|WX MODEL 21:|
Upslope Flow with Low Pressure
METEOROLOGIST JEFF HABY
Upslope flow occurs when surface winds flow from lower toward higher elevations. With a low pressure approaching/developing, this
lifting mechanism will help saturate the troposphere. Upslope flow enhances the amount of precipitation since it acts as an additional
lifting mechanism. The path of the low pressure will influence the areas that receive the greatest amount of upslope flow and thus
precipitation. The strength and speed that the low pressure system moves will also influence precipitation totals. A strong
slow moving low can allow upslope conditions to persist at certain locations which can
generate significant amounts of precipitation.
The two images below show an upslope flow event in Colorado. The first image is a surface model. Notice the flow moving from east to
west over Colorado. This will produce rising air due to upslope flow. The second image shows a surface pressure and precipitation
model. A developing low pressure along with upslope conditions are contributing to the significant
precipitation amounts in colors of green.