May 17, 2026 Sunday Spring Weather
Heat wave continues across Mid-Atlantic with widespread 90s
May 2026 was the 29th-warmest May in the 132-year national record (1895–2026), at 61.7°F against a 1991–2020 normal of 61.0°F (+0.6°F).
May 2026 was the 63rd-driest May in the 132-year national record (1895–2026), at 2.9in against a 1991–2020 normal of 3.1in (-0.2in).
NOAA/NCEI Climate at a Glance, contiguous United States. This is the observed record for the month, not a score of anything said in this piece — the forecast ledger begins 2026-08-17 and cannot reach earlier posts.
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Severe storms rumbling across the central Plains this evening
Temperature Anomaly Next 6-days — into Saturday
Heat wave finally breaks on Wednesday behind a strong cold front
Extensive cold pool across the Western U.S. shifts eastward
Sunday Evening Headlines
Ridge of high pressure —> Heat wave across Eastern U.S. into Wednesday but a major cold front erases the 90s in favor of much cooler air
Heavy rainfall for Texas and lower Mississippi River Valley with moisture plume / return flow out of the Gulf of Mexico and Subtropical Pacific
Precipitation Next 10-days | Blend of Models (v5.0)
Over next 10-days, upwards of 6-8” of rain across eastern Texas — but also widespread 1"-2” or locally more in slow moving thunderstorms in the moist air mass
High Temperatures Next 9-days until Tuesday May 26th
Very comfortable nationwide Wednesday into Thursday with cooler air behind strong cold front. Temperatures quickly heat up in the 80s and 90s by Memorial Day Weekend!
ECMWF 18z | Precipitation Type + MSLP | Next 6-days
Notable weather systems:
Strong low pressure system with heavy snowfall ejects out of Wyoming Rockies quickly in the Great Lakes and then Canada
Next system dips out of the Northern Rockies toward weekend — but weaker
Plenty of moisture + pop-up storms across Texas and the Deep South.
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ECMWF Flagship Ensemble Temperature Outlook
Temperature Anomaly | Next 15-days | ECMWF EPS 12z Ensemble Mean
Week #1 | Temperature Anomaly | May 17- May 23
Week #2 | Temperature Anomaly | May 24 - May 30
ECMWF HRES 18z | Forecast 6-days of Precipitable Water (my favorite parameter!)
Major return flow of moisture out of the subtropical Pacific + Gulf of Mexico
Cold front on Wed/Thurs battles back the southerly flow, but another storm system tracking into the Midwest this weekend will restart the cycle — repeating what we’ve just experienced this weekend
Integrated Vapor Transport | Next 10-days
Gulf of Mexico opens for business by Sunday — and we get a more sustained southerly flow into Memorial Day weekend behind the Bermuda subtropical high
RTMA Current Temperature Analysis | 7:45 PM ET
187 million at least 80°F earlier in the evening — but only 30s and 40s in Nevada
RTMA Current Temperature Anomaly Analysis | 7:45 PM ET
Lower 48 was -0.7°F BELOW normal with extreme chill across Nevada and into the northern Rockies
Lower 48 Weather This Evening into Monday Morning
Enhanced Risk of Severe Weather continues as Thunderstorms move into Iowa and Missouri: Radar Simulation (HRRR) next 18-hours
HRRR 18z — Radar Simulation Next 48-hours to Tuesday 2 PM ET
Weather on Monday | Moderate Risk of Severe Weather in Kansas
SPC: THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS TO SOUTHEAST NEBRASKA
Numerous severe thunderstorms are expected to develop Monday along a cold front and dryline extending from the Great Lakes into the central/southern Plains. Supercells capable of very large hail and strong to intense tornadoes are most likely from central Kansas into southeast Nebraska
Upper-Level Circulation Pattern
ECMWF AIFS-Single 18z | 500 mb Height Anomaly Next 10-days
Heat dome / ridge breaks down briefly by Wed/Thurs across the Eastern U.S. but the process repeats with another very sharp trough digging into the west = heat across Eastern U.S. into late-May!
Low Temperatures Monday Morning
Chilly across the Western U.S. with still enough area freezing for heavy snowfall
High Temperatures Monday
85 million at least 90°F … and 263 million at least 80°F = more like summer
High Temperatures on Tuesday
Mid-to-Upper 90s across the Mid-Atlantic including Washington D.C. and Philadelphia with 109 million population at least 90°F
High Temperatures on Wednesday
Still well into the 90s along the entire I-95 corridor from Virginia into New England.
NDFD NWS Total Precipitation Next 72-hours through Wednesday Afternoon
7-Day Total Precipitation | Blend of Models | Through next Thursday
Heavy Snowfall Across Utah, Wyoming, and Colorado with storm system
15-day Ensemble Median Precipitation | ECMWF 12z
Tropical Update
Three tropical waves from Caribbean into the far tropical Atlantic
African dust plume forecast next 10-days
North Atlantic Tropics | Quiet Next 7-days
A significant upper-level trough is digging well into the tropics … very hostile environment regardless of the chilly ocean temperatures typical for mid-May.
Precipitable water next 6-days = quiet with a surge of African / Saharan air coming across the MDR into next week
Western Pacific: No tropical storm activity expected in the next 7-days
Eastern Pacific Tropics | Quiet next 7-days
While the EPAC season started on May 15th, and SSTs are very warm, waiting on tropical waves to hold together crossing Central America. Large area of 28°C+ water = plenty of fuel for major hurricanes already.
Forecast from April 7, 2026: Atlantic Seasonal Hurricane Forecast: 11/5/2
9-13 Named Storms (11 most likely)
4-7 Hurricanes (5 or 6 most likely)
1-3 Major Hurricanes (2 most likely)
ACE: 75-85
Maps sourced from weathermodels.com designed and innovated by yours truly! Please subscribe there for real-time access to the newest maps, charts from all of the weather models including ECMWF and AIFS, and NOAA GFS/GEFS, HRRR/RRFS and Blend of Models (NBM). NOAA WPC and SPC for fronts/convective outlooks.
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- 937 · laid 2026-05-18T01:38:06.946000Z
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- https://weather.substack.com/p/may-17-2026-sunday-spring-weather
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