**Severe weather threat(s)...additional cold air outbreaks...stratospheric warming impact...recap of weekend's dramatic "back door" cold frontal passage**
Paul Dorian
An organized line of strong-to-severe thunderstorms is possible late this evening along the DC-to-Philly-to-NYC corridor as a strong cold front pushes into the region. Map courtesy NOAA, tropicaltidbits.com
Overview
Strong-to-severe thunderstorms are a threat later today and tonight across much of the eastern US including in the DC-to-Philly-to-NYC corridor as a strong cold front pushes eastward towards the Atlantic seaboard. This same frontal system resulted in numerous damaging wind gusts on Sunday across the Midwest/Mississippi Valley with a few tornadoes reported there as well and that same part of the nation will likely have a repeat performance of severe weather on Wednesday. In fact, numerous severe weather outbreaks are on the table for the month of April largely as the result of a recent stratospheric warming event which, in turn, enhances the likelihood for additional cold air outbreaks into the central and eastern states setting up “battle zone” regions. Finally, we’ll revisit the passage of a “back door” cold front this weekend that impacted the northeastern states and, in some locations, there were record-breaking temperature swings.
A strong cold front produced numerous damaging wind reports on Sunday across the Midwest and Mississippi Valley and this same front will bring strong-to-severe thunderstorms to the eastern states later today and tonight. Map courtesy NOAA/SPC
Severe weather threat(s) including later today/tonight in the DC-to-Philly-to-NYC corridor
A strong cold front produced numerous damaging wind gusts on Sunday across the Midwest and Mississippi Valley and that same frontal system is sliding towards the eastern seaboard. As a result, there will be strong-to-severe thunderstorms later today and tonight across much of the eastern US including the DC-to-Philly-to-NYC corridor and damaging wind gusts are on the table. In addition, hail and isolated tornadoes will be possible later today and tonight in the Mid-Atlantic region and there will be enhanced risk for tornadic activity farther to the south from the Carolinas-to-northern Florida. The rain can be heavy at times as well with this frontal passage and localized flash flooding is a threat along with the potential damaging wind gusts. The front slides off the east coast by early Tuesday and its passage will usher in much cooler air for the Mid-Atlantic and Northeast US to begin the month of April. One other note, the Phillies home opener is still scheduled for 3pm later today and there is a chance they can “sneak in” the game before storms arrive if it is played relatively quickly.
It looks like the 10-day period from April 6th to April 16th will feature much colder-than-normal conditions on average across the eastern and central US…largely the impact of a significant stratospheric warming event that got underway in February over the polar region of the northern hemisphere. Map courtesy NOAA, Weather Bell Analytics
Additional cold air outbreaks...an impact by recent stratospheric warming event
Largely the result of a significant stratospheric warming event that got underway in February over the polar region of the northern hemisphere, additional cold air outbreaks are quite likely in coming weeks across the central and eastern US. In recent years, a stratospheric warming event of this magnitude that took place from February into March - as it did this year - resulted in a colder-than-normal month of April across a large part of the nation and it certainly looks like there will be a long stretch of colder-than-normal weather across the central and eastern US this year.
A significant stratospheric warming event got underway in February across the northern hemisphere’s polar region and it is quite likely to result in additional cold air outbreaks for the central and eastern states well into the month of April. 30-day temperature loop in the stratosphere (10 millibars) courtesy NOAA
Big-league baseball got underway last week and, no doubt, there will be many early season games played in cold weather conditions as the result of colder-than-normal air masses making their way into the central and eastern states from northern Canada. This colder-than-normal temperature pattern in April can impact all baseball towns across the Midwest/Great Lakes and Northeast US and, in addition, there may be a big impact in Denver, Colorado where cold and snow will likely be a threat for some early season games including as soon as late this week/weekend.
The passage of the dreaded “back door” cold front this weekend was quite dramatic in New York City. In fact, Central Park recorded a 26-degree temperature drop in just one hour’s time which is a record-breaker and weather conditions changed from summer-like to winter-like in a New York minute. Maps courtesy NOAA, Weather Bell Analytics
Weekend “back door” cold front in the Mid-Atlantic/Northeast US with dramatic results
The weather on Saturday featured a strong continental flow of air across the Mid-Atlantic region with W-SW winds gusting up to 30 mph or so. This (warm) wind flow combined with some sunshine in the DC-to-Philly-to-NYC corridor to allow for temperatures to soar to the 80-degree mark all along the Mid-Atlantic’s I-95 corridor. Continuing a baseball theme, the strong winds on Saturday afternoon were blowing out in Yankee Stadium from a W-SW direction and temperatures reached the 80-degree mark...the result was 9 home runs in the game for the Yankees...their most ever for a single game in team history.
Shortly after the game ended, the dreaded “back door” cold front made a noteworthy appearance in the NYC metro region. During the day, temperatures actually held at winter-like levels across New England and even much of New York State on the north side of the front, but they were able to climb to the 80-degree in southeastern New York on the south side...and then a dramatic change in temperatures took place in NYC with the passage of the dreaded “back door” cold front that moved from northeast-to-southwest. (“Back door” reference comes from the fact that these kinds of fronts “sneak-in” from the northeast as compared to the more conventional west-to-east movement of cold fronts in this part of the nation).
Temperatures plunged a record-breaking 26 degrees in just one hour in Central Park (NYC) making for a quick change of season from summer-to-winter and the change in temperatures over a 3-hour period was a record breaker as well. “Back door” cold fronts are somewhat common this time of year in the Mid-Atlantic/Northeast US when western Atlantic Ocean water temperatures remain at very chilly levels and a low-level wind flow that shifts to an east or northeast direction from offshore can quickly change summer conditions to winter...exactly what happened this past weekend in NYC and other parts of the northeastern states.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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