Severe weather can be one of the biggest threats to an installation, with potential to destroy equipment and property on a large scale and even result in death. Planning for severe weather threats is everyone's responsibility. Everyone must know how to respond individually and how their organization will respond when threatening weather approaches.
Severe weather responses start with a forecast from the base meteorologists. They issue warnings to base agencies who then pass those warnings throughout their organizations. Each organization has a tailored response to different weather threats. For example, the Child Development Center will respond much differently to a heavy snow storm than will Civil Engineering. Engage your leadership for questions on what your unit's severe weather response actions are.
There are three fairly common severe weather threats to Hill Air Force Base.
The first is strong winds (more than 50 knots/57.5 mph) which are most often caused by high and low pressure differentials and collapsing storms. The mouth of the Weber Canyon at the northeast corner of the base is a direct contributor to the frequency of strong winds at Hill AFB. Think of the canyon as a high pressure hose that constricts the flow of water into a confined space. The pressure differential that would produce a mild breeze on a flat plain is constricted and amplified by the canyon, resulting in higher than normal wind speeds. In 1983 one such canyon wind event produced winds in excess of 104 mph at Hill.
The second common threat is heavy snow (greaer than 2 inches). Heavy snow can be especially dangerous because of the multitude of threats it poses. Roads can be dangerously slick or impassible, visibility is reduced, broken trees can cut power and heavy loads on rooftops can collapse buildings. Hill is more affected by heavy snow than most areas because of the Great Salt Lake.
A storm blowing from the west can pick up extra moisture over the lake which it then dumps on the base when it hits the mountains to our east. This is called "Lake Effect Snow" and can cause the east side of the lake to receive several more inches of snow than the west from the same storm.
The last common severe weather threat to Hill AFB is from thunderstorms. Thunderstorms are so common that it's difficult to think of them as severe but consider the following facts about lightning.
A bolt of lightning can travel ten miles, warms the air around it to 50,000 degrees Fahrenheit and can contain 100 million volts. This much force is very capable of killing people, starting fires and destroying property.
Thunderstorms also present the danger of large hail which can damage unprotected equipment. A collapsing thunderstorm can produce concentrations of heavy winds known as a microburst. A microburst at Andrews AFB in 1985 was clocked at 149.5 mph. Once again the Great Salt Lake can provide moisture to thunderstorms which makes storms at Hill AFB stronger and more frequent.
The base weather station and the regional Air Force Weather Hub at Davis-Monthan AFB have the responsibility of forecasting and observing weather that may affect Hill.
There are three notification categories. The first is an advisory, which states that a certain weather phenomena is currently happening or has been recently observed.
These usually describe conditions that aren't necessarily dangerous and are mostly related to aviation such as 25-knot crosswinds occurring on the runway.
The second two categories are for potentially dangerous conditions. These categories are watches and warnings. Watches are issued to notify operators that the conditions for a dangerous weather event exist. These should be used as a situational awareness tool to aid in planning.
Warnings are issued when a dangerous weather event is imminent and action must be taken.
For instance, the "Snow Accumulation > than 2 inch Watch" may be issued as far as twelve hours prior to the first snowflake, while the "Snow Accumulation > 2 inch Warning" will be issued about two hours prior to the accumulation actually reaching 2 inches in depth.
Another thing to be aware of is the Valid Time. Just because the Snow Accumulation > 2 Inc Watch was issued at noon doesn't mean it will start snowing immediately. If the Valid Time is 8 p.m. local, that means the forecaster expects the snow on Hill AFB to reach two inches at 8 pm.
Each of these weather events occur during different seasons.
Heavy snow falls in the winter of course. Thunderstorms are most common in the late spring and summer, but have the potential of occurring yearround. Strong winds most often occur in the winter, spring and summer.
Going into each new season it's important to make sure you understand the weather threat you will face and to understand what actions to take.
Each base agency should have their relevant response planned out.
There is no way to make Hill AFB "weatherproof" but if we all follow our local procedures we can help keep ourselves and government property as safe as possible.
For access to the latest Hill AFB forecasts and other weather information, please go to our SharePoint site at: https://org.eis.afmc.af.mil/sites/75OSS/OSW/default.aspx.
