Written by Sig Silber

HEADLINES (Updated 4:22 pm EDT) –

– Winter weather in Upper Midwest tonight, then across Pacific Northwest/Northern Rockies into weekend; rain and thunderstorms across Mississippi/Tennessee/Ohio Valleys

– There is a Slight Risk of severe thunderstorms over the Middle/Upper Mississippi Valley; there is a Slight Risk of excessive rainfall over parts of the Upper Midwest/Great Lakes

– Cold air dives south through Plains while warm air lingers in the East

– Critical Fire Risk will be over parts of Northern California and over Southern Rockies/High Plains

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 – 407 PM EDT Thu Oct 22 2020

Valid 00Z Fri Oct 23 2020 – 00Z Sun Oct 25 2020

…Winter weather in Upper Midwest tonight, then across Pacific Northwest/Northern Rockies into weekend; rain and thunderstorms across Mississippi/Tennessee/Ohio Valleys…

…There is a Slight Risk of severe thunderstorms over the Middle/Upper Mississippi Valley; there is a Slight Risk of excessive rainfall over parts of the Upper Midwest/Great Lakes…

…Cold air dives south through Plains while warm air lingers in the East...

…Critical Fire Risk will be over parts of Northern California and over Southern Rockies/High Plains…

An area of low pressure, currently traversing the Mississippi Valley, will be the impetus for rain and thunderstorms over points east of the Mississippi River through the beginning of the weekend. This low pressure system will produce potentially heavy snowfall in its cold sector over the Upper Midwest tonight. Winter Storm Warnings and Advisories are in effect for the Northern Plains and Upper Midwest. This system will also generate potentially heavy rainfall leading to a Slight Risk of flash flooding over eastern Iowa and into Lake Michigan, as well as a Slight Risk of severe thunderstorms over the Middle-Upper Mississippi Valleys tonight. Winter weather will end over the Upper Midwest tomorrow morning, while rain and thunderstorms will continue across the Mississippi, Tennessee and Ohio Valleys before losing much of its moisture component Friday night. Record warmth is forecast for tonight as the rising warm front keeps low temperatures in the 50s and 60s across parts of the Lower Mississippi Valley, Midwest and Northeast.

High pressure will continue to build steadily over the Northern Rockies and Great Plains behind the aforementioned low pressures system this weekend. This will drive cold continental Canadian air down into the Plains over the next couple of days. High temperatures will be between 15-20 degrees below average for much of the Plains and Northern Rockies with some isolated areas seeing temperatures fall to 25-30 degrees below average over this period.

Another potent disturbance will enter the Pacific Northwest tonight producing low-elevation rain and high-elevation snow to the Cascades and Northern Rockies tomorrow and Saturday. Another strong area of high pressure is likely to build in behind this system into the beginning of next week, bringing with it, once again, the chance for much below average temperatures to the Plains.

The threat for fire weather continues across northern California and the Southern Plains tonight as warm, dry and/or gusty conditions contribute to the Critical Risks in those areas. An elevated risk of fire weather lingers over northern California tomorrow.

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

Valid Sunday October 25 2020 – Thursday October 29 2020

Hazards:

– Heavy precipitation across portions of the Southern Rockies, the Central Plains, and the Southern Plains, Mon-Wed, Oct 26-Oct 28.

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

– Heavy rain across portions of the Central Plains, the Middle Mississippi Valley, the Lower Mississippi Valley, and the Southern Plains, Tue-Wed, Oct 27-Oct 28.

– Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, and the Ohio Valley, Thu, Oct 29.- Heavy snow across portions of the Central Rockies, the Central Plains, the Central Great Basin, and the Southwest, Sun-Mon, Oct 25-Oct 26.

– Heavy snow across portions of the Central Plains, the Central Rockies, the Central Great Basin, the Southern Rockies, the Southern Plains, and the Southwest, Mon-Wed, Oct 26-Oct 28.

– Flooding occurring or imminent across portions of the Southeast.

– Flooding likely across portions of the Southwest.

– High winds across portions of the Central Great Basin and California, Sun-Mon, Oct 25-Oct 26.

– Much below normal temperatures across portions of the Central Plains, the Central Great Basin, the Northern Plains, the Northern Rockies, the Central Rockies, California, the Northern Great Basin, the Upper Mississippi Valley, and the Pacific Northwest, Sun-Wed, Oct 25-Oct 28.

– Much below normal temperatures across portions of the Central Rockies, the Central Great Basin, the Southern Rockies, California, the Southern Plains, and the Southwest, Mon-Wed, Oct 26-Oct 28.

– Much below normal temperatures across portions of the Central Plains, the Central Rockies, the Lower Mississippi Valley, the Great Lakes, the Southern Rockies, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Southern Plains, Mon-Thu, Oct 26-Oct 29.

– Much below normal temperatures across portions of the Central Plains, the Northern Plains, the Great Lakes, the Central Rockies, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Southern Plains, Sun-Thu, Oct 25-Oct 29.

– Enhanced wildfire risk across portions of California, Sun, Oct 25.

– Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Oct 25-Oct 26 and lower Alaskan Panhandle, Sun-Thu, Oct 25-Oct 29.

Detailed Summary:

An Arctic outbreak is set to plunge much of the west-central U.S. into a wintry like pattern this weekend and into the first half of the upcoming week. An impressive upper trough will dig south across the Intermountain West eventually reaching the Southwest next Monday and Tuesday. An injection of frigid temperatures will overtake the Northwest, the Rockies, and the Great Plains this weekend and the first half of next week. Much below normal temperatures will also spread into the Midwest Latest NDFD forecast suggests numerous daily record cold max/min temperatures may be broken. Sub-zero temperatures are a good bet across the northern Rockies and High Plains where bitterly cold wind chills of -10 to -20 degrees are possible. The coldest temperatures are likely to occur where fresh and deep snow pack is present. Speaking of which, a late October snow storm looks to blanket much of the Intermountain West, including low lying valleys, in snow with the higher elevations most at risk for significant snow accumulations. Expect numerous travel delays in these areas which combined with gusty winds may lead to near whiteout conditions Sunday and into Monday.

How long the snow threat last in the Four Corners region next week is dependent upon what happens when the jet stream pattern lifts north and an intense ridge builds over the Northwest. This should force a cut-off upper low to take shape and keep mountain snow and inclement weather in the forecast through mid-week. A heavy precipitation area has been introduced to parts of the southern High Plains as there could be a series of potential scenarios. The first is the free-falling temperatures and over-running of southwest flow aloft may support heavy wintry precipitation across eastern New Mexico, western Oklahoma, and the Texas Panhandle. Should the low remain slower though, the threat for heavy rain and thunderstorms, or a heavy wintry mix in some cases, could transpire instead. Either way, the opportunity is there for disruptive precipitation amounts. Farther west in California, as the base of the trough swings through the Great Basin on Sunday, intense low-mid level winds will be embedded within the base and the backside of the upper trough. Combined with a very strong surface high pressure diving south over the Northwest, this may generate high winds in the northern Sierra Nevada and potential for downsloping winds in the Sacramento Valley. As a result, High Winds and Fire Weather hazards are in place. It is possible for favorable fire weather conditions in parts of central and southern California late Sunday and into Monday as well.

In the East, upper level ridging over the Southeast is likely to keep most of the region (as well as the Mid-Atlantic) under the influence of a persistent above normal temperature regime. Sunday looks to be a brief break in the abnormally warm temperatures in the norther Mid-Atlantic, but a warm-up arrives quickly on Monday as a low pressure system tracks into the eastern Great Lakes and a warm front tracks through northern New England. Some rain and mountain snow is possible in across northern New England on Monday, but the primary precipitation type ahead of an approaching cold front from the mid-Mississippi Valley to the Ohio Valley and northern Mid-Atlantic. As the upper low in the Southwest gradually advances east into the South Central U.S. around mid-week, rich moisture from the Gulf of Mexico should stream north from Texas to the Lower Mississippi Valley. This could lead to a threat for excessive rainfall and some severe storms in parts of these regions. Timing and totals are still subject to change in the days 6-7 time frame due to the lower confidence in when the upper trough exits the Four Corners region and how slowly it progresses through the southern Plains.

Across Alaska, an area of low pressure in the Gulf of Mexico will head towards the southeast mainland and be preceded by a southwesterly flow of very moist Pacific air. Expect heavy precipitation from southeastern portions of the mainland (Prince William Sound eastward) through Yakutat starting late in the weekend and continuing through Monday. The heaviest precipitation will then spread southward across nearly the entire Panhandle during Monday into Tuesday. Heaviest rainfall will generally be along the coast, with snow over higher elevations. A second round of heavy precipitation is possible across the Panhandle towards mid-late week as there may be another storm system that takes aim at the region.

(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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