Written by Sig Silber

HEADLINES (Updated 5:01 pm EDT) –

– A slow moving, blocked upper level pattern to support late season snows across portions of the Northern Plains, Central Rockies and northern Great Basin

– An Elevated to Critical Fire Weather threat expected across the Southwest Tuesday and Wednesday

– Additional Heavy rains possible along the Central Gulf Coast and Lower Mississippi Valley

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 300 PM EDT Mon Apr 12 2021
Valid 00Z Tue Apr 13 2021 – 00Z Thu Apr 15 2021
…A slow moving, blocked upper level pattern to support late season snows across portions of the Northern Plains, Central Rockies and northern Great Basin…
…An Elevated to Critical Fire Weather threat expected across the Southwest Tuesday and Wednesday…
…Additional Heavy rains possible along the Central Gulf Coast and Lower Mississippi Valley…
The mid to upper level flow pattern across much of North America will continue to exhibit a high degree of blocking, resulting in very slow moving systems affecting large portions of the nation. The lead slow moving upper low over the Northern Plains/Upper Mississippi Valley region will continue to support late season accumulating snows across northern to eastern North Dakota into northwestern Minnesota Monday night night into Tuesday. The snow threat from this system will decrease significantly late Tuesday into Wednesday with only light snow possible from the Northern Plains into the Upper Great Lakes.
While the lead mid to upper level system meanders over the Northern Plains/Upper Mississippi Valley region, a second slow moving system will develop over the Pacific Northwest on Tuesday and sink only slowly southward into the northern Great Basin by Wednesday. This system will not have a lot of associated precipitation initially, but should expand its precipitation effects from Tuesday night into Wednesday across the northern Great Basin and into the Central Rockies. Late season heavy snows are possible across the Rockies of Colorado and Wyoming and across the Wasatch and Unitas of Utah.
Additional heavy rains are on tap late Tuesday into Wednesday across the Lower Mississippi Valley and Central Gulf coastal regions. These areas have been wet over the past week with rain totals 200-300% of average. This has resulted in high stream flow values and saturated soils. The additional heavy rainfall threat will also lead to an increasing threat of flooding across portions of the Lower Mississippi Valley and Central Gulf coast late Tuesday into Wednesday.
In contrast to the wet conditions along the Central Gulf Coast into the Lower Mississippi Valley, dry conditions, low relative humidities and gusty winds will support an Elevated to Critical Fire Weather Threat over the Southwest Tuesday and Wednesday. With the large scale pattern not expected to change much over the western U.S., with the above mentioned slow moving mid to upper level system, there will likely continue to be a fire weather threat over the Southwest into the end of this week.

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 Thursday April 15 2021 – Monday April 19 2021
Hazards:
– Heavy rain across portions of the Southeast and the Lower Mississippi Valley, Sun-Mon, Apr 18-Apr 19.
– Heavy rain across portions of the Mid-Atlantic and the Northeast, Thu-Fri, Apr 15-Apr 16.
– Heavy snow across portions of the Central Rockies, the Central Plains, and the Northern Plains, Thu-Fri, Apr 15-Apr 16.
– Flooding possible across portions of the Middle Mississippi Valley.
– Flooding occurring or imminent across portions of the Middle Mississippi Valley and the Lower Mississippi Valley.
– Flooding likely across portions of the Middle Mississippi Valley.
– High winds across portions of the Mid-Atlantic and the Northeast, Thu-Fri, Apr 15-Apr 16.
Detailed Summary:
In the medium-range forecast period, the Hazards Chart has an area of heavy rain near the Southeast/Central Gulf Coast, heavy rain over parts of the Northeast/northern Mid-Atlantic, heavy snow over parts of the Central Rockies/Central High Plains, and high wind along parts of Southern New England Coast/Mid-Atlantic Coast. Low pressure along the Mid-Atlantic Coast on Thursday will deepen just south of Long Island and move to near the coast of Massachusetts on Friday. The low will move out over the Atlantic on Saturday. The low will stream moisture off the Atlantic into the Northeast, producing heavy rain over parts of the northern Mid-Atlantic and Southern New England on Thursday. The heavy rain will taper off over parts of the northern Mid-Atlantic on Thursday night into Friday. The heavy rain will linger over eastern Massachusetts on Friday. The pressure gradient associated with the low will produce high winds along the coast of Southern New England and the Mid-Atlantic on Thursday and Friday.
Additionally, the associated front extending from along most of the East Coast and parts of the Gulf Coast on Thursday will move southward over the Florida Peninsula, stalling out halfway down the peninsula on Saturday. Also, on Saturday, a wave of low pressure will develop along the front over the Gulf of Mexico. The low will move onshore over northeast Florida on Sunday. The boundary will start to move southward, again, over the peninsula on Monday. Moisture will be pooling along the front producing heavy rain over parts of Florida and parts of the Central Gulf Coast on Sunday and Monday.
A wave of low pressure on the western end of the front will develop over parts of the Great Basin and move southward into parts of the Southern High Plains by Friday. The low and upper-level energy will help produce heavy snow over parts of the Central Rockies and Central High Plains on Thursday into Friday.
For Alaska, an upper-level low over the mainland will move southward over the North Pacific by Saturday. Upper-level ridging will build over the mainland through Monday, when upper-level troughing will dip over the Far North. Temperatures over the Far North will get above freezing for a short period, but at this time, will not be a hazard. A deep low over the North Pacific will stream moisture into parts of the Gulf of Alaska that will produce precipitation along the coast and Prince William Sound region on Sunday into Monday. At this time, it appears the precipitation will not be heavy enough to be included as a hazard.

(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.

April Drought Outlook..

Seasonal Outlook Issued February 18, 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

Notice they are planning to use the new definition of Climatology namely the period of 1991 – 2020. It has been the three decades 1981 – 2010.

The focus above is the Atlantic.

Notice that they have not noticed any changes in the Eastern and Central Pacific.

I see that my friend Matt Rosencrans chimed in. I think he has a new (easier) job and he is a very good meteorologist. He was and still may be opertions manager and if you read my JAMSTEC article, you really do not want to be in charge of all systems worked perfectly. That is a way to get burned out.

Notice the reference to the AMO. I am impressed and pleased.

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