Blog Article
Slight Risk Storms Hit DC to NYC as Tropics Get Busy
A Slight Risk for severe storms spans DC to NYC today while four tropical disturbances develop offshore. Flash flood risk builds from the Mississippi Valley to the Mid-Atlantic.
Tropical Basin Gets Busy While a Slight Risk Sets Up From DC to NYC Tonight
Alright y'all, let's start where the map is the busiest today: the tropics. Then we'll come back home to the part of the forecast that actually affects your evening plans.
Tropical Roundup: A Crowded Basin, Nothing Aimed at Us
We've got two named systems on the books this morning. Tropical Storm Lala is drifting north through the Central Pacific, several hundred miles north of Kure Atoll, with 45 mph winds. Dry air and moderate westerly shear are chewing on the core, and the discussion out of the Central Pacific Hurricane Center says the circulation is losing definition on its southern and western side. Lala's closest approach to any land is still more than 1,100 miles out, and by then it's forecast to be down to 25 mph. This one's basically fading out over open water.
Post-Tropical Cyclone Iselle, out in the East Pacific about 1,000 miles west of the southern tip of Baja California, has already lost its thunderstorm structure and got its final advisory from NHC overnight. No threat there either.
Here's the part that's more interesting for the long haul: NHC is watching four separate disturbances with HIGH development odds, two in the East Pacific and one way out near the Cabo Verde Islands in the Atlantic (AL96, 70% chance of development in the next two days). We're closing in on the Atlantic's statistical peak of hurricane season, so it makes sense the basin's waking up. None of these systems have a track that points at US soil right now, but Invest 96AL is the one worth bookmarking. We'll keep an eye on it as it crosses the Atlantic over the next several days.
Today's Main Event: Slight Risk From DC to New York
Home turf now. SPC has a Slight Risk posted for parts of the Mid-Atlantic and Northeast today, covering New York City, Philadelphia, Washington DC, Baltimore, and Newark. There's a separate Marginal Risk area farther west covering Houston, San Antonio, Austin, Denver, and Colorado Springs, but that one's a lower-end concern.
The setup in the Northeast: moderate to potentially strong instability building south of a stalled front, with upper-level support riding overhead. If storms fire, the main threats are damaging wind gusts (SPC has that at a 15% scattered threat, with an isolated hatched pocket where gusts could reach 75 mph or more) and large hail up to 2 inches in the strongest cells. An isolated tornado can't be ruled out either, though that risk sits at just 2%.
This matters tonight specifically because the Bills host the Steelers in Orchard Park, New York, kicking off around 7 PM Eastern, right inside the window SPC has flagged (valid through 8 AM Friday). If you've got tickets or you're tailgating, keep half an eye on the sky and have a plan if the PA system starts talking about weather delays. Same goes if you're catching any of the Little League World Series action down in Williamsport, which sits within range of that unsettled Mid-Atlantic air mass too.
Flash Flood Watch: Lower Mississippi Valley Today, Then the Mid-Atlantic Friday
WPC has a Slight Risk for excessive rainfall today stretching from the Lower Mississippi Valley up into the Upper Great Lakes. A cold front pushing into Arkansas, combined with a shortwave diving out of the northwest, is going to squeeze out repeated rounds of heavy rain. This is the same corridor that took a beating yesterday, remember the flash flooding and downed trees across Arkansas, Alabama, and Mississippi from Wednesday's severe storms. Saturated ground means today's rain won't take much to cause problems again.
Friday, the excessive rainfall risk shifts east and gets bumped up to Slight again, this time targeting the coastal Carolinas into southeastern Virginia and the DC metro. WPC's discussion is blunt about it: a 70 to 90 knot upper jet streak digging in near peak heating, mixed-layer CAPE of 1,000 to 2,000+ J/kg, and precipitable water approaching 1.75 inches. Translation: rainfall rates could hit 2 inches an hour under the strongest cells, and training thunderstorms could bring scattered flash flooding right into the Friday evening commute for DC-area folks.
Fire Weather Still Critical Out West
Far northeastern California, northwestern Nevada, and southeastern Oregon remain in a Critical fire weather area both today and Friday. An upper-level trough keeps promoting gusty southwest winds and dry conditions across the Columbia Basin and northern Great Basin. This is a sparsely populated area, but it's the same zone that's carried Red Flag Warnings for days now, so fuels are primed.
Where's the Nice Day?
If you want the calm side of the map, look to Minnesota and southeastern South Dakota, right where the Minnesota State Fair is in full swing in Falcon Heights today. Post-frontal high pressure is giving that zone the best air quality and lightest winds in the country, good news if you're standing in line for cheese curds. Friday, that same kind of dry, quiet pattern spreads into the Great Lakes and central High Plains.
What We're Watching
- Slight Risk severe storms today from DC through Philadelphia, NYC, and Newark, damaging wind and large hail the main threats
- Marginal Risk severe storms across western Nebraska into northwest Kansas and separately near Houston, San Antonio, and Denver
- Slight Risk excessive rainfall today in the Lower Mississippi Valley into the Upper Great Lakes, expanding to the Carolinas and DC metro Friday
- Critical fire weather continuing across far northeastern California, northwestern Nevada, and southeastern Oregon
- Invest 96AL near the Cabo Verde Islands, 70% odds of development, one to track as we head into peak hurricane season
- A coronal hole high-speed stream arriving by midday that could nudge geomagnetic activity to unsettled or G1 (Minor) levels tonight
Bottom Line
Nothing in the tropics threatens the US right now, Lala and Iselle are both fading and the disturbances with high development odds are all still far from land. Closer to home, if you're anywhere from DC to New York City today, especially if you've got outdoor plans tonight like that Bills-Steelers game in Orchard Park, keep a weather eye out for pop-up storms capable of damaging wind and large hail. And if you're in the Lower Mississippi Valley or headed toward the Mid-Atlantic by Friday, don't ignore ponding water on the roads. Ground is still soaked from this week's rounds of storms, and it won't take much more to cause trouble again.