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Posted at 11:02 AM ET, 03/01/2013

March severe weather, and start of meteorological spring: in like a lion, or lamb?


(Dan Kitwood - GETTY IMAGES)
March 1 marks the start of meteorological spring. For those who are tired of the dark, damp, and disappointing days of winter this official demarcation of spring is a welcome thought. Most years this indoctrination of spring can be misleading because early March can feel like an extension of February. It becomes even more misleading when we remember that while meteorological spring has commenced, astronomical spring does not officially begin until much later in the month on March 21st.

March is a bizarre month when it comes to weather. It’s a transitional month where the season attempts to court the new spring while still flirting with winter.

During March, it is not uncommon to have tornado outbreaks (like last year across the Midwest and lower Mississippi Valley on March 2, 2012), and historic blizzards (see March 13, 1993).

CWG’s Ian Livingston provided an extensive climatological breakdown for the month of March last year. In his article he provides information on temperature averages and extremes, precipitation averages and extremes, as well as some snow climatology. In short: March as been there, done that, and seen it all! (What about a hurricane, you say? “Hurricane One” formed in the South Atlantic on March 6th, 1908.)

A storm chaser and lover of convective spring-time thunderstorms, I have been going through “storm deprivation syndrome (SDS)” since late-September. This got me wondering what severe weather climatology is like for our area during the month.

Is the beginning half of March usually more active, or the latter half? What is our dominant severe weather type? - tornadoes, wind, or hail? Some old weather folklore says that March is likely to enter with fierce weather (in like a lion) and leave with calmer weather (out like a lamb). Does this folklore normally ring true for the Washington, D.C area? What about this March in particular?


Let’s take a look at severe weather climatology (tornadoes, high wind, and hail reports) and break the month in half comparing early- mid March (days 1-15) and mid-late March (days 16-31). The maps above and below include data downloaded from the Storm Prediction Center for the period of 1950-2011. Hail reports include anything larger than 0.75” and wind reports include gusts of 50 mph or higher.


Comparing the first and second half of the month using the maps above, we can make a few observations. Wind events dominate the first half of the month. Hail and tornadoes, however, are more prevalent during the second half of the month (when the number of tornado events double compared to the first half). This is not surprising, since the latter half of the month usually features warmer conditions naturally more conducive to support hail-producing and tornadic thunderstorms.

Digging into the details, no March tornadoes in the immediate D.C. area and west of the Chesapeake Bay have exceeded the F/EF1 range (<118mph using the Fujita Scale and <110mph using the Enhanced Fujita scale implemented in 2007). March 29 appears to be somewhat of a prolific tornado-producing day, with four tornadoes on record: two in 1997 and two in 2003. At the end of the day, we do not get many tornadoes in March, and the ones we do get are weak. Definitely not our dominant severe weather type!

A list of the tornadoes on the map in the surrounding D.C. area and west of the Chesapeake Bay include:

March 3rd, 1972 – F1
March 21st, 1976 – Unknown rating
March 21st, 1976 – Unknown rating
March 29th, 1997 – F0
March 29th, 1997 – F0
March 29th, 2003 – F0
March 29th, 2003 – F0
March 10th, 2011 – EF0
March 10th, 2011 – EF0

Hail is much more likely to occur during the latter-half of March. Peak hailstone size has varied from 0.75-1.75”.

Wind events appear to be our most common severe weather event during the month of March, and especially during the first half. I’ve always associated spring as the windiest season.

Early March outlook

So how does the beginning of March look for the D.C. area? (Remember: Good ‘ole Punxsutawny Phil predicted an early spring.) According to the Climate Prediction Center, 6-10 day temperature and precipitation outlooks it appears we will experience below normal temperatures and normal precipitation amounts.


Temperature and precipitation forecast relative to normal for March 6 through 10. (NOAA)

For the fellow storm lovers like me out there, NOAA’s Storm Prediction Center does not hint at an active convective storm period over the next eight days either, at least not for the Washington, D.C. region. On the other hand, snow lovers (and haters), should keep a watchful eye on the period around March 6 for a possible storminess

Conclusion

Even though we have entered meteorological spring we have not yet entered astronomical spring, so we’re stuck in what I like to call “spring limbo” until we cross the astronomical spring threshold later this month. Nonetheless it’s best to prepare for the wild ride that will be March, as it will likely feature temperature extremes, precipitation extremes, and a lot of superfluous chatter about groundhogs, lions, and lambs.

By Kathryn Prociv  |  11:02 AM ET, 03/01/2013

Categories:  Latest, Thunderstorms, Local Climate

 
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