Drought — Polk, Nebraska

2024-04-01 to 2024-04-30 · Polk, Nebraska

Wider weather episode

April 2024 marked the fifth-consecutive month that at least a slight majority of South Central Nebraska received at least slightly above normal precipitation, fueling a continued, gradual improvement in a multi-year drought situation. Nonetheless, sizable portions of seven of the 24 counties spent the entire month assigned Severe Drought (D2) by the U.S. Drought Monitor (USDM), while a sliver of an eighth county (Merrick) also carried D2 through the vast majority of April until being improved to Moderate Drought (D1) on the April 30th USDM issuance. April marked the 27th-consecutive month with at least D2 drought plaguing portions of the 24-county area. But keeping the focus on the positive, April featured a continued modest reduction in the areal coverage of both D2/D1, as roughly two-thirds of South Central Nebraska tallied at least slightly above normal precipitation, much of which fell very late in the month (see below for more detailed monthly precipitation info). Focusing on April county-level USDM drought specifics, the month opened with roughly 59 percent of the 24-county area assigned drought categories ranging from D0 (Abnormally Dry) to D2, with a more detailed breakdown as follows: 1) D2 impacted roughly 22% of the 24-county area (all within eastern counties along/east of Highway 14)...2) A broad zone of D1 extended westward from the D2 to include most of the remainder of the eastern half of the area (and around 30% of the domain as a whole)...3) A very narrow buffer zone of D0 flanked the western fringes of the D1 (only comprising roughly 7% of the total area)...4) the remaining approximately 41% of South Central Nebraska featured drought-free D-nothing (almost entirely within counties west of Highway 281). As April played out, the first three USDM issuances held status quo, as most of the month was actually quite dry (the bulk of South Central Nebraska totaled no more than 0.25-1.25 through the 24th). However, a weather system dumped widespread rainfall of 1-4 of rain across roughly the northwestern two-thirds of the 24-county area on the 25th-26th, prompting a modest reduction in the areal coverage of both D2/D1 on the month's final USDM issuance (including the removal of D2 from most of Polk County and the removal of D1 from most of Hall County). In the wake of these improvements, the cumulative areal coverage of D1-D2 within South Central Nebraska decreased from roughly 52% to 41%. More specifically, the categorical breakdown at month's end stood as follows: 1) D2 coverage decreased to around 15% of the area (but still including at least the vast majority of Fillmore/Clay/York counties, along with portions of a few others)...2) D1 comprised roughly 26% of the domain (almost entirely within counties along/east of Highway 281)...3) Due to the reduction in the areal coverage of D1, there was a corresponding slight increase in the coverage of D0 (but only constituting around 12% of South Central Nebraska)...4) The remaining approximately 47% of the 24-county area boasted drought-free D-nothing (including several western and far northern counties).

Turning to April 2024 precipitation details, at least for the majority of South Central Nebraska, it was overall good news for the fifth-straight month. That being said, compared to recent months there was a sharper divide between the haves and the have nots. Putting numbers to it, roughly the northwesterly two thirds of the area received slightly to moderately above normal precipitation (meaning at least roughly 2.69). However, amounts really dropped off into the southeastern one-third of South Central Nebraska (especially south of a Minden-Hastings-Fairmont line), where below normal totals of no more than 1-2 were common. In fact, roughly 12% of the area (including much of Adams/Webster/Nuckolls/Thayer counties) tallied less than half of their April normal. Per around 170 NWS and NeRAIN/CoCoRaHS observers, some of the very-highest monthly tallies featured: 5.78 in Aurora, 5.72 near Elwood, 5.56 in Ravenna and 5.42 in both Riverdale and near Boelus. In sharp contrast, some of the leanest April totals from southeastern counties included: 0.79 in Cowles, 0.89 eight miles northwest of Superior, 0.98 in Lawrence, and 0.99 near Red Cloud. On one final note, and as a testament to the magnitude of lingering longer-term drought: despite April being the fifth-straight month of above normal precipitation at Central Nebraska Regional Airport (GRI), the station still totaled only 57.81 over the 37-month stretch from April 2021-April 2024...24.54 BELOW normal/70% of normal.

Source: NOAA Storm Events Database, event_id 1171006. Narrative written by the NWS forecast office that issued the report.