This Week in Weather — October 11, 2026

Rearview

Panama absorbed the week's most consequential seismic sequence. On October 9 at 12:56 p.m. local time, a M7.7 struck 12 km WSW of Pitaloza Arriba — the largest earthquake recorded globally in the past seven days and one of the stronger events in Central America in recent years. Two additional significant earthquakes followed in the same region: a M6.6 14 km west of Río Grande (which carried a tsunami flag) and a M6.0 7 km north of La Tronosa, along with a M5.8 near El Cacao. Four significant earthquakes in a single country within a compressed window is a genuine aftershock sequence, not coincidence.

USGS National Earthquake Information Center

On the atmospheric side, North Carolina bore the weight of the week's tornado activity. Between 12:52 and 1:24 p.m. EDT on October 11, the Wilmington, Raleigh, and Morehead City forecast offices issued six tornado warnings across Bladen, Columbus, Pender, Johnston, Wake, Sampson, Franklin, and Duplin counties — a tight geographic cluster that suggests a single organized convective system tracking northeast through the coastal plain. The SPC logged 15 tornado reports nationally for the week, with Iowa leading all states at 32 total storm reports.

Wikimedia Commons

The week's 618 NWS warnings included 106 flash flood warnings and 132 marine warnings — a distribution that reflects both the North Carolina convective event and likely coastal effects. Iowa's 32 storm reports were concentrated in hail and wind, consistent with fast-moving convective lines rather than discrete supercell activity.

Geomagnetic activity reached G3 (Strong) storm levels on October 10. NOAA's 3-hour Kp observations show a peak of 7 for the interval beginning at 15:00 UTC that day. In its forecast discussion issued October 11 at 12:30 UTC, NOAA attributed the storm to coronal mass ejections (CMEs) from October 7–8, whose arrival was detected at 14:34 UTC on October 10.

Roadmap

The week ahead is shaped by a split pattern: a resilient ridge holding across the Southeast and Pacific Coast, and a more active trough regime across the northern tier and Rockies. The jet stream is running well north of its October climatological position over the eastern Pacific, which is keeping the Pacific Coast dry and warm while funneling periodic shortwaves into the Rockies and northern Plains. The South Plains and Midwest sit in the transition zone — enough moisture to support isolated convection but no dominant forcing mechanism to organize it.

Northeast. The region carries the week's most significant precipitation signal. A 92% peak probability on October 11 — already underway as this publishes — is consistent with a frontal passage. The NYC area is looking at 1.31 inches of weekly accumulation, most of it front-loaded. Temperatures average near 70°F, which is about 5°F above the October 11 climatological normal for the region. Once the front clears, expect a brief return to dry conditions before the next shortwave approaches mid-week.

Midwest and Mountain West. Both regions share a mid-week focus. Chicago's 64% precipitation probability peaks on October 14, with 0.72 inches projected for the week. Denver's peak also lands on October 14 at 83%, with 0.36 inches likely — a number consistent with a shortwave trough dropping out of the northern Rockies and triggering afternoon convection over the Front Range before spreading precipitation east onto the Plains. This is the week's most coherent synoptic signal outside the Northeast. Anyone with outdoor plans in the Denver-to-Chicago corridor on Tuesday or Wednesday should treat October 14 as the primary watch date.

NOAA NESDIS

Southeast and Pacific Coast. Atlanta's weekly total is 0.00 inches, with a peak probability of 6% — effectively zero. San Francisco matches that: 0.00 inches, 0% peak probability, average high of 76°F. Both regions are under ridge control. Atlanta's 80°F average high is running warm for mid-October; the ridge suppressing precipitation is also suppressing the seasonal cool-down. No meaningful change is in the 7-day window for either region.

South Plains. Dallas sits in the transition zone with a 43% peak probability on October 15 and 0.44 inches projected. The late-week timing aligns with the same shortwave energy that drives the Midwest and Mountain West events earlier in the week, arriving at the South Plains on a slight lag as the trough axis rotates east. Whether that produces organized convection or stratiform rain depends on how much Gulf moisture is available by Thursday.

International callout. London averages 63°F for the week — unremarkable by October standards, but worth noting that the same ridge pattern suppressing Atlantic frontal passages is keeping the UK drier than its October average. The Azores high is positioned to deflect the primary Atlantic storm track northward, which tends to benefit Scandinavia at the expense of the British Isles' normal autumn rainfall.

Eyes on the Sky

• If you are in the Denver metro area, October 14 carries an 83% precipitation probability — plan outdoor work for October 13 or earlier in the day on the 14th, not after noon.
• The Panama seismic sequence is not resolved: a M7.7 with multiple M6+ aftershocks in 48 hours warrants continued monitoring for additional significant events in the coming days, particularly given the tsunami flag on the M6.6.
• The North Carolina tornado cluster on October 11 is a reminder that the Southeast's severe weather season does not end with summer — coastal plain setups in early October can still produce organized, warning-worthy convection.