ELEVATED RISKS FOR SEVERE WEATHER THIS APRIL

April is generally the month when spring finally loosens winter’s grip almost entirely and the nation advances markedly toward the warmer months. The severe weather season builds toward its peak in April as temperature differences across the country remain relatively high. As the jet stream migrates north, it brings warmer air from the south with it. However, colder air can still linger across parts of the country. The rate of daylight gain begins to slow down in April. Daylight lengths range from 12-14 hours per day across many locations. Average highs climb into the 50s and 60s across the northern part of the country with 70s and 80s taking hold in the South. Most of the country will see their last freezing temperatures for the season get put behind them in April, with the exception of areas near the Canadian Border or across portions of the northern interior West.

Above to well above normal temperatures dominated the story for much of the US this March, especially away from the Canadian border. The initial warm surge occurred over the first 10-12 days of the month, when much of the country saw temperatures as much as 10-20 degrees above normal. A trough over eastern Canada did delay this warmup until the start of week two for the Northeast. Many record highs were set during this stretch. Atlanta broke daily record highs four times between March 5-11, including three in a row between March 5-7. A disruption to this warm pattern occurred during mid-March, as a potent cold front brought a wave of below normal temperatures to the Central/Eastern US centered around the March 14-19 time frame. The cold blast didn’t last much more than 2-3 days for a given location, but temperatures dropped 10-20 degrees below normal during its peak, reaching as much as 25 degrees below normal in the Midwest. As this occurred, record-breaking heat returned to the Southwest for much of the second half of March. Phoenix recorded eight consecutive days of highs exceeding 100 degrees between March 18-25, including three straight days of highs reaching 105. This all occurred before what was previously the record for earliest 100 degree day on record for Phoenix, which was set on March 26, 1988. Warmth would spread across much of the Central/Eastern US during the final third of March as ridging build across the southern half of the US. Temperatures were more volatile across the Upper Midwest and the Northeast, particularly near the Canadian border as temperatures oscillated between solidly above normal and near to slightly below normal. Precipitation in March was a tale of haves and have nots. The Pacific Northwest saw above normal rain and mountain snow this month, peaking during mid-March. Mid-March was also quite active in terms of rain and snow across the Great Lakes. Drier than normal conditions otherwise were in place elsewhere in the US, with the driest anomalies favoring California as well as the Southeast. After a slightly slower start to 2026, severe weather ramped up in March with three notable systems. There were 37 tornado reports over March 5-7 with the first system, mainly in Oklahoma and Michigan. The next system over March 10-12 brought over 90 tornado reports, spreading from Texas towards Illinois/Indiana initially before focusing across the Southeast. The third system over March 15-16 produced more than 50 tornado reports from the Ohio Valley to the Mid-Atlantic/Southeast. This final system also brought 15-30″ of snow across portions of Wisconsin and northern Michigan.

A warm pattern is expected during the first week of April across the South with a ridge stationed overhead. However, this will contrast with a trough draped across Canada. This will maintain a volatile temperature pattern across the Midwest and the Northeast, with temperatures fluctuating from above normal to slightly below normal. The Southwest will see relief from the late March heat early in April, but a ridge should return late in week one and into week two, allowing for above normal temperatures to take hold across the region. A ridge should develop near Alaska during the second week of April. This may provide an opportunity for a more organized cold shot to sweep across the Midwest/East during week two, but it is unlikely to be accompanied with a -NAO ridge near Greenland. This should mean that any cold that does get ushered in should be allowed to exit, especially in the South. By the third week of April, tropical forcing should move across the Americas towards Africa. This is a signal for a trough to get placed across the eastern half of the US, and model guidance suggests that a ridge should begin to form near Greenland. In addition, an early breakdown of the polar vortex is anticipated early in April, and a split of the weakened vortex could eventually be directed towards North America by mid-April. These factors will once again increase cold risks across the Central/Eastern US, especially across the Midwest and the Northeast. With a -NAO ridge near Greenland expected, any cold that does form could be slower to exit for areas near the Canadian border. The highest risks for cold should fall in the April 15-25 window. Cold risks should gradually decline late in April across the South as tropical forcing drifts away from Africa and through the Indian Ocean towards the Maritime Continent, as this should allow for some ridging to attempt to reform over the South. The warmup will be slower to occur across the Midwest and the Northeast as troughing should remain nearby across Canada. With an expected wet pattern for much of the eastern half of the US developing in April, this should lessen the potential for substantial heat to the levels seen in March as the increased soil moisture from the rains should take some of the edge off of the warmer periods.

The clash between the ridge in the South and a trough over Canada should provide an active pattern to start April. The most active area over the first ten days of April should be from the Southern Plains through the Ohio Valley and the Great Lakes, with locally heavy rainfall anticipated along with an elevated risk for severe weather. One or two of these systems could carry the threat of wintry precipitation to portions of the Upper Midwest and the Northeast, mainly inland and away from the Northeast Urban Corridor. A trough early in April may allow for a system or two to bring rain and mountain snow to the Pacific Northwest and the Great Basin. As ridging takes hold in the West, however, a drier pattern should emerge by the second week of April that should be in place for most of the remainder of April. With the ridge expected to weaken during week two over the South, this may shift the storm track a touch further to the south and east. This should bring the wettest conditions and best chances for severe weather from the Southern Plains through the East while the Upper Midwest should see precipitation trend more seasonable. The storm track should shift back towards the north by the final week of April, which would reduce rainfall across the Southeast while the rain and storm threat should increase across portions of the Midwest. The most organized rain and highest storm threat should be from the Arklatex Region to the Great Lakes at the end of April.