* Dense fog advisory through 9 a.m. Monday *

EXPRESS FORECAST

Today: Foggy a.m., mostly cloudy p.m., mild. Near 60 to upper 60s. | Tonight: Chance of showers late. Near 50 to low 50s. | Tomorrow: Mostly cloudy. 40-50% chance of showers. 50s. | A Look Ahead | Get Express Forecast by E-mail

A somewhat subjective rating of the day’s weather, on a scale of 0 to 10


Mild temps near or past 60 worthy of high grade. But stubborn a.m. fog and probable p.m. clouds prevent picture-perfect look. Get the Digit on Twitter| Discuss on Facebook

A daily assessment of the potential for *accumulating* snow for the next week on a 0-10 scale. More info


SPI: 2 ↑ - Higher elevations north and west of D.C. may see on-and-off mixed precip Mon night through Wed. Light accum not out of question. Get the SPI on Twitter | Discuss on Facebook

FORECAST IN DETAIL

The atmosphere is having a major identity crisis. We are entering what is, on average, the coldest week of the year, yet highs today should reach at least near 60. Even with the fog and clouds, it should be a great day to go for a jog, walk the dog, or fire up the grill! A weak cold front moves in tonight and then may linger close to our south. The result is a cooler Monday and much cooler midweek. Some showers are possible tonight into Wednesday, maybe even mixed precipitation in spots starting Monday night. But the uncertain position of the front means overall forecast confidence is on the low side.

Today (Sunday): Like yesterday, expect the fog to slowly mix out from west to east hopefully eroding by around noon. Once the fog lifts, afternoon temperatures should quickly climb at least to near 60, and maybe to the upper 60s in the southern suburbs. Now, the monkey wrench in the equation is cloud cover. Winds from the southeast may very well preserve the clouds overhead, and if they are thick enough then most places may end up with highs in the lower end of the range, especially from near D.C. and to the north. Confidence: Medium-High

Tonight: Very warm by January standards, with lows hovering right around 50 or the low 50s. We should stay dry through the evening, but clouds thicken as a weak cold front approaches, and overnight shower chances increase from west to east to about 40%. Winds from the south shift to come from the west toward morning. Confidence: Medium-High

For related traffic news, check out Dr. Gridlock. Keep reading for the forecast through the weekend...

Tomorrow (Monday): The frontal passage keeps shower chances going through the day at around the 40-50% mark. But there are also some signs the front could fizzle enough to leave us with an extended period of little to no rain. Although technically a cold front, we’ll still be well on the warm side for mid-January with highs in the 50s. Though plenty of clouds and a cool breeze from the northwest may reflect your Monday mood. Confidence: Low-Medium

Tomorrow night: A bit tricky. Low pressure may develop along the front to our south. If so, then showers could become likely during the evening into the overnight with lows mainly in the mid-30s to near 40. And if the front pulls in enough cold air at the upper levels, areas north and west of D.C. could see some snow and sleet mixed in with the rain. As of now we don’t expect any accumulation. Perhaps this is the atmosphere’s attempt at snapping out of its identity crisis? Confidence: Low-Medium

A LOOK AHEAD

Tuesday through Wednesday, the front may linger close enough to keep skies mostly cloudy with a continued chance of showers, especially if a couple waves of low pressure manage to develop along the front. It’s colder, too, with highs both days probably only near 40 to the mid-40s, and Tuesday night lows near 30 to the mid-30s. Cold enough that some sleet and snow could mix in with any precipitation from around D.C. and I-95 toward points north and west. Note, it’s also possible the front slips farther south and leaves us drier, sunnier and a bit warmer. Confidence: Low

Dan Stillman contributed to this forecast.