Written by Sig Silber
Updated 8:06 pm Tuesday June 23, 2020 – “…Flash flooding possible over the Appalachians through tonight and southeastern Texas into Louisiana through Wednesday……A Slight Risk of severe weather is in place over the Southern High Plains through tonight……Hot temperatures Tuesday across the West and Northeast should moderate some Wednesday, but remain warm…”
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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CONUS Focal Points
Short Range Focal Points
Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 354 PM EDT Tue Jun 23 2020 Valid 00Z Wed Jun 24 2020 – 00Z Fri Jun 26 2020
…Flash flooding possible over the Appalachians through tonight and southeastern Texas into Louisiana through Wednesday…
…A Slight Risk of severe weather is in place over the Southern High Plains through tonight…
…Hot temperatures Tuesday across the West and Northeast should moderate some Wednesday, but remain warm…
An upper-level trough extending from the Midwest/Great Lakes back into Texas will urge a cold front southward and eastward over time, acting as a focus for thunderstorms. Locally heavy rain is possible through this evening for the Eastern Seaboard, and areas of the Appalachians and Mid-Atlantic could see flash flooding in areas that are sensitive. The highest rainfall totals through Wednesday are expected over southeastern Texas and southern parts of Louisiana, where 2 to 4 inches of rain should be widespread. Slight Risks of flash flooding are forecast for these areas today and Wednesday. Meanwhile, the best chance for severe weather is in place over the Southern High Plains today, where a Slight Risk of severe weather is delineated by the Storm Prediction Center for high wind and hail threats. Scattered thunderstorms remain possible in the Southeast through Thursday morning, but widespread severe weather is not expected.
In the West, an upper-level disturbance should approach and push a cold front into the Pacific Northwest and eventually into the Northern Plains and Great Basin by Thursday morning. This will lead to increasing rain and thunderstorm chances in the Great Basin and Northern Rockies Wednesday and into the Northern and Central Plains on Thursday.
Temperature-wise, this should be the last day for the Northeast to see record-breaking maximum temperatures, though morning lows on Wednesday could set record high minima before the cold front comes through later Wednesday. California is expected to remain warm over the next few days, though record highs do not look to be threatened, but Heat Advisories are in place from southwestern Oregon into the central valleys of California. High temperatures 5 to 15 degrees above normal are forecast across the Great Basin into the Northern High Plains Wednesday, but should shift into the Northern/Central Plains Thursday ahead of the cold front.
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 |
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These graphics update and can be clicked on to enlarge. You can see where the weather will be | |
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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
This loop showing the prior 40-hours provides perspective. We have not yet figured out how to make this loop update but it is still useful for a few days. An updated version and some other views can be found here.
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Day 3 – 7 Hazards
– Heavy rain across portions of the Central Plains, the Great Lakes, the Middle Mississippi Valley, the Southern Plains, and the Upper Mississippi Valley, Fri, Jun 26.
– Heavy rain across portions of the Great Lakes, the Northeast, the Central Appalachians, and the Ohio Valley, Sat, Jun 27.
– Heavy rain across portions of the Central Appalachians and the Ohio Valley, Sat-Sun, Jun 27-Jun 28.
– Heavy rain across portions of the Northern Plains, the Northern Rockies, the Middle Mississippi Valley, the Northern Great Basin, the Upper Mississippi Valley, the Great Lakes, and the Ohio Valley, Sun-Mon, Jun 28-Jun 29.
– Heavy rain across portions of the Northern Plains, Tue, Jun 30.
– Flooding possible across portions of the Middle Mississippi Valley, the Great Lakes, and the Upper Mississippi Valley.
– Flooding occurring or imminent across portions of the Mid-Atlantic, the Upper Mississippi Valley, and the Northern Plains.
– Flooding likely across portions of the Middle Mississippi Valley and the Upper Mississippi Valley.
– High winds across portions of the Central Rockies, the Central Great Basin, California, the Northern Great Basin, and the Southwest, Sun, Jun 28.
– Much above normal temperatures across portions of California, the Central Great Basin, the Pacific Northwest, the Northern Rockies, and the Northern Great Basin, Fri, Jun 26.
– Much above normal temperatures across portions of the Central Plains, the Upper Mississippi Valley, and the Northern Plains, Sun-Mon, Jun 28-Jun 29.
– Heavy rain across portions of northwest mainland Alaska, Sat-Sun, Jun 27-Jun 28.
– High winds across portions of northwest coastal Alaska, Sat-Sun, Jun 27-Jun 28.
Detailed Summary:
The last five days of June are shaping up to be quite wet from the northern Rockies to the northern Appalachians. The period starts with heavy thunderstorms in south-central Texas and portions of the central Plains on Friday. Farther north, an area of low pressure over the Midwest on Friday heads east to the northern Great Lakes and southern Ontario on Saturday. Rounds of showers and thunderstorms should sweep across these regions with localized flash flooding and severe weather possible from eastern Iowa to northern New York. The cold front associated with this low pressure system could also trigger strong thunderstorms and heavy rain in the Ohio Valley on Saturday. Showers and thunderstorms remain in the forecast over western Pennsylvania and northern West Virginia due to a nearby frontal boundary and upslope flow on Sunday. By Sunday and Monday, a weak upper-level disturbance will cut beneath a building upper level ridge over southern Canada. This feature may lead to more opportunities for heavy rainfall and strong thunderstorms from the Midwest to the Ohio Valley.
To the west, abnormally hot conditions will continue in parts of the Pacific Northwest and northern California on Friday before temperatures begin to cool off this weekend. This is because of an intensifying upper-level low tracking over the Pacific Northwest that looks to move southeastward to parts of the Northern Rockies early next week. The upper-level low will pull in moisture from the Pacific and the Plains into the Northern Rockies. Heavy rain with embedded thunderstorms should develop over the region. Temperatures aloft are so cool for the time of year, however, that some precipitation may fall in the form of snow in the higher elevations of northern Idaho, western Montana, and northwestern Wyoming. To the south, a strong southwesterly jet sets the stage for potential high winds in the Great Basin and Intermountain West. Given recent history with dry humidity levels and wildfires, there could also be a heightened risk for fire weather in these regions early next week. Downstream of the upper trough, much above normal temperatures are possible in the Northern Plains and Upper Midwest by the end of the month, along with a threat for heavy rain and thunderstorms in the Dakotas.
Over Alaska, a low pressure in the Gulf of Alaska will dissipate as it moves eastward to the Alaska Panhandle on Friday. Expect rain over parts of the Aleutians with some showers as far north as the Alaska Ridge, but totals look to remain below thresholds. However, guidance is gravitating towards a more robust upper trough diving from the East Siberian Sea to the northwest coast this weekend. Rainfall totals have increased on most of model guidance with the Baird mountains most at risk for heavy rainfall. In addition, a tight pressure gradient could lead to strong winds along the Seward Peninsula coast. There will be more chances for showers across much of the mainland as the upper trough tracks over the state, while simultaneously ushering in a fairly chilly air-mass for late June.
(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
We will resume more detailed coverage when the summer is over.
We will update the above map weekly but more frequent updates can be obtained here.
There is not much snow left.
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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 |
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Tropical Weather Outlook NWS National Hurricane Center Miami FL 500 PM PDT Tue Jun 23 2020
For the eastern North Pacific…east of 140 degrees west longitude:
1. A nearly stationary area of low pressure is located about 1600 miles southwest of the southern tip of the Baja California peninsula. Although this disturbance has a well-defined circulation, it is producing only limited shower activity. Environmental conditions are expected to support the redevelopment of thunderstorms and the system is likely to become a tropical depression during the next few days while it moves slowly westward.
* Formation chance through 48 hours…medium…60 percent.
* Formation chance through 5 days…high…70 percent.
2. An elongated area of low pressure located several hundred miles southwest of the southern tip of the Baja California peninsula continues to produce a wide area of disorganized showers and a few thunderstorms. This system could become a tropical depression during the next day or two before it moves over cooler waters that will inhibit further development.
* Formation chance through 48 hours…medium…40 percent.
* Formation chance through 5 days…medium…40 percent.
3. Disorganized showers and thunderstorms located a few hundred miles south-southwest of the Gulf of Tehuantepec are associated with a tropical wave. Environmental conditions are forecast to be favorable for development, and the system is likely to become a tropical depression in a few days while it moves west-northwestward parallel to the coast of Mexico.
* Formation chance through 48 hours…medium…50 percent.
* Formation chance through 5 days…high…80 percent.
4. Another area of low pressure is forecast to form south of the Gulf of Tehuantepec by late this week. Gradual development of this system will be possible over the weekend as it moves west-northwestward parallel to the coast of Mexico.
* Formation chance through 48 hours…low…near 0 percent.
* Formation chance through 5 days…low…30 percent.
Updates on individual named storms can be obtained here.
And the Western Pacific
Week 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
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And then Precipitation
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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.
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. |
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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
| 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. |
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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 | |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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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