Two Potential Tropical Developments
Currently, we are tracking two areas with potential for tropical development. The first is an elongated trough located just around Palau and Yap, positioned south and west of Guam, and east of the Philippines. The second is a monsoonal gyre setup likely extending across Vietnam into the West Philippine Sea. These systems are expected to bring significant weather impacts to the region.
Impact on the Philippines
The Philippines is in the direct path of these systems, and we anticipate heavy rainfall on both the east and west coasts. The moisture available in the atmosphere is substantial, as indicated by microwave imagery showing total precipitable water vapor. This imagery reveals a well-defined swirl and monsoonal gyre flow, indicating the presence of a lot of energy dispersed across this area.
Understanding the Weather Patterns
To better understand the current weather patterns, let’s take a look at the satellite data. The satellite images show a glitch that may cause a flicker, but the overall flow can be seen pushing northward, tapping into the rainy season front. This creates a one-two punch with the current system and the approaching flow. Analyzing the background flow and streamline analysis, we see positive vorticity in the trough, which means there’s a lot of energy but it’s spread out.
What Does Dispersed Energy Mean?
You might wonder, what does it mean when energy is dispersed? Isn’t that a bad thing? Dispersed energy means it’s harder for these lows to tighten up and become a full-on super typhoon. While a low pressure or tropical depression could form, the main concern is the heavy rainfall. The current setup means the Philippines will experience significant precipitation over the upcoming weekend and into next week.
Detailed Forecast for the Philippines
As we head into the weekend, the first low-pressure system is expected to tighten up by Saturday and into Sunday. Concurrently, a west coast flow will bring more rain from Sunday into Monday. According to the ECMWF model, which I favor for its accuracy, we’ll see significant rainfall in southeast Luzon by Tuesday and into Wednesday.
Rainfall Distribution
The east coast of Vietnam and Hainan will also experience heavy rainfall as the system moves through. The widespread precipitation will affect multiple regions, causing a flood threat. The monsoonal gyre over the West Philippine Sea will contribute to this, adding to the overall rainfall.
Model Predictions
Different weather models, including the GFS and ECMWF, show similar patterns. The GFS indicates a low trying to wrap up by Sunday and Monday off the East Coast of Mindanao and the Visayas. At the same time, the ECMWF shows a monsoonal gyre setup off the East Coast of Luzon. Spaghetti plots from the ECMWF show clusters picking up on developing storm systems, suggesting a significant weather event is likely.
Preparing for the Weather
It’s mid-July, and if you haven’t done so already, it’s time to prepare for potential evacuations. Make sure you have an emergency kit ready to go and stay informed through official sources. Floodwaters can rise quickly, so be smart and cautious even if we don’t get a named storm. The rain will pick up, and you might even see localized strong to severe thunderstorms due to the collision of air masses.
Localized Forecasts
Let’s take a closer look at specific areas:
- Cebu: Expect scattered showers from Thursday through the weekend as the low tracks east.
- Tacloban, Leyte, and Samar: Heavy rain is forecasted, especially over the weekend.
- Baguio: The southwest monsoon will bring scattered showers with highs in the 20s.
- Davao: Watch out for scattered showers due to inflow on the backside of the trough.