D.C. area forecast: Hot start to week with storm chances, then big late week rains, cooler

1:25 p.m. update: The complex of showers and storms we’ve been tracking has largely fallen apart – with just a few widely scattered showers cycling through the region.  Chance of rain is just 20-30 percent through this afternoon.

10:10 a.m. update: Cluster of showers/storms in West Virginia is holding together fairly well and short-term modeling now indicates an increased chance of showers and storms early this afternoon. I’m increasing the chance of rain to 50 percent east of I-95 and 60 percent west of I-95.

HRRR model shows storms moving through the area around 2 p.m. (WeatherBell.com)

HRRR model shows storms moving through the area around 2 p.m. (WeatherBell.com)

7:20 a.m. update: Radar and short-term modeling suggest remnants of the complex of showers and storms over Ohio may pass through the region between noon and two. By that time, they will have weakened substantially and should be hit or miss. Your chance of getting wet is around 40 percent in our western suburbs and 20 percent east of I-95. (We have bumped up today’s rain chances below).

Today’s Daily Digit

A somewhat subjective rating of the day’s weather, on a scale of 1 to 10.

6
On the verge of too muggy, but still manage-ably warm for most.

Express Forecast

Today: Partly sunny, chance shower/storm. Highs: 85-89.

Tonight: Evening t’storm possible, then partly cloudy. Lows: 62-68.

Tomorrow: Partly sunny, very warm and humid. Highs: 87-92.

FORECAST IN DETAIL

Temperature Map

Temperatures: Latest D.C. area temperature map. See interactive map on our Weather Wall.

Welcome back heat index (or not)! The term we put to bed at the end of last summer earns a mention to begin this week thanks to the arrival of decidedly sticky weather. Referring to the combination of heat and humidity, or the temperature it feels like, the heat index soars to around 90 today and into the low-to-mid 90s Tuesday.

Temperatures then step down mid-to-late week but a surge of tropical moisture arrives Thursday into early Friday, with a slug of heavy rain possible. That moves off and the weather settles down somewhat late Friday and into the weekend, but we may not be able to totally shake shower chances.

Today (Monday): Mostly sunny, very warm, and yes – a tad humid. Highs rise into the mid-to-upper 80s, but – with dew points in the mid-60s – it feels more like 90. This afternoon and evening, there’s a (20-30 percent) chance of showers and storms, with the highest chances in our western areas. Winds are light from the south at 5-10 mph. Confidence: Medium-High

Tonight: There’s a 20-30 percent chance of evening showers and storms. Otherwise, it’s partly to mostly cloudy for the balance of the night with muggy lows of only 62-68 (suburbs-city). Light winds from the south. Confidence: Medium-High

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

Tomorrow (Tuesday): The hottest day of the week and the hottest day of the calendar year so far. Under partly to mostly sunny skies, highs charge up to near 90. Factoring in the humidity, it feels as hot as 90-95 mid-afternoon. Late in the afternoon and especially into the evening, there’s a 30 percent chance of showers and storms. Light winds from the south. Confidence: Medium-High

Tomorrow night: A cooling thundershower is possible in the evening (30 percent chance); then it’s partly cloudy and not quite as warm as the night before.  Lows drop into the upper 50s and low 60s. Confidence: Medium-High

A LOOK AHEAD

Wednesday and Wednesday night are mostly cloudy and cooler, as a wind from the east – off the Atlantic – develops.  It may be damp at times with a 40 percent chance of showers and maybe a rumble of thunder.  Highs range from 70-75, with lows at night 60-65.  Winds from the east at 5-10 mph. Confidence: Medium

Temperatures rebound some Thursday as winds from the south return, funneling in a large amount of tropical moisture northward.  Showers and thunderstorms are likely by evening, that may put down some very heavy rain. Prior to the rain’s arrival, expect variably cloudy skies and humid highs near 80.  Showers and thunderstorms – some heavy – are likely overnight, with lows around 60.  There’s some potential for very heavy rainfall with this system, so we may have to keep a close eye on the flood potential.  Confidence: Medium

 Friday could begin with lingering showers/downpours, with slow clearing towards the afternoon and evening.  It’s not as warm, with highs around 70.  Clearing out Friday night, with lows in the 50s. Confidence: Medium

Overall the weekend looks pretty good.  Both days are partly cloudy with highs 70-75.  Some cold air streaming in at high altitude could set off an afternoon shower or two, with the best bet on Sunday.  Overnight lows are in the 50s . Confidence: Low-Medium

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D.C. area forecast: Perfectly pleasant for Mother's Day, then nearing 90 tomorrow