The North Atlantic tropics finally woke up after a weeks long period of dormancy…with the birth of Tropical Storm Beryl Thursday. The system formed in the west-central Atlantic after days in a formative stage as a tropical wave with no defined surface low.
Beryl is a very small system with tropical storm force winds only extending out 35 miles from the center of circulation Thursday night. However, it has continued to strengthen through Thursday Night and is expected to become a minimal hurricane later Friday.
Although the system is depicted to move near the Lesser Antilles late-Sunday, vertical wind shear…increasing wind speed with height…is expected to increase dramatically over Beryl as it approaches Sunday, leading to a rapid weakening and possible dissipation. This is highly likely given the small size of the circulation. However, regardless of what the status of the system is when it moves over the islands, accompanying what remains will be gusty winds, showers and thunderstorms and local downpours.
Meanwhile, in the Western Pacific, Maria has become a Category 5-equivalent super typhoon with maximum sustained winds of 160 mph. The first Category 5-equivalent cyclone observed in either the North Pacific or North Atlantic in 2018. Maria moved over Guam and the southern Mariana Islands as a tropical storm, bringing strong winds and locally heavy rainfall. Damage was reported to Rota’s power system, but no damage to personal property or injuries were reported. The system then became a typhoon west of the island chain, before rapidly intensifying to a Category 3-equivalent typhoon around 1800 UTC (1 pm CDT Thursday in the US), then to its present intensity (as of this post) several hours later.
Maria is expected to move generally northwestward over open water during the next three days. It will remain a powerful typhoon thanks to absolutely steamy waters warmer than 90 F/32 C, 1 C or more above normal. Afterwards, it will move over slightly cooler waters, but may remain a powerful Category 3 or 4 hurricane (115 mph+ winds) as it approaches some of the southern most small Japanese islands on Tuesday.
The most significant threats from Maria will be increasing high surf and rip currents for areas ahead of Maria (Philippines, southern Japan, Taiwan) followed by heavy rainfall and damaging winds for the remote southern Japanese islands as it moves closer toward mainland China midweek.
The North Pacific and North Atlantic appear to be fairly quiet as far as significant ocean storms. However, I wanted to make note of a likely developing tropical cyclone in the Eastern Pacific Basin (east of 140 W longitude). The US National Hurricane Center has pegged it with a 80% chance of development over the next 2 days before it moves northward toward much colder waters after Monday. It should be no threat to land at this time.
A couple of other tropical waves are ongoing east of the one mentioned above; one south of mainland Mexico, another offshore Central America. Numerical models indicate the two waves may merge and possibly form a tropical cyclone the second half of next week (after Tuesday). There’s also appears to be a favorable signal for elevated tropical cyclone development in the Eastern Pacific starting mid-week going into early the following week. Details become sketchy that far out of course, beyond the general pattern set up. The active pattern signals forecasters look for are 1) active monsoon trough…the convergence zone for abundant thunderstorm activity from Central America out over the very warm waters of the Eastern Pacific, 2) active Central American Gyre which provides thunderstorm complexes with mild spin as they move from land over open water, and 3) a low wind shear environment over the open ocean for systems to form without disruption. And with more cyclones means greater risk for landfall impacts as were seen with Bud and Carlotta. Waters over the basin continue to be abnormally warm (1-1.5 C/2-3 F above normal generally) relative to mid to late-20th century norms.
So something to watch later next week for more significant impacts to either Mexico or the Southwest US for remnant moisture yet again.
Brief update. Parts of Southeast Texas continue to face locally heavy rain this evening. Things should begin to improve tomorrow, but more of the same through tonight unfortunately. Hidalgo County, TX along the border with Mexico (in the Rio Grande Valley) suffered significant flooding in multiple communities, including Weslaco and Mercedes. The Weather Channel showed live footage this afternoon of people wading in the water and cars driving through flooded roads (please do not ever do that!). See their news story on the events in Texas HERE. Rainfall is currently impacting portions of far south Texas and near Houston and Galveston which have yet to receive significant heavy rainfall.