Weather to Watch: October 29, 2026

A dry radar picture can accompany dangerous swell, and a brief rain break can sit between two wetter periods. Today's five NWS lessons look at why local appearances and the larger weather pattern do not always move together.

1. Saipan and the Marianas: dry skies do not establish safe seas

When to watch: Late Thursday night, October 29, through Saturday afternoon, October 31, in Chamorro Standard Time.

NWS Tiyan describes mostly dry conditions across the Marianas, with only spotty light showers. Typhoon In-fa's main convection and wind field remain close to its center as it approaches the far northern CNMI. Large northeast swell can still carry wave energy outward into waters far from that core.

The discussion forecasts seas increasing quickly after midnight Thursday night and peaking Friday evening. North- and east-facing reefs are particularly exposed. This marine concern for Saipan, Tinian, Rota and Guam is distinct from the forecast typhoon-force winds in the farther-north islands of Agrihan, Pagan and Alamagan. The office retains uncertainty about the track.

What to notice: Compare remote marine observations and the official surf forecast with local radar. A nearly empty radar frame says little about waves arriving from a distant storm. Do not use a local rain lull or light wind as a reason to approach hazardous surf; follow current NWS tropical-cyclone and marine bulletins.

Source: NWS Tiyan discussion, issued October 29 at 6:03 PM ChST.

2. Southcentral Alaska: one moisture plume, several precipitation types

When to watch: Thursday, October 29, through Friday, October 30. The strongest front is expected Thursday night into Friday.

NWS Anchorage describes warm air arriving above colder surface air in the southern Susitna Valley. Snow is forecast to change toward rain, with freezing rain possible while the ground-level cold air remains in place, especially around Willow. Farther south, rain is expected from the Matanuska Valley through Anchorage and the Kenai Peninsula.

The stronger front and atmospheric river then increase precipitation. The northern Susitna Valley, including the Parks Highway corridor through Broad Pass, is expected to retain snow longer, while Seward and other coastal areas receive heavy rain. Terrain and the vertical temperature profile help explain those differences. An atmospheric river supplies moisture; it does not dictate rain everywhere it reaches.

What to notice: Compare official precipitation-type and road reports by elevation and valley. Freezing rain arrives as liquid and freezes on cold surfaces, so a surface thermometer or radar color alone cannot establish travel conditions. Keep Seward's rainfall concerns separate from the northern Susitna snow forecast and check updated local products.

Source: NWS Anchorage discussion, issued October 28 at 4:01 PM AKDT.

3. Northern Arizona: moisture needs lift to produce widespread rain

When to watch: Mainly dry Thursday, October 29; showers and storms Friday, October 30; another wetter period late Saturday night through early Monday, November 2.

NWS Flagstaff expects a Pacific trough to draw subtropical moisture northward. A smaller disturbance provides lift Friday, supporting showers and isolated thunderstorms, especially south of the Mogollon Rim and toward the Phoenix foothills. Repeated cells passing over the same location, often called training, could concentrate rainfall. The office also flags already saturated ground and recent flooding in Yavapai and northern Gila counties.

Saturday provides a useful comparison. Moisture remains, but weaker lift and instability are expected to reduce shower coverage. A stronger system and cold front then approach late in the weekend, bringing another opportunity for widespread precipitation. Timing and the alignment of those features remain uncertain.

What to notice: Compare successive radar frames to see whether cells cross the same area, then check actual rain totals and official flood information. One bright radar echo does not establish an accumulated rainfall amount. A quieter Saturday would not mean the weekend's second system has disappeared.

Source: NWS Flagstaff discussion, issued October 29 at 2:07 AM MST.

4. Hawaii: a weakening trough can still focus local downpours

When to watch: The overnight period from Wednesday, October 28, into early Thursday, October 29, followed by expected improvement during Thursday.

NWS Honolulu's Wednesday-evening update keeps the overnight flooding concern focused on localized showers near convergence boundaries and terrain. Much of the rain is expected to be light. A few nearly stationary cells could still deliver much more rain to a small area, particularly where moist air is lifted along slopes.

The trough is expected to shift east toward the Big Island early Thursday. The discussion expects more manageable rain rates later Thursday as the upper disturbance moves away, with trade winds gradually returning from west to east Thursday into Friday. Its word “tonight” refers to Wednesday night, rather than Thursday night.

What to notice: Compare repeated radar frames with local rain reports to distinguish a passing shower from one that stays near the same slope. Improving conditions elsewhere do not establish that every drainage has cleared. Use current NWS updates for the remaining local flood threat, and never cross water of unknown depth.

Source: NWS Honolulu discussion, issued October 28 at 8:19 PM HST.

5. Phoenix and central Arizona: duration can matter as much as intensity

When to watch: Friday, October 30, then late Saturday night into Sunday, November 1, with rain possibly lingering into early Monday.

NWS Phoenix describes two rain events separated by a mostly quieter Saturday. Friday's showers could contain embedded thunderstorms with locally higher rates. The second system brings a stronger subtropical moisture plume and a potentially longer period of light to moderate rain, especially across central and eastern Arizona.

Even without the highest short-term rain rates, hours of rain can add up. The office highlights terrain northeast of Phoenix, where air rising over slopes can enhance precipitation, and warns that Sunday's rain could compound problems from Friday. Forecast rainfall amounts still span a broad range.

What to notice: Compare rain-gauge accumulation over each event and the full multi-day period, using matching time windows. A lower radar intensity at one moment does not establish a smaller storm total. Follow official information for washes and low-water crossings; the forecast describes possible flooding rather than an observed outcome.

Source: NWS Phoenix discussion, issued October 28 at 10:51 PM MST.

Prepublication update: The October 29 NWS Phoenix discussion, issued at 4:03 AM MST, now includes a Flood Watch for Friday across portions of south-central and eastern Arizona, with a few strong to severe storms possible. It still separates Friday's storms from Sunday's longer period of rain. This update arrived after the edition's source cutoff.

This dated selection uses NWS discussions available by 6:30 AM Eastern on October 29. The Alaska, Hawaii and Phoenix sources were issued the previous local day. For current forecasts and warnings, follow the National Weather Service.