June 16, 2025 Heat Dome Building

Extreme heat builds across Great Lakes and Northeast into this weekend

Monday Evening Weather Headlines

1. Eastern Pacific hurricane basin: Five (05E) is designated as a potential tropical storm and is forecast to become Category 2 hurricane Erick prior to landfall in southern Mexico

2. No Atlantic hurricane activity for next 7-days and likely the rest of June.

3. A heat dome forms over the mid-Atlantic U.S. with temperatures in the 90s in Chicago and 100s in NYC peaking next Tuesday.

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Upper Level Weather Pattern | Height Anomaly next 10-days

A ridge forms downstream of a trough digging into the Southwest U.S. this weekend into early next week.

This will supply deep layer drying and warmth underneath the stationary ridge for the 4-5 days.

Actual Heights at Day 5 - 9

Very close to 600 dm heights at 500 mb = record heat likely with potential for > 100°F Sunday to Tuesday over a large area.

The ridge is very dry with moisture rounding the ridge = potential for long-lasting derecho or mesoscale convective complex formation

Next Tuesday snapshots of Water Vapor, Temperature Anomaly, and Integrated Vapor Transport (ECMWF 12z)

Next Tuesday Afternoon | ECMWF 12z

High Temperatures next 8 days

90s expand from coast to coast into the weekend with 225 million at/above 90°F by Monday June 23.

However, relief arrives from Canada with another series of cold fronts and troughs to minimize the extent and duration of this “heat dome” to 4-5 days.

Chicago Next 10-days

4-days of 90s with peak Sun/Mon at 96° to 97°F. Daily record highs are 97° to 104°F for the next 7-10 days at ORD.

Washington D.C.

Upper-90s for Monday-Friday next week … a solid 5-6 days of 10-15°F above normal late-June temperatures. Daily record highs are 99°F to 101°F.

New York City

NYC may be the hottest location due to the sinking air and extent of drying across the state with strong westerly winds. 102°F on Tuesday in Central Park would be earliest 100°F (6/26/1952) and hottest/earliest (July 3, 1966: 103°F).

Phoenix

Phoenix “cools down” to 102°F by Sunday/Monday with the approaching trough and a shot of “cooler” air from Canada. It’s all relative, of course.

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Eastern Pacific Hurricane Basin

Dalila (04E) is a remnant low, just a swirl of clouds. The next area of disturbed weather has formed into a “Potential Tropical Storm” Erick (05E) and is forecast to rapidly intensify into a hurricane prior to landfall on Thursday in southern Mexico.

Maximum winds at 80-knots is Category 2 — and there’s an outside shot of more rapid intensification and major hurricane status.

ATCF Track guidance does have some spread but the HCCA lies confidently in the middle of the pack and NHC usually follows it.

Precipitable Water Next 5-days

Previous model runs hinted at some reformation in the Gulf of Mexico, but Erick is forming further west and will be disrupted completely over the mountains of southern Mexico. However, moisture and heating from the convection will help fuel the development of the downstream ridge or “heat dome” over the Eastern U.S.

Atlantic Basin | 10-days Ensemble Tracks

Please see Morning Tropical Update / Hurricane Season Briefings for more information on the global tropics —> Link