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yoda

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  1. yoda
    Afternoon AFD from LWX... and here we go @Eskimo Joe @high risk SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... Closed upper-level low pressure will remain over the Great Lakes Monday and a potent jetmax associated with this system will move into the area during this time. This will cause the wind field aloft to increase while heights fall. A surface trough will most likely setup east of the Allegheny Front due to differential heating. Showers and thunderstorms are most likely to develop along the surface trough during the early to mid afternoon hours (approx 16-18z) before propagating eastward (additional showers and thunderstorms are likely west of the trough as well due to the breaking capping inversion from falling heights). Thunderstorms are expected to intensify as they propagate eastward, possibly congealing into linear segments that produce more widespread wind damage. Deep layer shear is progged to be around 25-40 kt, and mid-level lapse rates will be steep due to the falling heights. SBCAPE is progged to be around 1500-3000 J/KG with the highest amounts east of the Blue Ridge. DCAPE will most likely be over 1,000 J/KG for many locations, enhancing the threat for downbursts. Also, some of the fattest CAPE in the soundings is progged to be around the -20C level, suggesting that there is a potential for very large hail in addition to the damaging wind threat. Veering profiles also suggest that an isolated tornado is possible as well. Please pay attention to the latest forecasts for Monday afternoon/evening, and be prepared to seek shelter if warnings are issued. The most likely timing for severe storms is around noon to 4 PM west of the Blue Ridge Mountains, and 4 PM through 8 PM east of the Blue Ridge Mountains into the metro areas, and perhaps lingering until around 9 or 10 PM toward southern MD and the Bay. Convection should dissipate later Monday evening. However, if we do not get widespread convection during the afternoon/early evening, there is a threat for isolated to scattered severe storms well into the evening because the atmosphere will not be worked over. Overnight, most of the time should turn out dry with just an isolated shower or t-storm possible.
  2. yoda
    Baseball sized hail in IN in one of its STW
  3. yoda
    This was from this morning LWX AFD... haven't seen them mention destructive winds before SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... After a lackluster start to the severe weather season, things quickly begin to change as a robust upper trough sweeps through the Ohio Valley to Mid-Atlantic. Presently, the upper low is situated over the Upper Midwest while eventually racing toward the east-southeast during the next 12 to 36 hours. With warm sector temperatures rising into the upper 80s/low 90s and dew points reaching the low 70s, ample instability will be available for convective development. Depending on the forecast model, surface-based instability nears 3,000 J/kg, accompanied by unusually steep mid-level lapse rates. With such lapse rates into the 7 to 8 C/km range, there is an increasing threat for large hail, especially from the D.C. metro southward. Additionally, large downdraft CAPE values are evident in forecast soundings which supports damaging to locally destructive winds. The latest model suites favor early afternoon convective initiation over the terrain as well as along a well established lee trough. Seasonably high CAPE values should allow rather quick development of updrafts. Within a couple hours after initiation, high-resolution models favor upscale growth into a eastward propagating squall line. The Storm Prediction Center has placed areas east of I-81 in a Slight risk for severe thunderstorms, with an Enhanced risk grazing Spotsylvania and King George counties. Depending on how subsequent models and observational data indicate, some expansion of these threat areas are possible. With an above average precipitable water air mass advecting into the region, there will be some threat for flash flooding. The cold pool driven thunderstorm activity should keep convection on the move. However, a quick inch or two is possible within many of these storms. A Slight risk continues from the Blue Ridge eastward, but especially over the DC to Baltimore urban sprawl. As the cold front does not arrive until late Monday into early Tuesday morning, some of these thunderstorms may linger into the overnight hours. Nighttime low temperatures will range from the 60s to low 70s.
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    Arlington, VA is in the hatched while DC is just outside lol https://www.spc.noaa.gov/products/outlook/day2otlk.html
  9. yoda
    Good morning hatched hail
  10. yoda
    That escalated quickly
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  12. yoda
    USA getting lucky late with a goal late against Jamaica... I know some of the big guns aren't playing, but still, they have been struggling at times
  13. yoda
    00z HRRR at range of course, but that's pretty nice looking radar forecast from hours 43-48 Wouldn't mind the 00z NAM NEST or the 00z FV3 either
  14. yoda
    Quite an expansion on the updated Day 3 of the SLGT risk
  15. yoda
    Mark likes Monday still - @Ellinwood
  16. yoda
    Hmmm
  17. yoda
    12z NAM Nest also has some pretty decent UD Helicity Swaths between i66 and i70 Monday evening
  18. yoda
    Oh (NW Prince William County)
  19. yoda
    Some quite large hail markers on the SARS as well on the 12z NAM soundings on COD
  20. yoda
    Tornado Watch up for Central and Eastern Iowa https://www.spc.noaa.gov/products/watch/ww0370.html
  21. yoda

    Radar outage

    yoda replied to PSWired's topic in Mid Atlantic

    All I see from TBWI is out of service until further notice
  22. yoda
    Afternoon AFD from LWX Confidence continues to increase for severe weather Monday especially for areas near/east of the Interstate 81 corridor. 12z deterministic and ensemble guidance continues to show continuity in the timing and strength of the deepening/digging trough over the Great Lakes region and it`s associated cold front set to cross the region late Monday night into Tuesday morning. Both the deterministic and ensemble guidance continue to show a bit of a negative tilt to the trough as it sinks south into central Appalachians region. This will shift the best height falls and forcing along and ahead of the cold front as it pushes across the area Monday afternoon. Instability will be ample ahead of the boundary with ensemble mean CAPE around 1500-2500 j/kg per the latest 12z guidance. Bulk effective 0-6km shear values will also be on the order of 25-40 kts with mid- level lapse rates around 7-8 c/km during the peak heating period. This will further updraft growth along with organized and fairly linear activity compared to singular storms or complexes ahead of the boundary as it passes through. For that reason, the Storm Prediction Center currently highlights all areas east of the Alleghenies in a Marginal risk for severe thunderstorms. Flooding concerns will remain limited, but non-zero even with D1 and D2 drought antecedent conditions. The high precipitable water airmass (>1.25-1.50 inches) coupled with strongly forced convection should yield some opportunity for flooding, especially in urbanized areas. As a result, the Weather Prediction Center has painted a Slight risk for flooding over this area.
  23. yoda
    00z GFS still has a pretty impressive sim radar at 00z for the region
  24. yoda
    Some impressive soundings from the 00z NAM tonight across the region... some big hail markers too for Monday's threat on the SARS
  25. yoda
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