Issued: 8pm on Sunday, April 11th 2021
Technical Forecast Discussion
Short Term (Sunday 4-11-2021 through Tuesday 4-13-2021)
A closed upper level low will continue to influence the forecast area through much of the short term. Low geopotential heights will keep highs relatively cool–in the upper 50s and 60s for much of the forecast period. PDVA from both curvature and shear effects will allow for sufficiently negative omega for clouds and showers to remain over the forecast area through at least Sunday night. The VORT advection will shift signs as PVA propagates this closed upper level low east of the forecast area. NVA will allow for height rises across much of the forecast area Monday afternoon into Tuesday. AS these heights rise, positive omega will ensue due to NDVA. Heights will also rise due to NDTA that will ensue due to strong mid level CAA and weak low level WAA. With all of these forces combined, highs should rebound into the upper 60s once again on Tuesday, with partly cloudy skies.
Long Term (Wednesday 4-11-2021 through Saturday 4-14-2021)
Shortwave ridge will quickly propagate eastward due to strong curvature and low amplitude. Another cutoff upper low will begin propagating in due to a strong advection lobe of VORT forming due to shear and curvature effects in Wisconsin, Minnesota, and South Dakota. This will occur as A shortwave becomes more enhanced as VORT increases as it is stretched coming off the High Plains and Mexican Plateau. PDVA from both of these features will allow for sufficiently negative omega for precipitation formation Wednesday night. Activity should not be convective, however. After this small disturbance, strong PDVA will allow for the upper level low to dig down, and have a large impact on temperatures for Thursday and Friday. As PDVA will exist, negative omega will be generated for precipitation as well. Highs Thursday will have trouble reaching the 50s, with showers. Dreary weather continues over the weekend as PVA continues to keep heights low, PDVA allows for cloud and precipitation formation, and low heights keep highs in the upper 40s and low 50s. Slight NDTA Saturday will allow for heights to slightly rise once again, but PDVA will keep cloud cover around, only allowing highs to reach the upper 50s Saturday.