Written by Sig Silber

HEADLINES (Updated 5:44 PM EST) –

– A threat of severe weather will continue this New Years Eve across the Upper Texas Coast and expanding across portions of Louisiana, Mississippi, Alabama going into the overnight period

– Heavy rain and a localized threat of flash flooding will exist overnight across portions of the Lower Mississippi Valley

– Areas of snow heavy snow and icing are expected across portions of the Southern Plains and Midwest going into New Years Day, and gradually spreading into the Northeast by this weekend

– More stormy weather to impact the Pacific Northwest with heavy lower elevation rains and heavy mountain snows for the Cascades and the Northern Rockies

This article provides continuous updates for a variety of Weather and Weather-Related Threats as well as a general weather forecast. These are “Live” maps that continually update. Please pay attention to the Mesoscale Events maps — Mesoscale Events are potentially life-threatening situations.

Please share this article – Go to the very top of the page, right-hand side for social media buttons. Also, feel free to send this email to anyone you feel will benefit from it.

For those interested in longer-term forecasts, we just published the new NOAA Seasonal Outlook and it can be accessed here.

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CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD – 309 PM EST Thu Dec 31 2020

Valid 00Z Fri Jan 01 2021 – 00Z Sun Jan 03 2021

…A threat of severe weather will continue this New Years Eve across the Upper Texas Coast and expanding across portions of Louisiana, Mississippi, Alabama going into the overnight period…

…Heavy rain and a localized threat of flash flooding will exist overnight across portions of the Lower Mississippi Valley…

…Areas of snow heavy snow and icing are expected across portions of the Southern Plains and Midwest going into New Years Day, and gradually spreading into the Northeast by this weekend…

…More stormy weather to impact the Pacific Northwest with heavy lower elevation rains and heavy mountain snows for the Cascades and the Northern Rockies…

A very active and stormy weather pattern will be in place across large portions of the nation as we wrap up the last several hours of 2020 and then surge into 2021. A strong storm system currently situated across the southern Plains and lower Mississippi Valley region will be driving numerous weather-related hazards over the next couple of days and into the weekend as the storm system lifts northeast through the eastern U.S. In the short-term for the remainder of this New Years Eve and the overnight period, we have a concern for severe weather from areas of the upper Texas coast to downstream areas of Louisiana, Mississippi and Alabama. The Storm Prediction Center continues to advertise an Enhanced Risk of severe weather locally with concerns for strong damaging winds and tornadoes. Meanwhile, heavy rains continue to overspread the lower Mississippi Valley region and this will advance east across areas of the Tennessee Valley and southern Appalachians on New Years Day. Some localized concerns for flash flooding, especially over the lower Mississippi Valley tonight, will be possible and the Weather Prediction Center does have a Slight Risk of excessive rainfall depicted at this time.

On the northwest flank of this storm system will be an axis of heavy snowfall and some icing that will initially impact areas of the southern Plains tonight, but will then lift northeast across the middle Mississippi Valley and adjacent areas of the Midwest on New Years Day. As low pressure advances off to the northeast and impacts the eastern U.S. going into Saturday, there will likely be sufficient cold air in place for locally significant icing over parts of the central Appalachians and possible the northern Mid-Atlantic region. Snow is expected to develop across the interior of the Northeast as the system arrives on Saturday with locally heavy accumulations expected.

Across the Pacific Northwest and into the northern Rockies, the next in a series of Pacific cold fronts will arrive and drive strong onshore flow and moisture transport for heavy lower elevation rainfall and heavy mountain snows. In fact portions of the Washington Cascades and the northern Rockies should see an additional 6 to 12 inches of snow going through Saturday.

Overall, large portions of the nation will see relatively mild temperatures going into the start of the New Year as much the air across the nation will be Pacific in origin, and thus with a lack of Arctic air surging south from Canada over the next few days, expect generally above normal temperatures. Exceptions to this will be across parts of the southern U.S. where clouds and precipitation will help keep temperatures a bit below normal.

We try to keep this up to date but if is not you can find the updated version here.

When you click on this image it takes you to the SPC Fire Warning Page and you get a set of maps for Days 1, 2, 3 – 8, etc. You can then click on those for more detailed information. The map is a bit blurry as I tried to make it a bit larger than the map provided by NOAA but should be able to see where the current wildfire risks are. But if you click on this map, you will get to see three maps that show the risk for different time periods.

Thunderstorm Risk

This should play out something like shown in this 60 Hour Forecast Animation

Here is a national animation of weather fronts and precipitation forecasts with four 6-hour projections of the conditions that will apply covering the next 24 hours and a second day of two 12-hour projections the second of which is the forecast for 48 hours out and to the extent it applies for 12 hours, this animation is intended to provide coverage out to 60 hours. Beyond 60 hours, additional maps are available at links provided below. The explanation for the coding used in these maps, i.e. the full legend, can be found here although it includes some symbols that are no longer shown in the graphic because they are implemented by color-coding.

The two maps below break it down by day and may be easier to read.

Now, the Day One and Two CONUS Forecasts: These Maps Update Daily.

Day One CONUS Forecast	Day Two CONUS Forecast
These graphics update and can be clicked on to enlarge. You can see where the weather will be

During the winter much of our weather originates in the Pacific. That is why we pay attention to the near-term history of storms arriving.

Temperature

A version that shows a 20 hour animation and some other views can be found here

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Day 3 – 7 Hazards

Valid Sunday January 03 2021 – Thursday January 07 2021

Hazards:
– Heavy precipitation across portions of California, the Pacific Northwest, and the Northern Great Basin, Sun-Wed, Jan 3-Jan 6.

– Heavy precipitation across portions of the Central Great Basin, California, and the Southwest, Mon, Jan 4 and Wed-Thu, Jan 6-Jan 7.

– Heavy rain across portions of the Southeast, the Lower Mississippi Valley, and the Southern Plains, Wed-Thu, Jan 6-Jan 7.

– Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Sun-Thu, Jan 3-Jan 7.

– Heavy snow across portions of the Central Rockies and the Northern Rockies, Mon-Tue, Jan 4-Jan 5.

– Heavy snow across portions of the Mid-Atlantic and the Northeast, Sun-Mon, Jan 3-Jan 4.

– Flooding possible across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, the Southern Plains, and the Ohio Valley.

– High winds across portions of the Central Plains, the Northern Plains, and the Northern Rockies, Sun, Jan 3.

– High significant wave heights for coastal portions of California and the Pacific Northwest, Tue-Wed, Jan 5-Jan 6.

– High significant wave heights for coastal portions of the Pacific Northwest, Sun, Jan 3 and Tue-Wed, Jan 5-Jan 6.

Detailed Summary:

The medium range period (Sunday, January 3rd to Thursday, January 7th) will be fairly active across both the western and eastern United States. Starting in the East, an area of low pressure is forecast to move up the Mid-Atlantic and just off the New England coastline Sunday and Monday. As a result, precipitation to the northwest of the low could fall as snow from central Pennsylvania to Maine. The highest chance for heavy snow (greater than 4 inches) will be from northeast Pennsylvania to eastern Maine, where temperatures should remain below freezing. Forecast models have been trending northwest with this system over last few days, but overall confidence still remains relatively low and a trend back to the southeast is not out of the realm of possibility. Given the latest guidance and potential impacts, a highlighted area was added to the hazards graphic today.

Across the Pacific Northwest, multiple storm systems will make for an unsettled start to 2021. Large scale upper-level troughing will be responsible for the extended period of active weather and high elevation snow, with several smaller scale systems bringing locally hazardous weather. Several inches of rain are forecast along coastal sections of the Northwest and northern California, with potentially feet of snow falling across the Sierra and Cascade mountains between Sunday and Wednesday. Significant waves could lead to coastal hazards across the Northwest during this time period as well. Heavy snow is also forecast to enter the northern Rockies of Idaho and Montana through next week. As energy ejects into the northern Plains on Sunday, high winds with gusts over 50 mph could reach the surface across the northern High Plains.

By Wednesday, an area of low pressure is forecast to enter the central Plains, with warm/moist air surging ahead of an associated cold front. Showers and thunderstorms could bring areas of heavy rain/flash flooding from eastern Texas to the Lower Mississippi Valley. Further north, snow will be possible across the central Plains and Midwest.

Weather across Alaska will remain fairly quiet through early next week. Heavy precipitation (rain along the coast/lower elevations and snow inland/higher elevations) will remain a concern across the North Gulf Coast by Tuesday as a storm churns to the south. Total snowfall amounts appear marginal at the moment, therefore a highlighted area was not added today.

(This is updated only during the week) Note the first list is weather highlights, this list is hazards. Not sure there is that much of a difference but they come from two different parts of NOAA. The Day 3 – 7 Hazards List does not update on weekends. But it is still useful as it remains valid for the period of time it covers. Of course, all forecasts are subject to change. Later we show a map of the hazards. Perhaps we should show them together.

Click here for the latest complete Day 3 -7 Hazards forecast which updates only on weekdays. It includes the full discussion which I do not update in this article but only present the highlights.

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Ski Snow Reports

New Feature – Ski Reports. (We may be a tad premature but not by much). It is difficult to find reports that auto-update on-screen (and they are very long) but these links will get you to them – If you have additional suggestions make them in the comments section after every GEI Article and we may add those links. We will try to not have too much overlap as that can add to the confusion.

We will update the above map weekly but more frequent updates can be obtained here.

Snow Forecasts.

Day 1

Day 2

Additional snow information can be found here and here.

We also include drought information in this section.

New December Drought Outlook

Seasonal Outlook Issued November 19, 2020

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Tropical Events

I am replacing the large with three small maps but you can click on them to get larger versions. Even though they are small maps you should be able to tell if there is activity and If I see activity I will make the map where there is activity full size and when available add other related maps.

the Central Pacific.	the Eastern Pacific	the Atlantic and the Gulf of Mexico

Atlantic and Gulf of Mexico

And the Eastern Pacific

Updates on individual named storms can be obtained here.

And the Western Pacific

Weekly Tropical Forecast

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Intermediate-Term Weather Forecast

And shifting to the Alaska and CONUS Intermediate-Term Weather Forecast showing from left to right, Days 1- 5, 6 – 10, 8 – 14 and Weeks 3 – 4 You can click on these maps to have them enlarge, there are larger versions in the Addendum (More Weather the link is shown at the end of this section, and there are larger versions of these maps in the Addendum. Also, the discussions that go with these forecast maps can be found here (first two weeks) and here (Weeks 3 and 4).

First Temperature

And then Precipitation

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Mesoscale Events

The following map shows where mesoscale events are occurring or forecast. If you do not see any areas highlight on this map than there are no mesoscale events taking place or forecast. A mesoscale event is a very serious situation for a very small area and detailed information is provided for these events when they occur or are forecast. If a mesoscale event is shown, click on the map and more detail on the event will be shown.

Two different parts of the NWS issue this map and they are not always in agreement although they are pretty close. They (Norman Oklahoma and College Park Maryland) issue the alerts when they realize the need, so it is best to look on both maps and click one or both if you see areas highlighted.

This next map showing where “Headlines” have been issued for convection (and an animation of the recent movement of storms) should update and you should be able to click on to get additional details but if it does not update when you click on it, click here.

There is a slight difference between convection and thunderstorms. The below map shows where “Headlines” have been issued for Thunderstorms. You should be able to click on the map to get additional details but if it does not update, you can click here.

The map below shows the current wildfire risk which becomes more significant as we move into Summer. When you click on this image it takes you to the SPC Fire Warning Page and you get a set of maps for Days 1, 2, 3 – 8, etc. You can then click on those for more detailed information. The map is a bit blurry as I tried to make it a bit larger than the map provided by NOAA but should be able to see where the current wildfire risks are. But if you click on this map, you will get to see three maps that show the risk for different time periods.

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Now the Day 3 – 7 Hazards Outlook Maps

The orange and red outlined areas are what is most concerning of the forecasted Day 3 – 7 Hazards. This graphic does not update during the weekend. There is a discussion that goes with this graphic and you can access that discussion here.

The following is provided to help the reader relate the maps to how NWS will describe an area of the U.S.

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Now to our More Detailed Weather Report

This graphic is about Atmospheric Rivers i.e. thick concentrated movements of water moisture. More explanation on Atmospheric Rivers can be found by clicking here or if you want more theoretical information by clicking here. The idea is that we have now concluded that moisture often moves via narrow but deep channels in the atmosphere (especially when the source of the moisture is over water) rather than being very spread out. This raises the potential for extreme precipitation events.

500 MB Mid-Atmosphere View

The map below is the mid-atmosphere 3-Day chart rather than the surface highs and lows and weather features. In some cases, it provides a clearer less confusing picture as it shows only the major pressure gradients. This graphic auto-updates so when you look at it you will see NOAA’s latest thinking. The speed at which these troughs and ridges travel across the nation will determine the timing of weather impacts. This graphic auto-updates I think every six hours and it changes a lot. Thinking about clockwise movements around High-Pressure Systems and counterclockwise movements around Low-Pressure Systems provides a lot of information.

Day 3 Above, 6 Below	Day 4 Above,7 Below	Day 5 Above.

Here are the precipitation forecasts. First the cumulative for Days 1 – 3

Then cumulative for Days 1 – 5

Then cumulative for Days 1 – 7

Now we look at the forecast for the Maximum Temperature three days out.

Looking ahead to next week.

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Additional Tools to Obtain Watches and Warnings

Below you will see a number of different maps that are updated in real-time, making this a “live” report. If a part of one or more of the maps shows an area that is highlighted, you can click on it and get the full current report. By having the reader click on these active situations rather than having GEI do so, you will not miss any events in which you might have an interest and which we had not noticed and the page will not get cluttered with warnings, etc that have since expired.

Our focus here is events that are likely to last in the range of six hours but there can be longer or shorter events that are addressed by the Storm Prediction Center which is the main source of the information in this article. Long-term major events like a Hurricane are more likely to be in a separate article. But that may not always be the case. Since in general, all the links on this page transfer you into the NOAA system, in order to get back into this article you need to either close the tab to which you were transferred or click back on the tab that has this article.

Live Warning Maps which If Severe Weather is Shown can be Clicked on to get more detail about these events. If there is a current warning shown on the map, click on the map for additional information related to the event.	These maps are updated as risks are identified.
This is the current graphic showing any mesoscale discussions (MD’s) which are in effect over the contiguous United States. Please read the description of the purpose of our MD’s for further information. Details on all valid MD’s may be found on our Current Mesoscale Discussions page.
Convective Outlooks
This is today’s forecast for organized severe thunderstorms over the contiguous United States. Please read the description of the risk categories for further information. You may find the latest Day 1 Outlook available as well as all Outlooks issued today online.	Today’s Outlook
This is tomorrow’s forecast for organized severe thunderstorms over the contiguous United States. Please read the description of the risk categories for further information. The latest Day 2 Outlook is available as well as all Outlooks that have been issued today.	Tomorrow’s Outlook
This is the day after tomorrow’s (day 3) forecast for organized severe thunderstorms over the contiguous United States. Please read the description of the risk categories for further information. The latest Day 3 Outlook is available as well as all Outlooks that have been issued today.	Day 3 Outlook
This is the day 4-8 forecast for organized severe thunderstorms over the contiguous United States. The latest Day 4-8 Outlook is available as well as all Outlooks that have been issued today. Note: A severe weather area depicted in the Day 4-8 period indicates a 30% or higher probability for severe thunderstorms (e.g. a 30% chance that a severe thunderstorm will occur within 25 miles of any point).	Day 4-8 Outlook
The Thunderstorm Outlooks depict the probability of thunderstorms across the contiguous United States in 4 or 8 hour time periods. The probabilistic forecast directly expresses the best estimate of a thunderstorm occurring within 12 miles of a point. The three probabilistic forecast thresholds are 10, 40, and 70 percent.	Thunderstorm Outlook
Fire Weather Outlooks
This is today’s forecast for organized wildfires over the contiguous United States. Please read the description of the risk categories for further information about this product.	Today’s Outlook
This is tomorrow’s forecast for organized wildfires over the contiguous United States. Please read the description of the risk categories for further information about this product.	Tomorrow’s Outlook
This is day 3-8 forecast for organized wildfires over the contiguous United States. Please read the description of the risk categories for further information about this product.	Day 3-8 Outlook

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