George BM

I don't recommend getting an ulcer.

Currently 68/67 at IAD. Hoomid.

Nah. It's not out just yet.

JAS ONI: +1.3C (rounded to nearest tenth) JAS RONI: +0.81C

DCA: 2/01/24 IAD: 12/25 BWI: 2/01/24 RIC: 12/25 BWI Oct departure: +2.2F

Winter approaches. Happy October!

Forecast Discussion Tuesday, October 31, 2023 3:45AM EDT The strong arctic front is currently in eastern WV about to enter into western VA. A line of heavy gusty downpours and embedded thunderstorms stretches from NNE to SSW along this front. Temperatures have risen into the lower/mid 70s on strong south to SSE winds ahead of the front. These synoptic winds will continue to gust into the 35-45+ mph range w/ up to 50 mph gusts along the Potomac and Chesapeake shores and mountains to the west gusting into the 50 to 60 mph range with the 70+ kt LL jet overhead. A High Wind Warning for the highest elevations of the Blue Ridge and a Wind Advisory in the metro areas and near the Chesapeake Bay accounts for the wind threat ahead of the front. The main line will affect far western areas (between the VA/WV border and the Blue Ridge) between 8z and 10z, the Greater Metropolitan region in the 9-12z timeframe and eastern and southern MD eastwards through the rest of the Delmarva in the 11z-15z timeframe. Dewpoints ahead of this line are in the upper 60s to around 70F leading to around 500-1000 J/kg of CAPE. The main threat from the line of storms will be strong winds and perhaps a brief qlcs tornado given the low-level shear. With Pwats in excess of 1.75” there is a slight risk of flash flooding of some streams and low-lying areas, though the progressive nature of the line will prevent a bigger flood threat. Behind the front temperatures will fall rapidly on strong NNW winds as light/moderate anafrontal rain continues. In fact, temperatures in the metros will fall into the lower 40s by the early afternoon hours w/ upper 30s in the far NW suburbs. At the same time, a potent shortwave trough will have rounded the base of the longwave trough taking on a negative-tilt allowing another wave of low pressure to rapidly deepen along the front in the eastern Carolinas into the Virginia Beach area. This area of low-pressure will travel northeast along the front which will be situated along the Atlantic coastline through the afternoon and evening. As this occurs, more moisture will be thrown northwest into the cold airmass courtesy of the strongly negatively tilted trough increasing precip intensity. By mid-afternoon rain will change over to snow in the mountains with this changeover moving eastwards into the metros by 21-22z as temperatures fall to near freezing. Snowfall rates will be heavy with 1-2”+/hr rates commonplace, perhaps nearing 3”/hr at times in the heaviest bands that form. At the same time, courtesy of the increasing surface pressure gradient, NNW winds may gust over 50 mph at times from late afternoon through the evening. This will lead to low visibilities of under a quarter mile at times. A Winter Storm Warning is currently in place from the mid-afternoon hours into the early overnight hours for the metros with Blizzard warnings along the Blue Ridge and higher elevations. An upgrade to a Blizzard Warning for the majority of the region may very well be needed if current model and realtime trends continue this morning. Snow should taper off by midnight or 1am at latest with many areas receiving 6-10”+ of snow (locally up to a foot where the heaviest bands set up) with 10”-15”+ amounts in the mountains to the west. Temperatures will bottom out in record territory and hover in the lower/mid 20s through the overnight hours but the strong gusty NW winds will put wind chills in the single digits making for a mid-winter like start to November. Forecaster Wannabe: George BM

By December of 2018 if MBY got even as little as several hundredths of an inch of rain puddles would form in the low points of the lawn and walkways and remain all day. Bizarre.

When's the last time that you got at least three 1"+ rain days in a single month out there?

With the high clouds over Illinois and near the Mississippi River fairly far to the west areas that do not have too many low clouds from Ophelia yet, especially from the metro region westwards, may experience a, at least, briefly gorgeous sunset before any of the aforementioned Midwest clouds try to cut the show short (they're pretty far west so we'll see how long a gorgeous sunset lasts). The further WNW you are the better. (Medium confidence)

989.6mb extrapolated from flying at 250-300m.

Organizing relatively quickly atm all things considered.

Note: Nineteen year anniversary of northern/central VAs most prolific tornado outbreak, probably in recorded history.

IAD down to 49F earlier. The first sub-50F low since May 31st. It feels like Mother Nature diverted a tropical system from the Mid-Atlantic out there.

0.8" last night and a total of 3.45" for September (all in the last six days).

Margot the hurricane. AL, 14, 2023091118, , BEST, 0, 265N, 398W, 65, 988, HU

That would be yours truly but I'll one you up. Try Herndon watching those downbursty rain/hail curtains drop immediately to my west for two days. I salute @EastCoast NPZ for what he goes through.

Lee now a Category 4. Forecasted to become a 145kt Cat 5 tomorrow. Not sure I've ever seen a forecast that strong for a storm not already a 5. Maybe once before?

Fun fact: Nary more than a drop here a few miles to your southeast in Herndon.

IAD recently got into some sun and jumped to 97F. There's a storm cell in the area now, though.

So for today (assuming no late changes) it looks like: IAD: 100F BWI: 100F DCA: 98F ... RIC: 100F ETA: RIC: 101F

IAD just had a 100F reading for a single minute... awaiting climate report.

http://iadasos.org/IAD/index.html

For the fourth day in a row IAD hits 99F. Today's the best chance at a brief 100. We'll see what happens.