18-20 March 2012 severe prospects

[andyhb]

OK, this AFD from HGX highlights my concern for SE Texas later on tonight into tomorrow:

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

933 PM CDT MON MAR 19 2012

.DISCUSSION...

SHALLOW SHOWERS WERE STREAMING NORTHWARD ACROSS SE TX AT MID

EVENING. THE MAIN LINE OF THUNDERSTORMS WAS ALONG THE INTERSTATE

35 CORRIDOR. THE SHORT-RANGE MODELS DIFFERED ON THE TIMING OF THE

EVENTS...WITH THE NAM12 APPEARING TO BE TOO SLOW. THE 00Z RUC

LOOKED GOOD AND BROUGHT THE LINE INTO THE WESTERN COUNTIES OF THE

FORECAST AREA AROUND OR SHORTLY AFTER MIDNIGHT. DO EXPECT THE MAIN

LINE OF STORMS TO SLOW ITS EASTWARD MOVEMENT GIVEN THE

SOUTHWESTERLY FLOW ALOFT.

THE MAIN ITEMS OF CONCERN INCLUDE THE WIND ADVISORY...CHANCES FOR

STRONG OR SEVERE STORMS...AND HEAVY RAINFALL. WITH THE STRONG LOW-

LEVEL JET OVERHEAD...THE WINDS ARE STILL MIXING DOWN ENOUGH TO

KEEP SOME SITES ABOVE 25 MPH AND WILL KEEP THE ADVISORY IN PLACE.

SOUNDINGS FROM KCRP...KLCH...AND A SPECIAL SOUNDING AT COLLEGE

STATION ALL INDICATED THAT THE CAP WAS STRONGEST OVER THE

NORTHEASTERN AND EASTERN COUNTIES AT 00Z. THE COLLEGE STATION

SOUNDING SHOWED THE CAP PRETTY MUCH ERODED. THIS INFORMATION IN

ADDITION TO THE RUC FORECAST AND THE CURRENT EVOLUTION OF THE LIEN

OUT WEST INDICATES THAT THE WESTERN AREAS WILL LIKELY SEE CHANCES

FOR STRONG OR SEVERE STORMS BY 08Z. LOCALLY HEAVY RAINFALL STILL

LOOKS ON TRACK ON TUESDAY GIVEN THE SLIGHTLY SLOWER EASTWARD

MOVEMENT OF THE ENTIRE SYSTEM.

WILL ISSUE AN UPDATE TO MODIFY THE TIMING OF EVENTS FOR THE

REMAINDER OF TONIGHT.

The RUC and NAM both show an area east of the line with very weak CIN progressing towards the area as the line slowly moves east and mid/upper dynamic support increases from the west as the upper level jet streak approaches and the ULL begins to close off. Any cells forming out ahead of it would be bad news with incredible low level shear, much less meridional flow than further north and plentiful moisture as the LLJ intensifies to 50-60+ kts around 05-12z Tuesday morning. The line itself could be full of embedded circulations (somewhat similar to north in OK and Western AR) as well.

00z NAM hodograph at 3 AM between Houston and Victoria (both the NAM and RUC have this area uncapped at this time)

[Boogieman]

Jesus...telling people to go out and take video during the storm...

Was this the same met who was "obsessed with saying all SA gets is EF0/EF1." There's already enough complacency, even after the Joplin and Tuscaloosa hits, to downplay a potentially serious situation by saying something like that, on TV, no less, is beyond stupid.

And there really is no use encouraging more idiots to go out and try to shoot storms. The way I see it, if they're not in their shelters when there is a storm approaching, they're idiots. There are already way too many amateur storm chasers (read: morons with cell phones) getting in the way of Skywarn spotters and others who have a legit reason to be out in the fray, to tell people to do this is retarded, IMO.

Whoever this met is needs to be shown the door ASAP. What if an EF4 barreled through SA after the public were just assured that "we only get EF0/EF1 storms" by this yahoo?

[andyhb]

He was also constituting size to estimate the strength of the tornado...

Sure large wedges can tend to be more violent, but we've seen small tornadoes do tremendous damage too (Pampa/Elie/etc.)

[Chinook]

San Antonio general area- some of the areas that got multiple supercells/squall line areas ended up with 9.56" of rain, by radar estimate, and it's still raining.

[andyhb]

MESOSCALE DISCUSSION 0302

NWS STORM PREDICTION CENTER NORMAN OK

0243 AM CDT TUE MAR 20 2012

AREAS AFFECTED...PARTS OF S CNTRL TX INTO MID/UPPER TEXAS COASTAL

AREAS

CONCERNING...SEVERE THUNDERSTORM WATCH 91...

VALID 200743Z - 200915Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 91

CONTINUES.

CONVECTION ON THE SOUTHERN FLANK OF A MORE EXTENSIVE SQUALL LINE

APPEARS TO BE INTENSIFYING AND SHOWING SIGNS OF INCREASING

ORGANIZATION TO THE SOUTH AND SOUTHEAST OF SAN ANTONIO. HEAVY

PRECIPITATION LOADING AND EVAPORATIVE COOLING IN DOWNDRAFTS APPEAR

TO BE CONTRIBUTING TO THE DEVELOPMENT OF A SIGNIFICANT SURFACE COLD

POOL...WHICH APPEARS TO BE IN THE PROCESS OF SURGING EASTWARD AT UP

TO 40 KT. THE RISK FOR STRONG...POTENTIAL DAMAGING...WIND GUSTS

APPEARS TO BE INCREASING AS ACTIVITY SPREADS EAST NORTHEASTWARD INTO

VICTORIA AND ADJACENT MIDDLE TEXAS COASTAL AREAS THROUGH THE 09-11Z

TIME FRAME. IT DOES NOT SEEM OUT OF THE QUESTION THAT NORTHWARD

INTENSIFICATION OF ACTIVITY COULD OCCUR INTO AT LEAST SOUTHERN

PORTIONS OF THE HOUSTON METROPOLITAN AREA SHORTLY THEREAFTER.

THERE ALSO APPEARS AT LEAST SOME POTENTIAL FOR ISOLATED SUPERCELL

DEVELOPMENT JUST AHEAD OF THE EASTWARD ADVANCING COLD POOL...IN THE

PRESENCE OF MODERATELY LARGE BOUNDARY LAYER CAPE...AND STRONG

LOW-LEVEL SHEAR BENEATH A 50-70 KT SOUTHERLY 850 MB JET. IF THIS

OCCURS...A RISK FOR TORNADOES MAY ALSO DEVELOP.

..KERR.. 03/20/2012

[Boogieman]

San Antonio general area- some of the areas that got multiple supercells/squall line areas ended up with 9.56" of rain, by radar estimate, and it's still raining.

Oh, man! We'd be having a 100 to 200 year event here with that much rain. It's something I hope I never have to deal with.

[#NoPoles]

TX sure is taking a beating...lond day ahead of them...

[Cypress]

2 tornado warnings issued for harris co/houston metro area so far, radar indicated, 1 expired already http://www.srh.noaa.gov/hgx/

edit to add:

harris co flood control dstrict rainfall map link: http://www.harriscountyfws.org/

also, nmq site shows some impressive 72-hr qpe in cental/north tx: http://nmq.ou.edu/

the echo top view shows this is no where near the storm here that it's been the last couple days elsewhere

glad we got some rain, happy it wasn't drastic

[Cary]

Houston TV live streaming still:

KPRC: http://www.click2houston.com/WATCH-LIVE-NOW-Severe-Weather-Coverage/-/1736084/5632360/-/7ylh95z/-/index.html

KTRK: http://abclocal.go.com/ktrk/livenow?id=8587789

KRIV: http://www.myfoxhouston.com/subindex/live_video/

[Srain]

Some far the damage seems to be downed trees and fencing. HGX is still evaluating and receiving reports and reviewing video of the wall cloud and possible tornado.

[Srain]

E-mail from Jeff regarding the Devine Tornado 03/19/2012:

Large supercell produced a large tornado last evening just southwest of San Antonio. The radar showed an impressive hook echo and strong rotation prior to the public photos of a tornado. The tornado traveled nearly right along I-35 affecting the town of Devine. NWS storm survey will be conducted to determine path length and tornado intensity. Based on the pictures below this was likely in the EF2- EF3 range (111-165mph)

Radar velocity and reflectivity showing hooking echo and strong rotation. It is the northern cell on the image:

[Ellinwood]

E-mail from Jeff regarding the Devine Tornado 03/19/2012:

The first tornado image was proven to not be from this event, but from 2004.

[tornadotony]

000

NOUS43 KLBF 201732

PNSLBF

NEZ004>010-022>029-035>038-056>059-069>071-094-211500-

PUBLIC INFORMATION STATEMENT

NATIONAL WEATHER SERVICE NORTH PLATTE NE

1230 PM CDT TUE MAR 20 2012 /1130 AM MDT TUE MAR 20 2012/

...SUPERCELL THUNDERSTORM PRODUCES MULTIPLE TORNADOES MARCH 18TH...

MARCH 18TH...ISOLATED THUNDERSTORMS DEVELOPED AND MOVED NORTH ACROSS

SOUTHWEST NEBRASKA. ONE SUPERCELL THUNDERSTORM INTENSIFIED TO

PRODUCE MULTIPLE TORNADOES WHILE MOVING THROUGH CENTRAL LINCOLN

COUNTY. THE INITIAL TORNADO TOUCHED DOWN APPROXIMATELY 10 MILES

SOUTHWEST OF NORTH PLATTE WHERE DAMAGE WAS FOUND ALONG A PATH OF

NEARLY 13 MILES NORTHWARD TO THE WEST OF THE CITY OF NORTH PLATTE. A

STORM SURVEY CONDUCTED CONFIRMED A TOTAL OF FOUR TORNADOES ALONG A

13 MILE TRAJECTORY WHERE TWO HOMES WERE DESTROYED...SEVERAL HOMES

DAMAGED WITH NUMEROUS STORAGE AND OUTBUILDING DAMAGED OR

DESTROYED...SEVERAL PIVOT IRRIGATION SYSTEMS WERE OVERTURNED AND

EXTENSIVE TREE DAMAGE OCCURRED AT SEVERAL LOCATIONS. THERE ARE FOUR

CONFIRMED INJURIES AT THIS TIME. ADDITIONAL DETAILS FOR EACH

CONFIRMED TORNADOES INCLUDES:

TORNADO 1:

RATED: EF3 TORNADO

PATH LENGTH: 6.71 MILES

PATH WIDTH: 100 YARDS

INJURIES: 2

TORNADO TOUCHED DOWN 9.72 MILES SOUTHWEST OF NORTH PLATTE AND

TRAVELED NORTH DAMAGING TWO HOMES...SEVERAL OUTBUILDINGS AND GARAGES

DAMAGED OR DESTROYED...TWO PIVOT IRRIGATION SYSTEMS WERE

OVERTURNED...ONE METAL TRANSMISSION TOWER DESTROYED...ONE WOOD

TRANSMISSION TOWER DESTROYED AND EXTENSIVE POWER LINE DAMAGE ALONG

THE PATH IN ADDITION TO TREE DAMAGE. THE TORNADO DISSIPATED WHILE

MOVING NORTH OF WALKER ROAD.

TORNADO 2:

RATED: EF1

PATH LENGTH: 1.50 MILES

PATH WIDTH: 150 YARDS

INJURIES: 1

TORNADO TOUCHED DOWN 5 MILES WEST SOUTHWEST OF NORTH PLATTE TO THE

SOUTH OF INTERSTATE 80. THE TORNADO MOVED NORTH WHERE A SEMI WAS

DESTROYED WITH EXTENSIVE DEBRIS SPREAD NORTH AND NORTHWEST AS THE

TORNADO TRACKED NORTHWEST DAMAGING A GARAGE...OVERTURNING A PIVOT

IRRIGATION SYSTEM...DESTROYED FENCE LINE AND PRODUCED EXTENSIVE TREE

DAMAGE ON THE 1.5 MILE PATH BEFORE LIFTING SOUTH OF THE SOUTH PLATTE

RIVER.

TORNADO 3:

RATED: EF3

PATH LENGTH: 1.50 MILES

PATH WIDTH: 90 YARDS

INJURIES: 2

TORNADO TOUCHED DOWN 5.81 MILES NORTHWEST OF NORTH PLATTE ON FRONT

STREET AND TRAVELED NORTH AND NORTHEAST. THE TORNADO DAMAGE WAS

EXTENSIVE TO INCLUDE TWO HOMES DESTROYED AND TWO HOMES WITH

SIGNIFICANT DAMAGE FROM TREES BLOWN OVER AND WINDOWS BLOWN OUT. AS

THE TORNADO TRAVELED NORTH ACROSS THE UNION PACIFIC BAILEY YARDS AN

ESTIMATED 15 TANKER CARS WERE BLOWN OVER AND DEBRIS FOUND NORTH AND

EAST FOR 1.5 MILES. A PIVOT IRRIGATION SYSTEM WAS OVERTURNED NORTH

OF HIGHWAY 30 BEFORE THE TORNADO LIFTED 5.5 MILES NORTHWEST OF NORTH

PLATTE.

TORNADO 4:

RATED: EF2

PATH LENGTH: 1 MILE

PATH WIDTH: 40 YARDS

INJURIES: 0

TORNADO TOUCHED DOWN 6.5 MILES NORTHWEST OF NORTH PLATTE...JUST

SOUTH OF PLATTE VALLEY ROAD WHERE A TWO STORY BARN WAS DESTROYED

WITH SEVERAL OUTBUILDINGS DAMAGED. THE TORNADO TRAVELED NORTHEAST

WHERE A FIELD OF BOARDS FROM THE BARN WAS DRIVEN INTO THE

GROUND...ALONG WITH OTHER DEBRIS. AS THE TORNADO TRAVELED NORTHEAST

TWO HOMES WERE DAMAGED...A GARAGE HAD STRUCTURAL DAMAGE AND AN

OUTBUILDING DESTROYED. EXTENSIVE TREE DAMAGE OCCURRED BEFORE THE

TORNADO DISSIPATED 6.7 MILES NORTHWEST OF NORTH PLATTE.

ADDITIONAL DAMAGE RESULTED FROM OUTFLOW WINDS AS THE THUNDERSTORMS

MOVED NORTHEAST. ADDITIONAL INFORMATION WILL BE PROVIDED AS MORE

DETAILS ARE GATHERED.

$$

KECK

[David Reimer]

My video of the tornadoes north of Magnum, Oklahoma from Sunday. This was a BEAUTIFULLY structured supercell that I was on since it's inception south of Childress. It really looked disorganized until it hit the red river, then it looked like it turned right slightly and started to become more surface based. A wall cloud rapidly developed right over Hollis and tried very hard to put a tornado down. It was rotating very strongly. I spent the next 45 minutes navigating around local rivers and road holes, all while the storm became more organized. After I stopped for gas in Magnum and realized I lost my cell phone, I went north of town and let the storm come to me. This video is result of that...

[FSMweather]

Uniontown-Crawford- AR "PRELIMINARY EF-1 TORNADO DAMAGE FROM SW OF UNIONTOWN TO NE OF CEDARVILLE. TIME ESTIMATED"

http://www.spc.noaa.gov/climo/reports/yesterday.html

[SouthernNJ]

Been a fairly quiet day, with a couple of weak tornadoes reported.

However, the towns of Natchitoches and Campti in LA have had

to deal with a couple of areas of enhanced rotation during the

past several minutes.

[TruePatriot]

EF0 tornado assessed in Minnesota. Second earliest in state history.

http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=mpx&storyid=80895&source=0

[SouthernNJ]

Storms continue to rotate south of Natchitoches. A newer one

looks decent, but yet to have a warning.

[SouthernNJ]

Storms continue to rotate south of Natchitoches. A newer one

looks decent, but yet to have a warning.

I must say this storm is looking worrisome. Rotation has steadily

increased and it is approaching I-49 close to Natchez.

[bubba hotep]

Multiple tornado warnings in SE La right now. Talked to my brother and he said their are reports of damage but can't confirm if there was an actual tornado.

[andyhb]

Tight couplet very close to Pass Christian at this moment:

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE NEW ORLEANS LA

1008 PM CDT WED MAR 21 2012

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* TORNADO WARNING FOR...

CENTRAL HARRISON COUNTY IN SOUTHERN MISSISSIPPI...

THIS INCLUDES THE CITY OF LONG BEACH...

* UNTIL 1045 PM CDT

* AT 1007 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR PASS

CHRISTIAN...OR NEAR LONG BEACH...MOVING NORTH AT 20 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LYMAN

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. TAKE COVER NOW! IF YOU WAIT

TO SEE OR HEAR IT COMING...IT MAY BE TOO LATE TO GET TO A SAFE PLACE.

THE SAFEST PLACE TO BE DURING A TORNADO IS UNDER A WORKBENCH OR OTHER

PIECE OF STURDY FURNITURE. SEEK SHELTER ON THE LOWEST FLOOR OF THE

BUILDING IN AN INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE

BLANKETS OR PILLOWS TO COVER YOUR BODY AND ALWAYS STAY AWAY FROM

WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A

SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE

NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 AM CDT THURSDAY MORNING

FOR SOUTHERN MISSISSIPPI.

[andyhb]

Even though this event did not turn out as some, including myself, thought it would, we've still had at least 25 confirmed tornadoes and 6 significant tornadoes (4 EF2 and 2 EF3) and we now have more confirmed tornadoes this March than all of the reported tornadoes last March (We have more than double the amount of reports so far).