Written by Sig Silber

HEADLINES (Updated 4:25 PM and 6:10 PM EDT) –

– Heat intensifies across the Pacific Northwest while oppressive heat persists across the Northeast/Mid-Atlantic and the Mid-Mississippi Valley

– Daily rounds of strong-to-severe storms across the Great Lakes and northern Mid-Atlantic as Tropical Storm Fred is forecast to approach southern Florida late Friday

– 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 Wed Aug 11 2021

Valid 00Z Thu Aug 12 2021 – 00Z Sat Aug 14 2021

…Heat intensifies across the Pacific Northwest while oppressive heat persists across the Northeast/Mid-Atlantic and the Mid-Mississippi Valley…

…Daily rounds of strong-to-severe storms across the Great Lakes and northern Mid-Atlantic as Tropical Storm Fred is forecast to approach southern Florida late Friday…

…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 Heat Is On” for much of the U.S. mainland as a couple of strong upper-level ridges remain in firm control from coast to coast. Heat Advisories and some Excessive Heat Warnings remain in effect across much of the nation’s mid-section and into parts of the the Northeast and Mid-Atlantic. Some parts of the I-95 corridor could reach 100 degrees Thursday afternoon with oppressive heat indices ranging between 105-110 degrees.

Across the Pacific Northwest, daytime highs are forecast to soar above the century mark with high temperature departures anywhere from 15 to 25 degrees above normal. Temperatures on Thursday will even challenge some daily record highs in the Northeast and the Pacific Northwest. Speaking of records, numerous record warm lows are expected to be broken along the West Coast and east of the Mississippi River both Thursday and Friday mornings. Looking further ahead, this heat wave looks to stick around into Friday before gradually loosening its grip over these regions this weekend.

The Great Lakes are most at risk for severe storms later today as hot and humid conditions ahead of an approaching cold front sets the stage for another round of scattered thunderstorms. Damaging winds, large hail, and tornadoes could accompany any severe thunderstorms.

Meanwhile, scattered thunderstorms can be expected from the Midwest to the interior sections of the East Coast including the Northeast, as well as along the Gulf Coast and into Florida for the next couple of days. Most shower and thunderstorm activity will develop in the afternoon and linger into the evening hours each day. Some of these thunderstorms may contain heavy downpours that could result in localized flash flooding.

Elsewhere, wildfire smoke continues to plague parts of the West Coast, the Intermountain West, and High Plains with poor air quality through Wednesday. Also, monsoon showers and thunderstorms will be a daily occurrence in the Desert Southwest, helping to keep the heat at bay. That said, some areas of flash flooding are possible as well.

Farther north, temperatures in the northern Plains will remain below normal with multiple passages of dry cold fronts over the next couple days.

Lastly, eyes are turning to the tropics as Tropical Storm Fred is forecast to approach southern Florida from Cuba later on Friday. Some squalls associated with the outer rainbands of Fred could begin to impact southern Florida on Friday as heavy downpours become more frequent and winds become increasingly gusty later on Friday. Please visit the National Hurricane Center homepage for the latest forecast information on Tropical Storm Fred.

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 Saturday August 14 2021 – Wednesday August 18 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 Southern Appalachians, the Mid-Atlantic, and the Central Appalachians, Sat-Wed, Aug 14-Aug 18.

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

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

– Flooding occurring or imminent across portions of the Southeast.

– Flooding likely across portions of the Southeast.

– Excessive heat across portions of the Pacific Northwest, the Northern Rockies, and the Northern Great Basin, Sat, Aug 14.

– Excessive heat across portions of the Northern Plains, Sun, Aug 15.

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

– Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Tue-Wed, Aug 17-Aug 18.

Detailed Summary:

The medium range forecast period (August 14th to 18th) features an active period of late Summer hazards, including excessive heat in the West, monsoon activity in the Southwest, and heavy rain in the Southeast/Mid-Atlantic associated with Tropical Storm Fred. Over this weekend, a deep upper-trough centered over the Great Lakes will lift northeast, while a similarly amplified trough migrates over the Pacific Northwest and weakens the strong ridge centered around the Four Corners. At the surface, the main players include a cold front forecast to stall across the Mid-Atlantic/Southeast by the end of the weekend, and a progressive cold front moving through the West beginning next early week. To the south, Tropical Storm Fred is expected to impact Florida over the weekend, and parts of the Southeast/Mid-Atlantic by early next week.

Beginning Saturday, heavy rain is expected to envelop portions of the Mid-Atlantic and Florida. Over the northern heavy rain area, an initial round of thunderstorms packing intense rainfall rates are expected as the cold front associated with the Great Lakes trough interacts with a moist and unstable pre-frontal airmass. By the end of the weekend, the front is forecast to stall across the southern Mid-Atlantic/Southeast and spark additional thunderstorm development. While storms focus along the front to the north, Tropical Storm Fred should move into the Florida Keys by Saturday before turning north through the eastern Gulf of Mexico, producing heavy rain over Florida over the weekend.

By Monday, Fred is expected to cross the Peninsula inland to the Southeast, pulling an influx of tropical moisture north as it weakens. However, the heavy rain threat will continue through at least midweek as tropical moisture surges north of the remnants of Fred and interacts with the stalled Mid-Atlantic/Southeast front. Moreover, a potential track for Fred along the eastern spine of the Appalachians could further enhance rainfall efficiency via orographic lift. All this being said, uncertainty remains regarding the track/timing details of Fred (and associated heavy rain); users are highly encouraged to monitor the latest NHC forecast information as the event draws near.

Over the Southwest, the forecast remains on track for an uptick in monsoonal activity as above average precipitable water values surge into the region. The most active monsoon conditions are expected to abate beyond the 17th, although showers and thunderstorms below hazard levels tied to a weak upper low are likely. To the north in Montana, a progressive sweeping cold front will kick off showers and thunderstorms beginning Monday, although at this time the rainfall amounts do not appear to reach hazard levels. In fact, the activity will be beneficial in mitigating the ongoing drought over the region.

Triple digit excessive heat is anticipated to linger for one more day over areas east of the Cascades on Saturday before the brutal heat relaxes by the end of the weekend with the arrival of the cold front. Before the relief arrives, however, heat indices ranging from 100-105 on Saturday support a very high heat risk to those outside. Accordingly, Excessive Heat Warnings cover the region until Saturday evening. Fortunately, post-frontal temperatures should be pleasant as cooler air moves in behind the front, and high temperatures 5-10 degrees below average are forecast by Tuesday.

Ahead of the front in the Northern Plains, another shot of excessive heat is likely on Sunday beneath upper-level height rises forecast east of the Rockies. High temperatures 10-15 degrees above average are possible, with 100 degree heat indices before temperatures begin to moderate by Monday as the front approaches. Pleasant continental air behind the front, alongside clouds and precipitation provide refreshing temperatures beyond Monday, as temperatures 10-15 degrees below average are anticipated.

For Alaska, another chance of heavy rain will overspread West-Central Alaska from Sunday-Monday as a frontal complex approaches. Much of Alaska is anticipated to persist in a wet period through next week, although the next risk of hazardous heavy rain is apparent from the 17th-18th from the East Kenai Peninsula to the Inside Passage. Ensemble guidance maintains reasonable agreement for higher rainfall totals there ahead of an approaching atmospheric river.

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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