Written by Sig Silber

HEADLINES (Updated 4:59 PM EST) –

– A low pressure system will bring snow across the central Rockies and some mixed precipitation for the upper Midwest on Tuesday

– Rain will expand eastward from the central U.S. toward the eastern U.S. for the next couple of days

– More unsettled weather moving into the Northwest for the next couple of days

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.

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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 – 300 PM EST Mon Nov 23 2020

Valid 00Z Tue Nov 24 2020 – 00Z Thu Nov 26 2020

…A low pressure system will bring snow across the central Rockies and some mixed precipitation for the upper Midwest on Tuesday..

…Rain will expand eastward from the central U.S. toward the eastern U.S. for the next couple of days…

…More unsettled weather moving into the Northwest for the next couple of days…

Cold air behind a developing low pressure system exiting into the Canadian Maritimes will bring colder than normal temperatures along the East Coast into Tuesday night. Some snow showers are expected to linger in the lee of the lower Great Lakes through tonight into Tuesday morning.

A low pressure system complex is forecast to develop over the central Plains and then head toward the Great Lakes. Snow is expected to continue over the central Rockies into Tuesday before the system moves out into the central Plains Tuesday night. Some mixed precipitation can also be expected over the upper Midwest. Meanwhile, rain will develop and expand across the Midwest while some thunderstorms are likely farther south into the southern Plains. By Tuesday night into Wednesday, the rain will be pushing eastward into the Ohio Valley with thunderstorms likely across the mid and lower Mississippi Valley ahead of a cold front. As the center of the low pressure system nears the Great Lakes Wednesday evening, some snow is forecast to develop over interior New England well ahead of the system.

In the meantime, another energetic front moving into the Pacific Northwest will bring another round of mountain snow and coastal rain into the region on Tuesday. The snow will spread into the northern Intermountain region and the northern Rockies on Wednesday as the weakening front moves across. Drivers are advised to use caution as the snow could make driving conditions hazardous. Colder air will filter across much of the western U.S. on Wednesday behind the cold front.

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 Thursday November 26 2020 – Monday November 30 2020

Hazards:

– Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, and the Southern Plains, Thu-Sun, Nov 26-Nov 29.

– Flooding occurring or imminent across portions of the Southeast and the Mid-Atlantic.

– Heavy precipitation across portions of mainland Alaska and the Aleutians, Thu-Fri, Nov 26-Nov 27 and Sun, Nov 29.

– Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sat-Mon, Nov 28-Nov 30.

– High winds across portions of the Alaska Panhandle and mainland Alaska, Fri-Mon, Nov 27-Nov 30.

High winds across portions of mainland Alaska and the Aleutians, Thu-Mon, Nov 26-Nov 30.

Detailed Summary:

The final days of November feature a quick moving disturbance over the northern Mid-Atlantic on Thanksgiving that favors a wet day in parts of the Northeast. From a big picture standpoint, the Thanksgiving disturbance in the Northeast is just the appetizer to the main course this weekend; a disturbance breaking off of a long-wave trough tracking across the Upper Midwest. This disturbance likely becomes a cut-off upper low over the Southwest where it is likely to produce some higher elevation snowfall in the southern and central Rockies this Friday and into Saturday. This upper low and a low level frontal boundary over the Deep South are the keys in determining which areas of the South receive heavy rainfall. Upper lows are notoriously pesky and are known to be modeled to eject east out of the Southwest too quickly. In addition, ensemble guidance show differing strengths of the upper low with the EPS the strongest among itself, the GEFS and Canadian ensembles. That said, upper level divergence ahead of the trough and better frontogentical forcing is likely to occur from eastern Texas to the Lower Mississippi Valley where all three ensemble models pin point the heaviest amounts Friday into Saturday. By Sunday, the Deep South should be favored to remain wet but exactly where the heaviest amounts take place will be determined by the strength and forward speed of the upper trough. Precipitation may then spread up the East Coast by the start of next week once a new upper level disturbance dives south from central Canada and acts to speed up the progression of the southern storm system.

The Lower 48 remains void of temperature hazards to conclude November. The 5-day mean temperature anomalies in the East range from 4-8 degrees above normal. The coolest locations versus normal are forecast to occur from the Intermountain West and southern Plains to the Lower Mississippi Valley. For the southern regions in particular, the slightly cooler temperatures are a result of clouds and rainfall limiting daytime highs and keeping overnight lows seasonally mild.

The area with the most potential hazards to close out the month of November is Alaska. Along with above normal temperatures throughout much of “The Last Frontier”, the southern tier of the state is set to be battered by a pair of powerful storm systems starting first with an intensifying low pressure system near the Aleutians on Thanksgiving. The storm deepens further over the Bering Sea on Friday with strong winds and heavy showers over the Aleutians and up the southwest peninsula. Friday into Saturday is set to be the most unsettled period for the southern mainland coast and towards the Panhandle. Copious amounts of mountain snow and coastal/valley rain are expected with snow in the higher elevations being measured in feet. High winds will also make for high surf along the coasts. In addition, treacherous travel conditions are likely where snow levels are low as the combination of heavy snow and gusty winds cause whiteout conditions at times. While conditions may improve briefly along the southern coast and the Panhandle on Sunday, it will be very short lived as yet another strong cyclone reaches the Aleutians. Some ensemble guidance suggests this storm may have as much, if not more, atmospheric moisture to work with due to the storm’s moisture source stemming from the subtropical West Pacific. Look for conditions to deteriorate again in the Aleutians and southwest Peninsula late Saturday into early Sunday, followed by the southern coast and Panhandle late Sunday into Monday. Expect similar impacts to the first storm, although wind speeds and areas of high surf are slightly lower in confidence. While there is still some disagreement on timing and track, ensemble guidance supports a stormy signal to close out the month of November.

(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 November Drought Outlook

Seasonal Outlook Issued October 15, 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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