textproduct: Omaha/Valley

KEY MESSAGES

- Extreme fire conditions for northeast Nebraska Thursday with a Red Flag Warning in effect from 10am-7pm. Strong southerly winds and low humidity across our entire area combined with dry fuels in northeast Nebraska.

- Low chances (20-40%) for showers and storms on Thursday and Friday with better chances for rain holding off until Saturday night through Monday.

- Potential is increasing for periodic strong-to-severe storms Saturday through Monday.

DISCUSSION

Issued at 129 PM CDT Wed May 13 2026

Clear skies this afternoon with nearly calm winds as high pressure moves across the area. Water vapor imagery shows the upper-level ridge building into the Central US helping to contribute to subsidence across our region. Temperatures are already in the 70s as of noon and are expected to warm into the low 80s again across most of our area. Winds, light and variable as of midday will start to gradually increase out of the south- southeast this evening into the overnight hours as the surface ridge shifts eastward toward the Mississippi River Valley.

Tomorrow's main concern will be the extreme fire conditions expected to develop. As a compact upper-level trough moves across Saskatchewan into Manitoba, we'll see a mass response leading to a tightening pressure gradient and increasing wind speeds Thursday morning. A strong low-level jet develops in the warm conveyor belt of the deepening cyclone over south-central Canada, with wind speeds reaching 50-55 kts at 850 mb. This translates to wind gusts reaching 35 to 45 mph by 9-10am continuing into the afternoon. Strong winds combined with humidity dropping to 20 to 30 percent Thursday afternoon will lead to extreme fire conditions in areas with fuels dry enough for explosive fire growth. This is limited to a portion of northeast Nebraska where we have issued a Red Flag Warning.

n upper-level shortwave should generate at least echoes on radar if not a few isolated showers/storms. Dry low levels mean most of it will evaporate before reaching the ground (virga), but do have up to a 30% chance for rain Thursday morning. If anything accumulates, it will only be a couple hundredths of an inch. Thursday afternoon, temperatures will be a couple degrees warmer than today but still in the low-to-mid 80s, starting our warming trend going into the weekend. Far southeast Nebraska/southwest Iowa could get clipped by an isolated storm or two Thursday evening, with potential for large hail or damaging winds.

A much more active weather pattern sets up going into the weekend with a buckling zonal flow pattern setting up to send a series of waves through our area into early next week. The first of these waves brings lower pressure into the WY-western SD- northwest NE area on Friday ramping up warm-air advection into Nebraska and western Iowa. High temperatures will be very summer-like, getting into the upper 80s to mid 90s. We see another chance for scattered showers and storms Friday evening as a weak cold front pushes through, though dry lower levels will again limit rainfall amounts to generally less than a tenth of an inch.

Saturday our next system brings another flow reversal allowing highs to warm back up into the mid-to-upper 80s. We see the development of a stationary front across our area by Saturday afternoon, acting as a focus for potential showers and thunderstorms only increasing in coverage going into the evening with the amplification of the low-level jet. Steep lapse rates as well as moderate shear along and south of the boundary will lead to potential for strong to severe storms into the overnight hours. Two additional shortwaves will trigger additional chances for strong to severe storms through the period Sunday into Monday as well. Details still are murky, but all hazards including large hail, damaging winds, tornadoes, and flash flooding appear to be possible at times.

The active pattern looks to continue into next week with additional chances for showers and storms. Temperatures trend cooler after Monday, settling back around normal by midweek.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1207 PM CDT Wed May 13 2026

VFR conditions through the TAF period. Winds are shifting to the south-southeast this afternoon, and expected to gradually increase overnight. Wind speeds will ramp up towards 14Z on Thursday, starting with gusts to 20-25kt, but getting to 30 to 35kt near or just beyond the end of the TAF period.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Red Flag Warning from 10 AM to 7 PM CDT Thursday for NEZ011- 012-015>018-030>033. IA...None.