Cold And Wet Winter Ahead According To Farmers’ Almanac

Enjoy cold and wet weather during the winter? Well, you’re in luck according to the 2018 Farmers’ Almanac, which is predicting a cold and wet winter for much of the continental United States (outside of the West Coast). This is based on a 200-year-old formula used by the Almanac.

According to the Almanac, the Northeast should prepare for cold and snow. Cold and wet conditions will extend further south than the Northeast, too, which may place much of the South in a favorable region for above average wintry precipitation. The Northern Plains can expect cold and snow during the winter, but this region will experience more moderate (near average) temperatures compared to average. The Pacific Northwest will be drier than normal, while the Southwest will see precipitation near average with mild temperatures.

2018 Winter Outlook (Farmers’ Almanac)

Here’s a regional breakdown based on the Almanac:

Southeast:
Temperatures: Below average
Precipitation: Above average

Northeast:
Temperatures: Average
Precipitation: Above average

South-central:
Temperatures: Average
Precipitation: Above average

North-central:
Temperatures: Average
Precipitation: Average

Southwest:
Temperatures: Average to above average
Precipitation: Average

Northwest:
Temperatures: Average
Precipitation: Below average

This is not Firsthand Weather’s 2018 winter outlook, and this does not necessarily represent our views on the upcoming winter season. Firsthand Weather will have a winter outlook out in a few weeks, so keep checking back for details!

Modelcasting versus Forecasting: Why you can’t just use models

Modelcasting has become a big issue in the meteorological world.   Cell phone apps, websites, and even some forecasters simply look at what each individual run of the model shows them and makes that their forecast.  This has led to large changes in some forecasts and led many of you to ask us why the forecast in your local area has gone from rain, to snow, back to rain and then back to snow 22 times in the past 5 days only for the sun to be shining the day of.

The truth is, just as our knowledge of what the weather will do is imperfect, a computer’s knowledge of what the weather will do is just as imperfect.  A human forecaster can use logic to look at a map and realize that something doesn’t make sense.   A computer has rigid equations and programs and follows them to the letter.  It doesn’t matter to the computer if its showing the worst storm ever known to man, if that’s what the programs and equations say goes there, then the computer puts it there.

As trained forecasters, meteorologists are supposed to know better.  We know the model has biases, that the model has errors.  We are well aware that the model is just downright bad at forecasting certain storm evolutions.  This brings me to newly formed Tropical Depression 8, probably better known to many of you as Investigation area 99L.  A little while back in the comment section on an article about then Tropical Storm Franklin, I was asked about TD8 and how the Euro model was showing a stronger system than other models.   I explained then that the GFS was very weak in forecasting the type of system that 99L was and continues to be, with even the 06Z run this morning continuing to show barely any development of TD8 as we’ll see down below.

Reality against the Machine

The image above is the model forecast for early this morning.   The current NHC data shows that TD 8 has a minimum central pressure of 1011 mb while this model data shows a minimum pressure of 1014 mb.  As you can see from the image, it also doesn’t show much convection.

This is where a meteorologist needs to know their models and how those models do and don’t work.  We here at Firsthand have been looking at this system for Tropical development for days and first mentioned that the system might develop in this area in an article back on August 8th.  We did this despite models like the GFS not showing any development because we know of the models weakness and added value to the model based on our own meteorological knowledge.  This added value by the meteorologist is essential in any forecast.  We head to the image below for another example.

modelcasting

This image, which is the model forecast for Monday afternoon, shows no major closed circulation.  Based on the previous image, this image would even indicate that TD 8 is weakening.  However, the forecast from the National Hurricane Center doesn’t call for weakening.  The forecast expects that TD 8 will have been a Tropical Storm with winds between 50 and 60 mph.  Do you see that Tropical Storm on this image?   I certainly don’t.  Modelcasting this storm would be a disaster if you happened to be on a cruise ship in that area.

Finally,  this image shows what’s supposed to be a tropical system on Tuesday the 14th.  The forecast during this time period calls for a strengthening Tropical Storm with the NHC forecast heading up to 65 mph and nearing hurricane strength.   That type of forecast simply isn’t here on this model and it wouldn’t be on any app that uses this model for it’s forecast.

This same logic seen here with this forecast for TD 8 can be applied to many other scenarios.  Whether its the development of a winter storm, a major outbreak of severe weather, or even something as simple as the morning temperature, The data that goes into and comes out of computer models allows us a much better idea of what the weather is going to do, but that data and the programming that goes into creating those models is only as good as our understanding of that data and programming.

Modelcasting with a computer can solve a lot more equations, but if the equation itself isn’t perfect then the answer to it isn’t going to be perfect either.   The difference is that meteorologists who use the data as a tool, instead of just modelcasting and outright using the data, can understand what when the tool isn’t giving you the right answer.

 

Robert Millette

Say It Ain’t SNOW?!

An unusually frigid airmass has dropped into the Pacific Northwest and will continue to advance towards the southeast through the weekend into early next week. The closed upper-level low will move onshore tonight across the Pacific Northwest and is already generating snow this morning in the Cascade Mountains.

NAM 500mb Vorticity and Wind Map (Early Sunday Morning)

This low will advance southeastward, then eastward, over the weekend into early next week. This movement will generate snow for the Sierra-Nevada Mountains as well as the northern Rockies. It is possible that Yellowstone National Park and Glacier National Park may see snow by Monday night.

NAM 500mb Vorticity and Wind Map (Early Next Week)

In the Cascade Mountains, 12-20 inches of snow is possible in the higher elevations, but the snow levels may dip to 4,500 feet. The higher elevations of the Sierra-Nevada Mountains may see up to 10 inches of snow, but snow levels may dip to 6,000 feet.

NAM Snowfall Map (Saturday-Tuesday)

It should be noted, this system will generate strong winds in the higher elevations of the western mountains. Some gusts will exceed 70mph. High temperatures will be well below average for this time of the year in the west over the weekend into early next week.

GEFS Temperature Anomaly Map (Saturday-Thursday)

If you have any travel plans out west, please make sure you are aware of the rapidly changing weather conditions that will occur!

Preliminary Nor’easter Impact Map

Northeast
A significant nor’easter will take shape across the Mid-Atlantic and New England from late Monday night through early Wednesday morning. It’s likely that travel will be disrupted from Washington D.C. to Boston, and rural areas may see a loss of electricity. This is the vicinity that may see severe impacts from this winter storm; including several inches of snow (more than a foot from just north of Washington D.C. up through much of Maine), frigid temperatures, and wind gusts exceeding 50 mph.

Northern Plains and Mid-West
The Northern Plains and Mid-West will also see snowfall tonight into Monday–parts of the Northern Plains are receiving snowfall at this hour. Travel impacts are likely in this region, and Chicago will likely see several inches of snowfall, which will end the ‘snow-drought’ the city has recently been plagued by.

Southeast
It should also be noted, another round of precipitation will impact parts of the Southeast late Monday into Tuesday. It is possible, with surface temperatures just marginal enough for a wintry-mix, parts of northeastern Georgia (in the highest terrain) may see snow mix in with the rain overnight on Monday. Significant accumulations are not expected.

Tomorrow, we will release a detailed discussion outlining the technical details and potential accumulations for the nor’easter. Here is a preliminary nor’easter impact map, as well as impact map for the system impacting the Mid-West, for early this upcoming work week.

Southeast Snow?

Snow is already falling in parts of Arkansas and Tennessee this early afternoon, and the snow should eventually shift further south throughout the evening into Sunday as precipitation increases across the Southeast. This increase in precipitation chances across the region is in response to a shortwave moving out of Texas and one moving out of the Plains. These two features will phase together and cause an enhanced area of lift across the region.

With surface temperatures in the 30s and 40s, surface dewpoints in the teens and 20s, and cold air aloft, it is likely that far northern parts of Alabama, Georgia, and Upsate South Carolina will see snow mix in with the rain at some point late today or Sunday morning. Confidence is relatively high with this scenario. When it comes to accumulations, that’s when the confidence level drops. Right now, it doesn’t appear much accumulations will occur outside of Tennessee, the highest terrain of Georgia, and the mountainous regions of North Carolina. It should be noted, the dynamics with this system are pretty strong, so there is the potential for a small enhanced zone that sets up somewhere in the region. This could cause a quick inch or two of accumulations if it evolves, but again, this type of feature is too hard to forecast where it may setup. At this point, the best chance of accumulations will be on the roof of your car/homes and possibly on bridges/overpasses.

This pink region outlines which areas have the best chance of seeing snow mix in with the rain. This is not an accumulation map.

Weekend Snow Update–Trending South

Here is a brief update on the weekend system that may bring snow to parts of the Midwest, Tennessee Valley, Carolinas, and Mid-Atlantic. Confidence is increasing that these areas will see snow over the weekend, and the latest numerical guidance has trended south with the snow over the past 48 hours. This means the Tennessee Valley and parts of the Carolinas are now in ‘play’ for snow. So what’s the setup?

Initially, a cold front will move through this region on Friday. This will provide the cold surface temperatures necessary for wintry precipitation. Behind the cold front, a potent shortwave will dive into the Southern Plains and eventually move into the South. This shortwave appears it will merge with another piece of energy moving out of Texas to form a surface-low. This surface-low will develop somewhere across the Gulf States, probably Mississippi/Alabama, which will aid in wrapping cold air into the precipitation. The evolution of this low and track are crucial in which areas see precipitation, how much precipitation areas receive, and which areas see snow. The low will trek towards the East Coast by Sunday. So what’s the timing?

The initial shortwave diving southeast across the Plains will aid in snow for parts of the Plains and Midwest late Friday into Saturday. The snow chances will then increase for the Tennessee Valley on Saturday, and the Mid-Atlantic and Carolinas late Saturday into Sunday. What are the uncertainties?

The evolution and track of the low are uncertain at this point. The strength and tack are crucial because it will have large implications on what type of precipitation areas receive. The vertical temperature profile is uncertain at this time, too, as well as an warm-nose that may develop. If the low rapidly deepens, a strong warm-nose could evolve. Snowfall accumulation amounts are also uncertain at this time. There is high confidence in accumulations, but not exact amounts at this point. Marginal surface temperatures and the sun-angle of March could allow for fast melting in areas that do not receive heavy snow.

Again, this is a few days out and a lot may change. This map below shows which areas have the best chance to see wet snow. Please keep checking back for updates!

Say It Ain’t Snow?!

Here is a very brief write-up on the weekend time-frame for the Mid-Atlantic. Many people have inquired about a potential winter storm that some of the numerical guidance is showing. This potential event is several days out, and we all know many changes will emerge within the models on a run-to-run basis. It’s too early for all the specifics on the potential winter storm during this time frame, however, I will say, the Mid-Atlantic bears watching during this time-frame. So, what do we ‘know’ at this point?

It appears a cold airmass will move into Mid-Atlantic by Friday. This cold air will be in place as a potent low-pressure system potentially moves into the area from the west by Sunday. With the low possibly deepening as it moves out of the Tennessee Valley late-Saturday into early-Sunday, it’s likely the system will draw in deep Gulf moisture to aid in heavy precipitation. Some of this precipitation could fall in the cold airmass, which would set the stage for a heavy wet snow in parts of the Mid-Atlantic. What are the uncertainties?

The evolution, track, and timing of the system are uncertain. The amount of cold air that remains in place, the position of the freezing-line, and the vertical temperature profile of the atmosphere are uncertain. There should, however, be enough cold air in place for snow in some areas. It should be noted, with a low this strong, as some of the guidance is showing, it is possible for a warm-nose to develop and cause a forecasting headache.

Again, this is several days out and a lot will change, and there is considerable variance among the models; but there has been an overall trend in the models over the past 48 hours indicating a stronger, colder, further south solution. This map below shows which areas I am watching right now–in the pink shaded region. The red ‘L’ shows you the position of the low from late Friday near Arkansas, moving through the Tennessee Valley late in the day Saturday, and exiting the East Coast by Sunday afternoon. Please keep checking back for updates.

Sunday Snow Accumulations (Southeast)

Light snow is still expected across parts of the southeast on Sunday as a potent clipper dives into the area. Surface temperatures will be marginal, which will act to limit accumulations and possibly allow for a light rain/snow mixture across far northern parts of Alabama and Georgia. Another factor that will limit snowfall amounts is moisture. This system will create adequate lift, which will act to ‘squeeze’ out the available moisture, but moisture will be meager at the surface per the modeled soundings.

With that said, this system is potent (some instability will come into play), and light snow is possible across much of central and eastern Tennessee, far northern Alabama, northern Georgia, and western North Carolina. The snow will begin in Tennessee early Sunday morning and traverse towards the east-southeast throughout the day on Sunday, and continue into Monday morning for the mountains of North Carolina. Light accumulations are possible across the area; with higher elevations picking up a few inches.

Forecast Snowfall Accumulations: Sunday

Southeast Snow Update

Cooler temperatures have replaced the warm temperatures that dominated the southeast over the past several days. These cooler temperatures will help set the stage for the potential for a few areas to see frozen precipitation late this weekend. A potent disturbance will traverse towards southeast into the region due to the favorable upper-level flow. This clipper-like disturbance will generate enough lift for light precipitation to develop during the day on Sunday and into Sunday night.

Looking at modeled soundings for this timeframe, it is possible the precipitation may be a rain/snow mixture before changing over to all snow later in the day on Sunday. It should be noted, while this clipper will have strong lift associated with it, the moisture at the low-levels will be significantly lacking. This will keep precipitation light in nature. The lack of low-level moisture and marginal surface temperatures should keep accumulations light.

The best chance for snow will occur across Tennessee, northern Alabama, and northern Georgia on Sunday into Sunday night. I will keep a close eye on this system, and have an accumulations map (even though any accumulations should be minimal) by Saturday.

Snowfall Map For Sunday

Lake Effect Snow Machine slams into high gear

Cold air has returned to many areas in the East as a cold front advances off the Coast, as previously mentioned in Chris’s article.   This air, along with strong northwesterly winds, will combine with the unfrozen lakes to produce large quantities  of lake effect snow through this weekend.     I expect that the snow will continue to pile up through Sunday and beyond with some areas seeing several feet of snow.  New York, Pennsylvania, Vermont, Ohio, and Michigan will be impacted by this event.

lake effect

Above photos courtesy of NWS Buffalo and NWS Cleveland

 

Lake Effect Snow Warnings and Watches

Lake Effect Snow Warnings are in effect for Southern Erie, Wyoming, Cattaraugus and Chautauqua counties in Western New York.  The warning is in effect until 7:00 p.m. on January 29.  Storm total snowfall of 2 feet or more will be possible in the most persistent lake snows.

Lake Effect Snow Warnings are in effect for Jefferson, Oswego and Lewis counties in North Central New York.  The warning is in effect until 7:00 p.m. on January 29.  Storm total snowfall of 3 feet or more will be possible in the most persistent lake snows.

Lake Effect Snow Watches are in effect for Northern Erie and Genesee counties. The watch is in effect from morning through late night on Saturday January 28th.  Storm total snowfall accumulations of 5 to 10 inches are possible in the most persistent lake snows.

A Lake Effect Snow Watch is in effect for Allegany County through the evening on Sunday January 29th.  Storm total snowfall accumulations of 10 to 20 inches are possible in the most persistent lake snows.

No advisories are issued in Michigan at this time but they will likely be issued later on.

Travel Hazards

Interstates 75, 80 , 81, and 90 should expect to see heavy precipitation at times from now through the weekend.  Visibility in these areas can be 10 miles one minute and then suddenly drop to white out conditions as you enter the snow bands.  Travel in this area should be taken with a maximum of preparations and should be avoided if at all possible.  We have all seen the images of backed up traffic where several inches of snow piles up very quickly on roadways that can’t be plowed with the cars in the way.

 

Rob