Written by Sig Silber

HEADLINES (Updated 5:39 pm EDT) –

“– Tropical Storm Hanna to produce heavy rainfall for parts of the Gulf Coast this weekend; Tropical Storm Warnings up for the Texas Coast

– Heavy Rainfall/flash flooding possible for parts of the Southwest, Rockies, and the Northern and Central Plains over the next few days

– Cooler temperatures to return to the West”

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 358 PM EDT Fri Jul 24 2020

Valid 00Z Sat Jul 25 2020 – 00Z Mon Jul 27 2020

…Tropical Storm Hanna to produce heavy rainfall for parts of the Gulf Coast this weekend; Tropical Storm Warnings up for the Texas Coast…

…Heavy Rainfall/flash flooding possible for parts of the Southwest, Rockies, and the Northern and Central Plains over the next few days…

…Cooler temperatures to return to the West…

Tropical Storm Hanna has become more organized as its been tracking across the western Gulf of Mexico. Per the National Hurricane Center’s latest forecast, Hanna is expected to make landfall late Saturday afternoon/early evening over South Texas. Strong winds and heavy rain will proceed/accompany the storm along its path. Localized heavy rain may lead to flash flooding, in addition to possible minor to moderate river flooding. For more information on Hanna’s status as a tropical cyclone, see advisories from the National Hurricane Center.

Areas of locally heavy rain can be expected this weekend over the Four Corners region. Monsoonal moisture will be fairly steady during this period. Rainfall rates may be heavy at times with excessive rainfall a cause for concern in parts of Arizona and New Mexico on Saturday and Sunday, resulting in the issuance of a Slight Risk for flash flooding/excessive rainfall. Otherwise, much of the western U.S. can expect cooler than normal conditions with the upper-level trough in place.

Ridge over much of the central U.S. while keep temperatures much above average into Saturday from the Northern Plains to the Upper, with several locations only cooling off to the mid-70s during the overnight hours. A pair of low pressure systems along with monsoonal moisture curving around the ridge top will help fuel strong, organized thunderstorm activity. The environment will be very favorable for heavy rainfall across parts of the Plains and into the Upper Mississippi Valley/Upper Great Lakes region. Excessive rainfall will elevate the risk for flash flooding across this region this weekend.

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

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

Hazards:

– Heavy rain possible from Arkansas eastward across the interior Southeast into the Carolinas and southern Virginia, Wed-Fri, Jul 29-Jul 31.

– Heavy rain across portions of the central High Plains to central/southern Rockies, as well as along the central and eastern Gulf Coast, Mon-Tue, Jul 27-Jul 28.

– Flooding possible across portions of the central and southern Plains.

– Flooding occurring or imminent across portions of the northern and central Plains.

– Excessive heat across portions of the the Mid-Atlantic region, Mon-Tue, Jul 27-Jul 28.

– Much above normal temperatures across portions of the Pacific Northwest, Mon-Tue, Jul 27-Jul 28.

– Much above normal temperatures across portions of the northern Mid-Atlantic into southern New England, Mon, Jul 27.

– Heavy rain across portions of the Brooks Range and interior southeastern Alaska, Mon-Tue, Jul 27-Jul 28.

Detailed Summary:

Tropical Storm Hanna, currently moving generally westward toward southern Texas, is forecast to dissipate over the mountainous terrain of northern Mexico by next Monday according to the latest from the National Hurricane Center. The threat of heavy rain should be diminishing on Monday across southern Texas. However, lingering tropical moisture in the wake of Hanna could still bring heavy rain mainly along the central and eastern Gulf Coast next Monday and Tuesday.

Meanwhile, cooler and drier air behind a cold front will bring some relief from the heat and humidity first across the northern U.S., and then progressively eastward into the Northeast and the Mid-Atlantic by next Thursday. Before the arrival of the cold front however, much above normal temperatures are expected for parts of the northern Mid-Atlantic into southern New England on Monday. Meanwhile, high humidity farther south across a good portion of the Mid-Atlantic will make the heat feel very oppressive on Monday and Tuesday. By the middle of next week, the trailing portion of the front is forecast to stall across the Mid-Atlantic and the Tennessee Valley. This will increase the threat of heavy rain from Arkansas eastward across the interior Southeast into the Carolinas and southern Virginia from next Wednesday to Friday. Farther west, additional monsoonal moisture over the central/southern Rockies will spread eastward into the Plains ahead of the stalled front, which could lead to heavy rainfall Monday and Tuesday for these areas. Some quick-hitting heavy rain could also impact parts of the Ohio Valley and lower Great Lakes on Monday as thunderstorms are expected to form ahead of the cold front.

As the cool air mass settles into the northern and northeastern U.S. next week, the warm upper-level high will retreat westward into the western U.S. This pattern will promote above normal temperatures in the interior western U.S., especially for the Pacific Northwest where high temperatures are forecast to top the century mark for the interior valleys next Monday through Wednesday. The rest of the interior West should see above normal temperatures next week but at a tolerable level. Cooler air should spread into the Pacific Northwest toward the end of next week as the next Pacific cold front arrives.

Over Alaska, heavy rainfall associated with a weakening low pressure system across the southeastern mainland into the Panhandle should be tapering off on Monday. Farther north, models have trended toward a better defined low pressure system brushing across northwestern Alaska next week, with a well-defined front dipping into the area. A heavy rain area has been introduced for the Brooks Range for Monday and Tuesday along a stalled front ahead of a quick-moving low pressure system from northeastern Siberia. In contrast, the rain across interior southeastern Alaska appears more scattered and terrain-enhanced than earlier forecasts as models trend toward more ridging.

Finally, Hurricane Douglas continues to show a real threat to Hawaii with possible hurricane-force winds together with heavy rain and high seas on Sunday. The storm should most likely be weakening further as it tracks generally west to west-northwest across the outer islands of Hawaii toward the middle of next week.

(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

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

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

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

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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