is caused by a series of events set into motion by the advancing
storm; first, cool air settles along the ground where precipitation has just fallen.
As the cool air is brought in, the warmer air is displaced, and rises above it,
because it is less dense. When the warmer air reaches the bottom of the storm cloud,
it begins to cool again, and the resulting condensation is a visible shelf cloud.
Next Topic: Sleet
Weather Topic: What is Snow?
Home - Education - Precipitation - Snow
Next Topic: Stratocumulus Clouds
Snow is precipitation taking the form of ice crystals. Each ice crystal, or snowflake,
has unique characteristics, but all of them grow in a hexagonal structure.
Snowfall can last for sustained periods of time and result in significant buildup
of snow on the ground.
On the earth's surface, snow starts out light and powdery, but as it begins to melt
it tends to become more granular, producing small bits of ice which have the consistency of
sand. After several cycles of melting and freezing, snow can become very dense
and ice-like, commonly known as snow pack.
Next Topic: Stratocumulus Clouds
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