Written by Sig Silber

HEADLINES (Updated 6:39 pm EDT) –

– Tropical Storm Beta is forecast to weaken and gradually lose tropical characteristics while spreading flooding rains further inland across the lower Mississippi Valley

– Large swells generated by Hurricane Teddy could cause dangerous surf and rip current along the New England coast tonight

– Warm up in the Front Range and the Northern/Central Plains as rain moves into the Pacific Northwest.

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.

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CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD – 437 PM EDT Tue Sep 22 2020

Valid 00Z Wed Sep 23 2020 – 00Z Fri Sep 25 2020

…Tropical Depression Beta is forecast to weaken and gradually lose tropical characteristics while spreading flooding rains further inland across the lower Mississippi Valley.…

…Large swells generated by Hurricane Teddy could cause dangerous surf and rip current along the New England coast tonight…

…Warm up in the Front Range and the Northern/Central Plains as rain moves into the Pacific Northwest…

Tropical Depression Beta has weakened considerably since this morning when it was categorized as a Tropical Storm. It will continue to gradually lose it’s tropical characteristics as it traverses across coastal Texas, and toward the Lower Mississippi Valley tonight and Wednesday. Scattered thunderstorms as well as heavy rainfall and Flash Flooding are likely from the southeast Texas coast, where a High Risk of flash flooding was issued for this evening, up into the Southeast on Wednesday and Thursday where Slight Risks of Flash Flooding are in place. Beta will weaken to a Post-Tropical Cyclone and inherit frontal characteristics as it interacts with the surface boundaries draped across it by the time it reaches the Lower Mississippi Valley on Thursday, all-the-while producing dangerously heavy rainfall and flash flooding across these areas.

Meanwhile, the large and powerful Hurricane Teddy moving northward across the Atlantic Ocean is forecast to transform into a potent post-tropical cyclone as it makes landfall across Nova Scotia early on Wednesday. The expansive circulation of Teddy is expected to bring large swells along the Northeast coast, together with dangerous surf and rip currents. In addition to the high seas, Downeast Maine should get some rain, gusty winds from Teddy’s western edge tonight.

A large low pressure system will bring rain and cool temperatures to the Pacific Northwest through Thursday. The entrance of the associated upper-level trough will lead to the development of a new low pressure system over the Canadian Rockies on Thursday. Temperatures will warm up over the Front Range, ahead of an associated warm front. Some places may see record breaking high temperatures from this on Thursday. The current warm front stationed over the Northern Plains will raise temperatures across the Central/Northern Plains to above average across the once again tomorrow with some places seeing highs in the 90s.

An Elevated area of fire risk was issued by the Storm Prediction center for New England through tonight due to ongoing dry conditions and increased wind speeds. An elevated risk area is also in place over the Pacific Northwest on Wednesday due to strong surface wind gusts and the chance for sustained dry 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 20 hour animation and some other views can be found here OR SIMPLY CLICK ON THE IMAGE.

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Day 3 – 7 Hazards

Hazards:

– Heavy rain across portions of the Pacific Northwest and the Northern Great Basin, Fri-Sat, Sep 25-Sep 26.

– Heavy rain across portions of the Southeast, the Mid-Atlantic, and the Southern Appalachians, Fri, Sep 25.

– Heavy rain across portions of the Lower Great Lakes, the Mid-Atlantic, and the Northeast, Sun-Mon, Sep 27-Sep 28.

– Flooding possible across portions of the Lower Mississippi Valley and the Southern Plains.

– Flooding occurring or imminent across portions of the Southeast.

– Much above normal temperatures across portions of California, the Central Great Basin, the Pacific Northwest, and the Northern Great Basin, Sun-Tue, Sep 27-Sep 29.

– Much above normal temperatures across portions of the Central Plains, the Northern Plains, the Central Rockies, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Southern Plains, Fri, Sep 25.

– Much above normal temperatures across portions of the Southern Plains, Sat, Sep 26.

– Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Tue, Sep 29.

Detailed Summary:

Low pressure moves into the Pacific Northwest on Friday and Saturday. Moisture associated with thelow will aid in producing an area of heavy rain over parts of the Pacific Northwest on Friday and Saturday. The rain on Friday will be lighter than on Saturday but will meet the criteria for depicting an area of heavy rain on Friday. The heaviest rain will occur on Saturday. There will be some rain on Sunday but it will be lighter than what will fall on Friday so there is no area of heavy rain depicted on Sunday. Meanwhile, on Friday a quickly moving upper-level ridge will be over parts of the Upper Midwest will aid in producing temperatures that will be 12 degrees above average over parts of the Upper/Middle Mississippi Valley into parts of the Central Plains/High Plains into parts of the Southern High Plains on Friday. This meets the criteria for an area of much above normal temperatures over the region on Friday. On Saturday, upper-level troughing will move over the region on Saturday so the much above average temperatures will not be there. Upper-level ridging pokes eastward over parts of the Southern High Plains allowing the temperatures to remain above normal for one more day on Saturday.

Rain associated with Post-Tropical Cyclone Beta will produce an area of heavy rain over parts of the Southeast/Southern Appalachians on Friday. Furthermore, a front moving from the Lower Great Lakes to the Northeast Coast on Sunday into Monday will produce an area of heavy rain. The boundary will produce enough rain to meet the heavy rain criteria of one inch per 24 hours on Sunday into Monday. There is too much model uncertainty to put an area of heavy rain over the Northeast on Tuesday. Overnight Saturday an upper-level high will develop over parts of the West Coast. The high will allow temperatures to become much above normal over parts of the Pacific Northwest into parts of Northern/Central California from Sunday into Tuesday. In addition, strengthening high pressure over the Great Basin and Intermountain West may lead to increased wildfire risk due to dry conditions, low humidity levels, and the potential for high wind gusts. Southern California could contend with a Santa Ana wind event late this weekend into early next week should recent trends in model guidance persist.

For Alaska to start the medium range period as another potent storm system crosses the Gulf of Alaska and weakens. Moisture will moderate to low over the Gulf of Alaska and model uncertainty has made yesterdays are of heavy precipitation look too uncertain to include today. Another low over the North Pacific will move into the Gulf of Alaska on Tuesday. The moisture associated with this storm is much higher than the previous storm with the moisture streaming into the Alaska Panhandle. An area of heavy precipitation will extend from east of Valdez into the panhandle on Tuesday.

(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.

During the summer we might add some drought information in this section.

New Seasonal Outlook Issued August 20, 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

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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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