By: Charles Roop | WCTV Pinpoint Weather
May 16, 2019
TALLAHASSEE, Fla. (WCTV) — It’s not officially summertime yet, but it’s coming very soon. Guidance models are persistent with bringing a big upper-level ridge of high pressure over the Southeast during the week of May 20 to bring some hot temps across the Big Bend and South Georgia.
But what is it about a ridge that brings warmer temperatures?
In the northern hemisphere, the winds around a cell of high pressure rotate clockwise while winds around a low rotate counterclockwise. Aloft, the flow in between these features can create a stream of air, which can have kinks that cause troughs - dips in the stream of wind - and ridges.
Troughs in the upper levels normally carry colder air because of the lower “heights” containing more dense air and lower pressure. On the flip side, ridges have higher “heights” that contain less dense air and higher pressure. The higher pressure will allow for sinking air, leaving locations under a ridge generally cloud free and much drier.
Ridging was set up in the western part of the United States Thursday morning, with that ridge expected to move eastward over the next couple of days. This will keep us warm this weekend with minimal rain chances. The ridge is expected to be eroded as we get into late in the weekend, but it’s still expected to be very warm and fairly dry.
But a stronger ridge is expected to develop and be camped out over the Southeast as we get into late next week. This means higher heights and, therefore, warmer temperatures for the region. Though it may be overdoing it, some guidance models are hinting at temperatures in the triple digits in Georgia late next week.
The American GFS is a bit restrained compared to the European model, but temperatures will likely be above average. The average high temperature for Tallahassee doesn't hit 90 degrees until May 30.