Written by Sig Silber

Updated at 8:05 pm EDT Saturday May 30, 2020 – “…An Enhanced risk of severe thunderstorms, Slight Risk of excessive rainfall over parts of the Pacific Northwest, critical fire weather conditions in the Great Basin……The northern Rockies and Plains to bask in hot temperatures into the start of the upcoming week……Severe threat in the North Central region, heavy showers and strong storms possible in Texas on Monday…“

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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CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 321 PM EDT Sat May 30 2020 Valid 00Z Sun May 31 2020 – 00Z Tue Jun 02 2020

…An Enhanced risk of severe thunderstorms, Slight Risk of excessive rainfall over parts of the Pacific Northwest, critical fire weather conditions in the Great Basin…

…The northern Rockies and Plains to bask in hot temperatures into the start of the upcoming week…

…Severe threat in the North Central region, heavy showers and strong storms possible in Texas on Monday…

A potent upper-level low slamming into California this afternoon will head north this evening with heavy showers and thunderstorms developing out ahead of it. This storm system is responsible for several weather hazards, most notably the threats for severe weather and excessive rainfall. Central Oregon and central Washington are now under both Severe Thunderstorm and Flash Flood Watches through this evening. Parts of northern California and the northern Rockies could also contend with heavy rain and strong thunderstorms. In addition to precipitation, strong winds are likely across the Great Basin where High Wind Warnings and Wind Advisories are in place. The combination of brisk winds and low humidity levels are a recipe for critical fire weather conditions throughout the weekend in the Great Basin and Colorado River Valley. The storm system quickly races northward tonight and by Sunday scattered showers and thunderstorms should be confined to northern Washington, northern Idaho, and northwest Montana.

One more day of record breaking heat in the Snake River Valley this afternoon before cooler temperatures arrive throughout the Northwest on Sunday. Sizzling temperatures set up shop over the northern and central Rockies and High Plains where some daily record high temps are possible. A couple daily record high temps could also be set in the Arizona Desert as Excessive Heat warnings continue into Sunday. The regime of much above normal temperatures heads east on Monday with heat indices approaching the century mark in the northern Plains and Upper Midwest. While the North Central region bakes the Great Lakes, Northeast, and on south into the Carolinas will witness substantially cooler temperatures. Daily temperature departures are forecast to range between 5 to 15 degrees below normal both Sunday and Monday. Seasonally cool conditions versus normal are also be possible in the Rio Grande Valley and along the West Coast.

The threat for severe weather and heavy rainfall returns to the North Central U.S. on Monday as an area of low pressure passes overhead. To the south, areas of showers and thunderstorms will dot the central Rockies and Texas where heavy downpours are possible, along with the potential for some severe weather. A swath of heavy showers and strong thunderstorms track through the Great Lakes late Monday.

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.

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

Water Vapor.

This view of the past 24 hours provides a lot of insight as to what is happening. I changed the map to one that shows intensity. I think it may be relatively new. Not sure.

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Day 3 – 7 Hazards

– Heavy rain across portions of southern Florida, Thu-Fri, Jun 4-Jun 5.

– Flooding possible across portions of the Southeast, the Great Lakes, and the northern Great Basin.

– Flooding occurring or imminent across portions of the Great Plains, the Midwest, the northern Rockies, the Middle Mississippi Valley, and the Carolinas.

– Flooding likely across portions of the central Plains, South Carolina, the mid-Mississippi Valley, the northern Rockies, and the northern Great Basin.

– Much above normal temperatures from the central Great Basin, across portions of the northern and central Rockies into the northern and central Plains, Mon-Tue, Jun 1-Jun 2.

– Much above normal temperatures over the Seward Peninsula in western Alaska, Mon, Jun 1.

Detailed Summary:

An upper ridge slowly building eastward from the western U.S. into the Plains will spread well above normal temperatures from the northern and central Rockies eastward into the High Plains early next week, where high temperatures are forecast to soar well into the 90s through next Tuesday before cooler air arrives behind a cold front. Meanwhile, much of the eastern U.S. will start out next week with cooler than normal temperatures. But as the ridge of high pressure in the West builds eastward, increasingly warm and moist air will gradually filter toward the eastern U.S. next week. By late next week, summer-like weather will likely spread into much of the East Coast except for New England where temperatures are forecast to be near or slightly below normal. Somewhat drier air could spread farther south into the Mid-Atlantic behind a cold front by next Friday. Meanwhile, heat could begin to intensify across the northern and central High Plains next Friday.

Precipitation will generally be light across much of the mainland U.S. during the medium-range period. However, parts of southern Florida could see an increasing threat of heavy rainfall toward the end of next week. This is due to an influx of tropical moisture well ahead of a potential tropical low pressure system that could interact with a stationary front across southern Florida. There is considerable uncertainty regarding this potential tropical system. The potential of heavy rain along the Gulf Coast, including Florida, will likely be subject to change.

Over Alaska, well-above normal temperatures are forecast for the western portion of the state near and around the Seward Peninsula under an upper high. Meanwhile, a surface high over the Beaufort Sea will gradually filter cooler air across the North Slope toward central and western Alaska as the week progresses. Ice jam flooding remains a concern over the North Slope as rivers have not yet broken up, while minor snowmelt flooding is a possibility in central and southern parts of the mainland. Farther south, an occluded cyclone is forecast to track eastward from the Aleutians toward the Alaskan Panhandle. It appears that coastal sections of southern and southeastern Alaska will see the highest chance of sustained precipitation early next week. Rainfall amounts are generally forecast to remain below heavy rain criteria for mainland Alaska, but there is some potential for the rain to reach the 2-inch threshold over the Panhandle and the Kenai Peninsula. Farther inland, periods of terrain-influenced/enhanced precipitation are expected across southern Alaska, where snow can be expected for the higher elevations through much of next week.

(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

We will resume more detailed ski snow reports when Fall comes.

We will update the above map weekly but more frequent updates can be obtained here.

There is not much snow left.

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Tropical Events

This is now beyond the time of the year we pay special attention to Tropical Events other than the Western Pacific.

So 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.

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

Updates on individual named storms can be obtained here.

And the Western Pacific

Week 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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