Written by Sig Silber

HEADLINES (Updated 4:48 pm EDT) –

– Below average temperatures continue from Pacific Northwest to Upper Midwest through Wednesday; above average elsewhere

– Below average temperatures continue from Pacific Northwest to Upper Midwest through Wednesday; above average elsewhere

– Fire threat returns to northern California on Tuesday

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.

Directory

CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD – 418 PM EDT Mon Oct 19 2020

Valid 00Z Tue Oct 20 2020 – 00Z Thu Oct 22 2020

…Below average temperatures continue from Pacific Northwest to Upper Midwest through Wednesday; above average elsewhere…

…Chance for wintry weather for Northern Rockies/Plains and Upper Midwest through Wednesday…

…Fire threat returns to northern California on Tuesday…

Cool air will filter into the north and northwestern U.S. behind a pair of low pressure systems over the next couple of days. Temperatures will fall on the order of 15-25 degrees below average in some areas over the Northern Rockies/Plains and Upper Midwest through Wednesday. Temperatures are expected to remain above average across the rest of the U.S. through the short range with parts of the Southern Plains, Northern Appalachians and Northern California seeing high temperatures on the order of 15-20 degrees above average. Red Flag Warnings and Air Quality Alerts are in effect for parts of northern and central California respectively as above average temperatures, enhanced winds and abundant fuels will support elevated fire weather conditions on Tuesday, according to the Storm Prediction Center.

With air temperatures remaining below average in the Northern Rockies/Plains and the Upper Midwest over the next couple of days, the series of passing low pressure systems may produce a chance of wintry precipitation across those areas. Light high-elevation snow and low-elevation rain are possible for the Cascades on Tuesday, while the heavy snow threat exists over much of Minnesota and northwestern Wisconsin on Tuesday. There’s a higher chance for heavy snow over parts of central and western Montana on Wednesday.

A low pressure system currently extending from the Southern Plains through the Midwest and into the Northeast will lift north and east as it produces rain and scattered to isolated thunderstorms along its boundary over the next couple of days. Scattered to isolated thunderstorms are also expected for the Florida Peninsula during the short range period.

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 OR SIMPLY CLICK ON THE IMAGE.

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Day 3 – 7 Hazards

Hazards:

– Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Tennessee Valley, the Great Lakes, the Middle Mississippi Valley, the Southern Plains, and the Ohio Valley, Sun-Mon, Oct 25-Oct 26.

– Heavy rain across portions of the Southeast, the Great Lakes, and the Upper Mississippi Valley, Thu-Fri, Oct 22-Oct 23.

– Heavy rain across portions of the Northeast and the Great Lakes, Mon, Oct 26.

– Heavy snow across portions of the Northern Plains, the Northern Rockies, and the Northern Great Basin, Fri-Sat, Oct 23-Oct 24.

– Heavy snow across portions of the Central Rockies, the Central Plains, the Central Great Basin, the Northern Plains, and the Northern Rockies, Sat-Sun, Oct 24-Oct 25.

– Heavy snow across portions of the Upper Mississippi Valley and the Northern Plains, Thu, Oct 22.

– Flooding occurring or imminent across portions of the Lower Mississippi Valley.

– Much below normal temperatures across portions of the Central Plains, the Central Great Basin, the Northern Rockies, the Central Rockies, the Northern Great Basin, and the Pacific Northwest, Sun-Mon, Oct 25-Oct 26.

– Much below normal temperatures across portions of the Northern Plains, the Northern Rockies, and the Northern Great Basin, Thu-Mon, Oct 22-Oct 26.

– Much below normal temperatures across portions of the Central Plains, the Northern Plains, the Northern Rockies, the Central Rockies, the Middle Mississippi Valley, and the Upper Mississippi Valley, Fri-Mon, Oct 23-Oct 26.

– Heavy precipitation across portions of mainland Alaska and the Aleutians, Thu-Fri, Oct 22-Oct 23.

– Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Oct 25-Oct 26.

– Heavy snow across portions of mainland Alaska, Thu-Fri, Oct 22-Oct 23.

– High winds across portions of mainland Alaska and the Aleutians, Thu-Fri, Oct 22-Oct 23.

Detailed Summary:

An increasingly wintry weather pattern throughout the northern Rockies and Plains becomes the story of the medium range (Thurs. Oct 22 – Mon. Oct 26). The upper level pattern features an expansive upper level ridge over the northeast Pacific, a deep upper trough in central Canada and the north-central U.S., and upper level ridging over the northwest Atlantic. The resulting weather pattern forces a series of frigid Canadian air-masses to plunge south into the Nation’s Heartland. The northern High Plains and Rockies will be subjected to a prolonged stretch of very cold temperatures. Temperatures throughout a large portion of Montana will see daily minimum temperatures fall into the single digits. High temperature anomalies look to range between 25 to 35 degrees below normal throughout Montana and into the Dakotas. Other parts of the central High Plains and Upper Midwest can also anticipate a more winter-like temperature regime Friday and into Saturday. A second and more potent shot of colder temperatures should advance through the Northwest, northern Great Basin and into the central Plains and Upper Midwest this Sunday and into early next week. Heavy snow is also in the fold across the Upper Midwest on Thursday and in the northern Rockies and High Plains this Friday and Saturday. Snow totals may reach double digit totals in the higher elevations of the northern Rockies by this weekend.

Farther east, as upper-level troughs dig south into the North-Central U.S. this weekend, and eventually into the central Plains by early next week, unseasonably warm temperatures look to develop across the eastern third of the U.S. late week. Temperatures look to return to more seasonably levels in the Northeast by this weekend, but abnormally warm conditions look to persist in the Southeast. As a surface low responsible for the heavy snow in the Upper Midwest tracks into the northern Great Lakes on Friday, heavy rain is also anticipated in portions of these regions. Farther south, a surface trough and nearby tropical moisture may lead to heavy rainfall along portions of the central Gulf Coast. Lastly, another upper level trough swinging through the Rockies and central Plains look to bring about a new chance for heavy rainfall from the Mississippi and Ohio Valleys to the Great Lakes and interior Northeast this coming Sunday and Monday.

Over Alaska, an impressive and stout upper level low is forecast to pass over the Aleutians and occlude in the Bering Sea by the start of the weekend. This storm system is tapping into subtropical moisture and may generate anywhere from 2-3″ worth of liquid precipitation from the Upper Peninsula to Kodiak Island. Higher elevations should receive heavy snow while the primary precip type stays rain along the coast and lower elevations. Heavy snow in the mountain ranges of southwest Alaska are also likely along with strong gales that include wind gusts in excess of 60 mph along the coast. As that storm gradually weakens by the end of the weekend, a new storm system is expected to form in the Gulf of Alaska that then sends heavy precipitation into the northern Gulf Coast on south and east into the Panhandle. There is still some spread in model guidance so exact details in terms of totals and timing are still subject to change, but the setup should yield heavy coastal/valley rain and heavy mountain snow to close out the weekend and open next week.

(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 Seasonal Outlook Issued September 17, 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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