Written by Sig Silber

HEADLINES (Updated 4:05 PM and 7:29 PM EDT) –

– Heavy Monsoonal rainfall continues in the Desert Southwest, creating significant concern for flash flooding and excessive rainfall throughout the weekend

– Severe thunderstorms possible from the Northern Plains to the Upper Great Lakes through Sunday morning

– Elevated Risk of Fire Weather for portions of the Northern High Plains, Northern Rockies, and Northern Great Basin through Saturday morning

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

350 PM EDT Fri Jul 23 2021

Valid 00Z Sat Jul 24 2021 – 00Z Mon Jul 26 2021

…Heavy Monsoonal rainfall continues in the Desert Southwest, creating significant concern for flash flooding and excessive rainfall throughout the weekend…

…Severe thunderstorms possible from the Northern Plains to the Upper Great Lakes through Sunday morning…

…There is an Elevated Risk of Fire Weather for portions of the Northern High Plains, Northern Rockies, and Northern Great Basin through Saturday morning…

During the short-range period all eyes will be on the Desert Southwest, where monsoon driven heavy rainfall is forecast to persist throughout the weekend. An upper-level low retrograding over the Texas/New Mexico border will aid in ushering highly anomalous moisture into the region as well as provide strong forcing for ascent, thus providing ingredients that could allow developing storms to produce high rainfall rates from 1-2″/hr and widespread accumulations of 2-4+”. These rates combined with the antecedent saturated soils and numerous burn scars scattered throughout the area will be a significant cause of concern for widespread flash flooding events. As such, the Weather Prediction Center has issued a Moderate Risk for Excessive Rainfall for portions of Arizona and New Mexico that will be carried through Sunday morning. A Slight Risk for Excessive Rainfall is also in place for portions of southwest Utah, central New Mexico, and southwest/central Colorado where slow moving convection and strong upslope enhancement could produce heavy rain in some isolated areas. Flash Flood Watches are currently in effect for much of Arizona and the aforementioned regions.

Meanwhile, a cold front extending from the Upper Midwest through the Northern Plains is expected to slowly propagate to the south and east through the Great Lakes before reaching the Central Appalachians by Sunday evening. Showers and thunderstorms are forecast to develop along and ahead of the front, leaving behind light to moderate rainfall totals. Moderate forcing and instability along the front will allow for some severe thunderstorms with damaging winds and large hail to develop.

The Storm Prediction Center has issued a Slight Risk for severe thunderstorms from the central Dakotas to the western edge of Lake Superior. As the front progresses east into the Great Lakes the severe thunderstorm risk is forecast to shift east as well. From Saturday into Sunday morning severe thunderstorms will likely develop over portions of Michigan and coastal areas around southern Lake Michigan that could produce damaging winds, large hail, and an isolated tornado or two.

Elsewhere, an Elevated Risk for fire weather is in effect for portions of the Northern High Plains, Northern Rockies, and Northern Great Basin through Saturday morning. Drought conditions, gusty winds, and dry fuels will aid in producing conditions favorable for the development and/or spread of wildfires. Red Flag Warnings are currently in effect for much of Montana and portions of Idaho.

Off the southeastern coast, an area of low pressure and its associated stationary boundary will be the focus for showers and thunderstorms over Florida and its adjacent states through Sunday. The low pressure area itself is currently under watch by the National Hurricane Center and may develop into a tropical depression over the next couple of days.

Temperature-wise much of the country will experience temperatures at or close to normal. An exception to this rule will be the Desert Southwest, which will experience moderately below normal temperatures due to the increased cloud cover from monsoonal activity keeping temperatures unseasonably cool. Conversely, portions of the Central Plains and Upper/Middle Mississippi Valley will experience temperatures 5 to 10 degrees above normal on Saturday, with daily highs reaching the mid 90s. Heat Advisories are currently in effect for potions of the Middle Mississippi Valley and eastern Central Plains while an Excessive Heat Warning is in effect for the Kansas City metro area. On Sunday, above normal temperatures will be felt in northern California and the Northern Great Basin, where daily highs are forecast to hit the high 90s and low 100s.

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

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Day 3 – 7 Hazards

Valid Monday July 26 2021 – Friday July 30 2021

Hazards:

– Heavy rain across portions of the Mid-Atlantic, Mon, Jul 26.

– Flooding occurring or imminent across portions of the Lower Mississippi Valley.

– Excessive heat across portions of the Lower Mississippi Valley and ArkLaTex, Mon-Fri, Jul 26-Jul 30.

– Excessive heat across portions of the Northern High Plains, Mon-Tue, Jul 26-Jul 27.

– Excessive heat across portions of the Upper and Middle Missouri Valley, Mon-Wed, Jul 26-Jul 28.

– Excessive heat across portions of the Lower Missouri Valley and Middle Mississippi Valley, Wed-Thu, Jul 28-Jul 29.

– Excessive heat across portions of the interior Pacific Northwest, Thu-Fri, Jul 29-Jul 30.

– Much above normal temperatures across portions of the Northern Great Basin, Mon, Jul 26.

– Much above normal temperatures across portions of the Northern and Central Plains and the Midwest, Mon-Thu, Jul 26-Jul 29.

– Heavy rain across portions of mainland Alaska, Tue-Wed, Jul 27-Jul 28.

Detailed Summary:

A heat wave across the central and western U.S. highlights the hazards outlook for the medium-range forecast period (Monday, July 26 – Friday, July 30). At the start of the period, a persistent upper-level ridge will remain anchored in place over the Central Rockies. A combination of high temperatures and high humidity lead to several Excessive Heat areas through the forecast period. High temperatures in the mid-100s are forecast for eastern Montana on Monday (July 26) and Tuesday (July 27). Mid-100s are also forecast for portions of the Upper Missouri Valley Monday through Wednesday (July 28), with upper 100s possible for central South Dakota.

Further to the southeast, higher humidity will result in hazardous heat indices with dew points in the low to mid-70s in place throughout the Lower and Middle Mississippi and Missouri Valleys. High temperatures in the low to mid-100s combined with high humidity will lead to heat indices above 105 for the Middle Missouri Valley Monday through Wednesday. A back door cold front from the northeast combined with strengthening troughing to the east, weakening the ridge, should provide a slight cool down for the Upper and Middle Missouri Valley by Thursday.

However, high temperatures and moisture will begin to increase for the Middle Mississippi and Lower Missouri Valley. Highs in the upper 90s are forecast on Wednesday and Thursday (July 29), with dewpoints potentially rising as high as the upper 70s. Widespread heat indices over 105 are expected, with the potential for heat indices over 110 for urban areas such as St Louis. The southward moving front and strengthening trough over the eastern U.S. look to provide at least some relief by Friday (July 30) for these areas as well.

Further south, Excessive Heat is expected throughout the forecast period for portions of the Lower Mississippi Valley and ArkLaTex. Daily highs in the upper 90s to 100 degrees combined with the high humidity will keep peak heat indices consistently over 105 each day, with locally higher heat indices of 110 possible.

In addition to the noted Excessive Heat areas, above normal temperatures in the lower to mid-100s that have been in place across portions of Idaho and the the northern Great Basin look to continue into Monday. High temperatures across the Northern and Central Plains as well as western portions of the Midwest will remain much above average from Monday through Thursday as well, with highs outside of the Excessive Heat areas generally in the mid- to upper 90s.

On Thursday, the ridge will expand to the northwest, bringing hot weather back to the interior Pacific Northwest. Excessive Heat is expected both Thursday and Friday. On Thursday, high temperatures in the mid-90s are forecast for the Willamette Valley; around 100 for eastern Washington, northeastern Oregon, and western Idaho; and into the mid-100s for the Rogue Valley. Highs will climb into the 100s for eastern Washington, northeastern Oregon, and western Idaho on Friday. It is important to note that with the upper-level ridge in place, potentially hazardous heat could be seen on different days in different areas across the central and western U.S. The designated outlook areas were chosen to highlight regions and times when more widespread, higher temperatures and heat indices appear most likely.

In addition to the heat, showers and thunderstorms developing along a surface trough and southward moving cold front are expected to produce heavy rain for portions of southeastern Virginia and northeastern North Carolina on Monday. A series of fronts progressing slowly across the eastern U.S. may produce additional instances of heavy rain, particularly for New England on Wednesday. However, differences in model guidance on the timing and placement of any heavy rain preclude additional outlook areas at this time.

In Alaska, showers associated with a stationary boundary over the northern mainland are expected to lead to the threat for heavy rain across portions of the western and northwestern mainland on Tuesday and Wednesday. The threat appears to be most significant and longer in duration for the southern Seward Peninsula, where daily rain totals of 1-2 inches are possible. After Wednesday, model guidance begins to diverge in terms of the location of any additional heavy rain threats.

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

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

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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