Clouds of the Day - Thursday, June 11, 2020

Cumulus

Cumulus

Today’s Weather Map

This morning skies are clear across most of the nation. The exceptions are clouds in the Pacific Northwest and from the Great Lakes to the northeastern United States and near the Atlantic Coast. There is a patch of cloudiness in Kansas and southern Nebraska. Photo courtesy of NOAA/NESDIS/STAR.

Large high pressure covers most of the western United States southeast to the Plains and Gulf States. The centers of the high are over Colorado, Oklahoma, and northern Texas. High pressure is a region of downward air motion and dry air. Clouds in the Pacific Northwest are ahead of a cold front. Clouds cover most of Canada visible on this map across the northern Great Lakes and along the Atlantic Coast. Notice the station model plots to see the weather at any location. The station model plot format is available on our home page and also HERE.

Streamlines on the map show the wind direction. Compare the surface wind streamlines with the wind direction plotted at each station. The streamlines also show the air flowing out of the main high pressure centered near the Oklahoma - Arkansas border. No streamlines are plotted in the western United States because the surface is at different altitudes and the flow is weak and variable at the surface. Streamlines are a snapshot of wind direction at a moment in time. Practice your station model decoding using these maps.

Compare this map with the streamlines on the surface map above. This map is at 10,000 feet. The flow at this level gives a reasonable idea of the flow steering surface weather systems. Notice the direction of flow is in some areas is different at 10,000 feet than at the surface. In other places it is the same. The bullseye for the center of the surface high pressure is the Oklahoma-Arkansas border but is on the Texas-New Mexico border at 10,000 feet. It tilts southwest with height.