Written by Sig Silber
HEADLINES (Updated 3:28 PM EDT) –
– Excessive heat continues today over the interior Pacific Northwest, the South-Central U.S., and the Deep South before a cooling trend begins in on Sunday
– Strong to severe thunderstorms with locally heavy rainfall from the Central Plains and mid-Mississippi Valley to the Southeast this afternoon reaches the Gulf Coast for Sunday and Monday
– More rounds of monsoonal moisture expected across the interior western U.S. with flash flooding possible from the Great Basin to 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.
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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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CONUS Focal Points
Short Range Focal Points
Short Range Forecast Discussion NWS Weather Prediction Center College Park MD
319 PM EDT Sat Jul 31 2021
Valid 00Z Sun Aug 01 2021 – 00Z Tue Aug 03 2021
…Excessive heat continues today over the interior Pacific Northwest, the South-Central U.S., and the Deep South before a cooling trend begins in on Sunday…
…Strong to severe thunderstorms with locally heavy rainfall from the Central Plains and mid-Mississippi Valley to the Southeast this afternoon reaches the Gulf Coast for Sunday and Monday…
…More rounds of monsoonal moisture expected across the interior western U.S. with flash flooding possible from the Great Basin to the Rockies…
Oppressive summer heat has taken a vacation this weekend throughout the Midwest, Great Lakes, and Northeast thanks to a cold front ushering in a much cooler and drier airmass. Saturday’s stifling heat across the Deep South and Southeast will improve slightly on Sunday but a hot and humid air-mass remains in place to close out the weekend. However, a cold front responsible for the injection of cooler and drier conditions in the Northeast this weekend eventually reaches the Deep South by Monday. Muggy conditions will likely persist along the Gulf Coast while comfortable humidity levels stick around in the Northeast and Great Lakes into start of the work-week.
Precipitation-wise, waves of low pressure developing along an elongated frontal boundary draped from the central High Plains to the Southeast is forecast to trigger organized thunderstorms that could produce isolated tornadoes, damaging wind gusts, and large hail today from Kansas to the Carolinas. In addition, heavy downpours associated with these thunderstorms could lead to flash flooding in the mid-Mississippi River Valley today. The threat for severe weather and flash flooding pushes south and east on Sunday as the cold front becomes positioned over the Deep South.
Farther north, a reinforcing shot of cooler air from Canada ushering in a swath of showers and some storms across the Great Lakes today reaches the Northeast by Sunday afternoon. This system will attempt to merge with one of the aforementioned waves of low pressure reaching the Mid-Atlantic coast by late Sunday and produce a period of strong to possibly severe thunderstorms near the Mid-Atlantic coast. By Monday, high pressure is in control from the Midwest to the Northeast while scattered thunderstorms set up shop along the Gulf Coast.
In the West, a ridge of high pressure aloft has anchored itself over the region and continues to generate excessive heat this afternoon across the interior Pacific Northwest. An influx of monsoonal moisture being advected in from the Southwest should cool down temps in the interior Pacific Northwest on Sunday. Speaking of monsoonal moisture, there is no shortage of it across the drought-stricken Intermountain West. However, there is such a deep reservoir of monsoonal moisture available that showers and thunderstorms are capable of producing heavy rainfall rates and could trigger areas of flash flooding. Locations most at risk for flash flooding are where antecedent soil conditions are overly saturated or near burn scars. As a result, a handful of Slight risks for Excessive Rainfall are in place from the Great Basin to the central Rockies today. The Excessive Rainfall threat on Sunday shifts a into areas such as Bitterroots and Snake River Valley as well as the southern High Plains. More rounds of heavy showers and storms are possible up and down the spine of the Rockies on Monday.
Lastly, Air Quality Alerts remain in effect for portions of Montana, Wyoming, Minnesota, Wisconsin, Iowa, and the Tennessee Valley due to smoke associated with raging wildfires over western North America being advected into the regions by prevailing north-northwesterly winds.
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 |
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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
A version that shows a 40 hour animation and some other views can be found here
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Day 3 – 7 Hazards
Valid Monday August 02 2021 – Friday August 06 2021
Hazards:
– Heavy rain across portions of the Southeast and the Lower Mississippi Valley, Mon, Aug 2.
– Heavy rain across portions of the Southeast and the Mid-Atlantic, Mon-Thu, Aug 2-Aug 5.
Detailed Summary:
During the medium range period (Monday, August 2nd – Friday, August 6th) the upper-level pattern is forecast to consist of significant troughing over the eastern half of the CONUS that gives way to the development of a cut-off low over the Ohio Valley mid-week. Conversely, in the west strong ridging aloft is expected to be in place at the start of the period before weakening as low pressure off the coast of British Columbia disrupts the flow regime and eats away at the adjacent high pressure.
For the majority of next week all eyes will be on the Southeast and Mid-Atlantic where a frontal boundary will likely remain locked in place, delivering a significant amount of rain to the East Coast. It all begins on Monday when a cold front extending from North Carolina to central Texas brings showers and thunderstorms to the southern states alongside a dissipating stationary boundary. Over the next couple days the western edge of the front will be quickly forced south to the Gulf Coast by a digging upper-level trough working in tandem with southward moving surface high pressure. It is during this time states located in the Lower Mississippi Valley as well as Alabama will receive the most rain, with 1 to 2+ inch accumulations in 24 hours possible. Given the high soil moisture and above to much above normal streamflow in these areas, localized flash flooding may occur. Although the frontal boundary is expected to deliver more rain to the Gulf Coast as it becomes quasi-stationary for the rest of the period, any heavy rainfall will likely remain offshore.
In contrast to the evolution of the western half of the cold front the eastern half is forecast to slightly swing to the southeast, but remain predominantly stationary, as a low pressure wave along the boundary lifts north into Georgia on Tuesday. Sandwiched by high pressure on either side, the front is forecast to settle in over the Florida Panhandle, Georgia, and the Carolinas as a quasi-stationary boundary for the remainder of the period, leading to a multi-day heavy rain event over the Southeast and Mid-Atlantic. Four-day rainfall totals of 3 to 6 inches, with isolated higher amounts, will be possible from the Florida panhandle through southern Virginia. These high accumulation totals combined with already wet soils will make the risk of localized and urban flash flooding a significant concern.
Out west showers and thunderstorms driven by the influx of monsoonal moisture, diurnal heating, and favorable dynamics will continue across the Rockies and High Plains through Wednesday night. Though rainfall totals are forecast to be on the moderate side throughout these regions, there is potential for isolated instances of heavy rain to occur. Additionally, fueled by the inland transport of moisture from the Gulf of Mexico, surface troughs over New Mexico and the Sierra Madre are expected to generate showers and thunderstorms with moderate to sometimes heavy rainfall across southeastern New Mexico and western Texas on Wednesday and Thursday. No significant temperature anomalies or extremes are anticipated over the CONUS during the medium range period. In fact, across the country daily highs are forecast to remain close to or below normal, save for the Northern Plains and Upper Midwest which will experience daily highs a few degrees above normal.
No hazards have been posted for Alaska on today’s graphic, however, there are multiple instances of potentially heavy rain during the period that are worth mentioning. The first of these instances will occur on Tuesday, when a small portion of the Alaska Panhandle that borders the Yukon Territory may receive up to 2 inches of rain, with isolated higher totals, ahead of a cold front moving south through the eastern Interior. The following day a low pressure/frontal system is expected to settle over and bring heavy rain to Graham Island, some of which may spread north into the very southern tip of the Panhandle. While deterministic models are in agreement with rainfall totals of 2+ inches affecting the area, ensembles point to the heaviest rain being farther south. Due to the uncertainty among the deterministic and ensemble forecasts, it was decided a heavy rainfall area will not be included on today’s graphic.
Meanwhile on the other side of the state, a cold front progressing east through the Alaska Peninsula is forecast to bring rain to the region, with the heaviest rainfall likely occurring in the northern portion. While most of the rain is anticipated to be moderate in nature, some isolated areas could experience heavy rain with totals between 1.5 and 2 inches. As the cold front makes its way through the western Mainland on Thursday and Friday, heavy rain will also be possible over the Southwest and Southcentral regions. However, a high degree of uncertainty exists regarding where the heaviest rain will fall and how much due to discrepancies among the models, precluding the inclusion of a hazard area at this time. Temperature-wise, for the first half of the period daily highs are forecast to sit 10 to 15 degrees above normal before leveling off by the end of the week. In spite of the anomalous heat, temperatures are not expected to exceed 85 degrees and will thus remain non-hazardous.
(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 snow coverage in the Fall
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Drought Coverage
We include drought information in this section.
More information can be found here.
July Drought Outlook.
Seasonal Outlook Issued May 20, 2021
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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
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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
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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