Apr 15 2018 severe weather thread

[downeastnc]

Figure we would do a dedicated thread for this threat....

 

[shaggy]

Not saying this means we will have a tornado outbreak today or that it means we will have a hurricane later in the year but just showing that this date is significant in NC tornado history as we have seen major outbreaks on this date several times in the past.

 

[Solak]

The Caveat is back!!!

Quote

 Due
to expected limited/localized nature, do not plan to issue a flood
watch at this time. The caveat to the heavy rain potential is that a
band of convection crossing GA into SC this afternoon may disrupt
the 850mb moisture transport into central NC. If this occurs,
rainfall amounts will end up being much less.

 

[kvegas-wx]

Thoughts on tornado watches being hoisted today across the elevated risk areas of NC?

[Solak]

Brad Panovich‏Verified account @wxbrad 5m5 minutes ago

Updated Severe Weather Outlook expands the higher risk area to most of the Carolina's. #cltwx #ncwx #scwx

[Dunkman]

It should be noticed that the large elevated area is for 30% wind. The 10% tornado area is slightly smaller although still substantial. Specifically it doesn't include the triangle area. Any thoughts on an upgrade to moderate at 1630z? 

[fountainguy97]

55 minutes ago, Dunkman said:

It should be noticed that the large elevated area is for 30% wind. The 10% tornado area is slightly smaller although still substantial. Specifically it doesn't include the triangle area. Any thoughts on an upgrade to moderate at 1630z? 

Given weak instability and only moderate shear added to an evening and overnight timing I don’t think we will see anyone get a moderate risk.   Hrrr has been becoming less and less impressive with the cellular and linear line of storms this morning.

[ragtop50]

Latest from NWS which aligns with the map above

 

[SN_Lover]

4 minutes ago, ragtop50 said:

Latest from NWS which aligns with the map above

 

Brad's forecast is really not brads forecast. He extracted SPC's shapefile or kml's and called it his 

[MattPetrulli]

 Concerning...Severe potential...Watch likely 

   Valid 151515Z - 151715Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Storms are expected to undergo a gradual increase in
   organization and intensity through mid day and persist into the
   afternoon over the western through central Carolinas. Line segments
   with embedded bows/mesovortices and some supercell structures are
   expected with damaging wind and a few tornadoes the main threats. A
   tornado watch will likely be needed before 17Z.

   DISCUSSION...Late this morning a line of storms from the western
   Carolinas into southeast GA is moving northeast. An inflection is
   apparent in the line over east central GA in proximity to a
   northeast-advancing MCV. Downstream the warm sector continues to
   moisten with advection of upper 60s F dewpoints. The modest theta-e
   advection and a few cloud breaks will contribute to further
   destabilization. However, weak mid-level lapse rates will limit
   MLCAPE to generally 500-1000 J/kg. A gradual intensification of
   storms is expected as surface temperatures warm through the mid 70s.
   Strengthening low to mid-level winds associated with the MCV and
   northeast-ejecting upper trough will result in strong unidirectional
   shear and sufficiently large 0-1 km hodographs for a few low-level
   mesocyclones. Overall eastward speed of the lines will be tempered
   by the deep layer winds being largely parallel to the initiating
   boundaries. However, embedded bowing segments and mesovortices
   moving more rapidly northeast will pose a risk for damaging wind and
   a few tornadoes.

[Solak]

SUMMARY...FLASH FLOODING WILL BE POSSIBLE ACROSS PARTS OF WRN
SC...WRN NC...WRN VA INTO SRN WV WITH RAINFALL RATES OF 1-2 IN/HR
AND PERIODS OF TRAINING THROUGH 21Z. 6 HR RAINFALL TOTALS OF 3-5
INCHES WILL BE POSSIBLE WHERE IDEAL CELL TRAINING DEVELOPS.

[Solak]

[jpbart]

Tornado watch issued for SC and parts of GA.  

THE NATIONAL WEATHER SERVICE HAS ISSUED TORNADO WATCH 52 IN
EFFECT UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING AREAS
IN GEORGIA THIS WATCH INCLUDES 5 COUNTIES
IN EAST CENTRAL GEORGIA
BURKE                 COLUMBIA              LINCOLN
MCDUFFIE              RICHMOND

IN SOUTH CAROLINA THIS WATCH INCLUDES 14 COUNTIES
IN CENTRAL SOUTH CAROLINA
AIKEN                 BAMBERG               BARNWELL
CALHOUN               EDGEFIELD             FAIRFIELD
KERSHAW               LANCASTER             LEXINGTON
MCCORMICK             NEWBERRY              ORANGEBURG
RICHLAND              SALUDA

THIS INCLUDES THE CITIES OF AIKEN, AUGUSTA, BAMBERG, BARNWELL,
BLACKVILLE, BROOKDALE, CAMDEN, CAYCE, COLUMBIA, DENMARK,
EDGEFIELD, ELGIN, EVANS, JOHNSTON, LANCASTER, LANCASTER MILL,
LEXINGTON, LINCOLNTON, LUGOFF, MARTINEZ, MCCORMICK, NEWBERRY,
NORTH AUGUSTA, OAK GROVE, ORANGEBURG, RED BANK, RIDGE SPRING,
SALUDA, SEVEN OAKS, ST. MATTHEWS, THOMSON, WAYNESBORO,
WEST COLUMBIA, WILLISTON, WINNSBORO, AND WINNSBORO MILLS.

[WarmNose]

People in my area really dodged a bullet as this thing literally fired up just a couple miles east of me. The rain, however, is coming down in buckets 

[SENC]

Fairly strong S-SSE  winds are starting to crank up here on the coast.. 20~30 mph... partly cloudy/full sun..

Temps are in the Mid-70's, (Inland),  High 60's ON the beaches..

Short term Weather Service disco.

Near term /through tonight/...
as of 1000 am Sunday...there is an enhanced risk for severe weather
across all of northeast South Carolina and for most of southeast
North Carolina. The primary risk continues to be damaging
thunderstorm winds. However, there also remains a smaller risk for
tornadoes and large hail.

Sounding data shows moisture and instability increasing through
the afternoon hours in warm air mass ahead of the cold front
with mixed layer cape around 1100 j/kg and precipitable water
values around 1.80 inches. At the same time a low level jet of
around 60 kt within 2 kft of the surface impinges on the area.
The wind profile does veer slightly from the surface through 5
kft, from south-southeast to south-southwest. The model profile is supportive of
primarily a damaging wind threat. Discrete cells that develop
just ahead of the squall line will have the potential to produce
a tornado. Wet bulb zero heights of near 10 kft also support
large hail in the strongest updrafts.

Watching the squall line approaching from the West..

 

[downeastnc]

Need to watch those mostly discrete cells racing north in ahead of the main squall....those cells from just west of RDU back to south of Greensboro need to be watched starting to see some rotation in them and especially the one thats going to pass between Siler City and Asheboro....really all of them are getting that hooky look to them

[Solak]

 

Mesoscale Discussion 268

< Previous MD         Next MD >

Mesoscale Discussion 0268 NWS Storm Prediction Center Norman OK 0129 PM CDT Sun Apr 15 2018 Areas affected...portions of south-central VA...central NC into north-central SC Concerning...Severe potential...Watch likely Valid 151829Z - 152000Z Probability of Watch Issuance...80 percent SUMMARY...The severe threat will spread eastward into the NC/VA Piedmont vicinity this afternoon and evening. A threat of damaging wind and a few tornadoes will ensue as a line of convection across western NC/VA continues to track east-northeast across the region. A new tornado watch will be needed downstream of WW 52.

[Chinook]

Possible tornado for Charlotte metro area. Tornado warning. I am not totally convinced that is a tornado on the ground, but I thought I might post it anyway.

[ICEHOCEY77]

have a great view of this out my window. Not very organized, but there is a lowering

[JoshM]

Seen some marble sized hail near the Gastonia airport.

[ICEHOCEY77]

CLT tower reporting a 25kt gain over the runway. Bet that's nice to fly in.

[ICEHOCEY77]

CLT tower evacuating

[Wow]

looks close enough.. could be headed this way

[BullCityWx]

Just now, Wow said:

looks close enough.. could be headed this way

Yeah, I think it’s headed right This way. Brad Panovich is live on NBC.

[WxKnurd]

Pretty sure it just went right over my House or went up the river and brushed us.  Golf ball size hail and watched the wind whipping the trees that a straight line trees just don’t do.  Definitely was updraft associated with it.

[SENC]

My backyard temp is readin,, up from mid-70's to 82 currently.. It's in a "sunny" location though..

Tor watches creep ever closer..

current Obs.. 77°F

Humidity	74%
Wind Speed	S 21 G 33 mph
Barometer	29.95 in (1014.0 mb)
Dewpoint	68°F (20°C)
Visibility	10.00 mi
Heat Index	79°F (26°C)

[kvegas-wx]

Sirens going off at UNCC.  Any ground reports?

[ICEHOCEY77]

ASOS reporting 59KT gust at the airport

 

KCLT 151916Z 21035G59KT 1/4SM +TSRA BR BKN037CB BKN050 OVC065 21/17 A2980 RMK AO2 PK WND 20059/1913 LTG DSNT ALQDS RAB12 TSE01B02 PRESRR FRQ LTGICCCCG SW-W TS SW-W MOV NE P0000 T02110172 RVRNO

[SENC]

Everyone under "EHC" now..  

Latest from Meso NOAA

Mesoscale Discussion 0270
   NWS Storm Prediction Center Norman OK
   0217 PM CDT Sun Apr 15 2018

   Areas affected...central South Carolina through western North
   Carolina and southwest Virginia

   Concerning...Tornado Watch 52...

   Valid 151917Z - 152045Z

   The severe weather threat for Tornado Watch 52 continues.

   SUMMARY...Threat for damaging wind and a few tornadoes will persist
   across the remainder of tornado watch 52 including western North
   Carolina through central South Carolina next hour or so. Threat will
   shift east into tornado watch 53 by 21Z.

   DISCUSSION...Line of storms from southwest VA through western NC and
   central SC is moving east at generally 15-20 kt. The portion of the
   line over south Carolina has accelerated. Individual elements and
   bowing segments within the line are moving more rapidly northeast
   near 50 kt. The downstream boundary layer is warm and moist with
   dewpoints from near 60 F near the VA/NC border to mid and upper 60s
   farther south into the Carolinas. Weak mid-level lapse rates
   continue to limit buoyancy with MLCAPE from 500-1000 J/kg. Despite
   the marginal mid-level thermodynamic environment, strong forcing
   accompanying a northeast-ejecting upper trough and its intensifying
   low level jet as well as embedded MCVs will promote renewed
   development along the advancing gust front/squall line. Moreover the
   kinematic environment will remain favorable for embedded bowing
   segments and mesovortices through the afternoon.
 

 

[SENC]

   Valid 151917Z - 152045Z
   The severe weather threat for Tornado Watch 52 continues.
   SUMMARY...Threat for damaging wind and a few tornadoes will persist
   across the remainder of tornado watch 52 including western North
   Carolina through central South Carolina next hour or so. Threat will
   shift east into tornado watch 53 by 21Z.
   DISCUSSION...Line of storms from southwest VA through western NC and
   central SC is moving east at generally 15-20 kt. The portion of the
   line over south Carolina has accelerated. Individual elements and
   bowing segments within the line are moving more rapidly northeast
   near 50 kt. The downstream boundary layer is warm and moist with
   dewpoints from near 60 F near the VA/NC border to mid and upper 60s
   farther south into the Carolinas. Weak mid-level lapse rates
   continue to limit buoyancy with MLCAPE from 500-1000 J/kg. Despite
   the marginal mid-level thermodynamic environment, strong forcing
   accompanying a northeast-ejecting upper trough and its intensifying
   low level jet as well as embedded MCVs will promote renewed
   development along the advancing gust front/squall line. Moreover the
   kinematic environment will remain favorable for embedded bowing
   segments and mesovortices through the afternoon.