George BM

@yodaI see that you're finally up.

Yeah. I'm not sure I completely trust myself to be "smart" if a tornado is bearing down on me. I'm guessing my "flight" would eventually overpower my "fight"... but probably not until 2x4s are raining down and shooting past me... that's if I'm still on the ground ... ... Yeah I'm a psycho.

@mappy Sorry I'm late... but I'm really pulling for your sister to make a full recover. I wish your sister and family good luck in this time.

Lol. Zancildae, you KNOW that there is an ENH/MDT risk day in our future this year that will not be as exciting as this morning was for some ANYWHERE in the region.

I did actually hear thunder in Herndon near the start of this hour.

In all seriousness though. We just got a MRGL for parts of the region for TOR and WIND in the 1300z update.

This is how we do severe in these parts.

There could be some strong gusts with them.

Mesoscale Discussion 0105 NWS Storm Prediction Center Norman OK 0556 AM CST Fri Feb 07 2020 Areas affected...northern VA...District of Columbia...central MD Concerning...Severe potential...Watch unlikely Valid 071156Z - 071300Z Probability of Watch Issuance...5 percent SUMMARY...Strong to localized severe gusts (50-60 mph) are possible with a narrow, low-topped convective band rapidly moving across northern VA and the greater D.C. area during the 12z-1330z period. DISCUSSION...KLWX radar imagery shows an intensifying band of low-topped convection with a few lightning flashes with the deeper convection exhibiting 20kft echo tops. Surface analysis shows a surface low immediately northwest of D.C. developing to the east-northeast. A narrow plume of weakly buoyant air, with surface temperatures in the upper 50s and dewpoints in the upper 50s, is located downstream of the convective band over northern/eastern VA into MD. Objective analysis indicates around 250 J/kg SBCAPE with 40 kt effective shear. Given the strong, deep forcing for ascent co-located with weak instability, it is possible a few strong to locally severe gusts may accompany the bowing portions of the convective band. The damaging-gust threat appears too confined in space/time to warrant a severe thunderstorm watch. ..Smith/Edwards.. 02/07/2020 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...LWX... LAT...LON 39047766 39257701 39187648 38647665 38297716 37927819 39047766

28.99" Hg at IAD.

Yeah we should drop below 29" of mercury briefly. 29.05" at IAD currently.

URGENT - WEATHER MESSAGE National Weather Service Baltimore MD/Washington DC 930 PM EST Thu Feb 6 2020 DCZ001-MDZ003-011-013-014-016>018-503-504-506-VAZ052>055-057-505- 506-WVZ051>053-071030- /O.NEW.KLWX.WI.Y.0006.200207T1400Z-200207T2000Z/ District of Columbia-Washington-Southern Baltimore-Prince Georges- Anne Arundel-Charles-St. Marys-Calvert-Northwest Montgomery- Central and Southeast Montgomery-Central and Southeast Howard- Prince William/Manassas/Manassas Park-Fairfax- Arlington/Falls Church/Alexandria-Stafford-King George- Western Loudoun-Eastern Loudoun-Morgan-Berkeley-Jefferson- Including the cities of Washington, Hagerstown, Baltimore, Bowie, Suitland-Silver Hill, Clinton, College Park, Greenbelt, Laurel, Camp Springs, Glen Burnie, Annapolis, Severn, South Gate, Severna Park, Arnold, Odenton, St. Charles, Waldorf, Lexington Park, California, Chesapeake Beach, Huntingtown, Dunkirk, North Beach, Lusby, Prince Frederick, Germantown, Damascus, Bethesda, Rockville, Gaithersburg, Silver Spring, Columbia, Ellicott City, Dale City, Manassas, Woodbridge, Lake Ridge, Montclair, Reston, Herndon, Annandale, Centreville, Chantilly, McLean, Franconia, Arlington, Alexandria, Falls Church, Falmouth, Dahlgren, Purcellville, Leesburg, Ashburn, Sterling, Paw Paw, Martinsburg, Charles Town, and Shepherdstown 930 PM EST Thu Feb 6 2020 ...WIND ADVISORY IN EFFECT FROM 9 AM TO 3 PM EST FRIDAY... * WHAT...West winds 20 to 30 mph with gusts up to 50 mph expected. * WHERE...The District of Columbia, portions of central, north central, northern and southern Maryland, central and northern Virginia and the eastern panhandle of West Virginia. * WHEN...From 9 AM to 3 PM EST Friday. * IMPACTS...Gusty winds could blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Use extra caution when driving, especially if operating a high profile vehicle. Secure outdoor objects. && $$

Indeed. ... Congrats fellow weenies throughout this subforum. Sorry about getting the fringey finger out there @psuhoffman.

67/36 at IAD 2:45pm est.

Neat. Was this at the same place that you lived during "The Spooky Scary Goose Whiteout" nearly 5 years later?

In any other case of severe potential that we’ve had in recent years around here I too would be cautious about jumping all in on a severe threat in these parts. But today is different… very different. I very highly doubt that this line of storms will fizzle out or even weaken much at all as they move in. In fact, they may very well do the opposite. Yes, legit severe is DEFINITELY extremely hard to get in these parts. But we are into the low/mid 90’s with dewpoints into the mid 70’s everywhere now. There is already a confirmed large tornado with the southern supercell, the northern Montgomery county supercell already has signs of strong rotation. Also, based on the 20z mesoscale analysis mid-level lapse rates are around 7.5C/km yielding MLCAPE of 4000+ J/kg everywhere. The biggest thing for me to note is that low-level lapse rates are steep (near 9C/km) now. The main line of storms approaching from the west is steamrolling it east at around 65mph and is moving perpendicular to the flow. Now with those steep low-level lapse rates that I just mentioned downdraft winds will easily be mixed down to the surface. So, a lot of areas should see max wind gusts of at least 65mph. BUT… with decent downdraft CAPE as well (1000-1300+ J/kg) coupled with the very strong to extreme instability and high PW values (1.75”+) we could see strong downbursts bring down much stronger wind gusts on a more local basis. Now as for the line of storms holding together through our region, effective bulk shear is strong for this time of year (around 50kts). This will allow the storms to remain very well organized and perhaps even strengthen a bit as the get east of the mountains and into the highest CAPE. Low-level shear is very decent for the time of year as well (effective SRH of 150-300m2/s2) hence the tornadic supercells developing ahead of the main line of storms. A few QLCS tornadoes are also possible with the main line. This is the best that I’ve felt about a severe threat in these parts in a long time… perhaps even “ever”. I just very glad that we finally seem like we’re going to score a bigly areawide severe event. Even work has brought @WxWatcher007 back to DC for this one. However, RIP this afternoon's and evening's rush hour though. BTW, Here's the new 2000z Convective Outlook from NWS George BM headquarters: 2000z update Mid-Atlantic region: A few supercells have developed within the last hour or so affecting the WV panhandle, northern/central VA and northern MD. These storms could become tornadic with a strong tornado not out of the question given the 150-300m2/s2 effective SRH with very large hail and severe winds also a threat with these storms. The main line of storms associated with the severe MCS/derecho now stretch from PA through western MD and eastern WV and is now moving over the mountains and into northern and western VA and is moving east at around 55kts. This line may further strengthen as it moves east of the mountains into an airmass with MLCAPE of 4000+J/kg, 1000-1200+J/kg DCAPE and effective bulk-shear of around 50kts. Widespread severe winds w/ some significantly severe gusts, severe hail and a few QLCS tornadoes will be the main threat with these storms through the afternoon and evening hours before they all move out into the Atlantic by 2z. Tornado: 10% (Enhanced) Wind: 45% hatched (Moderate) Hail: 30% hatched (Enhanced) The threat for this upcoming Saturday also looks very decent for our standards especially near the MD/PA border. What a fun week of severe weather tracking.

Woo storms! 31/28 at IAD.

Next year will be a-buzzin'!

Woo storms?

From last night.

@PrinceFrederickWx Lovin' it! I'd be very curious to see these same graphs over the past 100+ years... or since record keeping began at the local airports.

Is anyone going to try and see whether two dead satellites collide over Pittsburgh at 6:39pm est tonight? The chances of a collision are very low (1/20-1/100) but still... maybe we may see something if they do collide. They will be 560mi above Pittsburgh so you'd have to look up high.

That storm had a super deathband with crazy rates early in the morning of the 13th. Probably comparable to the Feb 1983 storm... nah that storm had 5"/hr rates according to some and the Feb 1979 storm had 4"-6"/hr rates.

@mappy I see that you're a @WxUSAF now.