Good Evening Folks. We have a lot of ground to cover today so let's just go ahead and jump into the forecast.
Strong Nor'Easter
A high pressure system over Quebec has pushed a cold front southward, helping to trigger the development of a Nor’easter off the North Carolina coast. The system has since moved north and is currently sitting offshore of Delaware and New Jersey, where it has remained nearly stationary over the past several hours.
The Nor’easter continues to bring strong winds, heavy rain, and coastal flooding across portions of the Northeast. With the system expected to remain a significant influence over the region, rainfall totals of 3 to 5 inches are possible across parts of the Northeast particularly near the coast, however locally higher amounts can not be ruled out.
Atlantic Tropical Activity
Heading over to the Atlantic, things are active, but not particularly busy. We currently have Tropical Depression Fay, which came very close to becoming a Category 1 hurricane, falling just 4 mph short of hurricane strength. Meanwhile, Tropical Storm Gonzalo has transitioned to a post-tropical cyclone after its core tracked just east of the Cape Verde Islands.
The final area of interest is a small disturbance in the central subtropical Atlantic. A surface trough located several hundred miles southeast of Bermuda is producing an area of disorganized showers and thunderstorms. Environmental conditions appear somewhat favorable for gradual development as the system moves northward this weekend before turning eastward during the early to middle part of next week.
The National Hurricane Center currently gives the system a 10% chance of development through 48 hours and a 20% chance through week. At this point, there is no indication of a significant threat to land, but it is another area worth watching as this is about all the Atlantic is currently willing to offer.
Pacific Tropical Activity
Moving west into the Pacific, we can immediately see a major difference from the Atlantic. The Pacific remains extremely active, with three hurricanes currently ongoing and two additional areas of interest that could become tropical storms over the next week.
The first area of interest is southwest of the Gulf of Tehuantepec. Showers and thunderstorms continue to develop around an area of low pressure, and environmental conditions are expected to remain favorable for further development. A tropical depression is likely to form within the next day or so as the system moves slowly west-northwestward to northwestward, remaining generally parallel to the southern and southwestern coast of Mexico.
The National Hurricane Center gives this system a 90% chance of development through 48 hours
Farther west, another area of low pressure is located roughly 1,000 miles east-southeast of Hawaii. This system is becoming increasingly organized, and conditions are expected to become favorable enough for a tropical depression to form during the early to middle part of next week. The system is expected to move generally northeastward and should remain well east-southeast of the Hawaiian Islands. The National Hurricane Center currently gives it a 30% chance of development through 48 hours and a 70% chance through seven days.
Now for the currently active hurricanes, we have Hurricane Nolo, a Category 1 hurricane located roughly 150 miles south of the Big Island of Hawaii. The storm is expected to drift westward over the coming days while continuing to bring periods of heavy rain, gusty winds, and rough surf to Hawaii.
As Nolo moves farther west, it is expected to strengthen significantly, potentially reaching Category 3 or Category 4 intensity before eventually turning toward the northwest. Once it begins moving away from Hawaii, the storm should gradually weaken, and it is not currently expected to pose a threat to additional land areas.
Next up is Hurricane Odalys, which is currently sitting at Category 1 strength, but it did manage to become a Category 4 hurricane. The moisture from Hurricane Odalys will interact with a trough in the southern U.S. early next week. Fortunately, the storm itself has remained well away from land and has not directly impacted any populated areas so far.
Hurricane Polo, however, is a completely different story.
Polo has been an exceptionally powerful hurricane. The storm has reached Category 5 intensity three separate times, with peak winds of 180 mph. At its strongest, Polo's central pressure fell to 892 millibars, making it the second-lowest pressure ever recorded in an Eastern Pacific hurricane, behind only Hurricane Patricia in 2015.
Polo began as Invest 99E, which initially drifted northward before organizing into a tropical depression. It quickly strengthened into Tropical Storm Polo as it began turning eastward. By 1 p.m. CDT on September 21, Polo had strengthened into a Category 1 hurricane. Just 18 hours later, at 7 a.m. CDT on September 22, it had exploded to Category 5 strength and had reacehd its peak intensity.
After reaching peak intensity, Polo turned northward before quickly taking on a northwestward track that kept it generally along the Mexican coastline. Its intensity fluctuated as it continued northwestward, eventually turning due west and weakening back to Category 4 strength. The storm then strengthened back into a Category 5 hurricane as it turned northwest once again.
Polo is currently a Category 4 hurricane and is expected to gradually weaken as it turns north and eventually northeast toward Mexico, where it is forecast to make landfall as a Category 1 hurricane.
However, the story continues long after landfall
As Polo moves into Mexico, it is expected to interact with an upper-level trough currently positioned over the Desert Southwest. At the same time, moisture associated with Hurricane Odalys could become involved in the same system. This combination could significantly increase the amount of tropical moisture available to the trough as it moves eastward.
The result could be a prolonged period of heavy rainfall stretching from the Four Corners into Texas and the central Plains, with repeated rounds of rain potentially producing flash flooding and additional flooding concerns. Several inches of rain are likely across a very large area.
More Cold Fronts on the Way
Switching over to the temperature now, the models are generally in good agreement that a cold front will push through the central and southern Plains during the middle to latter portion of next week. The main disagreement right now is just how strong that front will be.
The GFS is currently showing a dramatic temperature drop in Dallas, with daytime highs falling from around 97°F on Monday to just 71°F by Thursday. The European model is considerably more conservative, showing temperatures starting in the upper 80s or perhaps lower 90s before falling into the lower 80s.
At this point, I think the eventual outcome will probably land somewhere between the two solutions.
Looking farther out, around 8 to 12 days, both the GFS and ECMWF are also hinting at another cold front moving through the region. There is considerably more uncertainty with this system, and both its timing and strength will likely change several times as we get closer.
To give you an idea of just how large the current model spread is, the GFS is showing the potential for Dallas temperatures to fall into the upper 50s for daytime highs, while the ECMWF has the front primarily affecting overnight temperatures, with lows falling into the 50s and highs remaining in the mid 70s
I am not buying upper-50s daytime highs in Dallas at this point. We are still too far out to have a clear picture, and the model spread is simply too large to have any confidence in that exact outcome. However, the fact that both major models are showing another significant frontal passage is worth watching. If the signal continues to hold over the coming days, we will have a much better idea of how substantial that second push of cooler air could be.
And with that, thank you for taking the time to read through another forecast.
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Thanks for reading, and I’ll see you in the next forecast!