WeatherHawks

My latest article on the WeatherHawks website discusses the PWAT Anomaly, the variance in precipitable water above or below regional and seasonal means. When evaluating atmospheric conditions, it's helpful in determine the chances of rain or severe thunderstorms.

Precipitable Water Revisited: The PWAT Anomaly The deviation from climatological means is helpful in predicting precipitation.

https://www.weatherhawks.com/the-how-and-why-of-our-changing-seasons/

The How and Why of Our Changing Seasons The earth’s position in its orbit relative to the sun determines when the seasons change. Most people are aware that spring begins in March, summer in late June, fall in late September, and Winter in late December. The actual date may vary from year to year by a day

https://www.weatherhawks.com/sunrise-sunset/

Sunrise, Sunset There’s more to the sun’s arrival and departure each day than most of us realize.

This is the drought map for the western US as of June 15th. If you think the North American Monsoon doesn't have an effect on our drought, look at Colorado compared to the rest of the West. The monsoon flows from the southwest, across Arizona, and into Colorado and the path can be clearly seen on the map.

For those of you who are CoCoRaHS observers or just enjoy measuring rainfall, a new rain gauge has been officially approved for CoCoRaHS observations. Made by Colorado-based Climalytics, the Tropo gauge is taller than the current gauge but the same 4" diameter, is easier to read, and better suited for taking snow cores in deep snow. You can find more information at climalytics.com.

Read my review at: https://www.weatherhawks.com/climalytic-offers-new-rain-gauge-design-for-observers/

Tropo on the left, standard Stratus rain gauge on the right.

California could be in for another round of intense rainfall as an atmospheric river approaches from the Pacific and comes ashore later this week. The danger comes as rain falls on areas of recent heavy snows, melting it and causing localized flooding. People in counties along the Big Sur region are being warned to stock up on supplies.

The chart below from the Ocean Prediction Center for 1200 UTC on 11 March clearly shows the forecast position of the AR on Saturday morning. Winds at the 500 MB level (~18,000 feet) range from 35 to 55 knots.

For more information on atmospheric rivers, check out my article on WeatherHawks.com (https://www.weatherhawks.com/atmospheric-rivers/).

The January 2023 total precipitation map from climate.gov. It would be unremarkable but for the intense rainfall along the west coast, particularly California, where several atmospheric rivers came ashore causing flooding and damage.

https://www.weatherhawks.com/subscription-weather-services/

Subscription Weather Services For the serious amateur meteorologist, sometimes you need a specialized service.

https://www.weatherhawks.com/the-lifted-index-and-k-index/

The Lifted Index and K Index—Indicators of Instability in the Atmosphere These two indexes give meteorologists an indication of the potential for convection and severe weather.

https://www.weatherhawks.com/the-planetary-boundary-layer/

The Planetary Boundary Layer The planetary boundary layer hugs the earth’s surface. It’s where much of the action takes place.

Weather balloons are an important component of data gathering for our daily forecasts. Check out our newest article to see how they work.
https://www.weatherhawks.com/weather-balloons/

Weather Balloons Weather balloons give us our best look at the vertical structure of the atmosphere…with limitations.

https://www.weatherhawks.com/thetae/

Theta‑e Theta‑e sounds complicated, but can give observers a hint as to atmospheric stability.

The current GFS model sounding for 1000 lcl Saturday morning off the coast of Massachusetts. The sounding shows the atmosphere saturated from the surface to almost the 200 mb level, plenty of moisture to provide snow. Note also the wind barbs on the right edge of the sounding and the abrupt shear at the 650 mb level. If the model holds true, New England, especially from Cape Cod to Maine, could be in for a wild weekend.

Weather models are indicating the possibility of a bomb cyclone moving north along the Atlantic coast this weekend, bringing high winds and heavy snow to the northeast. This map from the GFS model shows how deep the low may be. It's position off the coast will determine how far inland and how much snow affects the region.

Drylines are frequently overlooked as storm generators, but storm chasers know them well.
https://www.weatherhawks.com/drylinesstorm-chasers-love-em/

Drylines—storm chasers love ‘em Drylines can be a boon to storm chasers, or a dry hole.

If you think the weather is sporting where you are, be thankful you're not on a small boat in the northern Pacific.

The surface analysis chart tells the tale, with storms, gales, and freezing spray making life miserable for mariners.
https://ocean.weather.gov/P_sfc_full_ocean_color.png

ocean.weather.gov

With many areas of the country beginning to see some significant snowfall, here's an introduction to the dynamics of snow and its formation.https://www.weatherhawks.com/snow-dynamics/

An Introduction to Snow Dynamics—I There’s more to snow than just freezing some water.

If you think you'd like to take regular weather observations and contribute them to the various national databases, here are a few opportunities to do so.
https://www.weatherhawks.com/citizen-weather-observers/

Citizen Weather Observers There are many opportunities for citizen observers to contribute their observations. Here are a few to consider.

https://www.weatherhawks.com/interpreting-the-surface-analysis-chart/

Interpreting the Surface Analysis Chart The surface analysis chart is a good place to begin your understanding of the factors affecting your weather, now and in the future.