bluewave

The good news from a forecast confidence perspective is that all the models agree on the heavy rain and flash flood potential. So we have excellent agreement in that part of the forecast. The more tricky part of the forecast is the high wind potential.Several pieces of guidance like the Euro/EPS/RGEM/and HRRR loop the low back closer to MTP. Since that part of the forecast would be Wednesday night, there is time to issue high wind warnings after the 0z runs tonight should they be necessary. The HRRR gusts in knots would require high wind warnings for Long Island. Storms that loop back west are notorious for wind damage near their paths.

The 18z RGEM came west with the cyclonic loop closer to the 18z HRRR.

60-70 mph near MTP and 80 mph near MVY. We will really have to watch where that cyclonic loop occurs for the winds. Those storms that back in from the east are notorious for wind damage near the center.

While these long range SPV forecasts can be very speculative, the latest extended EPS doesn’t have the stronger rebound it did last week. So it’s now cooler in early November than a few days ago. It would be good news if that second dip near the start of December idea has merit. But these forecasts beyond 15 days can often be very uncertain. New run Old run Cool start to November

If you ignore the 0z run, the 12z Euro is similar to 12z yesterday. Still very heavy rains area wide and possible gusts near 70mph on Eastern Long Island. The problem with winter storm tracks was suppression even a day before the storms. So we will be ahead of the game if the suppression issue is fixed. This old bias led to snowfall shifted too far south like during the January 2016 blizzard. 12z today 12z yesterday

High of 77° so far at Newark and only 55° north of the warm front at BDL.

The HREF says make sure that leaves aren’t blocking your storm drains.

The 3km Nam has 70 mph gusts close to Eastern Long Island. But the exact location of where the cyclonic loop occurs will be important. Models may be struggling on where to place the subtropical system with the multiple weaker lows to the west.

New all-time 24 hr rainfall records around Sacramento and wettest October day in San Francisco.

That has been the story since the super El Niño. Warmer winters overall with a strong WAR or SE Ridge in the means. But impressive blocking intervals that always seemed to produce snowstorms for us. So more of a snowy and mild spring in the Rockies type of winter pattern. The record SSTs to the east were like rocket fuel for heavy snowstorms.

The 18z extended HRRR looks more like some of the EPS members.

Looks like the major upgrade also improved the EPS. https://www.ecmwf.int/file/299239/download?token=QzX-fS7a On 12 October, ECMWF implemented the second upgrade of its Integrated Forecasting System (IFS) in 2021. IFS Cycle 47r3 includes numerous changes to the forecast model, observation usage and data assimilation system, with contributions from many teams across the Centre. There are major developments to the representation of moist physics in the model and increased observation usage in cloudy regions in the assimilation. The upgrade improves the large- scale atmospheric circulation and reduces tropical cyclone track errors in both high-resolution (HRES) and ensemble (ENS) forecasts. Several forecast products are modified, such as visibility and wind gusts, and new products are introduced, including clear-air turbulence. Cycle 47r3 brings a major revision to the representation of moist physics in the IFS as well as improvements in the assimilation of observations and increased usage of satellite data in cloudy regions through the extension of the ‘all sky’ approach. An important impact on the forecast is the improvement of the atmospheric circulation, as seen in the increase in skill of extratropical geopotential heights and winds, and with a reduction in wind errors in the tropics of several per cent. The ensemble-mean of error in tropical cyclone position is reduced by 10% between forecast days 2 and 5. There are changes to the character of precipitation, with improvements in the precipitation PDF and in strongly forced convective systems. As well as the many positive signals, a significant change in the physics inevitably leads to some deteriorations, for example in total cloud cover, and these will be addressed in future IFS cycles. There are several new forecast products, such as clear-air turbulence, and improvements to existing products, including visibility and wind gusts. Overall, the package of changes in Cycle 47r3 is an important step in the development of the IFS, improving performance overall, extending our use of existing observations and providing a stronger foundation for further development of the model and data assimilation at current and higher resolutions.

New lowest pressure record for the area off the Pacific Northwest coast.

If the Euro performs reasonably well with this, then maybe the big moist physics upgrade will turn out to be a success. The hope is that the coastal storm track suppression issue with our snowstorms will be fixed. It would be nice seeing the Euro amped up with snowstorms like the NAM was with the January 16 blizzard. The 12 EPS is more tucked in than the OP

Impressive subtropical structure on the 12z Euro. Convection wraps almost completely around the center. An eye-like feature briefly develops.