Friday was the first official day of winter, the shortest and darkest day of the year.

Yet in Washington, a burst of balmy weather belied the new season's arrival, as temperatures swelled into the upper 60s and the sun broke through a wall of gray haze.

No one expects it to last very long. January is historically the coldest and dreariest month in the nation's capital.

Winter is coming.

It's a convenient but apt metaphor for the state of the Trump presidency, now nearing two full years in the making. For all the disruption and havoc its experienced in the six weeks since the bruising midterm elections, the challenges it will face in the initial months of 2019 are likely only to be more vexing and possibly debilitating.

Since Nov. 6, when Republicans lost control of the House, Trump has forced out his attorney general and squeezed out his chief of staff. He lost his secretary of interior to scandal and, most consequentially, his secretary of defense in a startling resignation that amounted to a pointed reprimand of Trump's foreign policy approach.

The president was implicated by federal prosecutors in court documents as directing a criminal conspiracy to violate campaign finance laws through his ordering of payments to women he allegedly had affairs with. His personal foundation was forced to close after the New York attorney general found "persistently illegal conduct," including "unlawful coordination" with his presidential campaign. Meanwhile, it was revealed his 2017 inauguration is being criminally probed for the misuse of funds and potential pay-for-play schemes.

In a sharp rebuke to the president's response to the brutal murder of journalist Jamal Khashoggi, the Senate voted to cut off support for Saudi Arabia's war in Yemen, marking the first time the body has ever invoked its war powers to challenge U.S. military engagement abroad. Unrelated or not, a week later, Trump sprung a pair of fateful foreign policy decrees, seeking U.S. troop withdrawals from Syria and possibly Afghanistan, moves that likely precipitated Defense Secretary Jim Mattis' departure.

All along, there's been the weekslong drama over funding the government.

During a theatrical and extraordinary televised Oval Office meeting with Democratic leaders last week, Trump boasted of taking ownership of a government shutdown – "I will be the one to shut it down. I won't blame you for it," he barked. But on the eve of that shutdown, he unsurprisingly reversed his political posture, attempting to pin blame on Democrats for opposing funding for his cherished southern border wall. "The Democrats now own the shutdown!" he tweeted Friday morning.

Even before the president declared on Friday he was "totally prepared for a very long shutdown," the hashtag #TrumpResign was trending on Twitter.

An abrupt resignation would be one of the few outcomes that could genuinely shock Washington in the Trump era, where most political players have become numb to the perpetual, almost hourly ritual of chaos followed by outrage.

But as the calendar turns to 2019, Trump will face an environment that's even more hostile to him and his agenda.

As Democrats wrest congressional gavels from Republicans in less than two weeks, they will immediately gain broad investigative authority to scrutinize and subpoena the Trump administration in ways not seen before.

House committee chairs in-waiting are priming to pounce on everything from the Department of Homeland Security's family separation policies to the mystery around Trump's unreleased tax returns to the details of what really transpired during the infamous Trump Tower meeting with the Russians.

"The oversight job after two years of Donald Trump is like coming upon a 73-car pileup on the highway," Democratic Rep. Jamie Raskin of Maryland told the New York Times Magazine .

In addition to the piles of investigations that will be launched on the House side of the chamber, the Trump administration will have to undergo a grueling series of at least four Senate confirmation hearings for attorney general, U.N. ambassador, secretary of defense and secretary of interior.

William Barr, Trump's choice to permanently replace former Attorney General Jeff Sessions, has already run into a buzzsaw for his memo earlier this year criticizing Robert Mueller's special counsel investigation and asserting that Trump didn't obstruct justice by firing FBI Director James Comey.

Even Trump ally Mike Huckabee said Heather Nauert, the president's pick to succeed U.S. Ambassador Nikki Haley at the United Nations, may need a medieval "armor suit" to survive her hearings.

Then again, given the towering importance of Trump's eventual pick to succeed Mattis, Nauert's hearing may end up looking mild, comparatively.

Ironically, the upheaval around personnel and the Democrats' newfound power may turn the third year of the Trump administration into a painful examination of the first two.

As Trump – and his third chief of staff, Mick Mulvaney – buckle up to play defense and shepherd through a host of new personnel, the looming and unknowable question of the Mueller inquiry lingers.

NBC News reported Thursday that Mueller is nearing the end of his investigation and could submit a report on Russian election interference and allegations of collusion as soon as mid-February.

What Mueller ultimately concludes will have enormous weight on Capitol Hill, where Democrats will have to make the tricky and politically risky decision of whether to initiate impeachment proceedings. A Morning Consult survey laid bare the dicey terrain, with 43 percent of voters saying Congress should not begin proceedings to remove the president, compared to 38 percent who think it should.

All of these threads will be unraveling just as the 2020 Democratic presidential primary season gets underway, with a double-digit list of candidates readying to launch campaigns as soon as the beginning of January and turning their fire on Trump.

Even the relatively healthy economy -- which Trump has revelled in taking credit for -- has begun to show signs of weakness. U.S. stock markets just endured their worst week in a decade.

One thing is clear: When Trump feels cornered, under attack or at a strategic disadvantage, his instincts are to reaffirm himself with his core base, the band of populist-nationalist everymen-and-women who propelled him to the presidency against all odds.

So as Congress held votes in an attempt to avoid a midnight shutdown, neither Democrats nor Trump showed much willingness to compromise on his demands for border wall funding.

Democratic Sen. Mazie Hirono of Hawaii said any effort by Trump to blame Democrats for the stalemate would be "such bulls---." A retiring Republican senator, Bob Corker of Tennessee, called the situation "tyranny," due to conservative talk show hosts' considerable sway over this temperamental president.