textproduct: Grand Forks

KEY MESSAGES

- Near critical fire weather conditions are expected this afternoon in southeastern North Dakota.

- Red Flag conditions are expected to develop in the Devils Lake Basin.

..FIRE WEATHER

Critical fire conditions are likely tomorrow afternoon. ERC Percentiles in the 95-97th percentile and HRB remaining at 30 indicate primed fuels for rapid fire spread. Wind speeds are likely to be there with a weak jet max crossing through, with westerly sustained winds tomorrow afternoon between 20-25 mph, with occasional gusts to 40 mph. The confluence of these two conditions brings likely marginal Red Flag conditions in the Devils Lake Basin as that is the location of the jet max tomorrow afternoon when RH values are the lowest. The main uncertainty will be the relative humidity getting low enough to hit criteria as the cold front today will increase dewpoints to the 30s. This means that temperatures need to rise into the low 70s at least to get to below 30%. Relatively solid thermal ridging at 925 and 850mb will be centered over eastern North Dakota, which likely will allow temperatures to rise into the mid to upper 60s in that area. Once again, the Devils Lake Basin is where the ridge axis intersects, so this will be the greatest area for 70+ temperatures. For these reasons, a Red Flag Warning has been issued for the Devils Lake Basin, with potential expansion possible if the wind field expands and the temperature field is warmer across eastern North Dakota. Northwest Minnesota looks to avoid the potential for Red Flag conditions at this time as the thermal ridge should remain upstream until after 00z tomorrow.

Additional chances for critical fire weather conditions arise late next week. Perpetual northwesterly flow continues to contribute to downsloping and dry airmasses over our region, so days with increasing temperatures bring an increased risk for critical fire conditions. The main question marks will be wind speeds which do appear likely late next week with a few clippers traversing the Canadian Prairies and whether fuel status will remain critical. While ERC percentiles are largely high, HRB is beginning to respond to green-up, so fire spread may become inhibited. At this time, Thursday and Friday appear to have the greatest likelihood for Red Flag conditions.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1222 PM CDT Sat May 2 2026

The only aviation impact for the TAF period should be mainly wind shifts that will occur. This afternoon, southwest to westerly winds will shift to northwesterly as a cold front pushes through the area. Showers may accompany this but cloud bases are very high due to dry air so precipitation is unlikely, and thus aviation impacts are unlikely even if we see any rainfall. Winds will diminish after sunset, remaining around 10 knots through midnight with eventually sub-10 knot winds expected thereafter. As the sun rises tomorrow, speeds will increase once more, particularly closer to the end of the TAF period where sustained winds will likely exceed 12 knots.

FGF WATCHES/WARNINGS/ADVISORIES

ND...Red Flag Warning from 11 AM to 9 PM CDT Sunday for NDZ006-007- 014-015-024-026-054. MN...None.