textproduct: Cheyenne

KEY MESSAGES

- Near to record warmth expected today and again on Wednesday under high pressure.

- Elevated to Near Critical fire weather conditions ongoing today over east central Wyoming and the northern Nebraska Panhandle.

- Critical fire conditions possible again on Thursday alongside strong winds, with dry conditions persisting through the end of the week before precipitation may make a return into the weekend alongside cooler conditions.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 245 PM MDT Mon May 11 2026

Late Spring heat and elevated to critical fire weather conditions are the main concerns in the short term. Warm temperatures ongoing across the area with highs peaking in the 70's to low 90's. Meanwhile breezy winds are bringing elevated to near critical fire weather concerns for Converse and Niobrara Counties as well as into the Nebraska Panhandle. While most of our Wyoming zones are experiencing enough greenup to preclude critical fire danger, our Nebraska zones remain dry enough that these elevated concerns could present fire danger.

Moving into this evening and overnight, a cold front will move across the region and briefly relieve the warmth we're experiencing today, though it will be short lived and temperatures remain above average moving into Tuesday. But for the overnight into early morning period, high resolution guidance is picking up on the potential for a few weak showers to develop along and just behind this boundary, with minimal precipitation likely from this weak system. Introduced some slight chances of showers along the WY/NE/SD border area alongside neighboring offices to account for this low potential.

Tuesday highs should be mostly relegated to the 70's across the area behind the front, remaining around 10 degrees above average. And by Wednesday the high will re-strengthen over the region, bringing similar temperatures to what we are experiencing today with a shot at tying or breaking records once again. While fire weather concerns will be elevated the next two days, RH values should remain just above critical thresholds despite very breezy southerly winds in the Nebraska Panhandle on Wednesday, but will need to continue to monitor trends for potential fire weather headlines then.

LONG TERM /THURSDAY THROUGH SUNDAY/

Issued at 245 PM MDT Mon May 11 2026

Models have brought the compact trough we've been monitoring the last few days well north in the last couple of run cycles today. This at odds with the trend observed yesterday. It may be safe to say at this point confidence in the progression of this system remains low until it is closer to the Northwest Coastline. Another aspect of the latest trends are for it to be more progressive, entering our area during the day Thursday. The surface cyclogenesis in advance of this upper level system may begin overnight Wednesday. Moisture transport along a low level jet in response from the developing low pressure to our north will begin to ramp up and extend into the morning hours. A dryline takes shape near the Laramie Range in the morning and mixes east before being overtaken by a Pacific cold front. These details are likely to change as the forecast period nears.

Here is the forecast as they currently align with the general consensus among guidance this afternoon. Conditions are likely to be dry area wide. Relative humidity values in the low teens and perhaps single digits could result behind the dryline/Pacific front. Due to the upper level system shifting northward, the surface low is likely to be deeper, inducing greater pressure gradients and stronger winds as a result. This is in contrast to the scenario yesterday with a more southward trough. Our machine learning wind models have increased probabilities of strong winds, favoring southwest to northeast oriented range gap locations. These probabilities are in the 40-60% ranges. We will continue to watch the placement and strength of this system for high wind concerns. Regardless, frequent gusts to 45-50 mph are possible over areas of very low RH values creating fire weather concerns. A very slight risk of thunderstorms may materialize along the dryline as it moves east. Coverage may only pertain to a single storm or two if any develop. Temperatures in the mountain ranges and basins are likely to be lower than Wednesday, peaking in the low 70s. Elsewhere temperatures in the mid 70s to mid 80s are possible.

This system departs overnight Thursday leaving behind a weak ridging pattern for Friday. Temperatures cool down slightly area wide with a general flow out of the northwest bringing in dry continental air. RH values do not improve much for Friday and winds remain breezy, though not as potent as they were Thursday.

This weekend could begin a period of more troughing for the northwest and extending into our areas. Still long range, but increasing deep layer moisture may give us a few chances of showers and storms along with increasing cloudiness. Surface conditions are still dry with the majority of the moisture from the Gulf being kept to our south and east. Sunday and Monday may have a better shot of more widespread storms, but at this range predictability is low.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1130 AM MDT Mon May 11 2026

Scattered high level clouds and VFR conditions will prevail across the regional terminals this afternoon. Wind gusts to 25 knots from the west at all terminals except at KRWL where gusts could reach 35 knots. Overnight a cold front moves in from the north. A wind shift out of the north-northeast and reduced ceilings along and north of the front can be expected. Flight rules should remain in VFR. Some low level wind shear may occur nearby KBFF in the 7-10z timeframe tonight given elevated gusts and convergence of winds along the valley ridges imposed by the cold front. Chances are too low to include in TAFS presently. Skies clear at terminals around day break except for a few lingering low level clouds.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.