Category: General Weather

Hurricane Fiona is grabbing the headlines, but it’s not the only area we’re watching this week.

Hurricane Fiona produced strong winds and catastrophic flooding across parts of the northeastern Caribbean over the weekend, especially Puerto Rico, and today it’s the Dominican Republic’s turn. Once it moves back into the Atlantic later today, a northward track is expected for the next few days. It may bring strong winds and heavy rain to the Turks and Caicos as well as parts of the southeastern Bahamas over the next few days, but as it moves over open water, additional strengthening is expected. By the latter half of the week, it could have Bermuda in its sights. Its still too early to determine what, if any, impact it will have on Bermuda, but anything from a glancing blow to a direct hit as a major hurricane is possible. By the end of the week,, it should be heading out into the North Atlantic and starting to weaken, though residents of Atlantic Canada and Newfoundland should keep an eye on Fiona.

Out West, an early-season storm will bring some much-needed rainfall to parts of California over the next few days. The rain began Sunday, but will continue into Tuesday or even Wednesday in parts of the state. Some spots could pick up 1-2 inches or more by the time everything winds down. This will help put a small dent in the ongoing drought across the state, but will also be a big help to the firefighting efforts for the numerous wildfires burning across the region.

Heat will return to the nation’s midsection over the next few days, gradually spreading into parts of the Mississippi Valley and the Deep South as the week goes on. High temperatures well into the 90s and possibly lower 100s are expected, which is 10-to-20 degrees above normal for late-September. Many record high temperatures are expected over the next several days.

While heat covers much of the nation, late in the week, cool weather will be the story from the Northern Plains to the Northeast. A strong cold front will produce some rain across these areas during the latter half of the week, but behind that front, much cooler air will settle in. Frost and freezing temperatures may bring an end to the growing season from parts of the Great Lakes into northern New England by the end of the week. In fact, as that front moves through, the rain may mix with or even change to wet snow across some of the higher elevations of northern New York and New England Thursday night and early Friday. While this is a bit early, it’s not that unusual for some of the higher peaks to see snow in late September. Atop New Hampshire’s Mt. Washington snow has already been reported a couple of times this month.

A rather active week is expected across much of the nation for the first full week of meteorological autumn.

A large ridge of high pressure remains in place across the West for a good portion of the upcoming week. As a result, the intense heat wave will continue from the Front Range of the Rockies westward to the Pacific Coast. Daily high temperatures well into the 90s and 100s are expected across the region, with many places across parts of interior California and the Southwest likely topping 110 degrees. Dozens of record highs are expected during each of the next several afternoons. Excessive Heat Warnings and Heat Advisories remain in effect for many locations. The heat, combined with low humidity and gusty winds will also result in a high fire danger for many areas. Fire Weather Watches and Red Flag Warnings are in effect for parts of the region. In addition to some of the ongoing fires, any new ones that develop could rapidly spread in this pattern.

Meanwhile, a slow-moving frontal system will bring some heavy rain from the Tennessee and Ohio Valleys into parts of the Mid-Atlantic states and the Northeast over the next few days. Many places could receive 1-3 inches of rain over this time frame, with some heavier totals possible. In the Ohio and Tennessee Valleys, this is not good news, as it will likely result in flooding in many locations. Flood Watches are in effect for parts of the area. From the Mid-Atlantic into the Northeast, the rain will be very welcome, despite much of it falling on Labor Day, as much of the region has been under a severe to extreme drought for the past few months. Any rain that falls is welcome, as it will help to replenish the rivers, lakes, ponds, and reservoirs across the region. With all of the cloud cover and rain, temperatures will be as much as 6-12 degrees below normal across parts of the area today and again on Tuesday.

Across the Southwest, what has been a very wet monsoon season thus far has slowed day in recent days, but that could change later this week. Tropical Storm Kay developed off the southwest coast of Mexico on Sunday. The current forecast calls for it to strengthen into a hurricane in the next few days while turning northwestward, paralleling the coast of Mexico. It could impact parts of the Baja California peninsula later this week. By the end of the week, the moisture from the system (or what’s left of it), may spread into parts of the Southwest, enhancing the monsoon once again and bringing the threat for flooding to parts of Arizona and southern California.

Elsewhere in the tropics, we have two named systems in the Atlantic – Hurricane Danielle and Tropical Storm Earl. Danielle is centered about 950 miles west of the Azores, but should start heading off toward the northeast and east over the next few days. Maximum sustained winds are near 90 mph, but as it moves over colder waters over the next few days, it will weaken and likely will become extratropical later this week. It may bring gusty winds and heavy rain to parts of the British Isles by the end of the week, after the system currently doing the same weakens and moves away from the UK.

Meanwhile, Tropical Storm Earl is gradually strengthening in the waters north of Puerto Rico and the Virgin Islands. Heavy rain and gusty winds will wind down across the islands today as Earl pulls away to the north. The forecast for Earl is fairly simple of the next day or two – it will continue in a general northerly direction while strengthening, and could become a hurricane. Beyond that, there is some uncertainty. Most of the models show an upper-level trough moving across the central Atlantic pulling Earl off toward the northeast and out into open water. However, if that trough does not pull Earl out to sea, it could continue northward or even northwestward, which would increase the threat Earl may pose to Bermuda, before another trough comes along and eventually does send Earl out to sea.

In the Western Pacific Ocean, Typhoon Hinnamnor will pass close to or across southeastern portions of South Korea today, with top winds likely still in the 100-110 mph range. Storm surge will likely be confined to just a small portion of the South Korean coastline, but that area includes the city of Busan, the 2nd most populous city in South Korea. Busan is also the 6th busiest port in the world. Heavy rain and gusty winds are likely across much of the Korean Peninsula, but also could impact parts of Japan over the next few days as the system heads northeastward while weakening and becoming extratropical.

The weather pattern across the US isn’t that active at the moment, but the Atlantic may be starting to get active finally.

A persistent trough of low pressure will remain in place across the Southeast and Florida for the next few days. This will act as a focus for shower and thunderstorm activity across the region. Severe weather will be very isolated in nature, but some heavy rainfall totals are possible, especially across much of Florida, southern Georgia, and coastal portions of the Carolinas. Many locations will receive 1-3 inches of rain over the next several days, with isolated totals in excess of 5 inches possible in spots. This will likely lead to some flash flooding.

Out West, where the monsoon has been quite active this summer, it will slow down this week, allowing heat to return. Excessive Heat Watches have been issued for parts of the Desert Southwest and Southern California. Triple digit highs are likely across the Southwest and interior California several days this week, as well as portions of the interior Northwest. Highs will soar well past 90 across much of the remainder of the West through the week, with numerous record highs possible each afternoon into next weekend.

Meanwhile, as we enter the peak of hurricane season, the Atlantic appears to be awakening from its 2 month slumber. There are several areas that the National Hurricane Center is keeping an eye on, but the most immediate threat appears to be a tropical wave and associated low pressure area several hundred miles east of the Lesser Antilles. The area is showing signs of organization, and conditions are somewhat favorable for development over the next few days. Most of the forecast the system to head northwestward for the next few days, passing north of the Lesser Antilles toward the end of the week. In terms of strength, several models either keep the system very weak or don’t develop it at all, and others do allow for some significant development. It could become a tropical depression later this week, but there are still significant questions as to the future of this system or if it even has a future.

There are a couple of other tropical waves we’re keeping an eye on. One of them is in the western Caribbean, and will bring some heavy rain and gusty winds to parts of the Yucatan and Central America today and tomorrow. Once it moves into the Gulf of Mexico, some forecast models show the potential for development, but others do not, so that wave will need to be monitored. Another wave will move off the coast of Africa tonight, and take its time crossing the Atlantic this week. Again, there are some models that show the potential for development, but others that don’t, so it will need to be monitored as well.