Hello NSCO community! This past week, we experienced cooler and drier conditions, with a high pressure that kept skies mostly clear across Nebraska. Temperatures ranged from the upper 30s and 40s in the east near Omaha to low 40s across central Nebraska. Humidity remained low and decreased as warmer and drier air arrived mid-week. By Thursday into Friday, a noticeable warm trend with highs going into the 60s and even 70s across south-central and eastern Nebraska.
At 850 mb, strong warm air advection increased ahead of a weak shortwave moving through the Northern Plains early in the week, allowing temperatures to rebound around Tuesday for the majority of the state. The 500-mb pattern showed a building ridge over the Rockies mid-week, shifting into the Central Plains by Thursday. Increasing southwesterly flow strengthened the warm air at lower levels. By Friday, heights begin falling again as a trough deepened to the west signaling the weekend cooldown and next precipitation chance early this week.
As mentioned in the millibar briefing, a weak surface trough passed through early in the week, briefly increasing clouds before skies cleared again Tuesday. Southerly winds gradually strengthened by mid-week, supporting the warm-up. Another cold front arrived Saturday with winds turning northwesterly statewide. Moisture remained limited during this time, with higher precipitation percentages expected for this week.
Precipitation across Nebraska this past week has been minimal, with most Mesonet and ASOS stations to trace amounts at the most. The state had remained under the influence of strong surface high pressure that originated from central Canada, increasing dry air entrainment throughout the troposphere. Dewpoints throughout the week held mostly in the 10s and 20s across western and central Nebraska, preventing saturation and development of precipitation events.
Any weak mid-level impulses that passed through early in the week lacked sufficient isentropic ascent or deep-layer moisture transport to generate measurable precipitation. The Gulf moisture return has also remained suppressed due to a strong southerly jet streak across the Deep South, which is preventing moisture trajectories from curving north into the Central Plains. As a result, the only measurable precipitation was recorded in central to western Nebraska, primarily North Platte, where just a few hundredths of an inch fell due to very shallow saturation beneath a passing mid-level cloud deck.
Overall, this week brought a rapid temperature trend, from chilly beginnings to well-above-normal warmth later in week. Temperatures will are trending cooler again to start next the next week. We will also be getting some convective action with precipitation expected throughout the week for eastern to central Nebraska, into eastern Nebraska.
