Philippe Papin

Philippe Papin

@pppapin.bsky.social

Sr. Hurricane Specialist at NHC 🌀 | Ph.D + M.S. via UAlbany & B.S. via UNCA | Enjoy all kinds of weather 🌤❄️⛈🌪| Thoughts are my own

4.8K followers557 following1.1K posts

A follow up thread to illustrate how sensitive #Hurricane #Simon's initial position to the col or "saddle point" was to its track. Compare forecasts of GFS & ECMWF w/ these steering diagnostics via weathernerds.org. GFS S of saddle & moves TC ↙️ ECMWF N of saddle & moves TC ↗️

Philippe Papin@pppapin.bsky.social

#Hurricane #Simon's track forecast today is exhibiting large uncertainty, related to it entering a COL in the steering flow or "saddle point". Here, small shifts in its initial position can result in very different track solutions. A visual helps explain things better👇

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Anyway, this is my attempt to sum it up today in the Tropical Cyclone Discussion for #Hurricane #Simon. Simon has been one of the more difficult track forecast events I have done & its why I spent time trying to explain the components. Thanks for coming to my TED talk. Fin.

A follow up thread to illustrate how sensitive #Hurricane #Simon's initial position to the col or "saddle point" was to its track. Compare forecasts of GFS & ECMWF w/ these steering diagnostics via weathernerds.org. GFS S of saddle & moves TC ↙️ ECMWF N of saddle & moves TC ↗️

Philippe Papin@pppapin.bsky.social

#Hurricane #Simon's track forecast today is exhibiting large uncertainty, related to it entering a COL in the steering flow or "saddle point". Here, small shifts in its initial position can result in very different track solutions. A visual helps explain things better👇

View full thread

We can contrast this with a model that had a pretty good initialization. The 12z HWRF model initilization was actually close to the correct location of #Simon. This is likely why it falls S of the saddle point and then tracks it further south.

That brings us to the dramatic shift seen in ensemble guidance for #Simon over the past day. In the Google DeepMind ensemble, we saw a nearly 180 degree shift in forecast track direction. ↗️ to ↙️ I suspect it is due to track errors shifting the TC position from N to S of steering saddle point.

A follow up thread to illustrate how sensitive #Hurricane #Simon's initial position to the col or "saddle point" was to its track. Compare forecasts of GFS & ECMWF w/ these steering diagnostics via weathernerds.org. GFS S of saddle & moves TC ↙️ ECMWF N of saddle & moves TC ↗️

Philippe Papin@pppapin.bsky.social

#Hurricane #Simon's track forecast today is exhibiting large uncertainty, related to it entering a COL in the steering flow or "saddle point". Here, small shifts in its initial position can result in very different track solutions. A visual helps explain things better👇

The saddle point is nearly identical, but #Simon's location was not. This is a case where good model init is essential to important to capturing the short-term track correctly. The 12z ECMWF initialization nearly a full degree too far N with Simon & likely why it falls N of saddle point.

Philippe Papin reposted

The first hurricane of the 2026 Atlantic hurricane season made landfall in the U.S. late last week. Watch this satellite view covering the full journey of Hurricane Isaias from its formation in the Gulf to its dissipation over the Eastern U.S.

#Hurricane #Simon's track forecast today is exhibiting large uncertainty, related to it entering a COL in the steering flow or "saddle point". Here, small shifts in its initial position can result in very different track solutions. A visual helps explain things better👇

Philippe Papin reposted

8 am EDT Oct 5 - A trough in the southwestern Gulf of America is producing disorganized showers and thunderstorms. Gradual development is becoming more likely, and a tropical depression is likely to form during the middle or latter portion of the week. This system is expected to... 🔗 hurricanes.gov

Philippe Papin reposted

Yesterday, the Moon’s shadow crossed parts of Europe during a total solar eclipse! 🌖 Our satellites captured the event over Earth from 36,000km in space, featuring live imagery during RTBF’s special broadcast. See the full animation & imagery in our Image of the Week: bit.ly/3SrZCi5 🛰️

Philippe Papin reposted

Take this storm seriously. Moderate to major impacts are expected from the Central US through to the Northeast through the weekend. - Hazardous to impossible driving conditions are expected. Avoid travel if at all possible. - Widespread closures and disruption to infrastructure may also occur.

Philippe Papin reposted

I’d be very careful with posting snow maps for the weekend storm this far out. There’s still significant uncertainty with the amplitude & progression of both SW US + north stream troughs, which drives both the event duration & how far north heavy snow expands into the Northeast.

Philippe Papin reposted

The National Weather Service is now hiring for both entry-level and seasoned meteorologist positions. Apply by January 29! The entry-level positions are available in: ▪️ Houston, TX ▪️ Ft. Worth, TX ▪️ Hastings, NE ▪️ Great Falls, MT ▪️ Marquette, MI Apply: www.usajobs.gov/job/854675700

Philippe Papin reposted

Unseasonable warmth is forecast across a large portion of the Lower 48 this week. High temps will soar to 30-40 degrees above normal, with some areas as much as 50 degrees above normal. Dozens of daily temp records could be broken. How warm will it be where you live this week? Check weather.gov.

Philippe Papin reposted

Wildfires can spread quickly — by the time one is nearby, you may not have much time. Have an evacuation plan, and prepare an emergency supply kit ahead of time. Listen to local officials for emergency information and any evacuation orders.

Philippe Papin reposted

❄️ D.C.'s first measurable snow of the season covers the capital in a hush of flurries. Winter is making a return with cooler than normal temperatures in the forecast for the next several days. Stay up to date with the latest forecast at weather.gov. Credit: Bob Hyatt, NWS

Impressed with the resilience of #Senyar… looks like a coherent circulation may have made it across #Malaysia. Nice radar coverage showing the last 24h revolution as it crossed from the Malacca Strait ➡️ South China Sea. Imagery courtesy of @zoom.earth

Philippe Papin reposted

Following the ongoing winter storm across the Upper Midwest, another storm system is forecast to impact parts of the Midwest and Great Lakes with wintry weather this weekend. Keep an eye on the forecast and check weather.gov for more information. ❄️

What is poor practice during Hurricane season is also poor practice in Winter Season. Do not share deterministic models forecasts >5-7 days out. Snowfall maps are an especially poor choice of model graphic to share with much lead time. My 2️⃣🪙

Dr. Stephen Bieda III@drwildcatwx.bsky.social

There is a reason why most (unfortunately I can’t say all) #meteorologists don’t show extended range ensemble forecasts for a reason. Even if a disclaimer like “this is not a forecast” is given, the forecast is still being shown and could be misinterpreted as such. 😒

Philippe Papin reposted

A horrific accident early Saturday morning left a car in the side of an NWS office and the office relying on the NWS service backup system. Service backup is important in situations like this - but also is being increasingly used due to NWS staffing and infrastructure issues. tinyurl.com/4txuyhbz

tinyurl.comTragic vehicle accident takes an NWS office offlineLooking at how the NWS offices back each other up. Severe weather and flash flooding in the south central US next couple of days.

Love observing the local effects of terrain on the boundary layer fog in California. For instance, Check out the drainage into the San Luis Reservoir where low level flow is forced to curve anticyclonic into the local saddle point of the Coastal Range. Makes for some photogenic views!

We just so happened to be driving along the San Luis Reservoir on Hwy 152 where this was observed today. A good 10F difference between being in the fog (49F) vs in the clear (60F)! #CAwx

That’s a lot of intense hurricanes over the past 5 years 😵‍💫 We added 4 more to the list this year, #Erin, #Gabrielle, #Humberto, & #Melissa.

cira-csu.bsky.social@cira-csu.bsky.social

Every Category 4 and 5 Atlantic hurricane since 2020, all together, in one group photo. H/t to @ferragamowx.bsky.social for the inspiration.

Philippe Papin reposted

Hurricane Melissa produced the fastest hurricane winds to be recorded by a dropsonde, verified by reviewing data at NSF NCAR! Hurricane Melissa’s 252 mph wind gust surpassed the previous record from Typhoon Megi over the Western Pacific in 2010, where a dropsonde measured wind gusts of 248 mph.

Still waiting for @bsky.app to build out functionality with direct messages. Namely, allow users to include images/videos in messages & ability to DM multiple users at once. Twitter's botched update on their platform for DMs should provide motivation to move here, but need similar functionality.⏰

Seems like the #Aurora is already visible over a large chunk of the CONUS tonight thanks to the #CME's over the last few days from a couple of significant X-class solar flares.

Aurora Forecast Update for 2025-11-12T01:30:26Z ALERT: Geomagnetic K-index of 8, 9- Threshold Reached: 2025 Nov 12 0121 UTC Synoptic Period: 0000-0300 UTC Active Warning: Yes NOAA Scale: G4 - Severe Additional Details Here.

I love how the wake-free zone of stratocu nicely corresponds to the area of >50F dewpoints advected off the Florida Peninsula & adjacent Gulf coast area. Taking a while for the sfc fluxes to moisten boundary layer enough to reach convective temp. Plot via @burgwx.bsky.social's RTMA analysis. #FLwx

Jeff Frame@vortexjeff.bsky.social

Satellite image of a wake free of cold-air stratocumulus clouds surrounding Florida. These clouds form when cold air moves over warm water.

This cold outbreak was also impressive in how far south it pushed, even to #Miami, FL. The Miami International Airport #KMIA set its first record low (49°F) in more than a decade! Between the last two record lows (11/2/14 to 11/11/25), there have been *97 new record highs* set at the airport. #FLwx

Jeff Berardelli @weatherprof.bsky.social

More than 80 record lows broken or tied this morning (dark blue)! This is a huge feat given that fall has warmed by about ~3F here in the SE in the last 50 years. I can’t remember a cold air outbreak in November with this many record lows. #winter #florida #freeze #cold

I'll just drop this in here too. bsky.app/profile/pppa...

Philippe Papin@pppapin.bsky.social

A few addendum: 1) Since posting, the CLIMIA came out indicating the low was actually 48°F! 2) Some of those record highs likely occurred on the same calendar day, but in different years b/w 2014-2025. 3) I'm using climo data 3/1/37 to now, which is the same period in xmacis.rcc-acis.org

Another way to put it -- in time it took to get 2️⃣ daily record lows at #KMIA, we set new record highs for more than a quarter of days in the calendar year b/w Nov 2014 to Nov 2025 (97/365 ~ 27% of all days). So yes, a remarkable cold snap, but got to put in proper context of record tends. #FLwx

Philippe Papin@pppapin.bsky.social

This cold outbreak was also impressive in how far south it pushed, even to #Miami, FL. The Miami International Airport #KMIA set its first record low (49°F) in more than a decade! Between the last two record lows (11/2/14 to 11/11/25), there have been *97 new record highs* set at the airport. #FLwx

A few addendum: 1) Since posting, the CLIMIA came out indicating the low was actually 48°F! 2) Some of those record highs likely occurred on the same calendar day, but in different years b/w 2014-2025. 3) I'm using climo data 3/1/37 to now, which is the same period in xmacis.rcc-acis.org

Philippe Papin reposted

In the century leading up to 1975, nearly 6000 freighters went down in the Great Lakes. The Edmund Fitzgerald was the last. The last. In 50 years, not a single commercial freighter has been lost in the Great Lakes. Why? It's NOAA. Of course it's NOAA.

Fascinating interaction of #wx scales near Lake Michigan tonight. A Lake Effect Snow #LES band streched N-to-S across the lake, but a potent vortmax dropped in just west, providing large-scale ascent & changing morphology of band into a mesolow, enhancing #snow over #Chicago & Indiana tonight. 🌨️

Here is a zoomed in view of the radar along the S shore of Lake Michigan tonight. Likely some multi inch per hour snowfall rates and potential whiteout conditions as this band moves over Chicago metro & adjacent areas. Good thing this is occurring overnight & not during a major travel period.

Philippe Papin reposted

A strong cold front this weekend will put the "ber" in November as frigid air spills out across the Plains and Mississippi Valley. This winter-like chill will flood across the eastern half of the country early next week, bringing the potential for record cold temperatures to the Gulf by Tuesday.

A couple of recent examples from WPAC #Typhoons that Google DeepMind has been too intense with. First #Kalmaegi & now #Fung-Wong. Would be nice to look at TC structure DeepMind members depicted to see what went awry. Fung-Wong is intensifying, just much slower than the model forecasted.

Tomer Burg@burgwx.bsky.social

And another one: