The Geminid meteor shower peaks this weekend on Dec. 13-14. If you’re planning to watch from the U.S., the weather forecast could make or break your view. Here’s what the skies and temperatures are expected to look like across the country.
It has been said on more than one occasion that if the Geminid meteor shower took place in a month with relatively mild nighttime temperatures, it would probably rival the Perseids in popularity. The Perseid meteor shower benefits from a long observing window (more than five weeks during the summer months of July and August when most people are on vacation in the Northern Hemisphere) and the comfortable observing temperatures enable everyone to enjoy this display without any problems. For this reason, the Perseids are the only meteor shower to have become well known among the public.
The good and the bad: Geminids weather forecast for the U.S.
This year, the peak of the Geminid meteor shower will occur during the predawn hours of Sunday, Dec. 14. The good news for prospective meteor observers is that about 75% of the country should enjoy good-to-excellent viewing conditions when the Geminids reach their maximum intensity.
Weather maps for early Sunday show a large and expansive area of high pressure, centered over the Central Great Plains, which should promote mainly clear skies from Wisconsin south to Arkansas and northern Mississippi and as far west as the Rocky Mountain states.
In contrast, a cold front, extending from southern Texas northeast to along the Atlantic Seaboard, is expected to generate widespread cloud cover for most locations in the eastern U.S. And a developing storm near the North Carolina coast may translate into rain and snow for the Middle Atlantic and Northeast U.S.
Meanwhile, another cold front, moving onshore from the Pacific coast, could bring cloudy, wet weather to much of Washington state and western Oregon.
But even for those places that will have clear skies, there will be a significant problem: Staying warm!
Numbs the word!
A surge of frigidly cold arctic air will settle into place over the Northern and Central Great Plains and the western Great Lakes. Check out the Sunday morning minimum temperature map, kindly provided by the National Weather Service. In this region, the forecast is for ambient (not wind chill) air temperatures in the subzero range with readings ranging from minus 1°F (minus 18°C) for Indianapolis, a gelid minus 3°F (minus 19°C) in Chicago, to a glacial minus 24°F (minus 33°C) at Fargo, North Dakota.
Even for the Deep South, northern Texas, and much of New Mexico, temperatures will stay below freezing. Probably the places with the most comfortable temperatures will be the southern portions of California and Arizona and parts of northern and central Florida, where, under clear-to-partly cloudy skies, temperatures will be in the comparatively mild 50’s.
As was noted in a prior Space.com column, and especially considering this year’s extremely cold conditions, you’re likely going to be outside near the coldest time of the 24-hour temperature cycle. Under a wide-open, clear sky, lying on a long lawn chair or a blanket, radiational cooling chills you even more. And unlike most things you do outside in the cold, meteor observing is motionless. So, be sure that you’re warm and comfortable. Heavy blankets, thick sleeping bags, ground cloths, auto cushions, and pillows are essential equipment. Try an electric heating pad inside your coat.
No two observers prepare for a meteor vigil the same way. It helps to take a late afternoon nap, a shower, and to wear fresh clothing. Hot cocoa, tea or coffee can take the edge off the chill, as well as provide a slight stimulus. And it’s even better if you can observe with a companion. That way, you can keep each other awake, as well as cover more sky.
Your local forecast
We have also included a second map, from the National Weather Service, which is valid for 7 a.m. Eastern Time on Sunday, Dec. 14, which provides forecast percentages of sky (cloud) cover for dozens of locations across the contiguous U.S. The lower the percentage, the clearer the sky. You can break things down into four categories:
EXCELLENT: Cloud coverage ranges from clear to just a few clouds; generally, a sky cover of no more than 20%.
GOOD: Cloud coverage ranges from just a few clouds to scattered cloud cover; generally, 20% to no more than 40%.
FAIR: Cloud coverage ranges from scattered to broken cloud cover; generally, 40% to no more than 70%.
POOR: Cloud coverage ranges from 70% to complete overcast.
For any late updates in your local weather forecast, check with your local National Weather Service Forecast Office. Just click on your area on the map and you’ll be taken to the NWS office that serves your area. Also, check here for the latest satellite imagery of your region courtesy of the GOES 16 weather satellite.
Final thoughts
If skies are clear Saturday night through Sunday morning, don’t miss this year’s Geminid display! A waning crescent moon will be in the sky during the predawn hours but its light will hardly disturb the Geminids. In the evening, the constellation Gemini, from where these meteors appear to emanate, is very low on the eastern horizon, but from midnight until around 4 a.m. Gemini attains a very favorable position almost directly overhead. The very high hourly rates, the richness in bright and moderately slow meteors, should motivate skywatchers to resist the cold.
Good luck and stay warm!
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.
