NEW YORK (CNN) — The weather, oddly enough, may be the most dependable element of the primary day equation heading into Super Tuesday: so far this year, mostly-localized, turnout-dampening storms have reliably hit on Election Day – and tomorrow is looking likely to fit that pattern, with miserable winter weather predicted to reach areas of some primary states from Illinois to Alabama. Another predictable primary eve arrival: the barrage of negative campaign e-mails flooding our inboxes — this time from Barack Obama's team, slamming Hillary Clinton on everything from health care mandates to the Iraq war.

(Some other pre-vote developments were a bit more unexpected. In a stunning display of confidence, or hubris — we’ll tell you which on February 6 — the Obama campaign unloaded a chunk of its $32 million January haul on a Super Bowl ad buys last night, airing local spots in states voting February 5-12.)

Weather aside, there's just one remotely safe guess as the week begins: short of an unprecedented last-minute shift — and this year, we’re not ruling anything out — neither of the Democratic candidates is likely to emerge from tomorrow's vote with the ability to claim a decisive advantage.

Granted, some of the polls in our rearview mirrors today may not be quite as close as they appear. The narrowing margin between the two Democratic frontrunners in most California surveys would mean a lot more if Clinton didn’t have a double-digit lead among votes cast via early balloting – meaning Obama would have to boast a record-breaking turnout operation just to keep that race close.

Of course, this year it’s not about states — it’s about reaching the nomination, one district and delegate at a time. Today, Hillary Clinton is looking to nail down her advantage in the Northeast, with stops in Connecticut, Massachusetts and a national town hall hosted live from New York City. Obama is spending the day taking her on on her home turf, with stops of his own in Connecticut and Massachusetts, and a Meadowlands rally in the shadow of the Big Apple.

On the Republican side, Mitt Romney isn’t ready to concede John McCain’s inevitability just yet. The former Massachusetts governor’s recent ad buys may be in the low range (for him). And for the third week in a row, he hasn’t pulled the trigger on any hard-hitting contrast spots. But post-Florida, Romney has picked up a few high-profile base-pleasing nods as the anybody-but-McCain forces coalesce around him, with Sean Hannity, Laura Ingraham and Rick Santorum rallying to his side. Some recent California polls show the GOP race there tightening to a virtual dead heat. And the Maine caucuses may not make for much momentum, but it looks like Romney will pull in another 18 delegates in that state – meaning he and McCain are still, technically, just about neck-and-neck in the all-important delegate count ahead of Tuesday’s contests.

– CNN Associate Political Editor Rebecca Sinderbrand