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ProbSevere was fairly high for this cell in our western CWA.

Lightning is diffuse and little VIL.  Would think this product (PS) would work better for cells distant from the radar, but in this case not sure.  No reports.

Another SPS

Cell with little Probsevere, but steady velocity signal coming toward OHX 88D.  Thinking some of these winds could mix down, but earlier cells may have stablilized the low levels some.

Warning Issued. Wind damage observed.

At 2026 UTC 8 June 2015 issued warning based reflectivity core aloft 50 dBZ up to the upper 30s Kft.  Afterwards the NOAA/CIMSS Severe prob went up to 92% as seen in the image below.  Wind Damage was reported at 2024 UTC in Washington county, MD. Wacha/MrSnow

Looking at Lightning Jump

We’ve got a lot of action going on across our CWA this afternoon, and most of the storms have had at least a 1 sigma lightning jump. Some of them have had a significant jump, up to 7 sigs.

One cell we were tracking (eventually turning more linear) was moving across Perry Co, PA. We spotted an 80 flash/min jump (from 20-100) in 10 minutes.

This area did receive reports of a tree down (~1950z) and pea-sized hail (~1950z) just before that huge jump. There was still a smaller jump taking place at that time (from 10-20/min over 10 minutes).

We did notice there were some tracking issues in terms of cells merging and determining a jump. We account this to the amount and speed of convection in our area. Visual jumps were spotted on the time series graph, but it did not show well on the LJDA map.

-BT

NUCAPS compared to Observed IAD sounding

18 UTC NUCAPS sounding near IAD, modified for IAD surface data showing 2200 J/kg when compared to 900 J/kg in the observed IAD 18 UTC sounding. The observed sounding also shows an elevated mixed layer and capping near 825 mb which is not seen in the NUCAPS sounding. MrSnow/Wacha

Prob SVR and LJ in VA severe storm.

First SVR report from downed trees in Shenandoah county at 1848 UTC 8 June 2015. Note the NOAA/CIMSS Prob. Severe Model showed an increase in Prob from  36 to 50 to 84% at 1834 UTC then a rapid decrease back to 36% by 1842 UTC. The using 84% would have resulted in a lead time of 14 minutes.  The animation below shows this evolution with the storm headed in to the ground clutter near the RDA.

There was also a notable lightning jump (LJ) from 1830-1835 UTC.    It might be useful to include a maximum lighting rate and rate of change value in the meta data of the lighting jump time section. MrSnow/Wacha.

Warning 1

Issued a warning on cell over Humphrey’s County…storm was in an environment that had already produced storms with severe hail. Noticed that it had not yet produced an overshooting top but looked close using the one minute Super rapid scan imagery also noticed local maximum area of cape out ahead of where the storm was developing with clear skies

Notice the lightning jump on the ENI time series…this may have added urgency to issue a warning had I used it to begin with. Did get wind damage reported and power outages with this cell.

Inthecards

Convection initiating in the Blue Ridge.

From the 19 UTC 8 June 2015 SPC mesoanalyses the 0-6km bulk effective shear was near 30 kts. 0-3km is nearly the same. Strong surface heating east of the mountains yielding temps of 85-90F and dew points around 70F is contributing MLCAPE across western MD 1500-2000 J/kg. Some CIN 50-100 J/kg over eastern part of the CWA into DE. GOES-R LAP CAPE is lagging SPC mesoanalyses by about 30 minutes or so (18Z is actually about valid 1830Z). The GOES-R lap values of CAPE are much less than the SPC with most of the CWA only in the hundreds of J/kg with a small area of 1000 J/kg in VA. GOES-R LAP PW values 1.5 to 1.7 on average which is slightly higher (0.1) but close to the SPC mesoanalyses.

Watching convection develop over western part of CWA in Madison, Rappahannock and Greene counties of VA where surface analysis shows a lee troffing. HRRR shows this area developing into a broken line of convection moving into the DCA/BWI area between 20 and 21 UTC followed by another line or two. The image below shows the visible satellite imagery and GOES-R Convective Initiation product indicating 50 to 60% with the convection developing along the edge of the Blue Ridge.

MrSnow/Wacha.

- Particiapnts were reminded that 

First Warning(s) of the Day

Most of the storms across CTP were already going when our shift started, so Shasta and I had to play catch up. We found using the ProbSevere model was the easiest to help discern which storms were the strongest and where we should focus our attention.

The first storm we warned was across Northumberland and Schuylkill Cos and we warned it for hail and wind. We did have a report of the storm previously producing a funnel cloud.

ProbSevere first went above 50% at 1756z (56%) with the funnel cloud reported at 1805z near Selinsgrove.

-Brick “BT” Tamland

ALY MD

A quick look at the environment shows a limited amount of instability based on LAP CAPE (up to 900 J/kg). LAP LI continues to drop (as low as -6) There is some clearing across our eastern counties which the CI product is expecting some development (50-60%). A line of storms is working into that area of clearing and wind velocities are starting to strengthen. Warnings will likely be issued soon.

-BT