Widespread critical to extremely critical winds are already being observed across most of the High Plains from near the Mexico border to near the Canadian Border.
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Relative humidity is already critically dry across much of the southern High Plains with additional warming needed in the central High Plains and northeast Montana before critical conditions are observed there.
Only change to this outlook was a slight eastward expansion of the elevated across western Oklahoma and southern Kansas.
Elevated to locally critical conditions are expected in the wake of the cold front after it moves through this area with poor recoveries expected through the overnight hours in this region.
Fire weather threats are expected to increase this afternoon along much of the High Plains.
A strong upper-level jet is noted in early-morning water vapor imagery and latest RAP analyses across the Pacific Northwest.
This features will dig slightly into the central Plains through the day and help shift a strong surface low, noted in the lee of the northern Rockies, into the upper MS river valley by late afternoon.
An attendant cold front will sweep southeast across the Plains this morning with a continental air mass in its wake, resulting in widespread dry, windy conditions.
Latest surface observations from eastern WY already show strong downslope 25-30 mph winds on the west side of the lee trough. These conditions are yielding poor overnight RH recovery with RH values holding steady in the 30-35% range.
As the cold front pushes east this morning, downslope winds will become more widespread across the central Plains. Latest guidance continues to show high probability for widespread sustained 20-30 mph winds from the Dakotas into northern KS.
Deep boundary-layer mixing up to 700-600 mb and a unidirectional wind profile will support the potential for 40-50 mph wind gusts - especially over the NE/CO/WY tri-state region where the strongest low to mid-level flow is expected.
Despite the deep mixing, cold advection and scattered cloud cover (and potentially light showers) may limit overall RH reductions. RH values may drop into the 15-20% range under persistent cloud breaks, but 20-25% RH values appear more probable.
Given very receptive fuels over the region, widespread critical, and localized extremely critical, conditions are expected.
A secondary surface low is expected to deepen over western OK/northwest TX through the afternoon. 20-25 mph westerly winds behind the low and attendant dryline will have trajectories emanating from the southern Rockies.
Downslope warming and drying will support widespread critical conditions as RH values fall into the low teens.
Extremely critical conditions are possible across far eastern NM and the southwestern TX Panhandle where the overlap of the low-level thermal ridge and 850-700 mb wind maxima will be maximized.
However, poor ensemble probabilities for sustained 30+ mph winds suggests such conditions will be localized and brief.
Portions of northwest TX within the Critical risk area have received well over 0.5 inches of rain over the past 24 hours, which has likely mitigated fuel receptiveness to a degree.
However, the critical wind/RH conditions will support fire spread outside of the narrow swaths that received higher amounts.
Widespread 20-30 mph winds (gusting to 50+ mph at times) are expected behind the cold front by early afternoon.
Due to cold air advection and lingering cloud cover, RH reductions are expected to be meager, falling to 25-35%.
Despite this, very dry fuels combined with strong winds will support critical fire weather concerns this afternoon. ■
A very active and complex mid-May weather pattern is set to produce numerous areas of severe weather, heavy rain, high winds, and anomalous temperatures through this weekend.