*Flood Watch in Effect Friday Morning Through Friday Evening*Don't let the 70s and 80s of the past couple days deceive you:
major weather changes are just on the doorstep. A very powerful spring cold front will come barreling through the area later today, which will drop temperatures some 30 degrees and bring scattered showers and thunderstorms today into tonight and
heavy rain on Friday. The rain may end as snow -- especially north and west of DC.
Today
Hang onto your hats. Talk about changeable! The morning hours will feature more clouds than sun, with temperatures spiking into the mid to upper 70s again. Isolated showers and thunderstorms associated with the aforementioned cold front are possible after 1pm, and temperatures by sunset will have plummeted some 30 degrees to the mid 40s! Much colder tonight, with periodic showers and lows near 40.
Tomorrow
Raw washout, some snow? Expect dense overcast skies on Friday with frequent periods of moderate to heavy rain and highs struggling to make it out of the low 40s. The rain may change to wet snow during the afternoon or evening, with minimal accumulation not out of the question for the metro area, especially north and west. Occasional snow showers will likely persist Friday night with temperatures falling through the 30s.
The Weekend
Drying but chilly. We'll look for more clouds than sun on Saturday with a slight chance of a stray snow or rain shower; most of the day, though, will be dry. Expect very chilly high temperatures only in the mid to upper 30s, with overnight lows from 25-30. Sunshine will return on Sunday, with breezy skies and highs nearing 45 degrees; overnight lows will range from the upper 20s to mid 30s.
LARSON'S LONG-RANGE
Pattern Overview
Our strong cold front is associated with sharp trough of low pressure in the upper-levels punching through the Northeast and Mid-Atlantic. As a result, from tomorrow through Sunday, we'll see almost a direct Arctic discharge from Canada; the core of the coldest temperatures will be from Saturday morning through Sunday morning, when I believe the NWS' temperatures may still be too optimistic.
Cooler than normal temperatures will linger on Monday, but we should return to near-normal temperatures for Tuesday through Thursday; beyond that, it's a question as to whether we stay near-normal or head back to the 60s once again.
Pictured above: the GFS forecast model shows a big-time surge of Arctic air discharging straight into the eastern third of the country; as depicted at 850mb for Saturday evening.Next week's forecastForecast highs/lows
: 57/42 (normal = 55/37)
Forecast precip: Near-normal
Monday will feature milder conditions with times of clouds and sun and highs near 50 with overnight lows near 40.
Tuesday and
Wednesday look to feature milder conditions, still, with partly sunny skies and highs in the mid 50s with lows in the upper 30s to mid 40s. Unsettled weather is possible for
Thursday and
Friday with models suggesting the possibility for increasing clouds and rain possible, with highs from 55-65 and overnight lows from 45-50.