Written by Sig Silber
HEADLINES (Updated 4:26 PM EDT) –
– Dangerous and record-breaking heat will continue across a large portion of the western U.S. and the central Plains
– Severe thunderstorms and heavy rainfall producing flash flooding are possible throughout the Midwest today and Ohio Valley on Friday
– Tropical rains and an increasing threat for flash flooding are expected along the northern Gulf Coast beginning Friday
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.
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
311 PM EDT Thu Jun 17 2021
Valid 00Z Fri Jun 18 2021 – 00Z Sun Jun 20 2021
…Dangerous and record-breaking heat will continue across a large portion of the western U.S. and the central Plains…
…Severe thunderstorms and heavy rainfall producing flash flooding are possible throughout the Midwest today and Ohio Valley on Friday…
…Tropical rains and an increasing threat for flash flooding are expected along the northern Gulf Coast beginning Friday…
As a dangerous heatwave continues, Excessive Heat Warnings and Heat Advisories remain in effect across much of California, Nevada, Arizona, and Utah. Temperatures are expected to once again reach record-breaking highs across much of the region today, with several records likely to fall on Friday and Saturday as well.
Heat Advisories are also in effect for portions of the central Plains today. Well-above normal temperatures are expected today across the region, with record-breaking highs expected from Colorado to Iowa and Missouri. While a front dropping into the region is expected to offer some relief, temperatures are forecast to remain well-above average on Friday and into the weekend.
Farther to the north, severe thunderstorms are expected late this afternoon into tonight across portions of the upper Mississippi Valley. The Storm Prediction Center is indicating an Enhanced Risk for severe thunderstorms across southern portions of Minnesota and Wisconsin, and northern portions of Iowa and Illinois, where conditions are likely to become favorable for severe thunderstorms to develop. These storms will have the potential to produce damaging wind and large hail, as well as a few tornadoes. Heavy rainfall, resulting in localized flooding is also possible.
Severe storms are likely to develop farther south and east on Friday. The Storm Prediction Center is indicating an Enhanced Risk for severe thunderstorms across portions of Illinois, Indiana, and Ohio. Conditions across the region will likely become favorable for severe thunderstorms to develop — capable of producing damaging wind, large hail, a few tornadoes, and localized flooding.
Heavy rainfall and windy conditions are expected to develop along the northern Gulf Coast on Friday before spreading north over the weekend. A broad area of low pressure over the southwestern Gulf of Mexico continues to become better organized. This system is expected to move generally to the north, and a tropical or subtropical depression is likely to form over the west-central Gulf of Mexico tonight or early Friday.
The National Hurricane Center has indicated that a Tropical Storm Warning will likely be required for a portion of the northern Gulf Coast later today. Regardless of development, heavy rainfall will be likely with the potential for flooding increasing along the coast Friday and Saturday.
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 Saturday June 19 2021 – Wednesday June 23 2021
Hazards:
– Heavy rain across portions of the Southeast, the Southern Appalachians, the Lower Mississippi Valley, the Southern Plains, and the Tennessee Valley, Sat-Wed, Jun 19-Jun 23.
– Heavy rain across portions of the Middle Mississippi Valley, the Great Lakes, and the Upper Mississippi Valley, Sun-Mon, Jun 20-Jun 21.
– Flooding occurring or imminent across portions of the Southeast, the Lower Mississippi Valley, the Southern Plains, and the Tennessee Valley.
– Excessive heat across portions of the Central Great Basin, the Northern Rockies, the Central Rockies, California, the Northern Great Basin, the Pacific Northwest, and the Southwest, Sat-Wed, Jun 19-Jun 23.
– Excessive heat across portions of the Central Great Basin, California, and the Southwest, Sat-Mon, Jun 19-Jun 21.
– Excessive heat across portions of the Southern Plains, Sun-Wed, Jun 20-Jun 23.
Detailed Summary:
The medium range hazards forecast period (June 19th-June 24th) continues to feature dangerous heat across the Western U.S., while heavy rain threatens the Gulf Coast beginning this weekend ahead of an area of disturbed weather located over the Gulf of Campeche. Additional heavy rain is possible over parts of the Midwest and Southeast early next week ahead of a series of frontal systems.
No significant changes to the thinking regarding the Western U.S.heat wave: dangerous temperatures will continue into next Wednesday throughout the region, associated with strong subsidence and dry soils below an abnormally strong upper ridge. By the 19th, the ridge axis will gradually migrate east before flattening early next week as a closed low develops off the California coast while a vigorous trough digs over the Midwest. However, this transition will occur gradually, and temperatures will remain 10-15 degrees above normal until at least the 21st in California, southern Nevada, and Arizona. In fact, locations in the Sacramento Valley could see 110 degrees this weekend, with even higher temperatures approaching 120 are possible in Southern California and Arizona. As such, a very high heat risk for the entire population extends over the area Saturday and Sunday, per experimental National Weather Service HeatRisk guidance.
Temperatures moderate slightly across the southern Excessive Heat area on the 21st with the approach of the closed low, although they are still warm and slightly above average. Elsewhere, a strong cold front associated with the Central U.S. trough will dive south from Canada Monday the 21st, and usher in much below average temperatures to the Northern Plains and Rockies. Post-frontal high temperatures quickly rebound north of the Great Basin to slightly above average on the 22nd, but overall heat indices remaining below 100 degrees prompted the removal of northeast portions from the Excessive Heat area. Hot temperatures continue through the 23rd from the Great Basin into the Pacific Northwest as the pesky ridge axis remains centered in the region, in spite of the overall flattening trend and eastward shift. Additional excessive heat is likely over South Texas beginning Sunday, where ensemble guidance highlighted a greater than fifty percent chance of exceeding 105 degree heat indices for multiple days as a tropical airmass surges out of the Gulf.
All eyes remain on Invest 92L located in the Gulf of Campeche, now with a high likelihood of tropical development over the next five days according to the National Hurricane Center. Over the last 24 hours, ensemble and deterministic model guidance has come into better agreement that by Saturday the 19th, this system will reside just offshore of far east Texas or Louisiana, bringing with it a plume of deep tropical moisture and subsequent significant heavy rain as it moves inland. Given the clustering of solutions toward the Texas-Louisiana border, have trimmed portions of the central Texas coastline, where heavy rain impacts appear less likely. However, it is emphasized that these forecasts can quickly change; users are encouraged to monitor the latest forecasts from the National Hurricane Center for the latest forecast information. As it stands, there are increasing concerns for potentially significant flooding along the central Gulf Coast, as heavy rain falls atop inundated soil from earlier flooding. An additional round of heavy rain is possible over the region from the 22nd-23rd as the aforementioned sweeping cold front interacts with remnant tropical moisture, potentially exasperating the situation.
North of the potential tropical system, some heavy rain is possible over parts of the Ohio Valley from the 19th-20th as a leading cold front may interact with the rich moisture moving north. Uncertainty regarding the influence of tropical storm track and the progressive front precludes a heavy rain area. More certain is the heavy rain over Corn Belt from the 20th-21st as convection initiates along and north of a warm front with the abundant moisture firmly in place. The Great Lakes will also be monitored for heavy rain from the 21st-22nd as the main cold front moves across the region with potentially favorable upper dynamics, but as of now the overall system appears to be too progressive to warrant a heavy rain area.
No hazardous weather is expected for Alaska across the current medium range hazards forecast period.
(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
We will resume snow coverage in the Fall
– Return to Directory
Drought Coverage
We include drought information in this section.
More information can be found here.
June Drought Outlook.
Seasonal Outlook Issued June 17, 2021
Here is the short version of the discussion that was released with the new forecast.
Latest Seasonal Assessment – Hot, dry weather continued to exacerbate drought conditions across the West, where close to 90 percent of the Western Climate Region is currently experiencing drought conditions, and more than 50 percent of the region is experiencing severe to exceptional drought. Abnormally warm conditions also promoted drought expansion across the northern Plains and parts of the upper Midwest in the last 30 days. In contrast, copious rainfall and below average temperatures eased drought conditions across much of Texas and parts of the Southern Plains. Additionally, pockets of drought have persisted in southern Florida, the mid-Atlantic, and Carolinas, while drought continued to expand across northern New England, highlighted by much below normal streamflows. During the upcoming three months, little relief is anticipated across California and the Great Basin, where much of the region is in its dry season and abnormal warmth is favored to persist. Monsoon convection may bring localized relief to parts of southern Arizona and New Mexico, while below-average precipitation favored for the Northwest CONUS may promote continued drought development. The forecast is more uncertain across the Great Plains and Midwest, where summer convection may ease drought locally, but is unlikely to overturn the longer term drought conditions. Drought development is possible in climatologically drier portions of the north-central High Plains. Along the Eastern Seaboard, the CPC seasonal outlook indicates enhanced chances for above-median rainfall, which would help ease the remaining drought conditions. No drought development is anticipated in Alaska, while forecasts for below-average dry season rainfall across Hawaii favor continued drought expansion. The onset of the summer wet season favors continued drought reduction in Puerto Rico.
– Return to Directory
Tropical Events
Atlantic and Gulf of Mexico
The Eastern Pacific
The Central 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
|
|
|
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
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 |
 | |
