Written by Sig Silber

HEADLINES (Updated 4:36 PM EDT) –

– Heavy rain and potential flooding for parts of the Central U.S. and the Desert Southwest

– Heat wave across the western U.S. abates in intensity through the end of the week

– Severe weather possible today over portions of the upper Midwest, and New England

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

405 PM EDT Wed Jul 14 2021

Valid 00Z Thu Jul 15 2021 – 00Z Sat Jul 17 2021

…Heavy rain and potential flooding for parts of the Central U.S. and the Desert Southwest…

…Heat wave across the western U.S. abates through the end of the week; some additional hot temperatures possible beginning this weekend…

…Severe weather possible today over portions of the upper Midwest, and New England…

The active summertime pattern of mainly afternoon/evening intense thunderstorms with heavy downpours will continue to make weather headlines through the middle of the week. This especially holds true for portions of the Upper Midwest, Central Plains, the Desert Southwest, and the Florida Peninsula. Through next week, a sprawling slow moving cold front currently positioned from northern Colorado into Quebec will meander southward, sparking thunderstorm development along the way each day. The front combined with several areas of enhanced lift aloft will support storms with high rainfall rates over the Upper Mississippi Valley today, where a Slight Risk of excessive rainfall remains until tomorrow morning.

In addition to the heavy rain threat today, an Enhanced Risk of severe weather extends from North-Central Iowa into West-Central Wisconsin through early tomorrow, per the Storm Prediction Center. Damaging winds are anticipated to be the primary threat over this area, although large hail and tornadoes are also possible.

Over the Desert Southwest, monsoon season is in full swing, and the upcoming week is expected to be no different. As rich monsoon moisture wraps into the region, afternoon and evening showers are expected to remain across the Four Corners each day, especially in southern Arizona and western New Mexico. Given relatively weak steering winds aloft, many of these storms will likely be slow moving and result in flash floods for canyons, burn scars, and other vulnerable areas. A Slight Risk for excessive rainfall is in effect over Central Arizona and far western New Mexico today, and Southeast Arizona/Southwest New Mexico tomorrow.

In the temperature department, the ongoing heat wave across much of the western U.S. is abating across the Southwest as monsoonal moisture increases, but noteworthy positive anomalies will still exist across interior portions of the Pacific Northwest and Great Basin through Thursday. Overnight low temperatures are expected to be above normal as well and across a greater portion of the western U.S. compared to the daytime highs.

Unfortunately, the return of triple digit highs are a distinct possibility over Central Montana beginning Saturday, before spreading into Idaho later this weekend as high pressure builds over the region. Accordingly, an Excessive Heat Watch is in effect beginning from Saturday through Wednesday evening.

Elsewhere, warm and humid conditions will persist across much of the Eastern U.S. through the end of the week before cooler weather arrives in time by 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

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Day 3 – 7 Hazards

Valid Saturday July 17 2021 – Wednesday July 21 2021

Hazards:

– Heavy rain across portions of the interior northern Mid-Atlantic, Sat-Sun, Jul 17-Jul 18.

– Heavy rain across portions of the Gila Mountains in eastern Arizona, Sat-Wed, Jul 17-Jul 21.

– Flooding possible across portions of the Middle Mississippi Valley, and the Upper Midwest.

– Flooding occurring or imminent across portions of northern Florida, the Middle Mississippi Valley, and eastern Texas.

– Excessive heat across portions of the northern Rockies and the northern Great Basin, Sun-Mon, Jul
18-Jul 19.

– Excessive heat across portions of the Northern Plains, Sat-Tue, Jul 17-Jul 20.

– Much above normal temperatures from across portions of the central and northern Great Basin, the northern to central Rockies, across the northern Plains, and into the Upper Midwest, Sat-Wed, Jul 17-Jul 21.

Detailed Summary:

During the medium range forecast period (Saturday, July 17th to Wednesday, July 21th), an upper-level trough settling across the Great Lakes and the Northeast will extend a cold front southwestward into the central Plains. The front is forecast to gradually push through the central U.S., then into the East Coast and across the Deep South by the middle of next week. Model guidance continues to indicate the likelihood of moderate rainfall ahead of this slowly advancing front but with a fair amount of uncertainty regarding if and where low pressure waves may form and develop along the front. The development of these frontal waves will be important in determining if and where heavier rainfall and thunderstorms will be triggered. No heavy rain areas are indicated across much of the central and eastern U.S. as well as the Deep South due to generally moderate rainfall amounts predicted along with a steady forward motion of the rain.

However, areas of heavy rainfall are possible especially near where low pressure waves form near the front, along with the possibility of mesoscale convective systems that may form in the Deep South ahead of the front toward the middle of next week. Nevertheless, portions of the interior Mid-Atlantic appear to be more susceptible to heavy rain associated with afternoon to early evening thunderstorms near a pre-frontal lee trough during the weekend.

Over the southern Rockies into the Desert Southwest, monsoonal moisture will keep a good chance of showers and afternoon/early evening thunderstorms through the medium-range period. Most areas should see rainfall below hazard levels at this time but the upslope portion of the Gila Mountains in eastern Arizona appears to be under the highest threat of heavy rain through the middle of next week when models indicate an increasing influx of the moisture from the south.

Meanwhile, the heatwave is expected to continue from the central and northern Great Basin eastward across the northern Plains and into the upper Midwest under a persistent upper ridge through much of the medium range period. The highest temperature anomalies are expected over the northern High Plains, where high temperatures into the triple digits are forecast through midweek next week. Excessive heat is indicated for this area. Excessive heat is also indicted along the Snake River valley and parts of the northern Rockies Sunday and Monday when the heat is forecast to be most intense. In addition, much of the Dakotas, northeast Wyoming, and the western half of Minnesota are experiencing severe to exceptional drought that will likely worsen due to the persistent heat and lack of rain.

For Alaska, a general increase in rain chances is expected for the western portions of the state by early next week as a series of occluded cyclones is forecast to steadily move into the Bering Sea. By midweek, models are indicating the possibility of moderate to perhaps heavy rain to reach southwestern Alaska ahead of a stronger occluded cyclone. However, no heavy rain areas are indicated for now due to a fair amount of uncertainty together with rainfall amounts generally less than 1.5 inches.

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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