textproduct: Grand Forks

KEY MESSAGES

- Near critical to critical fire weather conditions are expected over parts of the region as temperatures increase next week.

- Cold overnight and early morning temperatures are expected through Monday, with frost and freeze conditions over parts of the region.

UPDATE

Issued at 408 AM CDT Sun May 10 2026

Only minor changes to temps/RH grids the next 24 hours. Saturday saw dewpoint temps about 2-4 degree higher than HRRR had yesterday and RH barely reached near critical values. Today less wind aloft to mix and suspect overall a rather similar day today with lowest RH values holding 25 to 30 percent or just above the need for near critical fire weather conditions. Clouds are clearing out of NE ND and temps are falling blo freezing as of 08z and also in NW MN, so freezing warning looks fine. High pressure tonight will bring near calm wind to eastern fcst area and likely frost/freeze conditions esp east of the Red River this upcoming night. Rest of the week will see periods where RH values and winds reach a point where near critical to critical fire weather conditions may occur.

..Frost/freeze impacts Sunday and Monday mornings

Frost/freeze headlines issued for later tonight through Sunday Morning. Freeze headlines issued where ensemble probabilities for 32F or less temperatures were 80% or greater and frost advisories were 32-36F range is more likely. Urban heat island may result in marginal (32-34F) conditions in the immediate Grand Forks metro, however where this influence is less, temperatures are likely to drop below 32F during the early morning hours Saturday in Grand Forks and western Polk Counties.

There is still uncertainty in how much winds drop off (may hold around 10kt) in the Red River Valley (particularly in the south) due to the northerly component of the pressure gradient winds. There is also a signal for lingering pockets of mid level clouds, and the exact locations/coverage/timing in this type of pattern are often not well resolved. Current consensus favors southern part of our forecast area for these clouds, with more likely clearing in the north and northeast. These factors could complicate where widespread freeze conditions (32F or less) occur, and this factored into the decision on where headlines were drawn up. Even with clouds and winds around 10kt, low temperatures would be 36F or lower considering the cold nature of the air mass in place tonight. Where clearing/lighter winds occur within the frost advisory, impacts to sensitive vegetation would still be anticipated.

Sunday night/Monday AM frost/freeze potential: The pattern shift (building low pressure to the west/southwest) will result in moderating temperatures west to east and shifting low level flow to the southeast. The colder air mass will still remain in place across our eastern CWA and this is the type of set up where stronger gradient remains west allowing lighter winds to remain in place within the Red River Valley. There is a much better signal for clear skies Sunday night as well, so with better radiational conditions, it appears likely (greater than 60% probability) that freeze conditions will develop in northwest MN with a chance for frost/freeze within the Red River Valley. Chances for sub 36F temperatures are much lower due to this pattern shift west of the Red River Valley in ND Monday morning. We will ultimately need to consider additional frost/freeze headlines.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1132 PM CDT Sat May 9 2026

VFR will prevail throughout the TAF period. Overnight, ceilings will be on either side of 10,000 ft AGL, eventually SCT out towards morning. On Sunday, cloud bases may come down again a bit, but remain above 6,000 ft AGL. Winds overnight will be 5 knots or less. By mid morning Sunday, winds will return to the 12 knot range out of the north. These winds will continue through the afternoon and early evening, dying off after sunset.

FGF WATCHES/WARNINGS/ADVISORIES

ND...Freeze Warning until 9 AM CDT this morning for NDZ006>008- 014>016-024-026>030-038-054. Frost Advisory until 9 AM CDT this morning for NDZ039-049-052- 053. MN...Freeze Warning until 9 AM CDT this morning for MNZ001-002- 004>009-013>017-022>024-027-028. Frost Advisory until 9 AM CDT this morning for MNZ003-029>032- 040.