20161202_tempanomalies

Temperature anomaly maps on social media

Note: The tweets used are just examples of what many are posting on social media. This post is not intended to single out these tweets specifically; they were just the ones that caught my eye this morning since they were back-to-back.

Summary:

From your weather enthusiast Facebook page to nationally-renowned meteorologists, everyone is starting to talk about the upcoming cold shot that will impact much of the United States next week. COLD. IS. COMING.

Opinion:

But what audience are these images and comments trying to reach? Does this audience understand how these anomaly maps translate into sensible weather? Sure, it looks pretty and it’s eye-grabbing when blues and purples take over the country, but how does it prepare me for the weather beyond “it will be colder than normal”? Are we talking lows in the 20s, 10s, etc.? Does someone in Mobile or Atlanta need to get their winter coat out?

I’m probably being nitpicky with this one, but I think posting actual forecast lows/highs would be more productive because it would be easier for most people to understand. Maybe I’m just looking at it from the wrong angle? To me it’s part of the bigger argument that meteorologists face with reforming weather communication, which is generally steering more toward focusing on the weather’s impact. You can tell me “it will be cold,” or you can tell me “it will be cold, with lows in the 10s and 20s.” I have no way of telling what “it will be cold” means without more context, but letting me know what the actual temperatures will be is much more useful.

One could say that it’s too far out into the future to provide actual numbers, and I could understand that. But it would be better to say “temperatures could get as cold as [range]” than the more vague things that are being communicated.

20161129_spcoutlook20z

SPC issues a moderate risk for tornadoes

http://www.spc.noaa.gov/products/outlook/archive/2016/day1otlk_20161129_2000.html

Summary:

After yesterday’s mostly-failed setup in which tornadoes were more scarce than expected in the Deep South, much higher instability today will likely result in stronger discrete storms that can mature enough to become tornadic. The SPC is targeting the 00z-04z time frame as the most dangerous as the low-level jet picks up, meaning nighttime tornadoes will be a big concern.

Opinion:

The Deep South is no stranger to these after-dark tornado setups, and I agree with the SPC’s forecast. With moisture and energy available right next door in the Gulf of Mexico, all you need is a proper storm system to move through to create a tornado threat. The winds associated with this system are fairly strong, and now the CAPE/shear combo is balanced enough where supercells can more reliably become organized enough to produce tornadoes. There are already multiple classic-looking supercells in Louisiana that are tornado-warned, and it looks like the southern Mississippi Valley will be in for a long night.

Reviving the blog

I figured out a way to make weather-related blog posts that aren’t just snowfall forecasts that is both unique and something that I can be passionate about and maintain without feeling like I’m dragging myself in to do it.

The idea: find interesting weather articles/news, provide a summary, and put my own opinion with it. It’s mostly just an extension of what I do on Twitter, but it will be more fleshed out while also providing a tl;dr version of what is going on. This will be limited to things that I am interested in, and will likely focus 100% on weather, without diving into things that are indirectly weather-related or other earth sciences.

That’s the plan, anyway. And I’ll start today.

Winter Storm Threat: February 8-10 (Only/Final Call)

This storm has a complicated setup. You have multiple surface lows within a broader upper-level trough, marginal surface temperatures, and large discrepancies in QPF placement between the models.

Temperatures along and east of I-95 are the most uncertain, which are expected to be in the low-to-mid 30s through most of the event. Areas north and west of I-95 will start above freezing, and will cool to at or below freezing depending on how strong the snowfall rates are tonight.

Snowfall rates will be one of the most important factors in determining which areas see 4-8 inches, and which areas get 1-4 inches. The best rates are likely to be along the Maryland/Pennsylvania border into southern New Jersey.

20160208-09_MAsnow_final

The intensity of the initial coastal low, the secondary coastal low development, the strength of the low over the Great Lakes, and the timing of the strengthening and weakening of these lows are wreaking havoc on the QPF output on the various models.

I tried my best to offer a realistic compromise between the differences in QPF, while also accounting for the surface temperature and snowfall rate issues. I could definitely see a tighter gradient between accumulation amounts than what I have on the map.

Winter Storm Threat: January 22-24 (Final Call)

One final update before the frozen stuff starts to fall in the southwestern corner of my map. Made minor adjustments to the fringes in central/eastern North Carolina and up around NYC, with a slight expansion of the 18″+ contours.

20150122-24_MAsnow_final

Timing and impacts from this potential blizzard remain on track to what I said earlier today.

Winter Storm Threat: January 22-24 (Second Call)

The heavy snow in the core of the Mid-Atlantic remains on track, given the newest model data and latest trends. Two notable changes were made to the northern and southern fringes of the snow accumulation. General timing remains the same, with snow expected to start in the D.C. area between 3-6 p.m. Friday.

20150122-24_MAsnow_second

The northeastern edge of the snow accumulation was cut back as confidence increases in the storm track, leaving lower snow amounts across northeastern Pennsylvania into northern New Jersey. On the southern edge, western North Carolina into western Virginia and West Virginia saw snow increases due to better confidence in the QPF forecast and better temperature profiles. Further east, more warm air wrapping into the eastern side of the system made for lower snow forecasts across northeastern North Carolina, southeastern Virginia, and along the immediate Atlantic Coast.

Ice will also be an issue in the Southeast and in southwestern Virginia. Currently, areas in northern South Carolina and central North Carolina are forecast to receive 0.25-0.75″ of ice, according to the NWS.

20160121_RAH_Ice11am

At the moment, the NWS also has Blizzard Watches posted from the greater D.C. region up through Philadelphia and into NYC and Long Island.

20160121_BlizzardWatchesNoon

I will be posting a final forecast update this evening.

Winter Storm Threat: January 22-24 (Initial Call)

For those linked here from other sites, you can see my updated forecast here: Winter Storm Final Call

What can I say? This is a classic setup for feet of snow and possible/probable blizzard conditions across parts of the Mid-Atlantic. If you liked February 2010, then you’re gonna like this.

20150122-24_MAsnow_initial

The epicness that is this storm system will start on Friday and end Saturday night/Sunday morning. For the greater DC area, I’m expecting snow to start accumulating in the late afternoon or early evening on Friday. Once it starts, it won’t stop for quite some time, lasting through Saturday in most spots.

Temperatures won’t be frigid, so I-95 and areas south should see more of a dense, wet snow, while areas further north and west get into the drier, fluffier snow. Mixing issues with sleet and rain don’t really become a problem until you get south and east of I-95. The I-95 cities are expected to be at or below freezing at the surface throughout the storm.

On top of all this, strong winds will generate blizzard or close to blizzard conditions mainly in the DC/MD/Delmarva region. Persistent onshore flow will result in fairly high storm surge and beach erosion.

Get home early on Friday, because you won’t want to be out once it starts. Don’t plan on doing anything that involves going outside Friday night or Saturday… unless it’s sledding or a snowball fight.