A broad area of low pressure off the Pacific coast of Central America has a 30% chance of becoming a tropical depression, according to the National Hurricane Center outlook issued at 10 a.m. PST on Nov. 6. Even if it never organizes, the same low could still bring heavy rain to parts of Central America through the weekend. Forecasters say the setting for development is turning worse, not better.
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The disturbance is producing disorganized showers and thunderstorms around a weak, elongated circulation. That is a long way from a named storm. An outlook issued the night before, at 10 p.m. PST on Nov. 5, had set the formation odds at 40%, so the trend over the last day has been downward.
The hurricane center’s outlook and the falling odds
Hurricane center forecasters Evans and Adams wrote in the Eastern Pacific Tropical Weather Outlook that conditions are expected to become increasingly hostile over the weekend, which lowers the chance of development. They gave the low a “low” category of 30% through both 48 hours and seven days, with no separate bump later in the week. The same text says the system could still bring heavy rain to parts of Central America through the weekend, whether or not it ever earns a depression label. The earlier reading of 40% appears on the center’s graphical outlook page, which is where the odds are updated as new advisories come in.
What a tropical depression means in practice
A tropical depression sits at the bottom of the ladder. The hurricane center’s glossary defines it as a tropical cyclone with maximum sustained surface winds of 33 knots, or 38 mph, or less, while a tropical storm runs from 39 mph up to 73 mph. Rainfall does not track those wind categories neatly, which is why the outlook keeps the rain warning separate from the formation odds. A low that stays unnamed can still stall over mountainous terrain and dump rain on slopes that drain quickly into river valleys.
Timing also matters. The eastern Pacific hurricane season officially runs from May 15 to Nov. 30, and the hurricane center’s climatology page puts the average date for the 15th named storm of a season near Nov. 5 in the 1991 to 2020 record. Late-season systems occur, but the calendar and the hostile air both work against one here.
Ground that was already soaked
A Climate Prediction Center Central America hazards bulletin covering Oct. 22 to 28 recorded 100 to 200 millimeters of rain over the previous week across much of Guatemala, most of Belize, northern and eastern Honduras, central and eastern Costa Rica, and western and central Panama. The bulletin said flood risk remained elevated in Guatemala, Costa Rica and Panama and noted flooding and landslides in several countries. That product is two weeks old and no newer version was reachable, so it describes the backdrop rather than conditions on Nov. 6.
The bulletin’s forecast figures help explain the stakes of that earlier rain. For Oct. 22 to 28 it expected moderate to heavy rain in Guatemala, Costa Rica and Panama, with accumulations of 25 to 150 millimeters, and under 50 millimeters elsewhere in Central America. Rainfall during the preceding week ran 50 to 200 millimeters above average in Guatemala, Belize, Honduras, northern Nicaragua and parts of Costa Rica and Panama. Soil that wet sheds new rainfall quickly, so even a modest event can tip a river or hillside past its limit.
The outlook cadence is also worth noting. The hurricane center’s front page said its eastern Pacific outlook was issued at 4 a.m. PST on Nov. 6, and the text product used here carried the 10 a.m. update, so the odds move several times a day. The 10-point drop between the Nov. 5 and Nov. 6 issuances shows how quickly the numbers can move, and readers following the story should check the timestamp on any figure they see quoted.
A separate and far likelier system near Hawaii
Another disturbance in the same outlook is a different story. A trough several hundred miles southeast of the Big Island of Hawaii carries a 90% chance of becoming a tropical depression, with Evans and Adams expecting one to develop on Nov. 6 or Nov. 7 and move west-northwest at 10 to 15 mph, well south of the islands. The center’s main page lists no active tropical cyclones in the eastern Pacific or the Atlantic as of Nov. 6, so neither system had a name or advisory yet.
The unresolved piece is where any rain lands. The outlook gives no rainfall totals and no country-by-country breakdown, and Evans and Adams offered no estimate of how long the low would keep producing showers once the hostile air arrives. The next scheduled outlook will show whether 30% slips further.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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