Written by Sig Silber

HEADLINES (Updated 6:37 PM EDT) –

– Continuing rounds of showers and thunderstorms found across the Great Plains and Midwest before spreading into the Northeast on Wednesday

– Record heat forecast across the Mid-Atlantic States by midweek

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 350 PM EDT Mon May 24 2021

Valid 00Z Tue May 25 2021 – 00Z Thu May 27 2021

…Continuing rounds of showers and thunderstorms found across the Great Plains and Midwest before spreading into the Northeast on Wednesday…

…Record heat forecast across the Mid-Atlantic States by midweek…

Potentially hazardous weather will continue to be found across the central U.S. over the next few days as ample moisture continues to stream northward out of the western Gulf of Mexico. A potent low pressure system located over south-central Canada will slowly drift eastward through Tuesday before strengthening and racing northeastward. Meanwhile, an attached stationary boundary and slow moving cold front will be the focus for showers and thunderstorms tonight and Tuesday from the southern/central Plains to the Midwest.

A few thunderstorms may turn severe from the southern High Plains to Nebraska, with the highest chances for isolated tornadoes and large hail found across western Kansas tonight. Flash flooding is also a possibility across the central and southern Plains where thunderstorms stall or repeat over similar locations. Southeast Texas has received an abundance of rainfall over the last few weeks and additional thunderstorms over this region could lead to more flooding concerns this evening. WPC has issued a Slight Risk of Excessive Rainfall over parts of southeast Texas tonight, with Flash Flood Watches also in effect.

A separate system currently entering the Pacific Northwest is forecast to reach the central High Plains by Wednesday and produce an additional round of spring thunderstorms across the central Plains. The Storm Prediction Center has issued a slight risk of severe weather from eastern Wyoming to southwest Iowa and northwest Missouri on Wednesday. Showers will likely be found across the northern Rockies and Great Basin on Tuesday and Wednesday as well.

Throughout the eastern U.S., the brief shot of cool weather today across the Mid-Atlantic and Northeast will be short lived as a warm front lifts across the region by Wednesday. In fact, record-breaking warmth is forecast from North Carolina to New Jersey. High temperatures are expected to reach the low-to-mid 90s and around 10 to 20 degrees above average. The combination of warm temperatures and an approaching cold front may also lead to scattered thunderstorms Wednesday evening, with a few severe thunderstorms not out of the question.

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 May 27 2021 – Monday May 31 2021

Hazards:

– Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Great Lakes, the Middle Mississippi Valley, the Upper Mississippi Valley, the Southern Plains, and the Ohio Valley, Thu, May 27.

– Heavy rain across portions of the Central Plains, the Middle Mississippi Valley, and the Southern Plains, Sat-Mon, May 29-May 31.

– Heavy rain across portions of the Southern Appalachians, the Central Appalachians, and the Ohio Valley, Fri, May 28.

– Severe weather across portions of the Central Plains, the Middle Mississippi Valley, the Lower Mississippi Valley, and the Southern Plains, Thu, May 27.

– Flooding possible across portions of the Central Plains, the Middle Mississippi Valley, and the Northern Rockies.

– Flooding occurring or imminent across portions of the Central Plains, the Middle Mississippi Valley, the Lower Mississippi Valley, and the Southern Plains.

– Much above normal temperatures across portions of California, the Pacific Northwest, and the Northern Great Basin, Mon, May 31.

– Much above normal temperatures across portions of the Southeast, the Mid-Atlantic, the Southern Appalachians, and the Tennessee Valley, Thu-Fri, May 27-May 28.

– Much below normal temperatures across portions of the Upper Mississippi Valley and the Northern Plains, Thu, May 27.

– Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Fri-Sun, May 28-May 30.

Detailed Summary:

This upcoming Day 3-7 period, which includes the Memorial Day weekend, will feature a fairly active weather pattern, mostly focused around a wavy surface front stretching across the central and eastern CONUS. On Thursday, an area of low pressure along the front combined with flow of deep Gulf moisture, will bring widespread moderate to heavy rainfall to the upper Midwest, mid-Mississippi Valley, and south-central Plains. Amounts will mostly fall into the 1-2 inch range, but isolated heavier amounts are likely, especially along the trailing cold front. In addition to heavy rainfall, there is a threat for severe weather from Missouri southwestward through eastern Kansas and much of central and eastern Oklahoma. On Friday, this low will advance into the Ohio Valley and weaken, with a secondary low possibly developing off the mid-Atlantic coast Friday night-Saturday. Associated rainfall will push into this region, but likely will be less significant than over the central U.S. the previous day as the feed of Gulf moisture lessens.

Also very concerning will be the heavy rainfall potential over the central states during the long holiday weekend. A series of short wave troughs, one moving across the northern Plains, along with less well-defined impulses lifting out of a closed low forming in southwestern states will support multiple periods of organized shower/thundershower activity. Helping to focus the rainfall are the above mentioned wavy front along with a second boundary associated with the trough crossing the northern Plains. While there is uncertainty with exact details of timing and location, the general consensus supports the heaviest precipitation over Kansas, Nebraska, and possibly southward into western Texas and eastern New Mexico. With a nearly continuous feed of Gulf moisture, there are indications that some parts of this region will see repeat periods of shower/thundershower activity, which could lead to significant rainfall totals and the possibility of flash flooding.

Farther east and south of the front, hot weather will persist across the Carolinas, Georgia, Mississippi and northern sections of Florida Thursday-Friday. High temperatures are expected to top out in the mid-upper 90s both days (about 10-12 degrees above normal and close to record levels), then settle back closer to normal as a modestly cooler air mass builds in behind the developing low along the mid-Atlantic coast. On the other side of the CONUS, upper-level ridging will strengthen over the Pacific Northwest, resulting in above to much above normal high temperatures Sunday and Monday. Finally, there’s still some cool weather over the CONUS…namely over the northern High Plains and upper Midwest on Thursday due to a combination of a Canadian air mass and increasing clouds/precipitation associated with a short wave trough. The core of the coolest air will center over North Dakota, where high temperatures will range from 15-25 degrees below normal, with lows near or below freezing Thursday into Friday morning.

Over Alaska, a deepening upper-level trough south of the Aleutians and downstream upper ridging will result late this week in broad southerly onshore flow from the south-central mainland into the northern Panhandle. A series of short waves and associated frontal systems will be able to tap deep moisture from the tropical Pacific to support unsettled weather through much of the period. There’s some uncertainty with details, but at this time, the heaviest precipitation Friday will be across the northern Panhandle, then shift somewhat westward along the southern mainland over the weekend.

(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.

More information can be found here.

May Drought Outlook.

Seasonal Outlook Issued May 20, 2021

Here is the short version of the discussion that was released with the new forecast.

Latest Seasonal Assessment – Drought improved across parts of Texas, northeastern Colorado, central Wyoming and the Northeast in the past month due to heavy rainfall, while drought developed or intensified in many parts of California, the Pacific Northwest, Northern Intermountain West, Northern Rockies, and the Carolinas due to increasing precipitation deficits. Drought persistence or development is favored for most of the West and High Plains, based on elevated probabilities of below normal precipitation and above normal temperatures for June-July-August. Drought removal or improvement is expected across east-central Texas along with most of Oklahoma due to heavy recent rainfall and additional heavy rainfall forecast for the rest of May.Lack of a rainfall signal from monthly and seasonal precipitation outlooks supports drought persistence across the Midwest. The Great Plains and Corn Belt will be closely monitored in the monthly drought outlooks through the summer. The wet monthly and seasonal outlooks along with the onset of the convective season strongly support removal across the small drought areas in southern Florida. The persistence forecast for the Northeast is based on a weak rainfall signal and likelihood of above normal temperatures during June-July-August along with a favorable time for soil moisture discharge.

Alaska is forecast to remain drought-free through the end of August. Drought is favored to persist across Puerto Rico during the next few months. Drought development and persistence is forecast across the leeward sides of the Hawaiian Islands.

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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

The Eastern Pacific

NA

The Central Pacific

NA

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

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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