Written by Sig Silber

HEADLINES (Updated 6:07 pm EDT) –

“- There is a slight risk of severe thunderstorms and slight risk of excessive rainfall the Mid-Atlantic and Central Appalachians

– There is critical risk of wildfire over parts of the Great Basin”

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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CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 512 PM EDT Wed Jul 22 2020

Valid 00Z Thu Jul 23 2020 – 00Z Sat Jul 25 2020

…There is a slight risk of severe thunderstorms and slight risk of excessive rainfall the Mid-Atlantic and Central Appalachians…

…There is critical risk of wildfire over parts of the Great Basin…

Upper-level energy over the Mid-Atlantic and moisture rich air will aid in producing showers and thunderstorms will develop over the region. The SPC and WPC has issued a slight risk of severe thunderstorms and slight risk of excessive rainfall, respectfully, over the Mid-Atlantic area. The hazards associated with the severe thunderstorms are frequent lightning, damaging thunderstorm wind, hail and maybe a tornadoes through Thursday morning. The heavy rain associated with the thunderstorms will produce mainly localized scattered flash flooding over parts of the area. In addition the showers and thunderstorms continue over the Mid-Atlantic moving into the Carolinas by Friday and extending westward to the Ohio and Tennessee Valleys.

A disturbance over the Gulf Of Mexico will aid in triggering shows and thunderstorms over the Gulf coast States through Friday evening.

Across the western U.S., abnormally hot conditions continue over the Northern Rockies and High Plains. Meanwhile, a cold front sweeping through the Northwest delivers cooler weather to the Pacific Northwest lasting into Thursday. In addition, the SPC’s fire weather outlook includes a Critical Risk over parts of the Great Basin through Friday. The Southwest will trend slightly cooler as an upper-level trough swings through California and into the Great Basin on Thursday.

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

This loop showing the prior 40-hours provides perspective. We have not yet figured out how to make this loop update but it is still useful for a few days. An updated version and some other views can be found here.

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Day 3 – 7 Hazards

Hazards:

– Heavy rain across portions of the Central Plains, the Central Rockies, the Lower Mississippi Valley, the Central Great Basin, the Southern Rockies, the Northeast, the Southeast, the Central Appalachians, the Southern Plains, the Ohio Valley, and the Southwest, Mon-Tue, Jul 27-Jul 28.

– Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Northern Plains, the Upper Mississippi Valley, the Southern Plains, and the Southwest, Sat-Sun, Jul 25-Jul 26.

– Heavy rain across portions of the Central Plains, the Northeast, the Northern Plains, the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southern Appalachians, the Upper Mississippi Valley, the Southeast, and the Southern Plains, Wed, Jul 29.

– Flooding occurring or imminent across portions of the Central Plains and the Northern Plains.

– Excessive heat across portions of the Central Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Northern Plains, Sun, Jul 26.

– Excessive heat across portions of the Central Plains, the Upper Mississippi Valley, and the Northern Plains, Sat, Jul 25.

– Excessive heat across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, and the Ohio Valley, Mon, Jul 27.

– Excessive heat across portions of the Lower Mississippi Valley, the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southeast, and the Ohio Valley, Mon-Tue, Jul 27-Jul 28.

– Much above normal temperatures across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, the Upper Mississippi Valley, and the Northern Plains, Sat-Sun, Jul 25-Jul 26.

– Much above normal temperatures across portions of the Great Lakes, the Mid-Atlantic, the Northeast, and the Central Appalachians, Mon-Tue, Jul 27-Jul 28.

– Much above normal temperatures across portions of the Great Lakes, Sat-Mon, Jul 25-Jul 27.

– Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Sun-Tue, Jul 26-Jul 28.

– Heavy rain across portions of mainland Alaska, Mon-Tue, Jul 27-Jul 28.

Detailed Summary:

An expansive upper-level high will dominate much of the mainland U.S. through the medium range period Wednesday, July 29th as upper-level troughing tracks across from the Pacific Northwest to the North-central U.S. With this pattern in place, monsoonal moisture will transport northward through parts of the Southwest/Rockies and then curve through the Northern/Central Plains. Diurnal heating and the influx of moisture will result in localized heavy rainfall across parts of the Southwest/Southern Rockies. Across the Northern U.S., a cold front will move through and interact with the monsoonal moisture pooling over the central U.S. and trigger thunderstorms capable of producing heavy rain across parts of the Plains and Midwest. Meanwhile, showers and thunderstorms ahead of an exiting cold front should result in heavy rainfall on Friday across eastern North Carolina.

The National Hurricane Center continues to monitor the potential of a tropical cyclone forming in the Gulf to the south of the upper-level high, as the cyclone generally tracks west or west-northwest across the western Gulf Coast into southern Texas late this week into the weekend. The threat for heavy rainfall with this particular feature will increase across southern Texas/western Gulf Coast.

Although the upper-level high will expand across the eastern two-thirds of the country, the associated heat underneath the high is not expected to be too extreme, with forecast high temperatures staying below the 100 degrees through the extended period. Much above normal temperatures are expected from the Northern Plains to the Great Lakes Friday into the weekend ahead of the cold front. Increasing humidity ahead of the front will result in high heat indices during the afternoon over the northern Plains on Friday, gradually working its way southward into the lower Mississippi Valley by next Tuesday. Excessive heat have been highlighted on the Hazards map for these areas. Meanwhile, westerly winds descending from the Appalachians combining with increasing humidity will raise the likelihood of much above normal temperatures for parts of the Mid-Atlantic early next week.

Meanwhile, westerly winds descending from the Appalachians combining with increasing humidity will raise the likelihood of much above normal temperatures for parts of the Mid-Atlantic early next week.

In Alaska, a heavy rain area has been introduced for parts of the southern Interior on the 27th-28th while the heavy rain area continues for Southeastern Alaska. Some of the heavy rain could briefly spill into the southern coastal area of Alaska and then further inland across southern Alaska.

Hurricane Douglas, per the latest track from the National Hurricane Center, is forecast to clip the Big Island on Sunday. Heavy rain, strong winds, coastal flooding and storm surge may impact Hawaii this weekend and beyond.

(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

We will resume more detailed coverage when the summer is over.

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

There is not much snow left.

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Tropical Events

This is now beyond the time of the year we pay special attention to Tropical Events other than the Western Pacific.

So 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.

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

Updates on individual named storms can be obtained here.

And the Western Pacific

Week 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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