Tonight’s trick-or-treating festivities are shaping up to be a rough go for many, with a wild jet stream pattern slicing the nation in two and bringing weather of opposing extremes.

The stage is set for a possible severe weather outbreak in the East, a touch of snow over the Upper Midwest, and an Arctic blast over the Intermountain West with record-challenging cold. Unfortunately, the weather could be more of a trick than a treat across a large swath of the Lower 48. Here’s your region-by-region forecast.

Northeast and Mid-Atlantic

Firmly nestled just east of the approaching storm system, much of the Eastern Seaboard will find itself in the “warm sector” ahead of the cold front. Highs in the upper 60s to around 70 are likely in most spots, with the lower values west over the Appalachians. The cold front may near northern/western Maine, and the Tug Hill/Finger Lakes regions of Upstate New York, keeping temperatures slightly cooler, in the lower to middle 60s.

Originally it was looking like a soaker for the East, but the worst of the rain has a chance to hold off until 7 or 8 p.m. or so along the Interstate 95 corridor from Washington to Boston.

However, there is the threat of severe weather for a broad portion of the Mid-Atlantic today. A strong squall line will plow through this evening along the cold front. Ahead of it, clear-air southerly winds gusting upward of 40 mph are possible; if you’re trick-or-treating, try to avoid routes with overhanging tree branches, as the partially leafed vegetation will be susceptible to the strong winds.


(National Weather Service)

Anyone in the Mid-Atlantic ought to have a plan to move indoors as the squall quickly approaches. It will produce little or no thunder/lightning, so have a way to be notified. Strong to locally damaging winds are possible, with the risk of isolated tornadoes, as well.


More than an inch of rain is possible in many areas, while the Ohio Valley and New England could see 2-inch amounts.

Midwest and Tennessee Valley

A line of steady rain and downpours will continue marching east throughout the day. The front stretched from the Ohio Valley to extreme eastern Tennessee as of early afternoon Thursday. Tullahoma, Tenn., dropped 13 degrees in 20 minutes as the front moved through, with a 73-degree reading in eastern Tennessee at the same time parts of western Tennessee were in the upper 30s.

Temperatures will be quickly plummeting behind the front. Eastern areas may hold onto the 60s until perhaps near or even after sunset, while a bone-chilling air mass with temperatures in the 30s and 40s arrives behind.

Indianapolis could climb into the low 50s Thursday during the day, before temperatures tumble and a few snowflakes become possible tonight. Snow over Chicago, meanwhile, will probably wind down after sunset, leaving a few hours for trick-or-treating. Do be aware of patchy black ice.

Additional bands of moderate snow will continue to pivot over the Great Lakes through this evening, shifting east into Indiana, western Ohio and Michigan tonight as temperatures plummet.

Southeast

It was warm Thursday afternoon ahead of the front in the Southeast, with cloud cover over the Appalachians yielding to partial sunshine over the Carolinas.

That cold may sneak into Georgia northwest of the Chattahoochee River this afternoon, confining the heat to the southeast. The temperature in Atlanta will drop like a rock as that front blows through, falling from a high in the mid-70s to an overnight low in the upper 30s Friday morning.

Florida, meanwhile, will do what Florida always does; sunny skies there will give way to highs in the upper 80s to near 90.


Watch this cold front of chilly air blast through the East. (WeatherBell.com)

Mississippi River Valley

Colder north, warmer south. That front is still making slow progress south and east, with Tennessee and Alabama having already seen their warmest temperatures early in the day. The 50s and even some 40s will become ubiquitous on the map late this afternoon, though the rain should clear most of the way to the east. To the north over the Corn Belt, temperatures will fall into the 30s.

Great Plains/Ozarks

Spooky cold. Temperatures will hover most of the day in the 40s, with a few upper 30s over Kansas. Only extreme South Texas will escape the chill. Meanwhile, a few flurries are possible with a weak disturbance clipping through the Northern Plains.

If Kansas City hits the 22-degree low forecast by the National Weather Service before midnight — which appears possible — it will only be the ninth time the city has seen temperatures drop this low in October. Brrr!

Intermountain West

The weather will be straight-up inconsiderate in this part of the Lower 48, where temperatures some 10 to 15 degrees below average will limit how creative folks can be with their costumes. You’ll want to bundle up!

Fortunately, things will moderate some, with the center of the cold air mass finally shifting east. Denver will warm into the lower 40s this evening! The city hasn’t made it above freezing since Sunday, when temperatures dropped to 17 by midnight from a daytime high of 76.

Highs will struggle to make it past 40 in Salt Lake City this afternoon, too. In fact, 40 seems to be the magic number across the board for those on Mountain time — Billings, Mont.; Cheyenne, Wyo.; and Boise, Idaho, will all peak within a few degrees of 40. A few flurries may decorate the evening in those areas, as well, especially farther north.


A postal carrier struggles to push a load of parcels to his waiting van outside a post office in Denver as an autumn storm sweeps over the Intermountain West on Oct. 28. (David Zalubowski/AP)

Pacific Coast

Highs will be in the 50s to near 60 for much of Oregon and Washington, with 70s and 80s in California as dangerous fire weather persists there. Much of the Golden State will be alarmingly dry, with relative humidity levels between 15 and 30 percent. Temperatures will fall quickly this evening thanks to the dry air.

Gusty winds will continue most of the day into the overnight for central and Northern California.


Flames consume a home as the Kincade Fire tears through the Jimtown community of Sonoma County, Calif., on Oct. 24. (Noah Berger/AP)