Kmlwx Posted February 28, 2017 Share Posted February 28, 2017 4k NAM is not particularly exciting at all for DC proper anymore. Has a good cell go south of the area, though. 3km looks better with a squall coming through. Link to comment Share on other sites More sharing options...
WxReese Posted February 28, 2017 Share Posted February 28, 2017 17 minutes ago, Kmlwx said: 4k NAM is not particularly exciting at all for DC proper anymore. Has a good cell go south of the area, though. 3km looks better with a squall coming through. Yeah, the line @high risk has been talking about is more south on the 18Z 3km NAM, thus killing severe chances even for those of us near 64. However, seasonal trend has been to the NW, so that would buck that trend to happen. Can't wait to get in the HRRR window in a few hours. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted February 28, 2017 Share Posted February 28, 2017 Very bad trends this afternoon. Looks like a DC fail is unfolding. Link to comment Share on other sites More sharing options...
yoda Posted February 28, 2017 Share Posted February 28, 2017 6 minutes ago, Eskimo Joe said: Very bad trends this afternoon. Looks like a DC fail is unfolding. Are you serious? Link to comment Share on other sites More sharing options...
Kmlwx Posted February 28, 2017 Share Posted February 28, 2017 5 minutes ago, yoda said: Are you serious? The NAM did back off a good bit. But it's still early obviously. The trend hasn't been good if you like severe. Link to comment Share on other sites More sharing options...
Thanatos_I_Am Posted February 28, 2017 Share Posted February 28, 2017 What a sh***y day for KLOT radar to be down Link to comment Share on other sites More sharing options...
Kmlwx Posted February 28, 2017 Share Posted February 28, 2017 GFS continues once again to be rather unimpressive with parameters. What we knew earlier is still the case - the shear will not be the issue. The issue will be instability. GFS has CAPE lacking. Not going to cut it. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted February 28, 2017 Share Posted February 28, 2017 1 hour ago, yoda said: Are you serious? Yes. I only go for high end potential. I'm still "in" on this event, but I'm not liking the direction things are headed. Today seems pretty 'meh' out in the Midwest thus far. Link to comment Share on other sites More sharing options...
yoda Posted February 28, 2017 Share Posted February 28, 2017 3 minutes ago, Eskimo Joe said: Yes. I only go for high end potential. I'm still "in" on this event, but I'm not liking the direction things are headed. Today seems pretty 'meh' out in the Midwest thus far. Already reports of at least one fatality in Ottawa IL and large tornadoes in IL.... but yeah, guess that's "meh" to you Link to comment Share on other sites More sharing options...
ErinInTheSky Posted February 28, 2017 Share Posted February 28, 2017 Also, "Meh" in the midwest doesn't necessarily mean "Meh" here. The southern IL and IN/KY threat is just beginning, that's the worst threat of this system. Link to comment Share on other sites More sharing options...
yoda Posted March 1, 2017 Share Posted March 1, 2017 Possible Tornado Watch coming soon for NE IN/S MI/NW OH Link to comment Share on other sites More sharing options...
southmdwatcher Posted March 1, 2017 Share Posted March 1, 2017 It may end up being "meh", but this is way too early to blow this event off around here. Ohio Valley storms are moving northeast. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted March 1, 2017 Share Posted March 1, 2017 Please keep the Midwest chatter in it's appropriate regional forum. Link to comment Share on other sites More sharing options...
WinterWxLuvr Posted March 1, 2017 Share Posted March 1, 2017 1 hour ago, yoda said: Already reports of at least one fatality in Ottawa IL and large tornadoes in IL.... but yeah, guess that's "meh" to you Not enough Yoda. Death and destruction is all that will satisfy. Link to comment Share on other sites More sharing options...
yoda Posted March 1, 2017 Share Posted March 1, 2017 Well 00z NAM is... interesting.... soundings are ugly through 21z WED... then BAM they go through the roof 00z to 03z THUR Link to comment Share on other sites More sharing options...
yoda Posted March 1, 2017 Share Posted March 1, 2017 Why hello der Link to comment Share on other sites More sharing options...
high risk Posted March 1, 2017 Share Posted March 1, 2017 Both the ops and para NAM nests shown a significant threat between 00 and 03z, but they arrive at it in different ways. The ops brings the lead squall line through the area (mostly DC north) during the afternoon with major regeneration of storms behind it during the evening. The para washes out the squall line and has the evening cells as the only show. Link to comment Share on other sites More sharing options...
WxReese Posted March 1, 2017 Share Posted March 1, 2017 NAM suite definitely trended toward the cloud cover not abating, which is why we see the forecast soundings suck until late afternoon/early evening. Will be interesting to see how things play out around here tomorrow, specially with how strong some of the storms out west have been the past several hours. Link to comment Share on other sites More sharing options...
yoda Posted March 1, 2017 Share Posted March 1, 2017 Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 837 PM EST Tue Feb 28 2017 .SYNOPSIS... A warm front will lift to our north tonight and a strong cold front will pass through the area late Wednesday and Wednesday night. After a brief period of high pressure Thursday, an area of weak low pressure will cross the region Friday. High pressure returns for Saturday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A warm front located over the area late this evening will lift to the north overnight. Southerly flow behind the boundary will allow for more unusually mild conditions. Temps will hold steady or even rise overnight due to the southerly flow. An upper-level disturbance has triggered showers this evening. The upper-level disturbance will move away from the area overnight...causing coverage of showers to diminish across most areas. However...more upper-level energy is expected to move across the northern CWA late this evening and again toward morning. Elevated instability has increased across these areas due to the southerly flow. Latest mesoanalysis shows around 100 J/KG of MUCAPE approaching from the south and west. The instability along with the upper-level energy will trigger some showers and isolated thunderstorms. The best chance for precipitation will be across northern Maryland...eastern West Virginia and northern Virginia late this evening into the overnight...and then again toward morning. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... ..Significant weather day expected on Wednesday with strong to severe thunderstorms... Cold front will approach the region during the day on Wednesday with deep moist southwest flow out ahead of the front. Expecting temperatures to surge well into the 70s to near 80F, with dew points in the 50s to around 60F, which should help generate 500-1000 J/KG of MLCAPE. This combined with 0-6KM shear of 60-70 knots and 850-mb flow of 50-60 knots will set the stage for strong to severe thunderstorm development. Exact evolution of thunderstorms will be dependent on how remnant activity from today plays out, but expecting some morning activity across our northern zones to give way to main convective period from about 18z-03z. It should be noted that some solutions depict an earlier start time, beginning about 16z. Main threat is expected to be damaging winds associated with a squall line, but large hail and perhaps an isolated tornado are also possible given steep lapse rates and impressive shear profiles. Link to comment Share on other sites More sharing options...
yoda Posted March 1, 2017 Share Posted March 1, 2017 00z SPC WRF drives a monster squall line through the region between 20z and 22z... looks like there also are embedded sups in the line as well Link to comment Share on other sites More sharing options...
Roger Smith Posted March 1, 2017 Share Posted March 1, 2017 The gradual intensification of the upper level winds across the northeast U.S. overnight and Wednesday will allow any squall line development to accelerate and I think that severe wind gusts will develop along the entire frontal zone because of the extreme thermal gradient developing -- that part is only in a formative stage around IA-nwMO-eKS now and debris from all the action out ahead could spark sporadic severe threats in MD and PA at any time from late tonight to mid-day. Then I think it clears for a time with temps near 80 F, strong WSW winds, still fairly high dews, and the front, in whatever form, blasts through -- even if echo presentation is weak (and it may be strong) there will likely be gusts to 60-70 mph anyway, the 500-mb gradient is constantly tightening next 24h and there's also a downsloping factor with the very cold air rushing in to replace the warm sector. I would say 40% chance of a tornado somewhere in the MA forum, 70% chance of a severe thunderstorm and 99.9% chance of damaging wind gusts. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted March 1, 2017 Share Posted March 1, 2017 Day 1 ENHexpanded towards Hagerstown. Not bad, dynamics certainly there, just need the sun. Link to comment Share on other sites More sharing options...
mappy Posted March 1, 2017 Author Share Posted March 1, 2017 Please keep the Midwest chatter in it's appropriate regional forum.Wish I had seen this last night. Dude, you brought up the Midwest, of course people are going to reply in kind. lol at you then policing people over reply to you over it. Come on man... Link to comment Share on other sites More sharing options...
Kmlwx Posted March 1, 2017 Share Posted March 1, 2017 Yep - all about the sun. Some of the guidance isn't all that impressive - especially the GFS and the regular NAM. C'monnnn weather. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted March 1, 2017 Share Posted March 1, 2017 Socked in with thick clouds here in Reistersrown. Link to comment Share on other sites More sharing options...
MillvilleWx Posted March 1, 2017 Share Posted March 1, 2017 Been working the overnights and keeping track of how the models are handling the setup out in the Ohio Valley. The HRRR has been doing a pretty nice job overall with the placement of the precip shield and particular cells at times. The 3km NAM has been a little innocuous at times with some of the precip field, so I think it maybe under playing it to a degree. I still don't mind the look given the parameters its spitting out, so could be a time to ignore the future radar composite and look at the parameters at hand. Both the HRRR and 3km show a decent wave of precip motioning to the east-northeast out of SW PA and Western MD into the remainder of PA and the northern fringes of the forum getting scrapped as it passes. The main line will march east from the Ohio Valley with anticipated weakening of the shield somewhat as it reaches the mountains. That's when we'll have to watch what happens on the eastern side of the BR with regard to cloud cover and diurnal heating in the morning and afternoon. Current HRRR at 9z (Latest completed run) shows a break in the clouds toward noon with the line preparing to pass through the BR. The result of the clearing caused a sharp increase in SBCAPE and MUCAPE with indices shooting between 1-2k j/kg, as well as steady uptick in the LI to around -4. certainly a good sign if you want strong to severe cells. As the line passes through the 81 corridor, the destabilization ahead of the line allows the segment to congeal and increase in intensity as it interacts with the more favorable environment. It's noticeable that when there is a decrease in sky cover prior to the line, the proposed reflectivity looks more impressive with a good structure and a better organization of cells. We've mentioned repetitively about sky cover being important and its no secret that the key to anything substantial would be for a period of destabilization prior to the main line reaching past the 81 corridor. The one constant is no matter the case, temps should be into the low to mid 70's at minimum with DP's into the 50's to near 60 at the onset of any convection. It's a pretty nice setup for straight-line winds and possibly a spin up or two within any line that develops with a strong LLJ into the 50's and steep ML LR's around 7-8C/km. HRRR was showing potential for 60-70 knots mixing down with the passage of the line, so I think its safe to say that we should be on the lookout for potential outages if we were to get hit. The one saving grace is probably the lack of leaves on the trees. If this were later in spring or summer, it would be more worrisome. Here's a glimpse at the HRRR for KGAI this afternoon just prior to the line moving through the area. Not a bad look. Link to comment Share on other sites More sharing options...
Kmlwx Posted March 1, 2017 Share Posted March 1, 2017 Yeah HRRR does clear us out around 16z to 17z. The NAM4km looked less impressive with clearing but still some breaks in the clouds. Battle of the sun today. Looking forward to sun obs The 10z HRRR is pretty early too with the line. Has it plowing through around 19-20z. Makes it all the more important to get clearing as early as possible. The way the HRRR brings in the convection makes it look like it'll minimize the TOR threat (more squall line in nature vs cellular) Link to comment Share on other sites More sharing options...
H2O Posted March 1, 2017 Share Posted March 1, 2017 delay the squall line more and it will give more time for clearing ahead and heating. P standard look this morning. Clouds until 10ish or later then a quick warm up Link to comment Share on other sites More sharing options...
Kmlwx Posted March 1, 2017 Share Posted March 1, 2017 9 minutes ago, H2O said: delay the squall line more and it will give more time for clearing ahead and heating. P standard look this morning. Clouds until 10ish or later then a quick warm up The bad news is our squall line events like to come in earlier than expected. Either that or we tend to get pop up activity that ruins our priming before hand. Link to comment Share on other sites More sharing options...
H2O Posted March 1, 2017 Share Posted March 1, 2017 3 minutes ago, Kmlwx said: The bad news is our squall line events like to come in earlier than expected. Either that or we tend to get pop up activity that ruins our priming before hand. was just thinking that. We do see cells pop early before the main show and it clears out the juiced atmosphere. But all we can do is wait and see. i think today might surprise some. Link to comment Share on other sites More sharing options...
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