Wednesday, January 9, 2008

January Thaw ... is over ...

Hal Borland expressed the mystique of the January Thaw best in his book Sundial of the Seasons.
"The January thaw is special because it opens Winter's door a crack just when it seems that the ice has locked it tight. Through that crack one can see the certainty of March and April somewhere up ahead....The worst one can say about the January thaw is that it never lasts. It lifts the heart, then drops it with a cold thud when the warm spell passes and the chill congeals the earth again....But when January does relent, even for a day or two, we can celebrate, cautiously."

A January Thaw is expected usually following a strong cold snap, but need not occur every year.

In prime January Thaw country, the ideal weather pattern characteristic of the Thaw period unfolds in this manner. It begins after a cold air mass from northern or western regions has slid over the region (A), eventually moving out over the Atlantic Ocean. As that air mass leaves, the Bermuda High strengthens (B,C,D) and becomes positioned over the southern Atlantic Coast or southeastern US states while a broad low pressure trough moves slowly across northern Ontario and Quebec (B-E). The juxtaposition of the isobar patterns of these two map features (E) places the northeastern US and southeastern Canada border region into a south-southwesterly flow of warm air from the Gulf of Mexico. This air advects over the northern snow and ice fields and begins a thawing.

Often during this time, the upper air wind patterns are in a period of readjustment, and thus surface weather systems stall or creep slowly across the eastern continent's mid-latitude belt. After several days of warmth, the regional weather again comes under the influence of a strengthened polar high (F,G), and cold weather returns.

The period of thaw usually results in a significant reduction of snow cover and ice thickness that is welcomed by many as a release from winter's uncomfortable grip.
Here is PA the January Thaw is over as temps are dropping daily. With the warm up I see I lost one of my Goldfish in my pond. A beautiful gold shimmer is seen floating just under a lite ice coating. We reached a high of 67 degrees and now it is dipping into the 40's and falling.

Enjoy the sunshine -- cold. blustery days are coming again ...

No comments:

Post a Comment

Welcome and thanks for your comments. Be nice or Be deleted!

Note: Only a member of this blog may post a comment.