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yoda

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  1. https://www.wpc.ncep.noaa.gov/metwatch/metwatch_mpd_multi.php?md=0925&yr=2025

    mcd0925.gif

     

    Mesoscale Precipitation Discussion 0925
    NWS Weather Prediction Center College Park MD
    1025 AM EDT Wed Aug 13 2025
    
    Areas affected...Portions of the Central Appalachians and
    Mid-Atlantic
    
    Concerning...Heavy rainfall...Flash flooding likely
    
    Valid 131425Z - 132025Z
    
    SUMMARY...Clusters of heavy showers and thunderstorms with locally
    extreme rainfall rates will tend to expand in coverage over the
    next several hours. Scattered areas of flash flooding will
    gradually become likely, and especially later this afternoon
    closer to the I-95 corridor of the Mid-Atlantic where an urban
    flash flood threat is expected to evolve.
    
    DISCUSSION...The latest satellite and radar imagery shows a band
    of heavy showers and thunderstorms moving into northern WV, and
    the latest trends show cooling cloud tops associated with this
    activity.
    
    This convection is associated with the southwest flank of
    mid-level vort energy going into the central Appalachians which is
    embedded within a very moist and moderately unstable environment.
    MLCAPE values across northern WV and western MD, and areas east of
    the Blue Ridge over the Mid-Atlantic, are locally on the order of
    1000+ J/kg. However, the PWs are quite high and locally over 2
    standard deviations above normal.
    
    In fact, the 12Z RAOB soundings from KPIT and KIAD showed PWs of
    1.86 and 2.22 inches respectively with tall skinny CAPE profiles
    and elevated WBZ/freezing levels. This is strongly suggestive of a
    very efficient and tropical environment that will promote highly
    efficient processes for locally extreme rainfall rates that may
    reach well into the 2 to 3+ inch/hour range.
    
    Convection should tend to generally build in coverage over the
    next several hours as this vort energy advances off to the east
    across the central Appalachians and northern Mid-Atlantic region.
    This will support heavy showers and thunderstorms advancing east
    through central and northern WV, western MD and southwest PA in
    the near-term.
    
    However, as instability and convergent low-level flow becomes
    better established this afternoon east of the Blue Ridge and into
    the Chesapeake Bay region, there will likely be the development
    and expansion of very heavy showers and thunderstorms across much
    of northern VA, central to northeast MD and southern PA, including
    areas along the I-95 corridor from Washington D.C. to Philadelphia.
    
    The latest hires model guidance may be underplaying the rainfall
    potential given the level of moisture that is in place, and there
    will the influence of diurnal heating and orographics that will
    also support an uptick in coverage of showers and thunderstorms.
    
    Slow cell-motions and localized cell-training concerns coupled
    with locally extreme rainfall rates may support some localized
    rainfall totals of 3 to 5 inches. Areas of scattered flash
    flooding will become likely in time, and this will include an
    increasing urban flash flood threat near the I-95 corridor by
    later this afternoon.
    
    Orrison
    
    ATTN...WFO...AKQ...BGM...CTP...LWX...PBZ...PHI...RLX...RNK...
    
    ATTN...RFC...RHA...TIR...NWC...
    • Like 3
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  2.  
    Tropical Storm Henriette Discussion Number  18
    NWS Central Pacific Hurricane Center Honolulu HI   EP082025
    Issued by NWS National Hurricane Center Miami FL
    500 AM HST Fri Aug 08 2025
    
    Henriette has failed to produce deep convection for about 12 hours 
    now. The latest subjective Dvorak estimates are 25 kt from JTWC and 
    too weak to classify from SAB and PHFO.  Recent objective intensity 
    estimates range from 25 to 40 kt.  An earlier ASCAT pass from 0535 
    UTC showed a large area of 30-33 kt vectors on the north side of 
    Henriette.  Henriette will be maintained as a 35-kt tropical storm 
    for this advisory, but it could degenerate to a post-tropical 
    remnant low at any time today.
    
    The cyclone is moving just north of due west at 280/15 kt. A turn to 
    the west-northwest is expected soon as the cyclone tracks along the 
    southwestern periphery of a subtropical ridge to its northeast. A 
    turn toward the northwest is forecast late this weekend into early 
    next week as Henriette becomes steered between an amplifying 
    longwave trough northwest of Hawaii and the subtropical ridge to its 
    northeast.  The NHC track forecast is nearly identical to the 
    previous one and is in good agreement with the tightly clustered 
    consensus aids.  Confidence remains high that Henriette will remain 
    far to the north of Hawaii.
    
    Henriette is over 24C sea-surface temperatures (SSTs) and is 
    embedded within a dry airmass.  These cold SSTs are expected to 
    persist along the cyclone's track for another 12 to 24 h.  If 
    Henriette doesn't generate organized convection soon, it could 
    degenerate to a remnant low today, and this is explicitly shown in 
    the NHC forecast Beyond 24 h, Henriette (or its remnants) will 
    encounter progressively warmer water temperatures over the weekend, 
    peaking around 26-27C in about 3 days.  Upper-level temperatures are 
    also expected to decrease in a couple of days as the aforementioned 
    trough approaches Henriette, which would increase instability. These 
    factors, along with relatively low shear, will likely allow 
    Henriette to restrengthen later this weekend into early next week, 
    as depicted by most of the models.  The NHC intensity forecast is at 
    the low end of the guidance envelope through 36 h, and at the high 
    end of the guidance at 72-96 h.  Beyond day 4, wind shear from the 
    longwave trough and cooling SSTs should lead to steady weakening as 
    Henriette moves farther into the mid-latitudes.
    
    Even if Henriette becomes post-tropical today, given the high 
    likelihood of regeneration back into a tropical cyclone and 
    subsequent restrengthening, NHC plans on maintaining advisories 
    during the post-tropical phase.
     
     
    FORECAST POSITIONS AND MAX WINDS
     
    INIT  08/1500Z 19.7N 141.5W   35 KT  40 MPH
     12H  09/0000Z 20.3N 143.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
     24H  09/1200Z 21.3N 146.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
     36H  10/0000Z 22.6N 148.7W   35 KT  40 MPH...TROPICAL CYCLONE
     48H  10/1200Z 24.1N 150.9W   45 KT  50 MPH
     60H  11/0000Z 25.9N 153.2W   55 KT  65 MPH
     72H  11/1200Z 27.9N 155.7W   65 KT  75 MPH
     96H  12/1200Z 32.3N 160.4W   65 KT  75 MPH
    120H  13/1200Z 37.1N 165.1W   50 KT  60 MPH
     
    $$
    Forecaster Hagen
  3. Right turner?

     

    BULLETIN - IMMEDIATE BROADCAST REQUESTED
    Severe Thunderstorm Warning
    National Weather Service Baltimore MD/Washington DC
    402 PM EDT Thu Jul 31 2025
    
    The National Weather Service in Sterling Virginia has issued a
    
    * Severe Thunderstorm Warning for...
      Eastern Washington County in north central Maryland...
      Northwestern Frederick County in north central Maryland...
      Northeastern Jefferson County in the Panhandle of West Virginia...
      East central Berkeley County in the Panhandle of West Virginia...
    
    * Until 430 PM EDT.
    
    * At 402 PM EDT, severe thunderstorms were located along a line
      extending from Municipal Stadium to near Saint James to near
      Kearneysville, moving east at 30 mph.
    
      HAZARD...70 mph wind gusts and quarter size hail.
    
      SOURCE...Radar indicated.
    
      IMPACT...Damaging winds will cause some trees and large branches
               to fall. This could injure those outdoors, as well as
               damage homes and vehicles. Roadways may become blocked by
               downed trees. Localized power outages are possible.
               Unsecured light objects may become projectiles.
    
    * Locations impacted include...
      Hagerstown, Shepherdstown, Municipal Stadium, Robinwood, Boonsboro,
      Mount Aetna, Mount Lena, San Mar, Harpers Ferry, Wolfsville, Saint
      James, Halfway, Myersville, Cavetown, Keedysville, Funkstown,
      Sharpsburg, Fairplay, Chewsville, and Rohrersville.
    
    PRECAUTIONARY/PREPAREDNESS ACTIONS...
    
    For your protection move to an interior room on the lowest floor of a
    building.
    
    &&
    
    LAT...LON 3964 7746 3939 7753 3932 7776 3946 7792
          3954 7781 3965 7773
    TIME...MOT...LOC 2002Z 274DEG 25KT 3964 7771 3951 7776 3944 7788
    
    THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
    HAIL THREAT...RADAR INDICATED
    MAX HAIL SIZE...1.00 IN
    WIND THREAT...RADAR INDICATED
    MAX WIND GUST...70 MPH
  4. 1 minute ago, Eskimo Joe said:

    Borderline violent thunderstorm dropping south from Martinsburg, WV. Could go bonkers once it hits this dual outflow boundaries. This should have been an ENH risk for wind today IMO.

    Warned now for 70mph gusts

  5. 5 minutes ago, yoda said:

    Yes it was.  The report from the spotter was at 139pm per Radarscope and warning issued at 141pm

    Preliminary Local Storm Report
    National Weather Service Baltimore MD/Washington DC
    148 PM EDT Thu Jul 31 2025
    
    ..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
    ..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
                ..REMARKS..
    
    0139 PM     Waterspout       2 ENE Chase             39.38N  76.34W
    07/31/2025                   ANZ531             MD   Trained Spotter
    
                Trained spotter reports a waterspout east of Chase, MD
                over the Bird River moving east.
    
    
    &&
    
    Event Number LWX2506473
  6. Preliminary Local Storm Report
    National Weather Service Baltimore MD/Washington DC
    148 PM EDT Thu Jul 31 2025
    
    ..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
    ..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
                ..REMARKS..
    
    0139 PM     Waterspout       2 ENE Chase             39.38N  76.34W
    07/31/2025                   ANZ531             MD   Trained Spotter
    
                Trained spotter reports a waterspout east of Chase, MD
                over the Bird River moving east.
    
    
    &&
    
    Event Number LWX2506473
  7. Preliminary Local Storm Report...Corrected
    National Weather Service Baltimore MD/Washington DC
    243 PM EDT Thu Jul 31 2025
    
    ..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
    ..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
                ..REMARKS..
    
    0226 PM     Flash Flood      Gunpowder               39.41N  76.39W
    07/31/2025                   Baltimore          MD   911 Call Center
    
                Multiple swift water rescues ongoing along Pulaski Hwy
                between Allender Rd. and Joppa Farm Rd.
    
    
    &&
    
    Corrected county/state...location
    
    Event Number LWX2506475
  8. 1 minute ago, mappy said:

    Was that waterspout from the same cell that triggered the tornado warning? 

    Yes it was.  The report from the spotter was at 139pm per Radarscope and warning issued at 141pm

    • Like 1
  9. Hmmm

    https://www.spc.noaa.gov/products/md/md1852.html

    mcd1852.png

     

    Mesoscale Discussion 1852
       NWS Storm Prediction Center Norman OK
       1029 AM CDT Thu Jul 31 2025
    
       Areas affected...southeastern Pennsylvania...New
       Jersey...Delaware...central Maryland...and adjacent portions of
       northern Virginia...including DC
    
       Concerning...Severe potential...Watch possible 
    
       Valid 311529Z - 311800Z
    
       Probability of Watch Issuance...60 percent
    
       SUMMARY...Thunderstorms are in the process of developing, and likely
       to gradually intensify through 1-4 PM EDT, accompanied by increasing
       risk for potentially damaging wind gusts.  A brief tornado might
       also be possible, particularly across parts of east central and
       southeastern Pennsylvania into central New Jersey.
    
       DISCUSSION...Perhaps aided by forcing for ascent downstream of a
       short wave perturbation progressing through the southern periphery
       of larger-scale positively tilted mid-level troughing overspreading
       the northern Atlantic Seaboard, thunderstorms appear to be
       initiating along a stalled to slow moving frontal zone, and east of
       a weak surface low, across the northern Mid Atlantic.  This is
       occurring as insolation within a boundary-layer characterized by
       seasonably high moisture content (including mid 70s F surface dew
       points) erodes inhibition.  
    
       Lapse rates are generally modest to weak, and the boundary layer is
       not forecast to become deeply mixed, due to the moisture, but
       profiles still appear supportive of CAPE on the order of 1000-2000
       J/kg.  Beneath the southern fringe of the stronger westerlies, where
       flow at altitudes as low as 500 mb is around 30-40 kt, deep-layer
       shear is strong and supportive of supercell structures, and perhaps
       an organizing cluster, with potential to produce strong surface
       gusts aided by heavy precipitation loading and evaporative cooling
       in downdrafts.  
    
       Thermodynamic profiles appear generally warm with limited potential
       for severe hail.  A brief tornado might not be out of the question,
       but low-level hodographs, particularly south of the surface front,
       are likely to remain generally weak.
    
       ..Kerr/Smith.. 07/31/2025
    
       ...Please see www.spc.noaa.gov for graphic product...
    
       ATTN...WFO...OKX...PHI...CTP...LWX...
    
       LAT...LON   39747713 40357698 40687612 40957453 40617390 39087505
                   38667600 38597718 39107734 39747713 
    
       MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
       MOST PROBABLE PEAK WIND GUST...55-70 MPH
       MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
  10. https://www.wpc.ncep.noaa.gov/metwatch/metwatch_mpd_multi.php?md=0832&yr=2025

    mcd0832.gif

    Mesoscale Precipitation Discussion 0832
    NWS Weather Prediction Center College Park MD
    1101 AM EDT Thu Jul 31 2025
    
    Areas affected...Mid-Atlantic...
    
    Concerning...Heavy rainfall...Flash flooding likely
    
    Valid 311500Z - 312100Z
    
    SUMMARY...Potential for slow moving, highly efficient
    thunderstorms with localized 2-3"/hr rates possible.  Storm
    interactions may allow for localized totals of 2-4" totals and
    likely to induce flash flooding conditions by 21z.
    
    DISCUSSION...Surface analysis and visible GOES-E imagery shows a
    well defined stationary front within the Long Island sound
    intersecting to a surface low in the Delaware Valley before
    entering the terrain through the Lehigh Valley into south-central
    PA.  A secondary surface wave near MDT/THV has a sharpening Lee
    Trough extending southward along the lee of the Blue Ridge toward
    Roanoke, VA and points south.  Between the boundaries through the
    Mid-Atlantic, very moist and building instability can be seen with
    sfc Tds in the mid-70s with isolated low 80s dotted throughout the
    area.  Weak southerly, confluent flow through 700-500mb is noted
    in CIRA LPW layers with enhanced moisture which totals over 2"
    (KIAD already at 2.16" at 12z) and will be increasing toward
    2.25+" into the early afternoon.  MLCAPE values have reached 2000
    J/kg with weak capping noted and visible imagery shows expanding
    Cu field across much of the area, with some weak vertical
    development along major ridge lines of E PA, or near the
    stationary front/outflow boundary intersections across N NJ.
    
    Aloft, WV shows a very strong jet streak across the St.Lawrence
    River Valley with broad right entrance ascent pattern across much
    of the Upper OH valley through central NY into the Interior of New
    England.  The convectively enhanced shortwave continues to
    shear/elongate from SSW to NNE with upstream core over E OH and
    into confluent flow will continue, along with the right entrance
    ascent provide ample DPVA and ascent profiles throughout the
    Mid-Atlantic.  Bulk shear is greater near and north of the surface
    front likely to result in greater cell organization but is further
    distanced from deepest moisture/highest Theta-E near the
    Chesapeake Bay into SE PA.  As such, there is likely to be
    difference in convective activity/manner across the area.  Weak
    convergence along the lee trough/Blue Ridge is likely to expand
    areas of convection westward with time as well across NW VA.
    
    South of the Lehigh Valley, 12z guidance is increasing confidence
    in initial convective development through the 15-16z time frame. 
    Initial thunderstorms will be very slow moving, but have
    stronger/broader updrafts with 14-15Kft of warm cloud layer for
    highly efficient rainfall production.  While inflow will be weak,
    it is likely to pull multiple broad columns of that 2-2.25" Total
    PWat air to support 2-3"/hr rates by 18z given very slow cell
    motions (slower further south).  Storm scale interaction/cold pool
    generation is likely to be the dominant mode of propagation, so
    interactions/collisions/mergers are possible and may result in
    increased duration to support localized 3-4" totals.  
    
    The area remains saturated with 0-40cm soil ratios over 50-60%
    which is in the 70-80th percentile, combine that with proximity to
    large urban centers with impermeable surfaces; the shear rates are
    likely to overwhelm ground conditions quickly and result in flash
    flooding conditions; a localized considerable incident of flooding
    is possible as well.  
    
    Gallina
    
    ATTN...WFO...BGM...CTP...LWX...OKX...PHI...
    
    ATTN...RFC...RHA...TAR...NWC...

     

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  11. Area Forecast Discussion
    National Weather Service Baltimore MD/Washington DC
    939 AM EDT Thu Jul 31 2025
    
    .SYNOPSIS...
    A cold front will slowly move across the mid-Atlantic today
    through Friday. Strong high pressure will build into the area
    over the weekend, bringing below normal temperatures and
    humidity. High pressure weakens into next week while the next
    front is expected to slowly approaches from the south. Rain
    chances return by the middle of next week.
    
    &&
    
    .NEAR TERM /THROUGH FRIDAY/...
    Excessively humid conditions are being observed across the
    region with dew points well into the 70s to near 80 and PW in
    excess of 2 inches (even 70+ Tds over the higher terrain). This
    will fuel thunderstorms with very heavy rain beginning in a few
    hours (roughly midday onward).
    
    A cold front will sag south into our region today. A strong
    shortwave trough will move over our area this afternoon and
    evening. A persistent southerly flow will provide deep tropical
    moisture to help fuel numerous heavy showers and strong to
    severe thunderstorms this afternoon and evening. Dewpoint
    temperatures in the low to mid 70s will result in revealing
    PWATs of 2.2 to 2.3 inches. One final day of hot and humid
    conditions today with the developing convection. Highs are
    forecast to be in the upper 80s to low 90s, with peak heat
    indices between 95-105.
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