Written by Sig Silber

HEADLINES (Updated 5:25 PM EDT) –

– Strong to severe thunderstorms possible into Wednesday across parts of the upper Midwest to the lower Great Lakes

– Heat intensifies across the Pacific Northwest while sultry conditions persist across the Northeast/Mid-Atlantic and the mid-section of the country

– Poor air quality due to wildfire smoke continues in the western and central U.S., monsoon showers and storms to drench parts of the Southwest

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

400 PM EDT Tue Aug 10 2021

Valid 00Z Wed Aug 11 2021 – 00Z Fri Aug 13 2021

…Strong to severe thunderstorms possible into Wednesday across parts of the upper Midwest to the lower Great Lakes…

…Heat intensifies across the Pacific Northwest while sultry conditions persist across the Northeast/Mid-Atlantic and the mid-section of the country…

…Poor air quality due to wildfire smoke continues in the western and central U.S., monsoon showers and storms to drench parts of the Southwest…

The upper Midwest into the lower Great Lakes will remain the prime spot for more episodes of severe weather through tonight and later on Wednesday as multiple upper-level disturbances attempt to converge along a nearly stationary front in the vicinity. Damaging winds, large hail, and tornadoes could accompany these thunderstorms.

Meanwhile, scattered thunderstorms can be expected from the Midwest to the interior sections of the East Coast including New England, as well as along the Gulf Coast and into Florida for the next couple of days, especially during the afternoon into the evening. Some of these thunderstorms may contain heavy downpours that could result in localized flooding issues.

Much of U.S. mainland will remain under the grip of abnormally hot conditions through mid-week. Heat Advisories and some excessive heat warnings have been issued across much of the mid-section of the country and into parts of the the Northeast and Mid-Atlantic.

Across the Pacific Northwest, the heat is expected to intensify over the next few days as afternoon temperatures are forecast to soar above the century mark toward 110 degree at some locations across the interior section. Daytime lows will be quite warm along the West Coast and east of the Mississippi River where numerous record warm minimum temperatures are possible on Wednesday and Thursday mornings. Looking further ahead, this heat wave is expected to peak during the second half of the week.

Elsewhere, the evolving upper level pattern will favor wildfire smoke from the western U.S. to advance downstream into the central Plains and Midwest, resulting in reduced air quality through today. Smoke refuses to let up from northern California to the central Rockies and High Plains through mid-week. Also, monsoon showers and thunderstorms will be a daily occurrence in the Desert Southwest while keeping the heat at bay. In contrast, temperatures in the northern Plains will remain below normal with multiple passages of dry fronts over the next few days.

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 40 hour animation and some other views can be found here

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Day 3 – 7 Hazards

Valid Friday August 13 2021 – Tuesday August 17 2021

Hazards:

– Heavy rain across portions of the Southeast, the Southern Appalachians, the Mid-Atlantic, the Central Appalachians, and the Tennessee Valley, Sun-Tue, Aug 15-Aug 17.

– Heavy rain across portions of the Southeast, Sat-Sun, Aug 14-Aug 15.

– Heavy rain across portions of the Southwest, Sat-Tue, Aug 14-Aug 17.

– Severe weather across portions of the Great Lakes, the Mid-Atlantic, the Northeast, the Central Appalachians, and the Ohio Valley, Fri, Aug 13.

– Flooding possible across portions of the Central Plains and the Southeast.

– Flooding possible across portions of the Southeast.

– Flooding occurring or imminent across portions of the Southeast.

– Flooding likely across portions of the Southeast.

– Excessive heat across portions of California, the Central Great Basin, the Pacific Northwest, the Northern Rockies, and the Northern Great Basin, Fri-Sun, Aug 13-Aug 15.

– Excessive heat across portions of the Mid-Atlantic, the Lower Mississippi Valley, the Central Appalachians, the Tennessee Valley, the Middle Mississippi Valley, the Northeast, the Southern Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, Fri, Aug 13.

– Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Fri, Aug 13.

– Heavy rain across portions of mainland Alaska, Sun-Mon, Aug 15-Aug 16.

Detailed Summary:

The medium range forecast period (August 13th to 17th) is characterized by an active period of late-Summer hazards around the U.S.: heavy rain, dangerous heat, tropical activity, and severe weather. The general pattern to begin the weekend will feature a deep upper-level trough swinging through the North-Central U.S., flanked by ridging over the Mid-Atlantic and Great Basin. By early next week, the pattern is forecast to shift with the western ridge weakening in response to height falls associated with troughing over the western and central sections of the country. At the surface, the main features will be a refreshing cold front forecast to push from the Midwest and Central Plains towards the East Coast before stalling over the Southeast and Deep South, as well as Potential Tropical Cyclone Six currently located South of Puerto Rico.

On Friday, the aforementioned cold front is forecast to extend across the Great Lakes into the Central Plains and focus thunderstorm development as it interacts with a moist, unstable airmass. Accordingly, moderate to locally heavy rainfall is likely across the Northeast into the Ohio Valley, although confidence in widespread heavy rain is low. However, the Storm Prediction Center has highlighted a chance of severe weather on Friday across the Northeast and Ohio Valley, primarily for locally strong to severe wind gusts with storms that develop along and ahead of the front. As the cold front nears the Mid-Atlantic Saturday, it will spur more thunderstorms capable of packing intense rainfall rates before stalling across the Mid-Atlantic and Southeast on Sunday.

Meanwhile, the current forecast track of Potential Tropical Cyclone Six suggests heavy rain impacting Florida beginning Saturday, before spreading north toward the Peninsula by Sunday. As Six moves inland early next week, heavy rain chances overspread the Southeast as tropical moisture feeds inland and interacts with the stalled front. However, a fair amount of uncertainty remains regarding the track and timing of Six as it nears the coast, in part due to forecast upper-troughing over the Southern Plains on days 5-6. Users are encouraged to monitor the latest forecast track and intensity information from the National Hurricane Center as Six approaches the U.S.

In the Southwest, an uptick in monsoon activity is expected across parts of Arizona and southwest New Mexico this weekend into early next week. Total precipitable water amounts near 2 inches are possible and would produce a ripe environment for scattered thunderstorms and heavy rainfall. The Heavy Rain area over the Southwest was extended until the Tuesday given the consensus for continued monsoon activity in the region.

Another hazard to contend with for certain parts of the country will be excessive heat. Once again, an anomalous upper-level ridge over the Pacific Northwest will produce a scorching heat wave between Friday and Sunday. Highs into the upper 90s and low triple digits will impact highly populated regions east of the Cascade mountains through Saturday, as well as the interior Northwest through the end of the weekend. The mid-August heat will also be felt farther south into northern California and Nevada. Temperatures are expected to reach upwards of 20 degrees above average and break several daily high temperature records. The good news is that this heat wave is expected to relax by early next week as above average temperatures shift into the northern High Plains.

For the Mid/Deep South, lingering hot weather and oppressive humidity is forecast on Friday before a cold front brings much-needed relief. Heat indices should exceed 100 degrees both days and approach 100-105 during the peak heating hours of the afternoon. These high heat indices may continue across the Gulf Coast through Saturday, but temperatures are currently forecast to remain close to average. Last, but certainty not least, excessive heat remains a concern throughout the densely populated Mid-Atlantic and Northeast between Richmond, VA and Portland, ME on Friday. Heat indices are expected to reach near 105 degrees, with low temperatures only dipping into the mid-70s.

For Alaska, heavy rain associated with a potent atmospheric river event is anticipated to end the week over parts of the southeast mainland and northern panhandle. An impressive surge of moisture that reaches southwest toward ongoing typhoon activity in the west-central Pacific could lead to multiple inches of rain across both coastal and mountainous regions. Another chance of heavy rain will overspread West-Central Alaska beginning Sunday as a frontal complex approaches. The Heavy Rain area may need extended further north in subsequent updates, but have kept the area relatively confined given uncertainty regarding the northern extent of higher rainfall totals.

For Alaska, heavy rain associated with a potent atmospheric river event is anticipated to end the week over parts of the southeast mainland and northern panhandle. An impressive surge of moisture that reaches southwest toward ongoing typhoon activity in the west-central Pacific could lead to multiple inches of rain across both coastal and mountainous regions. Upwards of 8 to 10 inches of rain is a possibility near and surrounding Yakutat, Alaska.

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 snow coverage in the Fall

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Drought Coverage

We include drought information in this section.

More information can be found here.

August Drought Outlook.

Seasonal Outlook Issued July 15, 2021

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Tropical Events

Atlantic and Gulf of Mexico

The Eastern Pacific

The Central 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

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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