Written by Sig Silber

HEADLINES (Updated 6:08 pm EDT) –

– Hurricane Delta forecast to make landfall in southern Louisiana late Friday with life-threatening storm surge, destructive winds, and dangerous inland flooding

– Soaking rainfall to impact areas of the central Gulf Coast and Lower Mississippi Valley both Friday and Saturday with rain gradually overtaking the Ohio Valley and Mid-Atlantic the second half of the weekend

– Unsettled weather with heavy rain and some high elevation snowfall expected this weekend for the Pacific Northwest, summer-like heat in the Plains

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.

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La Nina News

CONUS Focal Points

Short Range Focal Points

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD – 359 PM EDT Thu Oct 08 2020

Valid 00Z Fri Oct 09 2020 – 00Z Sun Oct 11 2020

…Hurricane Delta forecast to make landfall in southern Louisiana late Friday with life-threatening storm surge, destructive winds, and dangerous inland flooding…

…Soaking rainfall to impact areas of the central Gulf Coast and Lower Mississippi Valley both Friday and Saturday with rain gradually overtaking the Ohio Valley and Mid-Atlantic the second half of the weekend…

…Unsettled weather with heavy rain and some high elevation snowfall expected this weekend for the Pacific Northwest, summer-like heat in the Plains…

Hurricane Delta is gradually restrengthening in the western Gulf of Mexico this afternoon and is forecast to obtain major hurricane status sometime this evening or overnight. Delta is forecast to make landfall in southwest Louisiana as a fierce category 2 hurricane late in the day on Friday. Storm Surge and Hurricane Warnings are in effect from the Upper Texas coast and along the coast of southern Louisiana. Residents in these areas should follow advice given by local officials and rush preparedness actions to completion as Delta’s impacts look to start as early as Friday morning.

Heavy rainfall from Delta will result in significant flash, urban, small stream and minor to moderate river flooding on Friday and Saturday from portions of the central Gulf Coast into portions of the Lower Mississippi Valley. In fact, the storm is currently forecast to produce as much as 5 to 10 inches of rain, with isolated maximum totals of 15 inches, for southwest to south-central Louisiana. As Delta moves farther inland, heavy rainfall is expected to overspread the Ohio Valley and Mid-Atlantic this weekend. Delta is also expected to produce a threat for a few tornadoes across portions of the Gulf Coast states with a Slight Risk for severe weather in place for Friday.

Elsewhere across the Lower 48, the weather pattern remains rather tranquil through Friday. However, by this weekend, the pattern becomes increasingly more active as a new cold front passes over the Great Lakes and a warm front traverses the Northeast. There should be a swath of showers and thunderstorms tracking through New England as a result, some of which could be severe. In the West, a pair of Pacific cold fronts traverse the Pacific Northwest this weekend which will bring a surge of healthy onshore flow and a likelihood of heavy rainfall for the coastal ranges and the Cascades. In fact, some of the higher peaks of the Cascades will see snow levels fall low enough to yield a threat for heavy snowfall.

Temperature-wise, the Plains will witness a more summer-like regime that is likely to persist throughout the weekend. There is also a threat for favorable fire weather conditions in parts of the High Plains this weekend. The Northeast, however, will experience a more typical autumnal air-mass on Friday before an arriving warm front Saturday sends a surge of above normal temperatures into the region. The Rockies can expect warm conditions to persist both Friday and Saturday. The West Coast is in for a seasonally cool weekend due to the pair of cold fronts sweeping through the region.

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 precipitation across portions of northern Idaho, Sun-Mon, Oct 11-Oct 12.

– Heavy precipitation across portions of northwestern Wyoming, Sun, Oct 11.

– Heavy rain across portions of the northwestern Washington, Sun-Wed, Oct 11-Oct 14.

– Heavy rain across portions of the Ohio Valley to the central Appalachians, the Mid-Atlantic, and into southern New England, Sun-Mon, Oct 11-Oct 12.

– Heavy precipitation across portions of northern Idaho, Sun, Oct 11.

– Heavy precipitation across portions of northwestern Wyoming, Sun, Oct 11.

– Severe weather possible across portions of the northern to central Plains into the upper Midwest, Sun, Oct 11.

– Flooding possible across portions of western Louisiana into the lower to middle Mississippi Valley.

– Flooding occurring or imminent across portions of northeastern Florida.

– Flooding likely over southwestern Louisiana.

– Much above normal temperatures across a large portion of the Great Plains, Sun, Oct 11.

– Enhanced wildfire risk across portions of the southern High Plains, Sun, Oct 11.

– Heavy precipitation across much of the Alaska Panhandle, Tue, Oct 13 and Thu, Oct 15.

Detailed Summary:

The medium range period will begin with moisture associated with the remnants of Hurricane Delta moving across the Ohio Valley into the central and southern Appalachians Sunday morning when the storm center is forecast to move across Tennessee. Heavy rainfall can be expected in these areas on Sunday, before shifting into portions of the Mid-Atlantic states followed by southern New England on Monday. Global models indicate that the circulation center of Delta should dissipate on Monday but the associated remnant moisture should continue to spread into the rest of New England on Tuesday ahead of an approaching cold front. This cold front, which signals a major change in the synoptic pattern across the U.S., appears to accompany with rather vigorous dynamics. While a region-wide heavy rain event is not expected at this point in time, it appears that some heavy downpours and gusty winds associated with strong thunderstorms are possible in New England on Tuesday ahead of the front.

Over the western U.S. a large dome of cold air associated with a deep upper trough will be ushered into the northern and central Plains on Sunday and Monday behind the strong cold front. The Storm Prediction Center is highlighting portions of northern to central Plains as well as nearby upper Midwest as the area to watch for the possibility of severe weather on Monday. Moisture being lifted in the cold air mass over the rugged terrain could bring a period of mixed precipitation to the higher elevations of northwestern Wyoming and northern Idaho on Monday before tapering off on Tuesday. Some meaningful snowfall accumulations can be expected at the coldest locations from northern Idaho to northwestern Wyoming, and possibly the higher elevations of northern Colorado as well.

Ahead of the strong cold front however, another day of much above normal temperatures is forecast for much of the Plains, especially for the southern Plains, where record high temperatures reaching into the upper 90s to near 100 are possible Sunday afternoon. In addition, an enhanced wildfire risk is forecast for the southern High Plains on Sunday. Meanwhile, an active weather pattern over the northeastern Pacific will likely bring persistent rain into the Pacific Northwest, particularly the higher elevations of northwestern Washington, into the middle of next week.

Finally, a relatively quiet start to the medium range period for Alaska will become more active toward the middle of next week when global models indicate the possibility of a couple of strong occluded cyclones edging close to the Alaska Panhandle. It appears that the most likely dates of seeing heavy precipitation impacting the Alaska Panhandle will be next Tuesday and Thursday. Nevertheless, the timing of the heavy precipitation is subject to change as global models are indicating a great deal of uncertainty forecasting this active synoptic pattern.

(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 Seasonal Outlook Issued September 17, 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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