“Superbomb” storm in northeast Pacific

An interesting weather event is forecast to evolve in the northeastern Pacific over the next 24-48 hours. The remnants of Tropical Storm Namtheun are in the process of converting into an extratropical storm system in the northern Pacific. This process will continue on Wednesday and Thursday and the system will rapidly deepen and intensify.

The system will intensify so much that the central pressure is forecast to drop to 950 mb or lower. This is a greater than 48 mb drop in barometric pressure in a short period of time. Because of such a quick drop in pressure during the intensifcation process, this system will become what is known as a superbomb cyclone late Wednesday. This occurs when a storm system observes a drop in pressure of at least 48 mb within a 24 hour period.

European 850 hPa Wind Speeds in knots (WeatherModels.com)
European 500hPa Geopotential Height (WeatherModels.com)

This storm is forecast to bring impacts to parts of British Columbia and Alaska late this week.

Los Angeles & SoCal rain

Light rain showers and patchy drizzle are in the forecast for SoCal tonight and Monday morning. The precipitation is expected to begin after midnight and continue a couple of hours after sunrise for coastal parts of SoCal. This includes Los Angeles, Long Beach, and San Diego.

Here is the simulated radar over the next several hours.

Simulated radar

Amounts are forecast to be light. Most areas will see less than one-tenth of an inch, however, spot areas could see up to a quarter of an inch of rain by midday Monday.

Rainfall forecast

This will make for a slippery commute. Give yourself extra time on the roadways.

Frost Advisory issued for parts of the Southeast and Carolinas

A chilly night is in the forecast for the South, Southeast, Tennessee Valley, and Carolinas. Temperatures will fall into the 40s with quite a few areas dipping into the 30s. The 30s are most likely across Tennessee, northern Mississippi, northern and central Alabama, northern Georgia, Upstate South Carolina, and the mountains and western North Carolina. This is where temperatures will fall between 33 and 39 degrees tonight. Join the Firsthand Weather Supporter Group today!

Fig. 1: Monday morning temperatures

Taking a deeper dive into the temperatures tonight, here is a look at more localized temperatures across northern Georgia and the Carolinas tonight.

Fig. 2: Monday morning temperatures for north Georgia
Fig. 3: Monday morning temperatures for the Carolinas

Because of the temperatures falling into the 30s, Frost Advisories have been issued for northeastern Georgia, western Tennessee, and the mountains of North Carolina tonight and early Monday morning. Frost is also possible outside of the Frost Advisory for the aforementioned areas that will fall into the 30s. Make sure you protect sensitive vegetation. Here is a look at the Frost Advisory (areas shaded in blue). Join the Firsthand Weather Supporter Group today!

Frost Advisory

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Chilly air moving into the South & Southeast

The much anticipated cold front is racing through the Southeast this afternoon. Behind the cold front, drier and cooler air is surging south. This will lead to pleasant afternoons over the next couple of days with highs in the 60s & 70s and chilly mornings. Lows will fall into the 40s for many areas with a few upper-30s for Tennesse, northern Mississippi, northern Alabama, northern Georgia, and western North Carolina. Enjoy and bundle up!

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Severe storms and isolated tornadoes are possible this afternoon and evening from the Mid-South into the Northeast

There is a slight risk (yellow area) of severe storms this afternoon and evening from the lower Mississippi and Tennessee Valley into the Ohio Valley and western parts of the Northeast (see Fig. 1). A potent cold front will work its way into the region, sparking showers and storms along and ahead of the cold front. These storms will become strong with a few reaching severe levels. The storms will have the capability to produce heavy rainfall, cloud-to-ground lightning, damaging wind gusts, hail, and isolated tornadoes.

Click here for a detailed forecast on today’s severe risk areas along with which areas have the highest chance to see tornadoes.

Fig. 1: Today’s severe risk

If you live in the slight (yellow) or marginal (dark green) severe risk areas, please keep a close eye on the forecast and be prepared to seek shelter if a warning is issued.

Chilly, fall air to move into the Southeast this weekend

The warm and humid weather as of late will abruptly end over the weekend as a strong cold front moves through the region. A potent upper-level storm system out west, that’s been dumping snow in the mountains, will continue to slowly move east. This storm system will send a cold front south and east into the South, Tennesee Valley, Southeast, and Carolinas this weekend.

The cold front will move into areas west of the Mississippi River overnight Friday and will move through the entire Southeast on Saturday. Temperatures will fall below average from Sunday (October 17) through Tuesday (October 19). Morning temperatures will actually be quite chilly! See how long the cool air will stick around, how low temperatures will go, along with details on a couple of other cold fonts in the forecast.

Fig. 1: Surface temperature departure from average once cold front moves through

Fall air to rush into the South and Southeast this weekend

It has been warm and humid across the South and Southeast as of late. This has left many people wondering when fall will arrive. To answer the question: soon–at least temporarily. A potent upper-level storm system out west will slowly move east throughout this week. That storm system will send a cold front south into the Southern Plains in a few days, followed by the cold front sneaking east into the South and Southeast late this weekend into early next week.

Temperatures will fall below average across the region from October 17 through October 19. Morning temperatures will actually be quite chilly! See the timing of the cold front, how long the cool air will stick around, and how low temperatures will go.

Fig. 1: Surface temperature departure from average early next week

Pattern change to deliver a BIG cool down to the South & Southeast

Tired of these summer-like temperatures? A pattern change will develop late this upcoming week, which will usher in cooler air into the South & Southeast by next weekend (October 16 & 17). Temperatures will fall below average with the cold front. See the timing of the cold front, how long the cool air will stick around, and how low temperatures will go.

Fig. 1: Temperature departure from average next weekend

A second stronger cold front also looks to be in the works for this region, delivering temperatures well below average. Get the latest here.

Fig. 2: Temperature departure from average with second cold front

Strong, violent tornadoes are possible today

This afternoon and evening will be active for the Southern Plains as a cold front moves into the region. This cold front, paired with a dryline, will help trigger storms in western Oklahoma and northwestern Texas late this afternoon. These storms will rapidly intensify as the move east becoming severe. There is a moderate [red] severe risk (level 4/5) and an enhanced [orange] severe risk (level 3/5) for a good chunk of Oklahoma and northern Texas. This is where numerous severe storms are expected. A slight [yellow] (level 2/5) and marginal [dark green] (level 1/5) risk surround the enhanced and moderate risk.

Fig. 1: Zoomed-in severe risk this afternoon/evening

All modes of severe weather are possible this afternoon/evening. This includes tornadoes, hail, and winds. A few strong, violent tornadoes and very large hail cannot be ruled out, especially in the enhanced risk area.

Fig. 2: Severe risk area this afternoon/evening (top left) along with the tornado (bottom left), hail (top right), and wind (bottom right)

It is best to prepare now for the severe storms. Here are some tips on how to best stay safe during severe weather and tornadoes.

Fig. 3: Severe weather safety tips

Increasing chance for tropical development off the coast of the Carolinas this weekend

A low pressure off the coast of the Carolinas has a medium chance to develop over the weekend into a subtropical or tropical depression or storm. The low pressure has started to slowly gather strength and organization over the past 24 hours. It appears the environmental conditions are growing increasingly conducive for development this weekend. The system will not ramp up quickly, so if it develops, it should remain weak. Regardless, impacts are possible for the Carolinas. See the expected impacts here.

Chance for tropical development this weekend (WLTX)