May Banter 2025

[George BM]

Forecast Discussion

Sunday May 25 2025 3:08PM EDT

This has been a destructively wet month for much of the region with back-to-back coastal lows/ nor’easters dropping 3-7” and 5-10” of rain across the forecast area. Followed by rounds of, sometimes, training thunderstorms early this past week tracking from WSW to ENE dumping another 4 inches to up to a foot of rain with parts of Montgomery and Howard counties into Baltimore getting those 10-12”+ totals. Needless to say, the drought that has been affecting much of the region over the last year or so has come to an abrupt end.

Now this afternoon, another very dangerous situation is in the process of unfolding. An MCS is currently moving across northern MD with severe thunderstorm warnings out for wind damage as well as severe hail. A Severe Thunderstorm Watch is in effect for everyone north of Fredericksburg and Culpeper, VA and north of southern MD until 10pm local time tonight to account for these storms and training thunderstorms that will develop over the Greater DC metro. With 2000+ J/kg MLCAPE and decent effective bulk-shear (~40kts) there could be embedded supercell structures that produce severe hail (1-2” in diameter). The magnitude of CAPE and moisture will cause localized strong to severe downburst winds with any embedded downbursts/microbursts as well.

The main story this afternoon and evening, however, will be from flash flooding from the storms that will start training over the same areas for several hours. Have issued a Flash Flood Watch is in effect for the entire forecast area until 4am. Decent low-level southerly flow will allow the storms that develop and back build to the south and west of the main MCS to be continuously reinvigorated as warm/moist/unstable air continuously lifts as it meets with the rain-cooled airmass to the north. Pwats of 1.75-2”+ will also make these storms efficient rainmakers. As a result, some areas could get several hours of 1-3”/hr rainfall rates leading to rainfall totals as high as 8-12” w/ locally higher amounts. A wave of energy will move along the front through the region this evening briefly allowing rain and storms to become more widespread. There could still be a few severe storms, mainly from the Potomac River and Route 50 southwards in MD where the airmass will be most unstable. As the wave moves to the east all the rain and storms will move out with it, exiting the Chesapeake Bay by 3am or so. However, the damage will be done by then.

We will get another brief reprieve through midweek with slightly above average temps and humidity (High in the 80s w/ mid/upper 60s dewpoints) before, unfortunately, our attention turns to newly formed Tropical Storm Barry located in the western Caribbean Sea. Models are slowly starting to come into better agreement that Barry will move north and then northeast across Florida before interacting with a shortwave trough that may pull the storm back north into eastern North Carolina or into the Chesapeake Bay by late week bringing a threat of significant rains as well as gusty winds depending on how strong the tropical system is.

[Jebman]

George BM I absolutely love your idea of severe weather! I really enjoyed this.

 

Forecast Discussion 

SAT 31 MAY 2025 655pm EDT

One of our senior forecasters, GBM, who has been with NWS for nearly twenty years, recently referred to our ongoing destructive wet weather this past month here in the greater Washington Metropolitan Region. Some communities have experienced upwards of 2 FEET of rainfall.

We are not certain how this has happened, but Barry has explosively deepened into a strong Category Five hurricane with 195 mph winds. FL winds were reported by hurricane hunters, when converted to mph, as 237 miles per hour. This is a very serious situation. Barry has been buffeting the coastal Carolinas for the past two days as it moves slowly north. Modeling has indicated that the storm will interact with a trough which will pull Barry into the mouth of the Chesapeake Bay then catastrophically slow down in the Bay, possibly for 12 to 24 hours.

Barry will probably cause generational impacts over the eastern Carolinas and Virginia over the upcoming 24 to 48 hours. Catastrophic Category Five wind gusts, extreme storm surge up the Bay, unbelievably strong battering waves on top of the surge as well as unprecedented amounts of rain will impact the entire region. 

Twenty to thirty feet of surge up the Bay with fifteen to twenty foot waves on top of the storm surge will produce extreme damage and severe beach erosion. Rain will be torrential, with rates of 2 to 4 inches at times within the stronger rainbands. Barry is a slow moving storm and is expected to possibly stall in the Bay.

Evacuations are underway in Eastern Virginia. Everyone except for essential personnel are urged to leave the coastline and move as far inland as possible. It's not just extreme surge and waves and extremely high winds and freshwater flooding that are concerns with Hurricane Barry. It's tornadoes as well. Numerous tornadoes are expected over the Carolinas and Virginia. 

Barry will push prodigious amounts of tropical moisture up against the Appalachian Cordillera resulting in catastrophic orographic rains. These rain tallies could very well be in excess of 50 inches in some communities. This would make the recent flooding in Asheville, NC seem like a pleasant afternoon  in Central Park, especially  when you take the extremely wet antecedent hydrology into account. GET OUT NOW. MOVE HUNDREDS OF MILES WEST.

This storm will result in totally uninhabitable conditions for many weeks, perhaps months. 

Further updates will be issued.

 

[nw baltimore wx]

I’d love to see St. Louis knock off Winnipeg in the first round.

Also rooting for Colorado tomorrow night. I hate all sport things Dallas.

[RickinBaltimore]

9 hours ago, nw baltimore wx said:

I’d love to see St. Louis knock off Winnipeg in the first round.

Also rooting for Colorado tomorrow night. I hate all sport things Dallas.

I mean, same here.

Hellebuyck has been chased 3/6 games in this series. If the Blues can get on the Jets early, they could take this Sunday