Written by Sig Silber

HEADLINES (Updated 3:51 PM EDT) –

– Heavy rain and severe thunderstorms possible across the central and southern Plains through at least Monday

– Critical Risk of fire weather over parts of the Great Basin/Southwest through Sunday morning

– Heavy rain and flooding possible next week for the Midwest, Mississippi Valley, the Plains, and some other areas farther west.

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.

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 333 PM EDT Sat May 15 2021
Valid 00Z Sun May 16 2021 – 00Z Tue May 18 2021
…Heavy rain and severe thunderstorms possible across the central and southern Plains through at least Monday…
…There is a Critical Risk of fire weather over parts of the central Great Basin/Southwest through Sunday morning…
A wet and active weather pattern will persist across central and south-central sections of the country through early next week. A stationary boundary extending from the central Rockies through the central Plains and into the Ohio/Tennessee valleys will be the focus for multiple rounds of showers and thunderstorms. This evening and overnight, a few thunderstorms may turn severe across the central and southern High Plains. Damaging wind gusts and large hail are the main concern, with isolated tornadoes possible throughout the central High Plains and southwest Texas. Downpours could lead to isolated flash flooding across central and eastern Kansas, as well as south-central Texas tonight. Sunday and Monday will feature similar weather hazards across the same region.
The Storm Prediction Center has issued a Slight Risk of severe weather on both Sunday and Monday that includes portions of the central High Plains and southern Plains. With the ongoing thunderstorms, flash flooding will remain a possibility across these regions while also extending into the Middle Mississippi Valley as well. WPC has issued a Slight Risk of Excessive Rainfall for Sunday that stretches from central Missouri to north-central Texas.
Elsewhere, scattered showers and thunderstorms will also be found across southern Florida, the Ohio Valley, Mid-Atlantic, and Northeast between tonight and Monday.
High temperatures are forecast to run well above normal across the Northern Plains, Upper Midwest, and northern Great Basin. Highs into the upper-70s and 80s will make it feel more like June and potentially worsen extreme drought conditions throughout in the Northern Plains.
Meanwhile, gusty winds and low relative humidity will create critical fire weather this evening across southern Nevada, southwest Utah, and northwest Arizona. Red Flag Warnings have also been issued for this area.

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.

Or for the Day 2 Fire Outlook click here. For the Day 3 – 8 Fire Outlook click here.

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 Monday May 17 2021 – Friday May 21 2021
Hazards:
– Heavy rain across portions of the Lower/Middle Mississippi Valley into the Midwest, Mon, May 17.
– Heavy rain across portions of the central/southern Plains into the Lower/Middle Mississippi Valley, Mon-Wed, May 17-May 19.
– Heavy rain across portions of the Lower Mississippi Valley and the Southern Plains, Tue-Fri, May 18-May 21.
– Flooding possible across portions of the Central Plains and the Northern Great Basin.
– Flooding occurring or imminent across portions of the Lower Mississippi Valley.
– Much above normal temperatures across portions of the Northern High Plains to the Upper Mississippi Valley, Mon-Tue, May 17-May 18.
Detailed Summary:
The main weather hazard during the medium-range forecast period (Monday, May 17 – Friday, May 21) will be heavy rainfall from the southern Plains to parts of the lower Mississippi Valley and the Midwest. This is in response to very moist return flow out of the Gulf of Mexico ahead of an initial southern Plains upper low then western U.S. mean troughing along with a quasi-stationary surface boundary draped from the Midwest to the Plains through next week. With this setup, a multi-day period of heavy to possibly significant rainfall (and some threat of strong to severe thunderstorms) is expected. At this time, the best chance for heavy rainfall should focus along the surface front from Oklahoma into the Midwest on Monday.
By Tuesday and beyond, the main activity may shift more west and south into central and eastern Texas, Oklahoma, and parts of the lower Mississippi Valley. Exact locations and magnitude of heaviest rainfall will likely vary on a day-to-day basis with specific details hard to resolve at these longer lead times.
Regardless, models have been consistent in showing a signal for a very wet pattern for parts of the southern and central U.S. over a region which is already very saturated due to well above normal precipitation in the past several weeks. This may increase the flood and flash flood threat for some locations.
Elsewhere, a small heavy rain area across parts of eastern Colorado was added today to the outlook due to upslope flow into the Colorado Rockies and a somewhat marginal threat for heavy to excessive rainfall. Given WPC does not issue this medium range hazards outlook over the weekend, felt an area was warranted for Monday even though there is some looming uncertainties in this.
In Florida, increased moisture across southern parts of the Sunshine state may support some organized heavy rainfall later next week but uncertainty in amounts and location was too high at this time to include an outlook area.
In terms of temperatures across the CONUS, the only notable region was an area of much above normal temperatures stretching across parts of the far northern tier and so an area was added to the graphic today given the potential for +10-20F temperatures early next week ahead of a Pacific cold front.
For Alaska, much of the area should remain relatively quiet through the greater part of next week. A potent storm system may impact the Aleutians on Tuesday and Wednesday, but models continue to show uncertainty in the details so any potential hazards associated with this system (particularly for rainfall) were kept off the map at this time. Thursday, but confidence is fairly low at the moment.
Temperatures across CONUS will start below average throughout the Southeast on Sunday before warming to near normal by the beginning of next week. Meanwhile, high temperatures will reach upwards of 10 to 20 degrees above average from the Northwest to the Northern Plains through Tuesday/Wednesday until a cold front slowly sweeps through the Intermountain West. Little to no precipitation is expected across the West outside of the Cascade and Olympic Mountains.
For Alaska, much of the area should remain relatively quiet through the greater part of next week. A potent storm system may impact the Aleutians on Tuesday and Wednesday, but wind gusts at the moment appear to remain below hazardous threshold. There is also a signal for heavy precipitation to enter coastal sections of the Gulf of Alaska on Thursday, but confidence is fairly low at the moment.

(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 (or maps) weekly (or more often when the situation is changing rapidly) 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.

The University of Nebraska Lincoln seems to have some computer problems. As of this morning, it appears that the two maps I am showing are correct.

More information can be found here. Normally the map in the upper left at this site is the two maps I normally show. You have to toggle between the current situation and the one-week change. That seems to be working now at the alternative site. I think the University of Nebraska – Lincoln will be working soon. But for those who want that information now, it is available at the alternative site that I have provided. But I think that what we show in the article is correct…but I am not positive about it. No date is shown so it may not be current as I think it is.

May Drought Outlook.

Seasonal Outlook Issued April 15, 2021

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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. Sorry for any confusion but the NHC maps do not update during the Winter except if there is activity. We leave them in simply because if there is a storm NOAA will start to update the relevant map even though it is not normally updated during the off season. The maps are a bit small but if you click the map you can see the date and time when it was updated.

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

Atlantic and Gulf of Mexico

Nothing to report

The Eastern Pacific

The Central Pacific

Updates on individual named storms can be obtained here.

And the Western Pacific

Weekly Tropical Forecast

This graphic updates on Tuesdays

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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

For those interested in more detail, there are additional weather maps and information in the MORE WEATHER Addendum. The link to the Addendum is here.

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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.

For the Day 2 Outlook click here. For Day 3, click here. For Days 4 – 8 click here. An explanation of the risk codes used can be found 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.

Or for the Day 2 Fire Outlook click here. For the Day 3 – 8 Fire Outlook click here.

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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.

In and of itself Atmospheric Rivers are not a definitive predictor of extreme weather but it shows where concentrated “rivers” of moist air are forecast to be impacting North America and that is part of the equation for severe weather.

This view provides a better view of the Northeast, the Antilles and also Europe.

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.

The above is the day by day projected pattern of highs and lows for Day 3 through 7. Earlier we show the pattern for Days 1 and 2.

Here are the precipitation forecasts. First the cumulative for Days 1 – 3

Then cumulative for Days 1 – 5

This represents five days of precipitation rather than three days as shown in the earlier graphic.

Then cumulative for Days 1 – 7

The areas that have cumulative seven-day precipitation increase. You can see where QPF is accumulating.

Now we look at the forecast for the Maximum Temperature three days out.

Looking ahead to next week.

Usually, nothing shows in this graphic for the following week as it is usually too far out to be forecasting severe weather. But this experimental graphic auto-updates. And further information is available here.

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Additional Tools to Obtain Watches and Warnings

Current watches, warnings, and advisories issued by the agencies of the National Weather Service. Hazards should show up in the various maps but the below links will take you to all outstanding watches and warnings in each category which may include some categories not covered in the various maps or difficult to find. So if there is a category of interest, click on the appropriate link below.

Winter Storm Warning
High Wind Warning
Storm Warning
Avalanche Warning
Coastal Flood Warning
Flood Warning
High Surf Warning
Flash Flood Watch
Gale Warning
Winter Weather Advisory
Flood Advisory
Coastal Flood Advisory
High Surf Advisory
Heavy Freezing Spray Warning
Dense Fog Advisory
Small Craft Advisory For Hazardous Seas
Small Craft Advisory For Rough Bar
Small Craft Advisory
Brisk Wind Advisory
Hazardous Seas Warning
Lake Wind Advisory
Wind Advisory
Rip Current Statement
Gale Watch
Winter Storm Watch
Flood Watch
High Wind Watch
Special Weather Statement
Air Quality Alert
Hydrologic Outlook

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.

Convective Outlooks
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.
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