RU848789

For Thanksgiving snow, our region hasn’t had much, but in 1989 4.4" fell in NYC, 6.0" fell in Newark and 4.6 fell in Philly from Weds night into T-giving. Before that one has to go back to 1938 for snow in NYC on Thanksgiving, when 3.9” fell. On average we get November snowfall once every 3 years, with the last major one being 11/15/2018, when 4-7” fell across most of the Philly-NJ-NYC corridor and NW of there (less towards the coast) - that was the storm that shut down much of the region as the snowfall was significantly underestimated by almost everyone, despite the Euro/NAM (EE rule, lol) being bullish on snow for the 95 corridor. Loved that storm, as I got out of work in Rahway by 2 pm, as I knew things were getting bad, and it only took me 30 min to get home (10 miles), while people who left an hour later took hours to get anywhere. https://en.as.com/latest_news/will-it-snow-in-new-york-on-thanksgiving-when-was-the-last-time-it-snowed-in-november-n/

The most interesting observation from the 12Z suite, so far, is that the GFS put the crack pipe down on the insane NNJ/nearby NEPA snowfall amounts and is much more in line with the other models. Will be happy to see mood flakes in the Edison area and would be ecstatic with a little coating from a heavier burst or two.

Nada on the CMC, but it's 10 days out...

I'd say a thread would be good. At ~4 am, the NWS put out a more bullish snowfall map, much more in line with the NBM map and they also updated their rainfall map, which is also a bit more bullish (I also love when they include large parts of the NWS-NYC CWA in their maps). Still room for changes, especially on the snowfall side of things, as the NWS-Philly mentioned in their discussion with regard to more snow possible for the Lehigh Valley and NWNJ and even a bit of measurable snow down to the 95 corridor; see the part I bolded below in the NWS-Philly discussion. Folks need to remember that even wet snow with borderline surface temps can accumulate quickly if the snowfall rate is fairly heavy, exceeding the melting rate and with much of the possible snow falling before sunrise on Friday, there won't be a solar insolation component to melting. On the flip side an extended period of light to moderate snow even at night with surface temps above 32F will largely result in white rain with minimal accumulations (and this is especially true if during the day). https://www.weather.gov/phi/ Area Forecast Discussion National Weather Service Mount Holly NJ 656 AM EST Wed Nov 20 2024 SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... Strong low pressure will be located near New York City Thursday evening, with strong and gusty northwest winds funneling cooler air southeastward across the region. The upper low will remain to our west in the upper Ohio Valley, and as that feature heads east, the surface low will actually retrograde slightly, with it becoming "captured" over our northern areas early Friday. Strong forcing over our northern zones relatively close to the surface low and northeast of the upper low will result in continued precipitation through the night, with precipitation tapering off further south and mostly dry conditions in the Delmarva. With the cold advection at the surface and aloft, odds favor a transition to heavy wet snow across the higher terrain, especially above 1500 feet on the Pocono Plateau and possibly a few higher ridges elsewhere in eastern PA and northern NJ. With the best odds of heavy wet snow being across the Poconos, have issued the first Winter Storm Watch of the season for Carbon and Monroe counties, specifically for at and above 1500 feet. Lower elevations may see far less snowfall, in fact the lowest valleys even up there may fail to get an entire inch of accumulation with this elevation-dependent system. As this will be a heavy wet snow with significant wind in the 20-30 mph range, a big potential is downed trees and power lines. Travel Thursday night in particular is discouraged. There are a few simulations which imply snow could reach significantly further south across our region, even down to the I-95 corridor and Philly metro, particularly the Canadian models. For the moment we`ve mostly discounted that guidance as being outliers, but will be keeping it in mind as we watch further progress with this system. Have allowed for some mixing across areas just north and west of the I-95 corridor Thursday night into early Friday, but little to no accumulation is currently expected outside the Poconos. Either way, brisk and cold will be the them for Thursday night, with lows in the 30s for most, upper 20s perhaps in the higher terrain of the Poconos. For the bulk of Friday, the surface low will remain captured under the upper low over our region, resulting in continued showers. Enough insolation likely develops to allow a transition from a rain/snow mix to just plain rain at the lower elevations, with significantly less accumulation in the higher terrain as well, with precipitation starting to taper off towards the end of the day as we start to see some movement eastward and the surface low begins to slowly fill. Regardless, a chilly, raw day will be had by most with temps generally no higher than the 40s region-wide, with temps not straying far from freezing in the Poconos.

The difference between the 0Z NAM and the 0Z GFS is astonishing, especially for NNJ/NEPA. I have a very hard time believing in the GFS here.

Definitely some snow potential for the Poconos, NWNJ, Catskills, etc. Potential for a few to several inches and today's 12Z models are even showing up to an inch of snow down to I-80 (W of 287). And we're now within 3-4 days, so not quite fantasy land anymore. More importantly, we need the rain.

NHC now calling for Sara to dissipate in the next 4-5 days near the end of its journey across the Yucatan Peninsula. This has to be great news for Florida, although clearly all of the models don't show dissipation. Environmental conditions are conducive for some strengthening during the next couple of days, but the main inhibiting factor is the sprawling structure of the cyclone and its close proximity to land. Given that the system is forecast to pass very close to the northern coast of Honduras, only modest strengthening is suggested by most of the guidance. The NHC intensity forecast calls for some strengthening during the next couple of days, follow by little change in intensity until the system moves over the Yucatan peninsula. It should be noted that a more northern track, could result in additional strengthening, but the global models and most of the intensity guidance does not favor that scenario. The global models indicate that the system will weakening quickly while it moves over the Yucatan peninsula and that the circulation is not likely to survive the passage over the peninsula. Therefore, the new forecast now calls for dissipation by day 5.

At 4 am EST, the NHC upgraded the system to a Tropical Depression... Tropical Depression Nineteen Discussion Number 3 NWS National Hurricane Center Miami FL AL192024 400 AM EST Thu Nov 14 2024 The satellite presentation of the system has gradually been improving. The latest subjective intensity estimates from TAFB and SAB are both T-2.0/30 kt. Based on the subjective Dvorak estimates and the improvement in the convective structure noted on satellite imagery, the system is upgraded to a tropical depression. This is supported by data from the Indian Oceansat scatterometer, which shows a well-defined circulation. The intensity is set to 30 kt based on the Dvorak estimates.

Yep, looks like a Cat 1 if one believes a 7-day op run...GFS shows nada and CMC has a weak low near LA by then. Very hard to glean much from this suite.

About 0.1" here. A little worried about flash flooding, lol. And with regard to the about to end rainless streaks, below is the NWS-Philly update on the latest counts of consecutive days without measurable precipitation at the major climate locations as of Saturday (last time there was measurable precipitation and the amount are in parentheses); the streaks should end for these stations tonight (or early Monday). By the way, the NJDEP is holding a hearing on Tuesday to discuss potential water use restrictions. Allentown 16 days (0.01" on October 24) - tied for 44th longest Atlantic City Airport 38 days (0.02" on October 2) - record longest Mount Pocono 26 days (0.05" on October 14) - tied for 2nd longest Philadelphia 42 days (0.11" on September 28) - record longest Reading 16 days (0.01" on October 24) - tied for 73rd longest Trenton 42 days (0.23" on September 28) - record longest Wilmington 42 days (0.04" on September 28) - record longest Georgetown 43 days (0.13" on September 27) - record longest One note on this, drought is a much longer term weather phenomena than most of the hazardous weather we talk about, so one rain event (especially one with as little as this), generally isn't enough to make any significant dent in the deficit and drought conditions. Therefore, please continue to heed any burn bans or water conservation efforts your localities may have in place! For the rest of the week, there is a small (emphasis on small) chance for rain on Thursday. Otherwise, it appears we'll have mostly dry conditions.

We now have potential tropical cyclone #18 in the Caribbean, which will likely become TS Rafael soon and the NHC forecast track takes it into the Gulf of Mexico strengthening into a weak hurricane near Cuba, but then weakening as it heads further north due to anticipated shear, but as per the NHC discussion, the error bars are pretty high on this one. FORECAST POSITIONS AND MAX WINDS INIT 03/2100Z 13.0N 77.1W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 04/0600Z 14.3N 77.1W 35 KT 40 MPH...TROPICAL CYCLONE 24H 04/1800Z 16.0N 77.7W 40 KT 45 MPH 36H 05/0600Z 17.7N 78.6W 50 KT 60 MPH 48H 05/1800Z 19.6N 80.4W 60 KT 70 MPH 60H 06/0600Z 21.5N 82.6W 70 KT 80 MPH 72H 06/1800Z 23.3N 84.5W 65 KT 75 MPH 96H 07/1800Z 25.4N 86.6W 60 KT 70 MPH 120H 08/1800Z 26.9N 88.6W 50 KT 60 MPH

The sun appears to have been obscured by dark grey objects in the sky and I observed some small water droplets falling to the earth, apparently from these grey objects. Can anyone explain these strange observations?

And we all know what happened at the end of October 2012, when Sandy slammed into NJ on 10/29/12. Not saying something like that is going to happen, but a pattern like that makes it more likely a tropical system could impact the east coast.

I know you're just sharing info, which is fine, but from my perspective, I find most "daily" records to be much less useful than event records. For example, having 10" on 2 consecutive days for 20" event total is far more relevant/useful than having 13" all in one day. IMO.

Update on the tornado from yesterday in Fort Pierce: it has been confirmed that 4 people died in the Spanish Lakes Country Club Village development in the Lakeland Park area of northern Ft. Pierce (only a mile or so from Vero Beach, so this kind of scared my dad and my brother/SO and my sister/SO, who all live in Vero in separate locations) from that EF3 (estimated) tornado that ripped through the area. Tornadoes are certainly common with hurricanes, but strong tornadoes are pretty unusual and the number of tornadoes was also unusual, with 125 tornado warnings issued and 38 actual tornadoes touching down (based on observations, not 100% confirmed yet). The video of the damage on TWC is heartbreaking with houses literally like they exploded. https://www.wpbf.com/.../officials-multiple.../62561027

Milton about to exit the FL east coast ~10 miles north of Cape Canaveral as an 85 mph Cat 1 hurricane still, which is pretty close to the forecast from the past few days. We'll begin to really see the extent of the damage at the coast and inland across the peninsula with sunrise soon. Hurricane Milton Tropical Cyclone Update NWS National Hurricane Center Miami FL AL142024 400 AM EDT Thu Oct 10 2024 ...STRONG WINDS SPREAD ALONG THE EAST COAST OF FLORIDA AS THE CENTER OF MILTON NEARS CAPE CANAVERAL... ...400 AM EDT POSITION UPDATE... A sustained wind of 83 mph (134 km/h) and a gust to 92 mph (148 km/h) was recently reported at a Weatherstem station in Marineland. A sustained wind of 67 mph (108 km/h) and a gust to 73 mph (117 km/h) was recently reported at a Weatherstem station on South Hutchinson Island. A sustained wind of 54 mph (87 km/h) and a gust of 83 mph (133 km/h) was recently reported at buoy 41069 near Ponce de Leon Inlet. A sustained wind of 54 mph (87 km/h) and a gust of 84 mph (135 km/h) was recently reported at Daytona Beach International Airport. This will be the final hourly position update for Milton since the center of the hurricane is moving offshore of the east coast of Florida. The next full forecast advisory for Milton will be at 500 AM EDT (0900 UTC). SUMMARY OF 400 AM EDT...0800 UTC...INFORMATION ----------------------------------------------- LOCATION...28.5N 80.7W ABOUT 10 MI...20 KM NW OF CAPE CANAVERAL FLORIDA ABOUT 35 MI...55 KM E OF ORLANDO FLORIDA MAXIMUM SUSTAINED WINDS...85 MPH...135 KM/H PRESENT MOVEMENT...NE OR 55 DEGREES AT 18 MPH...30 KM/H MINIMUM CENTRAL PRESSURE...977 MB...28.85 INCHES

There's friction at the water's surface - it's just a lot less than the friction over land, due to surface roughness/terrain. The boundary layer from the surface (water or land) goes from zero velocity right at the surface (the no slip condition, where molecules in contact with the stationary surface have no velocity) to a steady state velocity some height above the surface and that velocity is significantly lower at ~10m above the surface (where winds are measured) of land vs. water. It always surprises me that people don't understand that hurricane winds over land are almost never as strong as those over water, due to friction effects, mostly. Having said all that, I've always wondered how a hurricane's speed is measured when it's over land they report 10m surface winds, but I doubt Milton has 105 mph sustained winds at 10 m above the surface where wind speeds are typically measured. I believe there's still enough of a frictional effect at 10m to have the measured winds be lower over land than what the algorithms are spitting out for the hurricane (but I have no "proof" of that).

Another Flash Flood Emergency issued by the NWS for potentially catastrophic flooding for the I-4 corridor NE of Tampa into the center of the state from 8-12", so far, and more on the way. Flash Flood Warning National Weather Service Tampa Bay Ruskin FL 1011 PM EDT Wed Oct 9 2024 ...FLASH FLOOD EMERGENCY FOR LAKELAND, WINTER HAVEN, WESLEY CHAPEL... The National Weather Service in Tampa Bay Ruskin has extended the * Flash Flood Warning for... Northwestern Polk County in central Florida... Southeastern Sumter County in central Florida... Southwestern Hernando County in west central Florida... Northern Hillsborough County in west central Florida... Pasco County in west central Florida... Pinellas County in west central Florida... * Until 400 AM EDT. * At 1011 PM EDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Between 8 and 12 inches of rain have fallen. Flash flooding is ongoing or expected to begin shortly. This is a FLASH FLOOD EMERGENCY for Lakeland, Winter Haven, Wesley Chapel. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW! HAZARD...Life threatening flash flooding. Thunderstorms producing flash flooding. SOURCE...Radar. IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW! Life threatening flash flooding of low water crossings, small creeks and streams, urban areas, highways, streets and underpasses. * Some locations that will experience flash flooding include... Tampa, Spring Hill, Lakeland, Plant City, Winter Haven, Haines City, Bartow, New Port Richey, Lake Wales, Auburndale, Zephyrhills, Dade City, Brandon, Lutz, Fish Hawk, Hudson, Holiday, St. Leo, Zephyrhills South and Zephyrhills North. PRECAUTIONARY/PREPAREDNESS ACTIONS... Move to higher ground now! This is an extremely dangerous and life-threatening situation. Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order. Be especially cautious at night when it is harder to recognize the dangers of flooding. Stay away or be swept away. River banks and culverts can become unstable and unsafe.

The amount of rain (10-14" reported and probably more has fallen in some places with more to come) is just nuts. SIAP, but the NWS in Tampa just issued a Flash Flood Emergency for most of the Tampa/St. Pete area, which is rarely used - it's what was issued in our area when Ida's remnants unleashed that deadly deluge on CNJ/NNJ/NYC a few years ago. BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Tampa Bay Ruskin FL 926 PM EDT Wed Oct 9 2024 ...FLASH FLOOD EMERGENCY FOR ST. PETERSBURG, TAMPA, RIVERVIEW, AND PALMETTO... The National Weather Service in Tampa Bay Ruskin has extended the * Flash Flood Warning for... Central Hillsborough County in west central Florida... Northern Manatee County in west central Florida... Southeastern Pinellas County in west central Florida... * Until 230 AM EDT. * At 926 PM EDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Between 10 and 14 inches of rain have fallen. Flash flooding is already occurring. This is a FLASH FLOOD EMERGENCY for St. Petersburg, Tampa, Riverview, and Palmetto. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW! HAZARD...Life threatening flash flooding. Thunderstorms producing flash flooding. SOURCE...Radar. IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW! Life threatening flash flooding of low water crossings, small creeks and streams, urban areas, highways, streets and underpasses. * Some locations that will experience flash flooding include... Tampa, Clearwater, Largo, Bradenton, Pinellas Park, Temple Terrace, Seminole, Palmetto, Downtown Saint Petersburg, Saint Petersburg, Fort Desoto Park, Brandon, St. Petersburg, St. Pete Beach, Anna Maria, Gandy, Macdill Air Force Base, West And East Lealman, Feather Sound and Tampa International Airport. PRECAUTIONARY/PREPAREDNESS ACTIONS... Move to higher ground now! This is an extremely dangerous and life-threatening situation. Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order. Be especially cautious at night when it is harder to recognize the dangers of flooding. Stay away or be swept away. River banks and culverts can become unstable and unsafe.

So, assuming Milton passes 10-20 miles south of the mouth of Tampa Bay, I would assume this means much less surge in Tampa Bay than the 8-12' still forecast (and maybe reverse surge with winds from the east-ish). Is there a model showing the surge before and after landfall for that scenario (and will there eventually be some surge on the backside, with maybe NW winds?

Well the NHC did back off a bit on surge from Tampa, northward, to 9-13' from the Anclote River to Egmont Key (was 10-15'), but kept the Tampa Bay at 10-15' (not sure why- maybe the angle of approach allows enough of a southerly wind component to push water into the Bay); they also expanded the 10-15' surge forecast south about 15 miles from Englewood to Boca Grande.

11 pm advisory: 160 mph/915 mbar and no real track change from 5 pm. Edit - map up now... The official track forecast is very similar to the previous one, and is generally a little north of the model trackers, but follows the actual model predicted cyclone center locations. This is close to a blend of the latest GFS and ECMWF model solutions. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 23.4N 86.5W 140 KT 160 MPH 12H 09/1200Z 24.7N 85.3W 135 KT 155 MPH 24H 10/0000Z 26.5N 83.6W 115 KT 130 MPH 36H 10/1200Z 27.9N 81.4W 75 KT 85 MPH...INLAND 48H 11/0000Z 28.5N 78.8W 70 KT 80 MPH...OVER WATER 60H 11/1200Z 29.0N 75.5W 65 KT 75 MPH 72H 12/0000Z 29.4N 72.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 96H 13/0000Z 30.4N 65.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 14/0000Z 31.5N 57.9W 40 KT 45 MPH...POST-TROP/EXTRATROP

I'm assuming the NHC won't lower the storm surge forecasts for the Tampa area until and unless the forecast confidence in a track at least 10-20 miles south of Tampa Bay is very high; probably not until 12-18 hours before landfall, maybe tomorrow at 11 am. Evacuating "unnecessarily" for a 10-15' storm surge is far less of an issue than dropping the surge forecast now and then having many people not evacuate (or even have some return) and then having the track actually head into TB with 10-15' of surge, causing far more loss of life. Having spent many years doing risk analysis in the chemical industry, one usually doesn't discount a catastrophic risk impact (high severity) until the probability of that risk being realized becomes quite low and we're not there yet. And there are still quite a few 18Z models (GFS, NAM, ICON, RDPS, HWRF, HMON and the HAFs) showing landfall either in Tampa Bay or within 5-10 miles of it, so the probability of a Tampa Bay landfall is still too high to lower the surge forecast, IMO.

And if that convection in those cells makes it on shore in SW FL - and especially if we get some training - the WPC rainfall forecast is going to be way underdone for SW FL...

155 mph at 5 am EDT with forecast track nudged very slightly north vs. 11 pm; Tampa area still under the gun if center of forecast track verifies, but the track cone is a bit wider than the typical error at 48 hrs (~65 miles), so landfall location is obviously still a bit of a guess. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 22.3N 88.9W 135 KT 155 MPH 12H 08/1800Z 22.9N 87.5W 140 KT 160 MPH 24H 09/0600Z 24.2N 85.8W 135 KT 155 MPH 36H 09/1800Z 26.0N 84.2W 125 KT 145 MPH 48H 10/0600Z 27.6N 82.6W 110 KT 125 MPH...NEAR THE COAST 60H 10/1800Z 28.8N 79.9W 70 KT 80 MPH...OVER WATER 72H 11/0600Z 29.7N 76.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 12/0600Z 30.4N 69.9W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 13/0600Z 31.5N 63.8W 35 KT 40 MPH...POST-TROP/EXTRATROP