Written by Sig Silber

HEADLINES (Updated 6:01 PM EST) –

– Excessive heavy lower elevation rain to bring dangerous flash flood risk to coastal central California tonight and into Thursda

– Extreme snowfall amounts expected across the Sierra Nevada through early Friday

– A quick burst of light to moderate snow to impact portions of the southern Appalachians and southern Mid-Atlantic tonight through early Thursday morning

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 220 PM EST Wed Jan 27 2021
Valid 00Z Thu Jan 28 2021 – 00Z Sat Jan 30 2021
…Excessive heavy lower elevation rain to bring dangerous flash flood risk to coastal central California tonight and into Thursday…
…Extreme snowfall amounts expected across the Sierra Nevada through early Friday…
..A quick burst of light to moderate snow to impact portions of the southern Appalachians and southern Mid-Atlantic tonight through early Thursday morning…
A moderate to heavy rainfall event is ongoing across central California and will spread south on Thursday as a robust Pacific front and associated atmospheric river moves inland. Deep moisture will be directed onshore and will help produce several inches of rain along the coast and lower elevations. Flash flooding and debris flows near recent burn scars are likely. WPC has highlighted part of this region as having a High Risk for excessive rainfall through Thursday morning. These delineations are reserved for rare events where flash flooding is likely to put lives and property in danger. Up to 7 to 10 additional inches of rain could fall over the next two days across the region. Higher up in elevation, mountain snow will likely be heavy at times across the Sierra Nevada. Several feet of snow (as much as 10 feet in total accumulation) will add up through Friday morning, with road closures and travel delays very likely. Numerous locations have Winter Storm Warnings and Winter Weather Advisories in effect. Blizzard Warnings are also in effect for parts of the Sierra Nevada where gusty winds will accompany the heavy snow. Much of the heavy precipitation across California and the Southwest will come to an end on Friday.
Further east, scattered to widespread rain is expected to move through parts of the Southeast and lower Mid-Atlantic region tonight and into Thursday morning as a low pressure system moves across the region. With cold Canadian air settling in over the central U.S. behind an associated cold front, snow will spread from the lower Ohio Valley to the southern Mid-Atlantic. Early on Thursday, the area of low pressure is expected to rapidly strengthen off the Southeast coast. This will help draw even colder air across portions of Virginia and northern North Carolina. As a result, a few inches of snow can be expected here with as much as 6 inches of snowfall possible across the mountains of North Carolina and southern Virginia. Winter Weather Advisories currently stretch from southern Illinois to northeast North Carolina.

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

US Day 3-7 Hazards Outlook
Valid Saturday January 30 2021 – Wednesday February 03 2021
Hazards:
– Heavy precipitation across portions of the Mid-Atlantic and the Central Appalachians, Sun-Tue, Jan 31-Feb 2.
– Heavy rain across portions of California and the Pacific Northwest, Sun-Tue, Jan 31-Feb 2.
– Heavy rain across portions of the Lower Mississippi Valley and the Southern Plains, Wed, Feb 3.
– Heavy rain across portions of the Central Plains, the Southeast, the Middle Mississippi Valley, the Mid-Atlantic, and the Ohio Valley, Sat-Sun, Jan 30-Jan 31.
– Heavy snow across portions of California, the Pacific Northwest, the Northern Rockies, and the Northern Great Basin, Sat-Mon, Jan 30-Feb 1.
– Heavy snow across portions of the Central Great Basin, California, and the Southwest, Sat-Tue, Jan 30-Feb 2.
– Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Mon-Tue, Feb 1-Feb 2.
– Heavy snow across portions of the Central Rockies, the Central Great Basin, the Northern Rockies, and the Northern Great Basin, Tue-Wed, Feb 2-Feb 3.
– Heavy snow across portions of the Central Rockies, the Central Great Basin, and the Southwest, Wed, Feb 3.
– Heavy snow across portions of the Middle Mississippi Valley, the Great Lakes, the Ohio Valley, and the Upper Mississippi Valley, Sat-Sun, Jan 30-Jan 31.
– Heavy snow across portions of the Northeast, the Central Appalachians, the Mid-Atlantic, the Southern Appalachians, the Great Lakes, and the Ohio Valley, Sun-Tue, Jan 31-Feb 2.
– Much below normal temperatures across portions of the Mid-Atlantic, the Northeast, and the Great Lakes, Sat-Sun, Jan 30-Jan 31.
Detailed Summary:
A climactic end to January features medium range hazards along the West Coast extending into Mountain West and Mid-Atlantic regions. In the west, digging energy in the Northern Pacific will amplify an area of low pressure in the Pacific Northwest with an ample supply of Pacific moisture to siphon northeastward ahead of a frontal system this weekend. Although precipitable water anomalies are only marginally above normal ahead of the system, the sheer duration of the atmospheric river event only serves to exasperate ongoing effects from recent heavy rain and heavy mountain snow in the region. As the trough moves inland early next week, additional high-elevation heavy snow is likely across portions of the Mountain West which may provide beneficial water to drought stricken areas there. Meanwhile, a deep Colorado low develops and quickly races eastward Saturday as the trough digs into the Southern Plains. As the storm taps into a fetch of Gulf moisture, areas of heavy rain and snow develop over the Midwest. Hazardous travel conditions may arise with blowing snow in the heavy snow area as the low deepens. Farther east, “much below normal” temperatures are expected in New England Saturday and Sunday as strong cold air advection on the back end of a deep low pressure system in the Northwest Atlantic pulls down frigid Canadian air, with minimum temperature anomalies around fifteen degrees below normal.
This wedge of cold air spills down the spine of the Appalachians Sunday and sets the stage for a clash between rich Gulf of Mexico moisture ahead of the Midwest storm system and sub-freezing air at low levels in the Mid-Atlantic. As the upper low approaches, precipitation looks to fall in the form of snow from the Ohio Valley and central Appalachians early Sunday to the Mid-Atlantic I-95 corridor later in the day. Ensemble guidance remain at odds over the the speed of the approaching upper trough with the GEFS remaining on the faster side of guidance. The Euro ensemble is slower while also having a closed upper low tracking over Virginia by Monday afternoon. The subtle differences can mean drastically different positions where the axis of heavy snow becomes oriented. This is especially true in the Mid-Atlantic, because the longer the coastal low takes to develop and the main low in the Ohio Valley stays dominant (i.e. GFS/GEFS) the better the chances a warm nose aloft and/or dry slot may limit snow totals. The Euro ensemble makes the transition faster and farther south, leading to a greater signal for heavier snowfall in the Mid-Atlantic region. While these aspects of the forecast are still murky this much is clear: confidence is growing that a potentially significant winter storm may impact much of the Mid-Atlantic and Northeast late Sunday and into the first half of next week with hazards that would include heavy snow, treacherous ice (central Virginia into central North Carolina most notably), heavy rain (Southeast), gusty winds, and coastal flooding.
In Alaska, a passing cold front delivers a shot of below normal temperatures to most of the western regions, but departures appear to fall short of “much below normal” criteria. The next potential weather maker comes in the form of a strong cyclone west of the Aleutians. Gusty winds are likely Sunday and into Monday but do not appear to reach excessive levels. Ensemble guidance does suggest a plume of rich Pacific moisture streams north towards the Gulf shores by early next week, but high spread in ensemble members continue to keep confidence in totals low at this time. Will revisit this tomorrow to see if confidence improves enough to add a “heavy precipitation” area on Thursday.

(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 weekly 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.

New December Drought Outlook

Seasonal Outlook Issued November 19, 2020

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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.

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

Atlantic and Gulf of Mexico

And the Eastern 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