From California to Maine, the heat is on.. If you think it’s hot today across the Midwest and Ohio Valley think again, the ridge will not only intensify with it will pump those 100s sizzingly western high plains this afternoon on eastwards during Tuesday with highs likely to approach 100 in Chicago thanks to a jet blowing out of the southwest just north of the city. The perfect orientation for enhanced warming beneath the nose of the jet.

Downstate Illinois should likewise eye the century mark along with such cities as Kansas City and St Louis as the Southwest heat pumps cranks. The Eastern Seaboard today should enjoy those LOW 70s from DC to Trenton while it lasts. It’s in the chilly 60s in New York just now thanks to an east, southeast wind blowing in off the ocean. Note in the map above how it’s in the upper 70s up across northern New England, this is thanks to a southwest flow drawing warmth in.

 Colorado, Nebraska Reach 107 degrees This Afternoon

A very powerful ridge of high pressure which exploded over the Four Corners is first and foremost the reason for the upper 90s all the way to Salt Lake and Denver but the key to the eastward expansion of the ridge and it’s hot air is thanks to a storm system dropping into the Pacific Northwest, this is leaning against the Great Basin heat and is pushing it east over the Rockies. Highs are currently reading 107 in Lamar, Colo, 107 Culbertson, Neb with 100s dominating the Plains from West Texas to northern Nebraska.

A frontal boundary stretched from Michigan to the Arklatex today is keeping the heat and bay and from spreading east. It is triggering strong storms over northern Ohio up into Michigan just now but once the front pushes across the Appalachains and off the East Coast, then the ridge bulks up from the Midwest to East Coast over the next 36 hours.

Tomorrow will see the heat core centre from the eastern Plains to Ohio Valley with widespread upper 90s streatching from Tennessee to northern Illinois and southern Michigan. Heights are lower across the Southeast and so the heat is focused further north. Storms blowing up today across the Dakotas east through Minnesota and the Great Lakes will continue tomorrow keeping the UP and northern LP out of the swelter. The first finger of 90s spread into Baltimore-Washington, possibly Philadelphia tomorrow while upper 80s reach Trenton, low to mid-80s reach New York.

By Wednesday the heat eases from the Plains northeast towards Chicago where highs may be around 96 compared to Tuesday near 100. The upper 90s sweat DC, Baltimore, Philadelphia, Trenton and possibly Newark Wednesday with temps between 96-98. New York should warm to around 94. Thursday I think will be the hottest with quite possibly a run at 100 from DC to Philly.

Nights from Chicago to St Louis to DC to New York will all struggle to get below 80 in between the hottest afternoons. High humidity will make it feel worse and will hold onto the heat long into the night. Don’t be surprised if the inner cities fail be get below 90 even at 10 or 11pm.

Those living in the Dakotas east through Minnesota and the Lakes need to watch out for powerful storms rimming the heat. Also watch out for storms across eastern and south Texas which may spread across the Southeast over the next few days as the heat core pushes into the Mid-Atlantic.