Newman - 33andrain Jump to content

Newman

Senior Enthusiast
  • Content Count

    370
  • Joined

  • Last visited

Community Reputation

923 Excellent

About Newman

  • Rank
    Advanced Member

Personal Information

  • Location
    Fleetwood, PA

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Areas affected...southeast PA and central and southern New Jersey...southward across northern Virginia and the Delmarva Peninsula Concerning...Severe potential...Watch possible Valid 181623Z - 181800Z Probability of Watch Issuance...60 percent SUMMARY...Storms are forecast to gradually increase this afternoon, with attendant/increasing risk for locally damaging winds, and possibly some hail. WW may be needed. DISCUSSION...Latest objective analysis shows ongoing airmass destabilization across the Mid Atlantic region, as gradual heating of a moist boundary layer (low 70s dewpoints) through broken cloud cover, has resulted in 1000 to 1500 J/kg mixed-layer CAPE as of 16Z. Though cumulus remains suppressed south of the Mason/Dixon line at this time, visible imagery shows deepening convection over southeast PA, just upstream of the axis of greatest instability. Area VWPs indicate moderate (35 to 45 kt) mid-level westerly flow, which will likely provide ample shear for organized convection. As such, risk for locally damaging winds should gradually increase this afternoon, along with potential for hail with the strongest cells. Additionally, backed low-level flow is indicated across parts of eastern PA and into NJ north of a northwest-to-southeast surface boundary lying across southeast PA/southern NJ per recent surface analysis. Given this local enhancement to the low-level shear profile, a tornado is also not out of the question with any isolated/rotating storm which may evolve.
  2. Holy crap! Was just flanking/chasing that storm currently in Lehigh County and caught these. I turned around and headed home but should've kept going lol. Looks like a strong tornado signature. Definitely over 2" hail where I was, and the storm appears to be strengthening.
  3. SBCAPE creeping near 4000 here in eastern PA.
  4. Areas affected...Portions of eastern OH...the northern WV Panhandle...much of PA...and NJ Concerning...Severe potential...Watch likely Valid 291606Z - 291730Z Probability of Watch Issuance...95 percent SUMMARY...Scattered severe thunderstorms are expected to develop this afternoon. Large hail and damaging winds should be the main threats, but isolated tornadoes will also be possible. Watch issuance is likely by 17Z (1 PM EDT). DISCUSSION...A shortwave trough over central OH and Lake Erie at 16Z will move eastward today across PA and vicinity. Isolated thunderstorms have recently initiated across central OH and northwestern PA in association with this feature. A belt of strong 50-65 kt mid-level westerly winds will be present across eastern OH, much of PA, and NJ today. Long, nearly straight hodographs through mid levels and related 40-50 kt of effective bulk shear should favor scattered splitting supercells early this afternoon. Large hail will probably be the initial concern with this convection, with some increase in the damaging wind threat with time as storms potentially congeal into one or more bowing line segments as they move east-southeastward across PA into NJ. A marine front located over the NYC metro area and adjacent northern NJ will likely limit the northeastern extent of the substantial severe threat this afternoon. In addition to the large hail and damaging wind risk, isolated tornadoes could also occur over mainly parts of central/eastern PA into portions of NJ to the east of a weak surface low where low-level southwesterly winds are forecast to be somewhat stronger. Watch issuance will likely be needed across this region by 17Z (1 PM EDT).
  5. Updated 1300z discussion from SPC: ...Upper Ohio Valley/central Appalachians to Mid-Atlantic... A convectively enhanced shortwave trough approaching Lake Erie this morning will continue eastward and cross Pennsylvania and the coastal Northeast this afternoon/early evening in conjunction with a belt of strengthening mid-level winds (50-70 kt at 500 mb). As the air mass steadily destabilizes and inhibition erodes by afternoon, scattered thunderstorms are expected to develop and intensify as early as midday across Pennsylvania, and subsequently spread into/across adjacent parts of New Jersey, Maryland, Delaware, and northern Virginia. With the air mass likely to become moderately unstable by afternoon, storms will quickly intensify, organizationally aided by the intensifying belt of strong westerly deep-layer flow across the area. Large hail and damaging winds can be expected. Some tornado risk may also exist, particularly across eastern Pennsylvania/New Jersey southward toward the Delmarva vicinity, in relatively close proximity to a surface low and adjacent warm front. A supercell risk aside, at least loosely organized clusters/bands of east/southeastward-moving storms should evolve across most of the region, which carries with it the potential for a relatively widespread wind risk to evolve as storms spread toward the I-95 corridor/coastal areas. Farther to the south/southwest, a bit removed from the strongest westerlies aloft, a cluster of storms moving out of southern Illinois/Indiana (and other preceding development) and others crossing the Mississippi River could persist generally eastward today across Kentucky/southern Ohio into West Virginia and eventually western Virginia. A warm/unstable downstream environment would support the potential for damaging winds within this regional corridor.
  6. LOL. But seriously, I don't think any of the storms in PA right now are warned for less than golf ball sized hail. Most are ping pong ball sized.
  7. The hail threat is going to be larger than we usually see. Most warned storms in PA are for at least golf ball sized hail and then there's this one: Destructive, baseball-size hail and wind gusts to 70 mph.
  8. Mount Holly's updated thoughts: 145 pm mesoscale update: Warm front is draped northwest to southeast across the CWA. Low clouds, relatively cooler temperatures, scattered showers (and isolated storms), and southeasterly winds exist to the northeast of the front, whereas the warm sector is characterized by somewhat higher cloud bases, warmer temperatures, and stronger south to southeast winds. A cumulus field has developed in much of PA and surrounding areas within the warm sector, and showers/storms are beginning to develop. The environment will become quite favorable for severe convection this afternoon, with MLCAPE 1500+ J/kg and effective bulk shear 35-45+ kts. Differential heating boundaries and the aforementioned warm front will serve as initiating mechanisms for storms, with the warm front serving as a source of stronger low-level helicity. Hodographs look quite favorable for supercells should convection remain quasi-discrete. Convection- allowing models continue to favor the 21z to 04z time window for storms in our area. Given the thermodynamic/kinematic environment, all severe hazards are possible (including tornadoes). Main question this afternoon is the inhibiting effects of the lingering clouds in northeast portions of the area (i.e., where the warm front ends up). The best potential for tornadoes will be near the front, where low-level helicity will be maximized. Additionally, should discrete storms split, the right movers will be particularly effective ingesting streamwise vorticity. General thinking is the front`s position will not make much progress northeastward, and may hover near or northeast of an Allentown to Belmar line for much of the afternoon/evening.
  9. Probabilities with the Tor Watch: Probability of 2 or more tornadoes Mod (50%) Probability of 1 or more strong (EF2-EF5) tornadoes Low (20%) Wind Probability of 10 or more severe wind events Mod (60%) Probability of 1 or more wind events > 65 knots Low (20%) Hail Probability of 10 or more severe hail events Mod (60%) Probability of 1 or more hailstones > 2 inches Mod (30%) Combined Severe Hail/Wind Probability of 6 or more combined severe hail/wind events High (>95%)
  10. Tornado watch has been issued: * Tornado Watch for portions of Western New Jersey Extreme east central Ohio Pennsylvania The extreme northern West Virginia Panhandle * Effective this Tuesday afternoon and evening from 145 PM until 1000 PM EDT. * Primary threats include... A few tornadoes possible Scattered large hail likely with isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph likely SUMMARY...Scattered severe thunderstorm development is expected this afternoon from Ohio into Pennsylvania, and storms will spread generally eastward through this evening. The storm environment will be favorable for supercells capable of producing large hail and damaging winds. A more favorable environment for tornadoes is expected across northern and eastern Pennsylvania into western New Jersey as the low levels destabilize.
  11. For PA, we're almost there. Much of western and central areas have cleared. Eastern PA and NJ will have to wait a little more.
  12. A multiple ingredient, composite index that includes effective storm-relative helicity (ESRH, based on Bunkers right supercell motion), most unstable parcel CAPE (muCAPE), and effective bulk wind difference (EBWD). Each ingredient is normalized to supercell "threshold" values, and larger values of SCP denote greater "overlap" in the three supercell ingredients. Only positive values of SCP are displayed, which correspond to environments favoring right-moving (cyclonic) supercells.
×
×
  • Create New...