George BM

May already? Geeze. Looking forward to pollen-washing and drought-denting rains.

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.

0.17" of rain from a downpour early in the 2am hour that didn't wake me up due to there being no lightning with it.

Now you know what to do come wintertime.

84 for a high today, warmest day of the year so far.

0.79", 2.43" for the month

Looking at the positive side if this is the case... I'm looking forward to us getting Cedar Rapided with 100-140+ mph wind gusts.

I can still faintly see light in the western sky after 9pm! Long days are upon us.

IAD w/ a 48kt(55mph) wind gust.

Currently 61/33 at IAD w/ a peak gust of 45mph so far.

March 2nd, 2018 was epic.

SPC mesoscale 18z analysis showing 0-3km lapse rates of 10+C/km stretching from Carroll County, MD down southwest through Prince Williams County, VA. That will help any showers bring down enhanced wind gusts this afternoon.

I ended up with 0.78" IMBY. (Herndon, VA) 1.42" for April so far.

MBY Snow totals Winter 2024-2025 11/21/2024: T (A brief gusty rain/graupel shower around 6pm.) 11/22/2024: T (Flurries/light wet snow fell between 10am and 11:45am before mixing with and changing to light rain by 12:30pm.) 12/01/2024: T (Flurries off and on during the 4pm and 5pm hour.) 12/05/2024: T (Mixed light rain/snow between 4:30-5am w/ another brief light rain//snow mix between 7:30-7:40am.) 12/15/2024: T (A few ice pellets starting around 11:30am, then mixing with and changing to an off and on drizzle of rain/snow (intensified briefly into a light rain/snow mix during the 1pm hour). This lasted until after 3pm when precip again intensified into a light rain/snow mix before changing to all rain by 3:40pm.) 12/20/2024: T(A drizzle of rain/snow (8:30am-9am). A period of light snow between 10:30-11:15am, briefly approaching moderate intensity between 10:35am and 10:50am. Flurries continuing until midday. A few more flakes in the 6pm hour based on radar returns.) 12/24/2024: 0.1" (Light sleet started around 6:30am occasionally mixing with freezing rain through about 9am or so (more IP than ZR). Precip was very light but below freezing temps and a cold ground allowed for whitening of hard surfaces. Was originally going to call it a trace but with all of the 0.1" reports immediately surrounding me and taking into account sleet pellets piled at least two pellets high in depth... a tenth of an inch is the final measurement I went with making it the first measurable white stuff of the season for me.) 1/03/2025: 0.2" (Brief light rain/snow/graupel shower around 2pm. Heavy snow associated with a developing snow squall between 2:50pm-3:15pm with a brief brake in intensity to light snow between 3:00pm and 3:05pm. A second snow squall from 4:13pm to 4:25pm. Snow was light to moderate with the second squall until 4:22pm when rates briefly became as heavy as during first squall. Peak snowfall rates from both squalls in the 1-2"/hr range.) 1/06/2025: 6.2" (First flakes around or shortly after midnight on the 6th. Light snow becoming moderate at times by 2:00am lasting through 7am before becoming intermittent and tapering off to a few small flakes/crystals by 9:45am. A brief moderate snow shower around 1:40pm tapering off to a light snow then flurries by 2:20pm and holding near that intensity until the 4pm hour when it became a very light snowfall again. Light snow, approaching moderate intensity at times from the 5pm hour through 8:30pm, then very light snow/flurries until 10:15pm when snow tapered off.) 1/10-11/2025: 1.7" (Flurries/light snow starting in the 10pm hour intensifying to light/moderate snow 10:50-10:55pm. Snow became moderate to even mod/heavy at times with peak snowfall rates of 1"+/hr at times between 11pm and 12:45am. Snow then became occasional and light until the mid-overnight hours when it ended.) 1/14/2025: T (Flurries moved through between 9:15pm and 9:50pm.) 1/16/2025: 0.5" (Occasional flurries/light snow starting around 5:45pm. A burst of near moderate snow between 6:35pm and 6:43pm. Flurries/very light snow/graupel until 7:30pm or so followed by a burst of moderate/heavy snow until near 7:45pm. Flurries taper off by 8:15pm.) 1/19/2025: 1.6" (Some wet snowflakes mixing in with light rain in the 9am hour. Off and on light rain w/ a wet flake or two until 1pm when more snow started mixing in until it was all snow by 1:30pm coming down at a moderate clip. Snow lightened up and turned into a snow/graupel mix, then mainly graupel with a little sleet mixed in during a good chuck of the 2pm hour. More snow started mixing back in around 2:45pm before becoming all snow with a legitimately heavy burst between 3:10pm and 3:16pm (2"+/hr rates). Snow became light afterwards before picking back up to moderate intensity by 4pm. By 4:30pm snow tapered off to flurries which continued on occasion into the 6pm hour before ending all together.) 2/08/2025: T (A few flakes fell between 8:45am and 9:15am, then flurries/very light wet snow from 9:15am until sometime in the 10am hour when it tapered to drizzle. Occasional drizzle throughout the day until the late afternoon when temps fell to 31F with light freezing rain.) 2/11-12/2025: 5.5" (A few flakes/flurries starting around 12:15-12:20pm picking up to a light snow by 2pm. Snow increased to moderate intensity by 5pm continuing at moderate+ rates until around 8-9pm. Light snow continuing until after midnight with flurries tapering off during the 1am hour.) 2/19/2025: T (Occasional flurries occurred between 10:45am and 1:30pm.) 2/20/2025: T (A few flakes started falling around 8:45am. Snow intensity briefly increased to 'light' between 10:05am and 10:15am before tapering back off to flurries and ending before midday.) Snow totals IMBY as of April 10, 2025: 15.8" ------------------------------------------------------------------------------------------------------------------------------------- Yes. That's right... I bumped this thread just to add two traces that I received nearly two months ago. Sue me with all your might!

Beautiful tree with vibrant hot pink blossoms IMFY yesterday... Duller and more orangish/brownish today. RIP Temps got into the upper 20s. IAD bottomed out at 26F.

National Weather Service Baltimore MD/Washington DC 200 PM EDT Tue Apr 8 2025 ... ..."Have gone ahead and started the growing season early and issued Freeze Warnings in coordination with surrounding offices. This is due to recent warmth and the fact we are only a few days from the typical start of the growing season for areas near and east of I-81 (excluding the Blue Ridge Mountains)"...

IAD up to 77F.

@CAPE What storm day is your new profile pic from?

Random ETA: IAD actually had a midnight high of 57F. Afternoon high of 56F. Currently 53/34 there.

A rare sunny day where afternoon high temps underperformed somewhat. IADs forecasted high: 61F Actual high: 56F

Looks like showers will continue into the turn of the month. Happy April!

May 4 2025 2:00AM EDT A dangerous predawn is on tap for the region. Supercells associated with an extremely violent and catastrophic tornado outbreak that has been going on across the southern US over the past 12 hours or so will continue to congeal into an intense QLCS line and blast through our region over the next couple hours. These storms will bring the threat of multiple tornadoes (some strong), destructive hurricane-force wind gusts and large hail. QLCS is currently moving through into West Virginia and southwestern Virginia. There are still supercells embedded within the line and some just out ahead of the line producing significant tornadoes. In the region as of 2am temps have risen into the upper 70sF with dewpoints getting into the 70s as a plume of unseasonably warm/moist air moves in with a powerful 80+kt LLJ. The strong LLJ and strong air pressure gradient ahead of the front will help winds gust into the 40 to 55mph range. A Wind Advisory is in place to account for this. The main story by far, obviously, will be the storms that will race across the region over the next couple of hours. Ahead of the line, temps may rise up to 80F with lower 70s dewpoints (record breaking for this time of night during this time of year). Coupled with steep MLLRs aloft (7.5-8C/km) and -11 to -12C 500mb temps, CAPE will eclipse 3,000 J/kg. Low-level shear will be very strong (500-700+ m2/s2 effective SRH) with effective bulk wind shear of 80+kts. This line will form NE moving bowing segments that (because of high DCAPE of 1200-1400+ J/kg) will contain swaths of high-end severe winds with gusts of 75-100mph leading to extensive to extreme wind damage. With the strong to extreme LL shear a couple QLCS tornadoes look likely. A strong tornado or two is possible with embedded supercells. These storms will be along the I-81 corridor around 3am moving through the Greater Washington/Baltimore metros in the 4am and 5am hours exiting east of the Bay by the 6am hour. Once storms move out winds will shift to the WNW with 30+ mph wind gusts behind the cold front with temps rebounding into the low 70s w/ much lower humidity after falling into the low 60s behind the storms. A great day for the cleanup process to begin.

Quick look at the SPC mesoscale analysis archive. MLLRs June 4, 2008: 6.5-7C/km (modestly steep) MLLRs June 29, 2012: 8+C/km (very steep). Evening sounding confirmed MLLRs of 8.6C/km.

0z IAD sounding. MLCAPE is more accurate than SBCAPE due to the erroneous 65F surface dewpt reading. Actual dewpoint is around 60F.

IAD just gusted up to 44kts(51mph) w/ the temperature up to 75F with some sunshine.