Written by Sig Silber

HEADLINES –

– Lingering areas of snow and freezing rain to cause travel concerns from the eastern Great Lakes to New England this morning

– Frigid Arctic air and dangerously cold wind chills to persist in the Great Plains and Mississippi Valley through midweek

– A new winter storm emerging in the Southern Plains on Tuesday heads for the Mid-South on Wednesday

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.

Please share this article – Go to the very top of the page, right-hand side for social media buttons. Also, feel free to send this email to anyone you feel will benefit from it.

For those interested in longer-term forecasts, we just published the new NOAA Seasonal Outlook and it can be accessed here.

Directory

CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 304 AM EST Tue Feb 16 2021

Valid 12Z Tue Feb 16 2021 – 12Z Thu Feb 18 2021

…Lingering areas of snow and freezing rain to cause travel concerns from the eastern Great Lakes to New England this morning…

…Frigid Arctic air and dangerously cold wind chills to persist in the Great Plains and Mississippi Valley through midweek…

…A new winter storm emerging in the Southern Plains on Tuesday heads for the Mid-South on Wednesday…

The major winter storm responsible for producing significant snow and ice accumulations in parts of the central and eastern U.S. the last couple days is making a beeline for eastern Canada, but not before it causes heavy snow and freezing rain in parts of the eastern Great Lakes and New England. Several more inches of snow are possible in the eastern Great Lakes and northern New England while ice totals up to a quarter inch are possible in central New England. Farther south, the storm’s trailing cold front is forecast to trigger showers and thunderstorms over South Florida where Marginal Risks for both severe weather and flash flooding are in place. In the storm’s wake, the same area of Arctic high pressure that has enveloped the Heartland in record cold temperatures will spill over towards the East Coast Tuesday evening and into Wednesday. Temperatures will dip to below normal levels on Wednesday but not to the bitterly cold levels that transpired across the Plains and Mississippi Valley in recent days.

Speaking of bitter cold, the Arctic high pressure over the Heartland will ensure one more day or frigid temperatures east of the Rockies and west of the Appalachians. Numerous record cold maximum and minimum temperatures are expected today with the bulk of them occurring in the South Central U.S. where daily anomalies range between 35 to 45 degrees below normal. Wind Chill Warnings and Advisories span a massive area from the US/Canada border to the US/Mexico border. Where Wind Chill Warnings are in place, wind chills may plummet to a dangerous 50 degrees below zero at times. The Arctic air-mass begins to modify on Wednesday with fewer record cold temperatures expected but still remain well below normal. Wednesday’s low temps are likely to drop below zero from the Midwest to the Lower Great Lakes.

An upper level trough tracking through the Four Corners region today is responsible for heavy mountain snow across the Intermountain West. As the trough ejects into the Southern Plains this afternoon, periods of snow will breakout across parts of the Southern Plains with Oklahoma the epicenter for the heaviest accumulations through Tuesday night. Snowfall accumulations over 6 inches are expected there and extending into Arkansas as the upper trough marches east on Wednesday. The same upper trough will help to create a new wave of low pressure in the Gulf of Mexico that becomes the next winter storm to track across the Lower Mississippi Valley and into the Ohio and Tennessee Valleys. Snowfall accumulations on Wednesday appear to be on the order of 3 to 6 inches in these areas, while significant ice accumulations take shape from east Texas to the Mississippi Delta region. Ice accumulations ranging between a quarter to a half inch are possible which would make for hazardous travel conditions, induce more power outages, and cause additional tree damage in these areas. Eventually, this storm system will head for the Mid-Atlantic by Thursday where accumulating snow and ice will likely lead to more treacherous travel conditions.

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

– Return to Directory

Day 3 – 7 Hazards

Valid Thursday February 18 2021 – Monday February 22 2021

 

Hazards:

– Heavy snow across portions of the Great Lakes, the Northeast, the Central Appalachians, and the Ohio Valley, Thu-Fri, Feb 18-Feb 19.

– Heavy precipitation across portions of the Mid-Atlantic, the Lower Mississippi Valley, the Central/Southern Appalachians, the Tennessee Valley, the Northeast, and the Ohio Valley, Thu-Fri, Feb 18-Feb 19.

– Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Mid-Atlantic, the Southern Appalachians, and the Southeast, Thu, Feb 18.

– Severe weather across portions of the Southeast, Thu, Feb 18.

– Flooding possible across portions of the Southeast, the Southern Appalachians, the Mid-Atlantic, the Central Appalachians, and the Ohio Valley.

– Flooding occurring or imminent across portions of the Mid-Atlantic.

– Flooding likely across portions of the Southeast and the Mid-Atlantic.

– Heavy precipitation across portions of California and the Pacific Northwest, Thu-Mon, Feb 18-Feb 22.

– Heavy snow across portions of the Central Great Basin and California, Fri, Feb 19.

– Heavy snow across portions of the Northern Great Basin, Thu-Fri, Feb 18-Feb 19 and Sun-Mon, Feb 21-Feb 22.

– Heavy snow across portions of the Northern Rockies, Fri, Feb 19 and Sun-Mon, Feb 21-Feb 22.

– High winds across portions of the Pacific Northwest, Sun, Feb 21.

– High winds across portions of the Northern/Central Rockies and the Northern Plains, Sun-Mon, Feb 21-Feb 22.

– Much below normal temperatures across portions of the Northern/Central/Southern Plains, the Upper/Middle/Lower Mississippi Valley, the Tennessee Valley, the Great Lakes, and the Ohio Valley, Thu-Sat, Feb 18-Feb 20.

– Heavy precipitation across portions of mainland Alaska, Thu, Feb 18.

– Much below normal temperatures across portions of mainland Alaska, Sun-Mon, Feb 21-Feb 22.

 

Detailed Summary:

 

During the medium range period (Thursday, February 18th – Monday, February 22nd) strong upper-level troughing will act as the force behind below average temperatures and very active weather across the country. Thursday into Friday all eyes will be on the East, where the second winter storm of the week is forecast to follow in it’s predecessors footsteps as it makes its way from the Lower Mississippi Valley to the Northeast, bringing snow, mixed precipitation, and rain to many of the same areas hit a few days prior. The current guidance suggests that heavy rain, which could be severe at times, will impact the southern and Mid-Atlantic states, where rainfall totals up to and exceeding 2 inches in 24 hours may occur. Meanwhile, the greatest potential for heavy snowfall lies in the Ohio Valley, Central Appalachians and interior Northeast, with some locations expected to receive 6 to 8 inches of snow. Elsewhere, the storm is expected to bring a mix of snow, sleet, and freezing rain, which may result in ice accumulations up to one-tenth of an inch in the Lower Mississippi Valley and up to a quarter of an inch in the Mid-Atlantic. Along with travel being significantly impacted, areas subject to accumulating ice may also experience widespread power outages.

 

In the West, a series of moisture-rich low pressure/frontal systems forecast to move onshore from the eastern Pacific will serve as the impetus for heavy snowfall in the higher elevation Cascade and Olympic Mountains throughout the period. Heavy rain along coastal northern California, Oregon and Washington will also accompany these systems, however, more moderate, non-hazardous amounts are expected on Friday and Monday. As the first low pressure/frontal system progresses southeast through the western terrain Thursday into Friday it will leave behind a trail of heavy snow in the high elevation mountain ranges of the Northern/Central Great Basin and Rockies as well as the Sierra Nevada. Driven by surface shortwave energy immediately followed by a cold front descending from Canada, a second round of heavy snowfall is expected for the high elevation mountain ranges throughout the Northern Great Basin and Rockies, Sunday into Monday. Concurrently, a tight pressure gradient over the northwest quadrant of the country will cause hazardous wind gusts to develop over the Pacific Northwest, Northern/Central Rockies, and the Northern Plains.

 

Through the first half of the period, high pressure at the surface will keep temperatures well below normal over the central U.S. As opposed to the beginning of the week, by week’s end temperatures are expected to become slightly more moderate, with daily low temperatures in most places reaching closer to or above zero and plateauing at approximately 10 to 20 degrees below normal. However, residents of the Central/Southern Plains and Middle/Lower Mississippi Valley will have to endure temperatures 20 to 30 degrees below normal for a few days longer. As the surface high pressure moves east through the weekend the cold air will follow suit, dropping low temperatures in the Ohio valley to 20 degrees below normal on Saturday before moderately cooling down the eastern seaboard on Sunday. These widespread anomalously low temperatures can pose a threat to health and safety and should be taken seriously in all affected locations, particularly in the North/Central Plains and Upper Mississippi Valley where prolonged exposure to near-zero and negative could cause frostbite on uncovered areas of skin.

 

Over Alaska, a busy pattern over the mainland in addition to a series of deep low pressure/frontal systems forecast to pass through the Gulf of Alaska, will bring precipitation to the Aleutians, Mainland, and Panhandle. While precipitation over the Aleutians is expected to be moderate, recent model guidance has significantly increased the amount of precipitation expected to fall over the southern Mainland Thursday, suggesting hazardous levels could be reached or exceeded for the region. Heavy precipitation may occur in the Panhandle region towards the end of the medium range period, however, there is still a significant amount of uncertainty in the precipitation forecast, so no hazard area has been drawn at this time. Additionally, daily low temperatures are expected to be much below normal for portions of the Interior Sunday and Monday. With temperatures reaching as low as -20F, extreme caution should be taken when traveling outdoors to prevent frostbite and illness.

(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.

– Return to Directory

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 a lot 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 February Drought Outlook

Seasonal Outlook Issued January 21, 2021

– Return to Directory

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

– Return to Directory

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

– Return to Directory

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.

– Return to Directory

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.

– Return to Directory

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.

– Return to Directory

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

– Return to Directory