WASHINGTON, Aug. 1 (DC Times Online) — The National Hurricane Center was forecasting no tropical activity in the Atlantic, Caribbean or Gulf of Mexico for the seven days covered by its Aug. 1 outlook. Even so, forecasters are watching several tropical waves moving west from the African coast, where wind shear, Saharan dust and ocean temperatures will determine whether any can develop.
For residents of the U.S. Gulf Coast and Southeast, the immediate action is to monitor the National Hurricane Center’s daily Tropical Weather Outlook. The current forecast does not identify a storm threat or call for emergency action, but conditions can change as tropical waves move across the Atlantic.
Why the Atlantic is quiet
The main factor suppressing development is El Niño, a climate pattern marked by warmer-than-average water in the central and eastern tropical Pacific Ocean. During El Niño, changes in the atmosphere can produce stronger winds high above the Atlantic tropics.
Those winds can create vertical wind shear — a difference in wind speed or direction with height. Strong wind shear can tilt or break apart thunderstorms, making it harder for a tropical disturbance to organize into a depression or storm.
NOAA’s Climate Prediction Center has said El Niño is strengthening. Forecast information cited by the FOX Forecast Center indicated that the event could become one of the strongest observed since 1950, although the supplied outlooks do not establish that it will set a record.
Saharan dust is adding another obstacle. Dry, stable air carried west from Africa can limit the thunderstorms that tropical systems need. The FOX Forecast Center said dust and hostile upper-level winds were suppressing activity across parts of the tropical Atlantic.
What is happening near Africa?
Several tropical waves — elongated areas of unsettled weather — were moving off Africa into the Atlantic’s Main Development Region. This is the part of the basin where many long-track Atlantic hurricanes form.
Their presence does not mean a storm will form. The National Hurricane Center’s Aug. 1 outlook listed no area for tropical development during the seven-day period. The FOX Forecast Center said the waves would face strong wind shear and Saharan dust, while warm ocean water could provide some support.
Ocean temperatures are one ingredient needed for tropical development, but warm water alone is not enough. A disturbance also needs persistent thunderstorms and an atmosphere that allows its circulation to become organized. In the current pattern, the effects of warm water are being offset by El Niño-related winds and dry air.
What does the season’s pace mean?
By July 31, the FOX Forecast Center said the Atlantic season had produced two named storms, one in June and one in July. That pace was behind the seasonal forecasts issued by several groups, but a slow start does not rule out a more active second half of the season.
NOAA’s seasonal outlook called for 8 to 14 named storms, three to six hurricanes and one to three major hurricanes. Colorado State University forecast 11 named storms, five hurricanes and two major hurricanes. AccuWeather forecast 8 to 14 named storms, four to seven hurricanes and two to four major hurricanes.
A named storm has sustained winds of at least 39 mph. A hurricane reaches at least 74 mph, while a major hurricane is classified as Category 3 or stronger, with winds of at least 111 mph.
These are seasonal ranges, not storm-by-storm predictions. They describe the expected overall level of activity and cannot determine whether a specific U.S. community will be affected.
What should residents watch next?
The National Hurricane Center’s seven-day outlook is the clearest short-term guide. Residents should watch whether any tropical wave is assigned an area of interest, whether its chance of development increases, and whether forecasts begin identifying possible impacts to land.
For now, the basin has no identified tropical threat. But the hurricane season continues, and the same factors that are suppressing development — El Niño, wind shear and Saharan dust — can weaken or shift over time.