Tropical Weather Update:
— Tropical Wave 26: This tropical wave moved across Trinidad and Tobago over the last 24 hours, bringing no significant change to weather acros T&T, beyond a surge in Saharan Dust.
— Tropical Wave 27: This tropical wave is embedded with a surge of Saharan Dust. A mild increase in low-level moisture and marginal instability may bring some showers, mainly north of T&T over the next 24 hours. No significant rainfall forecast.
— Tropical Wave 28: This tropical wave is located further east, forecast to move across the Lesser Antilles on Thursday. A dry atmosphere is forecast to persist, inhibiting showers. No significant rainfall is forecast, but we can expect isolated showers interrupting mostly sunny skies across T&T, particularly on Thursday.
— Tropical Wave 29: This tropical wave has just moved off the West African Coast, more than 5 days away from T&T. While it is too soon to tell definitive impacts, a notable surge of moisture is forecast to move across the Lesser Antilles at the beginning of next week, increasing chances of showers and possible thunderstorms.
— Tropical Depression Three: As of 11:00 AM, this tropical depression has dissipated as it curves away from the Southeastern U.S. Atlantic Coast.
— Gulf of Mexico Area of Interest: The National Hurricane Center is monitoring this area for the formation of a non-tropical low-pressure system, which may acquire tropical characteristics by the end of the week. Low chances of development.
Before we dive into the Tropical Updates on the tropical waves, a few notes:
- Tropical waves are a normal part of the rainy season.
- Not every tropical wave will form into a tropical cyclone.
- Tropical waves at the beginning of the Hurricane Season are typically weak, producing more rainfall across Eastern parts of the islands with mostly cloudy conditions and a few showers across western parts of the islands.
- Rainfall will be more isolated and intermittent with weaker tropical waves that do not have ITCZ or upper-level support.
- Saharan Dust may weaken tropical waves.
You can read more about the weather associated with Tropical Waves, as well as what to expect as these waves move through the region below.
Tropical Wave 26
This tropical wave moved across the Lesser Antilles without much convective activity. However, a surge of Saharan Dust follows the axis of this wave, bringing hazy skies across T&T and the Lesser Antilles.
The axis of this wave extends its axis along 65W, between 20N and 5N, moving west at 15 knots. No significant rainfall accompanied the passage of this wave
Tropical Wave 27 & 28
Tropical Wave 27’s axis is located along 53-54W, between 4N-18N, moving westward at 15 knots. A mild surge of moisture and marginal instability is supporting shallow convection, mainly north of Trinidad and Tobago. This wave is forecast to bring partly to mostly cloudy skies to islands north of Trinidad and Tobago, with brisk, isolated to scattered showers. No significant rainfall forecast.
Further east, Tropical Wave 28’s axis along 43W to 46W, between 3N and 22N, moving westward at 10-15 knots. This wave is located in a more moist environment compared to the wave ahead of it. However, dry mid-level conditions are forecast to persist, with unfavorable upper-level conditions also forecast. Hence, no significant convection is forecast across T&T at this time.
This wave is forecast to move across T&T on Thursday, with much of the active weather occurring north of T&T. Isolated heavy showers and thunderstorms are possible, particularly on Thursday, interrupting sunny skies. Street flooding may be possible in heavy downpours. No significant rainfall or widespread severe weather is forecast.
Tropical Wave 29
Tropical Wave 29 has just moved off the West Coast of Africa, along 23-24W, between 24N and 2N, moving west at approximately 10-15 knots. This wave is still more than 5 days away but the latest model guidance shows increased moisture moving across the Lesser Antilles beginning during the latter half of Sunday through Tuesday.
This post will be updated later this afternoon with the latest model guidance if there’s any support for tropical development. However, Saharan Dust remains prevalent across the Atlantic, creating dry mid-level conditions, inhibiting development.
As with most tropical waves, a surge in moisture is forecast to support an increase in cloudiness, showers and isolated thunderstorms, particularly between Sunday and Tuesday next week.
Additional updates on specific impacts will be posted within the daily tropical update.
Remnants of Tropical Depression Three
At 11:00 AM, the remnants of Three were located near 29.0 N, 80.0 W, well northwest of Trinidad, Tobago and the Lesser Antilles. The remnants are moving toward the north near 28 KM/H. A turn toward the north-northeast is expected later today.
Maximum sustained winds are near 55 KM/H with higher gusts. The remnants are expected to continue producing gusty winds through tonight. The estimated minimum central pressure is 1014 millibars. Regardless of designation, additional rainfall amounts of 1 to 3 inches (25 – 75 millimeters) are possible across the northwest Bahamas today.
Recent surface observations and data from an Air Force Reserve reconnaissance aircraft indicate that the depression has degenerated into a trough of low pressure. Although the plane found a weak closed circulation near the northwestern edge of the convection earlier this morning, the last pass through that area has shown light southwesterly winds and no evidence of a surface circulation.
Area of Interest in the NE Gulf of Mexico
A non-tropical low-pressure area could form over the northern Gulf of Mexico by late Wednesday or Thursday. Thereafter, conditions could become marginally conducive for some subtropical or tropical development as it moves slowly northeastward through the end of the week.
Chances of development remain low, at 0% over the next 48 hours and 20% over the next 5 days.
If this system develops into a named tropical cyclone, it will be named Chantal and will be no threat to Trinidad, Tobago and the Lesser Antilles.
Tropical Cyclone Climatology
Tropical Cyclone Points of Origin during the month of July. This month, the attention goes to tropical waves moving across the Atlantic, particularly as they near the Lesser Antilles, as well as low-pressure systems in the Gulf of Mexico and troughs Southeast of the United States.
In July, we turn our eyes to East of the Lesser Antilles, the Southeastern areas of the United States and the Gulf of Mexico for the formation of tropical cyclones in the Atlantic Basin, historically. However, tropical cyclones can form in the Atlantic Basin, without regard for the location once conditions support development. Stay updated with the latest tropical update!
There are NO tropical cyclone threats to the Eastern Caribbean, including Trinidad and Tobago at this time in the latest Tropical Update.