The “Born Loser” comic strip on Mar. 15, 2014 said it all. The cartoon starts with an, “Oh, no…what’s the matter” panel (Fig. 1). It ends with a…well, take a look and see the full cartoon.
For many in the eastern half of the U.S., the cartoon's message may be far too accurate.
March is known as a battleground month in weather circles. Winter is waning, but cold northern air masses are still able to penetrate deeply into the U.S. Tropical warmth wants to push northward as higher sun angles and longer daylight periods increase seasonal warming. In the middle lie the states east of the Rocky Mountains and from the Gulf of Mexico to Canada.
It is here that the battle for air mass supremacy takes place. Usually beginning along the Gulf Coast early in February and March, the warfare zone follows the Sun and moves northward to the Great Lakes and northern Plains by early summer. Thereafter, the zone retraces its steps southward (still in synch with the Sun) and is mostly gone from the U.S. by November and December.
The transition doesn’t play out uniformly, but, more-or-less, follows the above-described pattern. It’s often punctuated by rapid swings in temperature, wind direction and precipitation type.
Each day, meteorological warfare is raged globally (Fig. 2) in the form of battles along weather fronts. It is the periodic low-pressure systems that travel along weather fronts that allow warm air to push poleward (or northward in the Northern hemisphere as a warm front; behind the moving low, winds turn and cold air surges Equatorward (southward in the Northern Hemisphere) as a cold front. The polar and Equatorward directions are flipped “down under.”
One can thank the Bergen (Norwegian) School of Meteorology (in particular, Wilheim Bjerknes) for the use of the descriptor term, “front.” He viewed the meteorological air mass conflict as similar to that of wars raged in Europe. The weather pattern early this Sunday morning (Fig. 1) is truly reminiscent of how war used to be fought, with opposing sides (here opposing air masses) pushing against each other along the battle “front.”
Today, warm, moist air from the Gulf of Mexico is already moving northward into the lower Mississippi River Valley and Gulf Coast states. To the north, cold air has been advancing south from Canada. Both air masses are on a collision course (Fig. 3) that will impact a large part of the eastern U.S.
Yesterday, severe storms (hail and high winds) struck eastern Texas (Fig. 4), while heavy rainfall also fell in parts of Texas, Oklahoma, Arkansas and Louisiana (Fig. 5). This severe and wet weather pattern will head eastward today, before starting to exit the East Coast later on Monday (Fig. 6).
To the north of this thunderstorm region, colder air is establishing itself. Precipitation has already started to transition from rain to snow across parts of Missouri and Illinois early this Sunday morning. The mixed frozen precipitation - snow zone will advance eastward later today, affecting much of the lower Ohio Valley and the central Appalachians, before smacking the mid-Atlantic by late today and tonight. Pennsylvania and southern New York State should receive only some lighter snow and snow showers.
As this storm system departs, another storm is expected to arrive across the northern Rockies and northern Plains (Fig. 7). By late Tuesday and Wednesday, look for a band of heavy snow to develop from eastern Colorado to Minnesota and Wisconsin.
Finally, by week’s end, a weaker system should bring snow to the Great Lakes region.
Out west (with the exception of parts of Oregon and Washington into the northern Rockies), it’s a continued dry weather pattern. Warm weather will continue across southern California. Look for the development of a windy weather regime to set up in coastal and coastal mountain areas by Tuesday.
Looking further ahead, the 8 to 14 day outlook, just issued by NOAA’s Climate Prediction Center, indicates a status quo weather pattern. Stormy and chilly weather is on tap for much of the east, while warm and dry weather dominates out west (Fig. 8).
© 2014 H. Michael Mogil