Tornadoes, huge hail pound the Midwest, but bring little Texas drought relief

Severe weather blasted the Midwest again yesterday, with NOAA's Storm Prediction Center logging 32 reports of tornadoes, 399 reports of damaging thunderstorm winds, and 325 instances of large hail (including softball-sized hail of 4.25 - 4.5" diameter in Clarkesville, MO and Stringtown, OK.) Fortunately, no deaths or injuries were reported from yesterday's storms. The storm also brought the heaviest snow so late in the season to Green Bay, Wisconsin--9.9 inches. This brought the seasonal total for Green Bay to 92.4", the third most on record.

The storm responsible will trek eastwards today, bringing the threat of severe weather to regions of the Southeast hard-hit by last week's remarkable tornado outbreak. NOAA's Storm Prediction Center has placed a wide swath of the country from Eastern Texas to New Jersey under their "slight risk" for severe weather. According to the latest tornado tallies on the excellent Wikipedia page on the April 14 - 16 tornado outbreak, 128 tornadoes are confirmed to have occurred, with 39 of these strong EF-2 and EF-3 twisters. Remarkably, there have been no violent EF-4 or EF-5 tornadoes reported yet in 2011, despite the fact that the preliminary 2011 tornado count as compiled by SPC is 611, which will likely make 2011 the most active tornado season on record for this point in the year.


Figure 1. Satellite image taken at 8pm EDT on Tuesday, April 19, 2011, of the storm system that brought severe weather to the Midwest. Image credit: NASA/GSFC.


Figure 2. Severe weather outlook for today.

Yesterday's storms bring little drought relief for Texas
Yesterday's severe weather outbreak brought a few thunderstorms to the Dallas/Fort Worth area last night, with up to two inches of welcome rain falling in isolated areas. However, the rains missed the areas of Texas where the worst fires area burning, and strong winds associated with the spring storm helped whip up the fires. Winds will not be as strong today, and the latest 1 - 5 day rainfall forecasts show the possibility of isolated thunderstorms bringing drought relief to the same portions of Texas that benefited from last night's rains. These rains will not be enough to significantly slow down the record fires scorching Texas, though, and the latest 2-week forecast from the GFS model shows little chance of drought-busting rains over Texas into early May.


Figure 2. Total rainfall for North Texas from last night's storms brought only isolated drought relief.

Atlantic tropical disturbance
As a reminder that hurricane season is not that far away, an area of disturbed weather has formed in the Atlantic near 23N, 80W, about 700 miles northeast of Puerto Rico. This system is under a hefty 60 knots of wind shear, but does have a surface circulation. The disturbance's heavy thunderstorm activity has been removed well to the northeast of the surface circulation center by the high wind shear. The storm is expected to move northwest into a region of lower wind shear on Thursday and Friday, and should begin building more heavy thunderstorms during the next three days. The storm is not a threat to any land areas, and will likely be ripped apart by high wind shear this weekend. It has perhaps a 10% chance of becoming a subtropical depression before then. Climatology argues against this storm becoming the first named storm of the year; there has only been once named April storm in the Atlantic since 1851, Tropical Storm Ana of 2003.


Figure 4. Morning satellite image of the Atlantic tropical disturbance 700 miles northeast of Puerto Rico.

Jeff Masters