Written by Sig Silber

HEADLINES (Updated 5:55 PM EDT) –

– Tropical Storm Fred to bring heavy rain, gusty winds, and dangerous storm surge to portions of the Florida Panhandle this evening

– Heavy rainfall and flash flooding are expected along a slow-moving frontal system over the eastern Ohio Valley, Appalachians, and the Mid-Atlantic this evening before moisture associated with Fred enters the region on Tuesday

– Oppressive heat, poor air quality, and fire weather concerns continue for parts of the West and Northern Plains ahead of a potent cold front set to swing across the Northwest and Northern Rockies 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.

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CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD

319 PM EDT Mon Aug 16 2021

Valid 00Z Tue Aug 17 2021 – 00Z Thu Aug 19 2021

…Tropical Storm Fred to bring heavy rain, gusty winds, and dangerous storm surge to portions of the Florida Panhandle this evening…

…Heavy rainfall and flash flooding are expected along a slow-moving frontal system over the eastern Ohio Valley, Appalachians, and the Mid-Atlantic this evening before moisture associated with Fred enters the region on Tuesday…

…Oppressive heat, poor air quality, and fire weather concerns continue for parts of the West and Northern Plains ahead of a potent cold front set to swing across the Northwest and Northern Rockies on Tuesday…

Tropical Storm Fred is forecast to continue tracking northward and push inland across the western/central Florida Panhandle tonight and eventually into the Southeast. Heavy rainfall and gusty winds can be expected along its track, as well as potentially dangerous storm surge for coastal regions near and to the east of the center of Fred. Flash flooding is a threat with the heavy rain, with a Moderate Risk of excessive rainfall in effect for portions of the Florida Panhandle and southeastern Alabama/southwestern Georgia tonight and a Slight Risk stretching farther inland. Flash Flood Watches have also been issued. Trailing bands of rain could affect the Florida Big Bend again on Tuesday and cause flash flooding issues, even after Fred’s center has moved north. Tropical Storm Fred is currently forecast to weaken into a tropical depression by Tuesday morning and dissipate by Wednesday morning over the eastern Ohio Valley.

As tropical moisture from Fred streams northward, it will feed into a frontal system lifting slowly northward across the Ohio Valley and Mid-Atlantic. While much of the eastern third of the U.S. should see rain and thunderstorms through midweek, the front will provide an additional place for the moisture to focus, enhancing rainfall totals and the possibility of flash flooding. A Slight Risk of excessive rainfall is in place through tonight from eastern portions of the Ohio Valley through the Central Appalachians and portions of the Mid-Atlantic, where scattered flash floods are possible.

Then on Tuesday, as Fred moves farther inland along with its associated moisture plume, a large Slight Risk of excessive rainfall stretches from the Southeast to New York State. In addition, a small Moderate Risk area is delineated for parts of the Southern Appalachians Tuesday into Tuesday night, as several inches of rain could occur in mountainous areas that are particularly sensitive to heavy rainfall.

Another day of heavy rain is possible on Wednesday from the Mid-Atlantic to the Southern Appalachians as the tropical airmass in place refuses to exit. Another day of hotter than normal temperatures is forecast for much of the West into the Northern Plains today. Highs topping 100F across much of California, the Central Great Basin, and into the Northern High Plains have led to the issuance of Excessive Heat Warnings and Heat Advisories for portions of these areas, and some daily records have the potential to be set once again. The heat will not be the only threat for these areas, as Elevated to Critical Risks of fire weather are in place today and Tuesday, along with the potential for additional fire ignitions from dry thunderstorms. Air quality is already an issue over much of the Northwest given smoke from fires and high ozone levels.

However, cooler temperatures creeping into the Pacific Northwest tonight is a sign of what is to come on Tuesday and Wednesday–a potent cold front pushed by an upper-level low that will bring cooler and refreshing air to the Northwest, as well as increasing rain chances especially for the Northern Rockies on Tuesday. Meanwhile farther south, cooler temperatures are expected over portions of the Southwest into the Southern High Plains, along with the chance for rain and thunderstorms as monsoonal moisture continues to stream into the region. Flash floods are possible over the next couple days, with Flash Flood Watches remaining in effect today over southern Arizona and New Mexico, as well as into far western Texas. A few strong to severe thunderstorms are also possible. Meanwhile, above average temperatures with highs into the upper-90s and low triple digits are expected to remain across the Northern Plains and Upper Midwest through at least Wednesday.

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 Thursday August 19 2021 – Monday August 23 2021

Hazards:
– Heavy rain across portions of the Upper Mississippi Valley and the Northern Plains, Fri, Aug 20.

– Heavy rain across portions of the Mid-Atlantic and the Northeast, Thu, Aug 19.

– Flooding occurring or imminent across portions of the Southeast.

Detailed Summary:

Tropical moisture pooling along a trough and front will aid in producing heavy rain over parts of the northern Mid-Atlantic into parts of Southern New England on Thursday. A second front over the Northern Plains will be quasi-stationary over the region on Thursday and Friday before moving eastward on Saturday. There is a lot of uncertainty associated with this system. Some of the models show more significant areas of rain; however, others show less. The stationary front over a region for a day or two suggests heavy rain along and near the boundary. At this time, the confidence in an area of heavy rain is low; therefore, a smaller region of heavy rain is depicted on the Hazards Chart for Friday. Nevertheless, the heavy rain could extend as far south as Nebraska and develop on Thursday, too.

The excessive heat over the country will get a break as a deep upper-level trough is over the West that only starts to weaken on Monday. As a result, below-normal temperatures will be over the West through Saturday. However, that is not seen as a hazard at this time of the year but more as relief from the heat. The temperatures over the East will be close to normal.

For Alaska, the upper-level pattern will be dominated by troughing, which will be conducive to wet weather. At the surface, low pressure and a front will be across the Bering Sea into the Interior of Alaska, then into Canada that will move into Canada by Saturday. Another front, along the Gulf of Alaska Coast, moves towards the Panhandle by Friday. The systems will produce rain over parts of the state through Monday. Yet, the precipitation totals will not reach the criteria for a hazard for this time of year. There is some uncertainty for heavy rain along the Gulf Coast, with the ECMWF being the most robust with the precipitation totals.

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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