Written by Sig Silber
Updated at 7 pm EDT Wednesday April 29, 2020 – “…There is a Slight Risk of Excessive Rainfall for portions of the Central/Southern Appalachians and for SE Wisconsin/NE Illinois through Thursday morning……There is a Slight Risk of Excessive Rainfall Friday for portions of the Mid-Atlantic to southern New England……Temperatures will be 10 to 20 degrees above average over parts of the Southwest, Great Basin, and parts of the Rockies…”
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. We include a Ski Report.
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
Readers can scan through this article or jump to where they want to go via the links to the right. To get back to the Directory, hit the back arrow at the top of the URL bar on your screen. But in many cases, one of my Editors has graciously inserted a Return to Directory link to click so that is even easier. This is so high tech that I hardly believe it. |
|
CONUS Focal Points
Short Range Focal Points
Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 345 PM EDT Wed Apr 29 2020 Valid 00Z Thu Apr 30 2020 – 00Z Sat May 02 2020
…There is a Slight Risk of Excessive Rainfall for portions of the Central/Southern Appalachians and for SE Wisconsin/NE Illinois through Thursday morning…
…There is a Slight Risk of Excessive Rainfall Friday for portions of the Mid-Atlantic to southern New England…
…Temperatures will be 10 to 20 degrees above average over parts of the Southwest, Great Basin, and parts of the Rockies…
Scattered to widespread showers and thunderstorms are expected along and ahead of a cold front passing that will pass through eastern third of the country. The strong, possibly severe, thunderstorms will be capable of producing heavy rainfall across portions of the Lower Great Lakes/Ohio Valley, Tennessee Valley, Southeast, Mid-Atlantic and portions of the Northeast through Thursday morning. WPC has a Slight Risk for Excessive Rainfall in effect for parts of the Central/Southern Appalachians, as well as, areas near and north of the Chicago metro area. The area of heavy rainfall and increased risk for flash flooding will shift to the Mid-Atlantic to southern New England region by Friday– where a Slight and Marginal Risk is now in effect.
High pressure across much of the Southwest and Southern U.S. will keep daily temperatures well above seasonal normal for late April and early May. Daily reading may be as much of 10 to 20 degrees above average. 100 degrees. By Thursday, some of this very warm air will begin to shift eastward and should begin to advance out across the High Plains as the ridge shifts eastward in response to an upper trough approaching the West Coast.
Click here for the latest complete NWS/WPC Short Range Discussion. (Sometimes we provide part of or even the full discussion above and you can tell because it goes beyond the bullet points. We do that when we think the bullet points do not provide enough information. But the link just provided always takes you to the full discussion with updates twice a day and sometimes we are a bit late updating the bullet points so that link will get you there. You can tell if we are late by the time of the stamped update. This time of the year, NOAA does the updates at around 3 a.m. and 3 p.m. EST. We try to do the updates in our article as close to that as possible but it is not always possible.)
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.
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
Water Vapor.
This view of the past 24 hours provides a lot of insight as to what is happening.
– Return to Directory
Day 3 – 7 Hazards
– Heavy rain across portions of the Central/Southern Plains, the Middle/Lower Mississippi Valley, the Tennessee Valley, the Southern Appalachians, and the Ohio Valley, Mon-Tue, May 4-May 5. – Heavy rain across portions of the Upper Mississippi Valley and the Northern Plains, Sun-Mon, May 3-May 4.
– Heavy rain across portions of the Southern/Central Appalachians, the Middle Mississippi Valley, the Ohio Valley, and the Tennessee Valley, Sat-Sun, May 2-May 3.
– Flooding possible across portions of the Northeast, the Central Appalachians, the Middle/Upper Mississippi Valley, the Mid-Atlantic, the Great Lakes, and the Ohio Valley.
– Flooding occurring or imminent across portions of the Southeast, the Mississippi Valley, and the Northern Plains.
– Flooding likely across portions of the Southeast, the Middle Mississippi Valley, and the Northern Rockies.
– Much above normal temperatures across portions of California and the Southwest, Tue-Wed, May 5-May 6. – Much above normal temperatures across portions of the Central/Southern Plains, the Central/Southern Rockies, the Central Great Basin, and the Southwest, Sat-Wed, May 2-May 6.
– Much above normal temperatures across portions of the Central Rockies, the Central Great Basin, and the Southern/Central Plains, Sat-Mon, May 2-May 4.
– Much above normal temperatures across portions of the Southern Plains, Sat-Tue, May 2-May 5.
Detailed Summary:
The medium range period will begin on Saturday 5/2 with an upper-level low over the Northeast and upper-level ridging over the central U.S. An upper high slowly making its way northward from central Mexico should help keep heights above normal through the period over the southwestern quadrant of the nation. This will lead to much above normal temperatures over the Four Corners states and into the Central/Southern Plains through Monday, with much of Texas experiencing the heat through Tuesday. Record highs are possible for the Southern Plains over the weekend, with temperatures nearing 100 degrees or even exceeding it in parts of Texas. The Southwest is forecast to remain hot as well, with temperatures increasing a few degrees on Tuesday and Wednesday of next week.
Potential for heavy rainfall exists over the weekend as moisture increases along a frontal system moving through the Ohio Valley. The best chance for heavy rain is currently outlined over the Ohio Valley and Central Appalachians, though differences in the latitude of the axis of heaviest rain remain. Additionally, rain which could be heavy may occur to the east somewhere over the Mid-Atlantic, but the area of heaviest rain is even more uncertain there.
Early next week, an upper-level trough/low is forecast to move into the Northwest and eastward into the Northern Plains by Tuesday, bringing chances for precipitation over those areas. Over the Pacific Northwest, precipitation does not seem to be anomalously high, but once precipitation spreads into the Northern High Plains, even rain amounts around an inch would be unusually high, so a heavy rain hazard area was placed there. Recent model guidance has trended lower with rain amounts compared to the past couple of days, and focused a little farther east, so will continue to monitor if these trends continue. Most precipitation should fall as rain, but higher elevation light snows in the Cascades and Northern Rockies are expected as temperatures cool down with the trough. Windy conditions are also possible over the Great Basin Sunday and over the Rockies and Plains Monday, but winds should remain below hazards criteria. Downstream of the trough, another round of heavy rainfall is possible over portions of the Mississippi, Tennessee, and Ohio Valleys. Once again, confidence in the placement of the heavy rain is not too high, but moisture flowing into the vicinity of and overrunning a front is expected and could create a threat.
Over Alaska, no hazards are posted. However, ice jam and snowmelt flooding are possible over portions of the mainland, though specific locations where these issues could occur are hard to pin down in advance. Precipitation is forecast for the Panhandle and then for the Gulf of Alaska coast as a low pressure system sits over the Northeast Pacific, but widespread heavy amounts are not currently expected, and temperature anomalies are not expected to be significant.
(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. 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.
– Return to Directory
Tropical Events
This is now beyond the time of the year we pay special attention to Tropical Events other than the Western Pacific.
So 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.
the Central Pacific. | the Eastern Pacific | the Atlantic and the Gulf of Mexico |
Updates on individual named storms can be obtained here.
And the Western Pacific
Week 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
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. |
– 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
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. |
|
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 |