Quite a handful of us across the country will keep singing the same song and dance over the next 7 days. Under a low-high-low upper air regime, this will once again bring severe thunderstorm chances for those around the Great Lakes and upper-Midwest, while the northeast looks to receive more rounds of rainfall in the short and long-term. Once this pattern breaks down towards the end of the week, ridging is forecasted to build over the southwestern US and allow for air temperatures to really bump up the mercury by the weekend. With a fairly busy and active weather discussion ahead, let’s break it down and highlight these aforementioned regions.
Severe Potential in the Upper Midwest
Starting with the most pressing of weather events at hand, we have a couple days of possible severe weather upcoming in the Upper Midwest. Up above, broad westerly flow rounding the top of the high-pressure system in the southern US will overspread the area today and tomorrow. The main triggering mechanisms for these storms will be shortwaves embedded with this westerly flow, which will help provide enough of a disturbance to get these storms to form. Down at the surface, we will have temperatures in the upper 70s to mid 80s and dew point temperatures in the 60s across Minnesota, Iowa, and portions of Wisconsin. Modest instability and moderate deep-layer shear will be favorable for supercells after 3pm with all hazards possible. These storms will look to coalesce into an MCS complex and move southeast through southern Wisconsin in the overnight hours, with damaging winds being the primary concern.
By tomorrow, the severe threat will shift southeast towards central and northern Illinois, as well as western Indiana. Much more robust instability (with ML CAPE reaching and exceeding 4000 J/kg) coupled with very steep lapse rates and strong vertical shear will support mainly a large hail and damaging wind risk for most of this area by the afternoon and evening. These storms will move in from the northwest by the afternoon, attaining supercellular characteristics before possibly forming an MCS and moving off to the southeast during the evening hours through eastern Illinois and western Indiana.
The West says “Hello” to scorching temperatures
While the desert southwest is already no stranger to very hot temperatures, places further west into California, Oregon, and Washington will start to get in on the action throughout the rest of the week and into the weekend. An upper-level high will start to replace the current trough situated over the state and intensify throughout the week, creating that opportunity for steadily rising temperatures in the region. Forecasted temperatures throughout the rest of the week see southwest and central California easily clearing the century mark for multiple days, with places further north into Washington and Oregon reaching into the mid to upper 90s. By next week, widespread temperatures in the upper 90s to low 100s will be evident throughout most of the western US, as high pressure sits firmly over much of the southwest US.
More rain for the Northeast US
Keeping the soggy theme over the last few days up here, more showers and thunderstorms are to be expected across this corner of the country. Daily chances for precipitation due to traversing surface lows across the area will exist for many over the next week here. These multiple rounds of showers will drive up the QPF total through the next 7 days, with widespread rain totals in the amount of 1.5 inches, and some places potentially receiving 4+ inches of rain during this period. Flooding may become a hazard due to the continuous rainfall, especially in places that see heavier showers and thunderstorms with higher rainfall rates.
Travel Impacts
Main travel concerns across the country through the rest of the week and into next week will mainly be in portions of the Midwest and Northeast US. Severe thunderstorms in the Midwest today and tomorrow may force flight delays or cancellations as these storms roll through areas such as Minneapolis-St. Paul, La Crosse, Milwaukee, Chicago, and Peoria. Road conditions will also have to be monitored with these severe thunderstorms, and alternate routes should be considered if possible in these areas. As always, be sure to have a way to receive multiple weather warnings, especially if you are out on the roads during these storms. Up in the Northeast US, rainfall may cause some flight delays and localized flooding may affect roadways throughout the next 7 days. Be mindful of road conditions and do not drive through flood waters if you encounter them.
Extended Outlook
The latter half of the week and early next week will see a pattern flip over most of the country. High pressure will make its presence felt across the southern and central US, bringing above average temperatures for many. In the Midwest, more chances for severe thunderstorms may arise heading into the weekend, although exact details are too muddy to accurately say what may or may not happen, as well as overall model confidence coming into question. It is summer though and things can, and often do, happen quickly, so always stay weather aware and watch the forecast over these upcoming days. The northeastern US does not look to get a break from the rain anytime soon, as these surface low-pressure systems move through one after another, bringing repeated rainfall chances over the next week.
Conclusion
Severe thunderstorms will be possible across the Midwest today and tomorrow, with all hazards possible with these storms. Further updates and information can be found at the Storm Prediction Center’s website, as well as tuning into your local news station for up-to-date weather information. As the week progresses, in the west, high pressure will start to build up and really bring in the heat for the rest of the week and into next week. Temperatures regularly look to be in the mid to upper-90s to low 100s every day for many as this ridge builds. Ending in the northeast, scattered showers will come in round after round throughout the next 7 days. Total rainfall amounts look to be around 1-2 inches, with the possibility of higher amounts up to 4+ inches in places that see the heaviest rainfall.
