Windspeed

Michael's band of > -80°C cloudtops at landfall was the most impressive I can remember at landfall for an Atlantic hurricane.

HWRF has been intensifying Oscar down into the 950s with consistency. Based on SSTs and a cold upper troposphere analysis, convective instability should be great for a few days. A major seems most likely at this point.

Oscar's transformation to a deep tropical system has been gorgeous. A nice eye band is establishing and a core with CDO. May have a hurricane before too much longer.

Oscar's vortex is actually not too horrible at the moment despite its sheared and tilted appearance of a persistent MCS. It has been interesting watching its circulation rotate around the northern half of the mid-to-upper cutoff trough on visible and IR imagery today. You can actually see the transformation to a more tropical low. As such, the NHC forecasts Oscar to become a purely tropical storm over night. Oscar is also forecast to become a hurricane in a few days after turning poleward, if upper level winds cooperate.

Yutu continues to buzzsaw along due west.

But who got what right here? Are you are singling out CNN for stating the island is underwater or just sea level rise? As for the the first, the opening line of the Gaurdian video states the island has "disappeared"; and The Weather Network article states "Researchers confirmed this week that East Island, a remote part of the Hawaiian chain, was washed off the map." As for sea level rise, I'm not getting into climate change rhetoric or debate in this thread between the associations of such, especially since nearly every report like this universally mentions it now. But since you seem to be targeting it with respect to the CNN article, it's worth noting that the scientist himself, Dr Chip Fletcher, brought it up: "The probability of occurrences like this goes up with climate change." As it happens, Dr. Fletcher specializes in research on rising sea levels: Look, I understand bad reporting needs to be called out. But I'm not getting the CNN bashing here when every other article is on the same source.

Yutu appears to be reintensifying. The ERC completed many hours ago and both microwave and visible imagery confirm a large and well-developed eyewall that continues to clear out. It is surrounded by a rather large CDO -- a big donut. Yutu may also not be done with land either. Some of the globals are flirting with Luzon. It is possible Yutu could even have a south of west motion for a time as heights may rebuild west under a lifting trough to the north. That trough was originally capturing Yutu, but that solution is losing recent model support.

Loving the detail in this thread. I don't post much but I follow everyone and thoroughly enjoy the discussion. My knowledge is better suited to ironing out tropical stuff, but even that lacks significantly in comparison to the knowledge base shared here with regards to pattern/climate speculation for our region. I will say that based on what has been posted so far, I am feeling more optimistic for the eastern Valley's chances of some substantial snowfall events this season. John and Carver have mentioned the disparity between the last 30 years and the 50s-70s, when even large positive or negative swings in oscillations made less of an impact on snow accumulations. It seems like our Winters back then were just more eventful and memorable. I grew up in the 80s/90s though so that was before my time. However, regardless of mean temperatures and pattern oscillations, a southerly low-level jet likely still dominated most of those memorable snow storms. As the past decade has shown, bitter cold patterns do not necessarily result in significant totals of frozen accumulation. Last January was a somber reminder that polar deserts are no fun with weeks of polar airmass in place without a sniff of flakes. My limited experience always shifts back to the big events of the 90s where even an above normal seasonal mean in temperature still included large snowfall events. Some of our best snows came from falling temperatures and just enough cold reinforcement out of the Midwest/Kentucky versus long duration events of deep cold established throughout the Valley. Yes, moisture feed and eastern 500mb spatial DAM heights and blocking have to be there there as well. But it seems like Miller storm track/southerly jet combo has frequently bit us in the rear the last few decades. We have watched countless big CAD/SE events score huge totals in the Southeast to Mid-Atlantic while the western side of the Appalachians get downsloped to death and shafted. Of course, we even seemed to struggle with modeled 2-3" variety northwesterly clippers holding together for the eastern half of the Valley the past few years. Despite my Debbie Downer attitude, and I apologize for that, I really am feeling positive about this season now. Otherwise, I will slip back into lurk mode so as to not taint this discussion any further.

Night time visible band uses moon light and some other remote sensing techniques. You can see the stadium shape of the eye down near the surface and lower level. The northern portion of Saipan may have missed the worst of the eyewall but it's still a guess at this point. The southern half may have got the worst. Clearly all of Tinian experienced full frontal and backside winds. I want to refrain from hyperbole, but there probably is catastrophic devestation for anything not built within the strictest of code. Image courtesy of CIMSS and William Straka and Scott Bachmeier: Use the direct link here if you want full resolution from CIMSS as the GIF is too large to post or is just will not animate correctly as posted to the forum.

And the non-colorized loop:

AVN loop of Yutu through landfall:

Hey Chinook! Scroll up, you're a little late to the party. [emoji851] Good to see you posting besides though.

Very clean microwave during landfall. Distinct concentric features with an ERC in early stages. Two wind maxima were probably experienced in Tinian and Saipan with the larger outter band and insanely intense inner eyewall. Infared can be deceiving for exact path of the wall over those islands as well. The Himawari satellite is positioned at a plane of lower latitude and at an acute angle south of the typhoon. IR images reflect colder cloud tops that only start to resolve at the mid-to-upper level of the eye. You must account for the height of the eyewall cylinder down to the surface at that distance. A visible image with sunlight at the same angle will show the lower-level circulation, closer to the surface, at the bottom of the eyewall cylinder. It's frustrating we don't have observable radar for a US territory besides, but it is what it is. Luckily we did have the clean microwave scan at landfall. And perhaps the airport/military will have some closed network remote sensing before all hell broke lose; and hopefully some instrumentation survived for pressure distribution.

Yowza! I probably over use maximum potential even if there are cases where the environment isn't perfect. But in Yutu's case, it is definitely maxing out. Almost looks as insane as Haiyan. Almost... I am noticing a subtle bend back towards a more westward component in the extended loop. Not sure if that is merely short term, but hopefully that allows Yutu's intense core to miss Tinian/Saipan or any other population centers for that matter.

Papin had some interesting comments on why Willa seemed to hold together so well prior to landfall despite the lack of modeling support. My thoughts are that Intensity modeling was subpar with Willa throughout its life cycle. Before rapid intendification Sunday night, the HWRF runs struggled to get Willa much below 950 mb until it was initialized much lower based on ADT analysis. Obviously when it bombed out to Cat 5, the environment was only going to temporarily support that intensity, despite the inevitable ERC. Though maximum potential was short-lived, even its decay and rapid weakening was overdone. Yes, Cat 5 to 966 mb Cat 3 is significant weakening, but that wasn't unexpected. What seemed more unexpected was how that weakening trend abated and Willa leveled off to a steady state, if not perhaps even some slight restrengthening based on satellites estimates prior to landfall; where as intensity modeling wanted to rapidly weaken Willa much further prior to landfall.

I wouldn't base rapid deterioration from this point out on anything other than the fact that there are 8-12k ft coastal ranges and volcanic peaks that will shred a low-level vorticity. Even the most powerful cyclones get ripped to shreds rapidly. The mid level circulation will probably hold together for a while though and even the remnant low will eventually make its way into Texas to develop into a frontal low.

AVN loop through landfall courtesy of Weathernerds:

000 WTPZ64 KNHC 240104 TCUEP4 Hurricane Willa Tropical Cyclone Update NWS National Hurricane Center Miami FL EP242018 700 PM MDT Tue Oct 23 2018 ...CATEGORY 3 WILLA MAKES LANDFALL NEAR ISLA DEL BOSQUE, SINALOA... At 700 PM MDT, satellite images indicate that Willa has made landfall near Isla Del Bosque, Sinaloa, or about 10 miles (15 km) south of Escuinapa. Maximum winds at landfall were estimated to be 120 mph (195 km/h), with a minimum central pressure of 965 mb (28.50 inches). A Mexican weather station near Marismas Nacionales recently reported a wind gust to 95 mph (153 km/h). SUMMARY OF 700 PM MDT...0100 UTC...INFORMATION ---------------------------------------------- LOCATION...22.7N 105.8W ABOUT 50 MI...80 KM SE OF MAZATLAN MEXICO MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H PRESENT MOVEMENT...NNE OR 030 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...965 MB...28.50 INCHES $$ Forecaster Blake

Thanks for posting that MW pass!

Eastern eyewall is over land. Big uptick in GLM remote sensing lightning strikes as well. Shouldn't be long now.

Last advisory for Willa before landfall: 000 WTPZ34 KNHC 232343 TCPEP4 BULLETIN Hurricane Willa Intermediate Advisory Number 15A NWS National Hurricane Center Miami FL EP242018 600 PM MDT Tue Oct 23 2018 ...EYE OF WILLA ABOUT TO MAKE LANDFALL ALONG THE WEST-CENTRAL COAST OF MEXICO... ...DO NOT VENTURE OUT INTO THE RELATIVE CALM OF THE EYE SINCE HAZARDOUS WINDS WILL SUDDENLY INCREASE AS THE EYE PASSES... SUMMARY OF 600 PM MDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...22.6N 106.0W ABOUT 50 MI...80 KM SSE OF MAZATLAN MEXICO MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H PRESENT MOVEMENT...NNE OR 30 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...965 MB...28.50 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * San Blas to Mazatlan, including Las Islas Marias A Tropical Storm Warning is in effect for... * Playa Perula to San Blas * North of Mazatlan to Bahia Tempehuaya A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 600 PM MDT (0000 UTC), the eye of Hurricane Willa was located near latitude 22.6 North, longitude 106.0 West. Willa is moving toward the north-northeast near 10 mph (17 km/h). A faster motion toward the northeast is expected tonight. On the forecast track, the eye of Willa will make landfall along the coast of west-central Mexico within the hurricane warning area within the next hour or so. Maximum sustained winds remain near 120 mph (195 km/h) with higher gusts. Willa is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Little change in strength is expected before Willa crosses the coast of Mexico. Very rapid weakening is expected after landfall, and Willa is expected to dissipate over northern Mexico on Wednesday. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 115 miles (185 km). The estimated minimum central pressure is 965 mb (28.50 inches). HAZARDS AFFECTING LAND ---------------------- STORM SURGE: An extremely dangerous storm surge is occurring along portions of the coast of southwestern Mexico in southern Sinaloa and Nayarit, with the highest surge likely to occur near and to the south of where the center of Willa makes landfall. Near the coast, the surge will be accompanied by large and destructive waves. RAINFALL: Willa is expected to produce storm total rainfall accumulations of 6 to 12 inches, with local amounts to 18 inches, across portions of western Jalisco, western Nayarit, southern Sinaloa, and far southern Durango in Mexico. This rainfall will cause life-threatening flash flooding and landslides. Farther inland, Willa is expected to produce rainfall amounts of 1 to 3 inches across the rest of Durango and portions of Zacateca, southeast Chihuahua, and Coahuila, with local amounts to 5 inches possible. WIND: Hurricane conditions will gradually subside in Las Islas Marias. Hurricane conditions will continue to spread into the hurricane warning area along the coast of mainland Mexico this evening. Tropical storm conditions will continue along the coast of mainland Mexico within the warning area through tonight. Wind speeds atop and on the windward sides of hills and mountains are often up to 30 percent stronger than the near-surface winds indicated in this advisory, and in some elevated locations could be even greater. SURF: Large swells generated by Willa will continue to affect portions of the coast of southwestern and west-central mainland Mexico, and the coast of the southern Baja California peninsula during the next day or two. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 900 PM MDT. $$ Forecaster Avila

Looks like we are within two hours of landfall.

SW mid-to-upper flow may be 20-25 kts but given current bending NNE to NE motion at 10-12 kts, shear is being offset somewhat and analysis is more around 15 kts. It is increasing with time but so is Willa's NE motion. Granted, that is still substantial shear, but Willa is managing ok against it. We're quickly approaching landfall in a few hours though so it's probably going to remain classified a major hurricane in advisory regardless. Edit: My bad, that particular MW pass was old. The recent AMSR2 missed. We may not get another good pass before landfall.