Severe Weather - Week of May 22 Sunday thru Thursday

[tireman4]

Tomorrow could be a very very bad day in the plains. Just starting this thread....

[tireman4]

Some STRONG wording for tomorrow.

SPC AC 231716

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1216 PM CDT MON MAY 23 2011

VALID 241200Z - 251200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM NWRN TX TO SRN NEB...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK OVER
THE SRN/CNTRL PLAINS THROUGH THE OH/TN VALLEY TO SRN NY...

...TORNADIC OUTBREAK POSSIBLE ACROSS THE CENTRAL AND SOUTHERN PLAINS
TUESDAY. AN UPGRADE TO HIGH RISK MAY BE WARRANTED AS SITUATION
BECOMES MORE CERTAIN...

A CLASSIC PLAINS TORNADIC OUTBREAK APPEARS TO BE EVOLVING ACROSS THE
CNTRL/SRN PLAINS...ESPECIALLY FOR KANSAS AND OKLAHOMA. LATEST MODEL
GUIDANCE IS CONSISTENT REGARDING THE PROGRESSION OF A VERY STRONG
MID LEVEL SHORTWAVE TROUGH...CURRENTLY DIGGING ESEWD ACROSS SRN
CA...INTO THE SWRN U.S./SRN ROCKIES BEFORE EJECTING INTO THE PLAINS
BY PEAK HEATING. A VERY DIFFLUENT UPPER FLOW REGIME WILL OVERSPREAD
THE PLAINS AS 30-60M 12HR HEIGHT FALLS EDGE EWD. ADDITIONALLY...H5
SPEED MAX APPROACHING 80-90KT...AS NOTED IN THE GFS...WILL RACE TO A
POSITION OVER NWRN TX/SWRN OK BY 25/00Z WHICH WILL GENERATE VERY
STRONG SHEAR ACROSS THE WARM SECTOR FOR AREAS NEAR THE RED RIVER
REGION...NWD INTO KS AND EVEN SRN NEB. NEEDLESS TO SAY A VERY
DYNAMIC SHORTWAVE TROUGH SHOULD TIME FAVORABLY FOR RAPID SEVERE
THUNDERSTORM INITIATION ALONG/AHEAD OF THE DRYLINE AS ATMOSPHERIC
HEATING IS MAXIMIZED.

EARLY IN THE MORNING A FEW THUNDERSTORM CLUSTERS MAY BE ONGOING
WITHIN THE STRONGEST ZONE OF WARM ADVECTION FROM KS EWD INTO MO AND
THE LOWER OH VALLEY. THIS REGION OF ASCENT AND STORMS MAY
TEMPORARILY FORCE A CONVECTIVE OUTFLOW INTO NRN AR...NWWD INTO SRN
KS. HOWEVER...A NWD RETREAT IS LIKELY TO AT LEAST THE I-70 CORRIDOR
IN KS AS DAYTIME HEATING OCCURS ACROSS THE WARM SECTOR. FOR THIS
REASON IT APPEARS A VERY UNSTABLE AIRMASS WILL BE IN PLACE FROM NRN
TX INTO SRN KS WHERE SBCAPE VALUES COULD EXCEED 5000 J/KG WHERE SFC
DEW POINTS HOLD IN THE LOWER 70S. FORECAST SOUNDINGS ACROSS THE
WARM SECTOR EXHIBIT CLASSIC TORNADIC SUPERCELL STRUCTURES WITH
STRONG LOW LEVEL HELICITY ACROSS KS/OK WITH DEEP LAYER SHEAR ON THE
ORDER OF 50-60KT. BY MID AFTERNOON...STRONG HEATING SHOULD BE NOTED
ALONG/WEST OF THE DRYLINE FORCING TEMPERATURES TO SOAR WELL INTO THE
90S...EFFECTIVELY REMOVING INHIBITION FOR CONVECTIVE DEVELOPMENT
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. AT THIS TIME IT APPEARS
TSTMS SHOULD INITIATE ALONG THE DRYLINE BY 21Z...ALTHOUGH ACTIVITY
COULD DEVELOP MUCH QUICKER WITHIN THE STRONGER FORCING ACROSS THE
CNTRL HIGH PLAINS TO THE NORTH-EAST OF THE SFC LOW WITHIN STRONGEST
UPSLOPE FLOW.

WHILE DRYLINE SUPERCELLS LIFE CYCLE WILL BE MAXIMIZED BETWEEN
21Z-04Z...STRONG WARM ADVECTION ACROSS THE CNTRL PLAINS SHOULD
MAINTAIN A ZONE OF CONCENTRATED SEVERE NEAR/NORTH OF THE WARM FRONT
ACROSS KS/NEB INTO MO DURING THE OVERNIGHT HOURS.

...TN/OH VALLEY TO SRN NY...

WEAK SHORTWAVE TROUGH WILL EJECT EWD ACROSS THE OH VALLEY DURING THE
DAY WITH AN 18Z POSITION FROM CNTRL OH...SWD INTO ERN TN. THIS
FEATURE...COMBINED WITH DIURNAL HEATING ALONG A ZONE OF LOW LEVEL
CONFLUENCE...SHOULD INDUCE STRONG TO POTENTIALLY SEVERE THUNDERSTORM
DEVELOPMENT. FORECAST SHEAR PROFILES SUGGEST THE VAST MAJORITY OF
UPDRAFTS SHOULD BE MULTI-CELLULAR IN NATURE BUT CERTAINLY CAPABLE OF
PRODUCING GUSTY WINDS AND HAIL.

[srainhoutx]

Thanks for starting this, tireman4. Although this will not be our problem in SE TX, I would not be surprised to see a High Risk issued at some point tomorrow. Those of us that follow severe weather will likely be very busy and hopefully posting data and updates as they come in...hint...hint...

[tireman4]

With this South wind howling around here ( added to that the moist Gulf heat), someone is going to get pounded.

[srainhoutx]

Early SREF data suggests E KS/E OK/W MO could see the greatest threat of significant weather tomorrow (Tuesday).

[Ptarmigan]

Photos from the Joplin Tornado
http://www.chron.com/disp/photo.mpl/pho ... hwest.html

So horrible. Condolences to everyone who lost loved ones.

[srainhoutx]

An active evening across OK...

[unome]

this, after 497 storm reports yesterday:

Public Severe Weather Outlook
Print Version
Note: During early morning hours (approximately 6am Central time), the SPC will produce a multimedia briefing MP4 file shortly after the PWO issuance. Please check back momentarily for a link to this MP4 file on this page. Please note the briefing may be out of date 5 hours after its issuance and there will be no subsequent updates during the day. Please send comments or questions to spc.feedback@noaa.gov or via the feedback page.
ZCZC SPCPWOSPC ALL
WOUS40 KWNS 240919
ARZ000-KSZ000-MOZ000-OKZ000-TXZ000-241800-

PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0419 AM CDT TUE MAY 24 2011

...TORNADO OUTBREAK EXPECTED OVER PARTS OF THE SOUTHERN AND CENTRAL
PLAINS AND OZARKS THIS AFTERNOON THROUGH EARLY WEDNESDAY...

THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF A FEW STRONG TORNADOES...VERY LARGE HAIL...AND
DAMAGING WINDS OVER PARTS OF THE SOUTHERN AND CENTRAL PLAINS AND
OZARKS THIS AFTERNOON AND TONIGHT.

THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE

WESTERN AND NORTHERN ARKANSAS
CENTRAL AND EASTERN KANSAS
WESTERN AND SOUTHERN MISSOURI
CENTRAL AND EASTERN OKLAHOMA
NORTH TEXAS

ELSEWHERE...SURROUNDING THE AREA OF GREATEST RISK...SEVERE STORMS
ARE ALSO POSSIBLE FROM THE CENTRAL HIGH PLAINS THROUGH THE MID
MISSISSIPPI AND OHIO VALLEYS INTO THE MID ATLANTIC AND NEW ENGLAND
STATES.

A STRONG JET STREAM DISTURBANCE NOW OVER THE SOUTHWESTERN DESERTS
WILL SWEEP EAST ACROSS THE SOUTHERN ROCKIES TODAY...AND ACROSS THE
SOUTHERN PLAINS TONIGHT...BEFORE REACHING THE OZARKS EARLY
WEDNESDAY.

AS THIS OCCURS...AN ASSOCIATED SURFACE LOW WILL DEEPEN AND MOVE
NORTHEAST FROM THE TEXAS PANHANDLE INTO CENTRAL KANSAS.

STRENGTHENING LOW-LEVEL SOUTHERLY WINDS EAST OF THE LOW WILL
TRANSPORT INCREASINGLY WARM AND HUMID AIR NORTHWARD ACROSS THE
PLAINS AND OZARKS...BENEATH UNUSUALLY STRONG WEST-SOUTHWESTERLY
WINDS IN THE JET STREAM.

SCATTERED INTENSE THUNDERSTORMS WILL FORM THIS AFTERNOON AND EVENING
IN AN ARC FROM CENTRAL KANSAS SOUTHWARD THROUGH CENTRAL OKLAHOMA
INTO NORTH TEXAS AS DAYTIME HEATING FURTHER DESTABILIZES THE REGION
AHEAD OF THE DEEPENING LOW.

CONDITIONS WILL BE FAVORABLE FOR THE STORMS TO ASSUME
STRONG...SUSTAINED ROTATION...AND TO PRODUCE POSSIBLY VIOLENT
TORNADOES AND VERY LARGE HAIL AS THEY MOVE / DEVELOP GENERALLY
NORTHEASTWARD INTO EASTERN PORTIONS OF KANSAS AND OKLAHOMA.

THE STORMS LIKELY WILL ORGANIZE INTO AN EXTENSIVE BAND THIS
EVENING...EXTENDING THE RISK FOR DAMAGING WIND...LARGE HAIL...AND A
FEW TORNADOES EAST AND NORTHEAST INTO PARTS OF ARKANSAS AND MISSOURI
BY EARLY WEDNESDAY.

STATE AND LOCAL EMERGENCY MANAGERS ARE MONITORING THIS POTENTIALLY
VERY DANGEROUS SITUATION. THOSE IN THE THREATENED AREA ARE URGED TO
REVIEW SEVERE WEATHER SAFETY RULES AND TO LISTEN TO
RADIO...TELEVISION...AND NOAA WEATHER RADIO FOR POSSIBLE
WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.

..CORFIDI.. 05/24/2011

[unome]

NWS Tulsa Weather Briefing Issued:05/24/2011 07:21 GMT

http://www.srh.noaa.gov/tsa/?n=camtasiaBriefing

http://www.srh.noaa.gov/media/tsa/camBr ... d=90606859

Decision Support Page: http://www.srh.noaa.gov/tsa/dsp/dsp.php


Springfield, MO Multi-Media Hazardous Weather Briefing

http://www.crh.noaa.gov/sgf/?n=webbriefing


Wichita, KS Severe Weather Information

http://www.crh.noaa.gov/news/display_cm ... 7&source=0

video: http://www.crh.noaa.gov/ict/?n=webbriefing

[srainhoutx]

Keeping a eye on a strong jet streak (500mb) across the Southern Plains for later today.

[unome]

already a large plume of moisture coming into Kansas from CO & a Mesoscale Discussion





MESOSCALE DISCUSSION 0919
NWS STORM PREDICTION CENTER NORMAN OK
0621 AM CDT TUE MAY 24 2011

AREAS AFFECTED...CENTRAL/NORTHERN KS AND EXTREME SOUTHERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 241121Z - 241215Z

IT APPEARS THAT A NEW SEVERE TSTM WATCH WILL BE NEEDED THIS MORNING
MAINLY FOR PORTIONS OF CENTRAL/NORTHERN KS.

AMID AMPLE ELEVATED INSTABILITY/STEEP LAPSE RATES ALOFT...A
PERSISTENT/RELATIVELY WELL-ORGANIZED CLUSTERS OF TSTMS ONGOING
ACROSS NORTHWEST/NORTH-CENTRAL KS SEEM LIKELY TO CONTINUE TO
PROGRESS EAST-SOUTHEASTWARD AND POTENTIALLY GROW UPSCALE THROUGH THE
MORNING ACROSS KS. SEVERE HAIL WILL BE THE INITIAL CONCERN...BUT
DAMAGING WINDS MAY BECOME MORE OF A THREAT AS THE BOUNDARY LAYER
HEATS AFTER SUNRISE.

..GUYER.. 05/24/2011


ATTN...WFO...OAX...TOP...ICT...GID...DDC...GLD...

LAT...LON 39349983 40089865 39979670 37869613 37709938 39349983

[srainhoutx]

E-mail from Jeff concerning the Joplin tornado and today:

Less than a month after one of the worst tornado outbreaks in US history across the southern US, the single highest death toll from a tornado in over 60 years then strikes Joplin, MO.

Unlike the Alabama tornadoes on April 27th which were powerful and on the ground for hundreds of miles, the Joplin tornado was fairly short in length (6 miles), but was extreme strong (high end EF 4 rating with surface winds estimated at 198mph. The tornado was produced from a supercell thunderstorms that crossed into the state from NE OK, and was heavily photographed (chased) by multiple chasers. Strong circulation was noted on both radar and by spotters southwest of Joplin which resulted in the issuance of a tornado warning 20 minutes prior to the tornado entering the city. The small tornado grew rapidly to over 3/4ths of a mile wide upon entering the city and produced a large damage path of 6 miles by 3/4th to 1 miles wide across the central/southern part of the town. Roughly 30-45% of the town was leveled an estimated 2000 homes destroyed. The tornado struck the Regional Hospital causing extensive damage to a well built structure (EF 4 damage) and 6 fatalities. It then destroyed the high school a strongly built structure (high end EF 4 damage) and the local Wal Mart and Home Depot. As with the Alabama tornadoes debris from the Regional Hospital (X-rays) were lofted well into the storm and carry over 70 miles to the NE by the updrafts.

Once again as with the Alabama tornadoes in April warnings were in place well in advance of the tornado and the town’s siren system did go off. From those interviewed on the news most residents did the correct actions of taking cover in either basements of interior rooms, but as stated after the Alabama tornadoes there is little chance of surviving an EF 4/5 tornado unless underground.

The US has been very unfortunate this year in the fact that strong violent tornadoes have struck highly populated areas resulting in tremendous damages and high loss of life. Regardless of the location (tornado alley) or elsewhere anytime you have a powerful tornado impact an urban type area there is going to be significant damage. We have been very lucky in the past several decades that tornadoes have impacted small towns or mainly rural areas.

Risks are faced in even larger urban areas such as Oklahoma City, Dallas/Fort Worth, Chicago, St Louis, Kansas City, Little Rock, some of these cities have been struck before with strong but narrow tornadoes, but the risk is there for large powerful tornadoes to impact these large urban areas.

2 of the top 10 deadliest tornado days in US history have happened this year:
· April 27, 2011 (Ala., Tenn., Ga., Miss., Va.): 315
· April 3, 1974 ("Super Outbreak"): 307
· April 11, 1965 ("Palm Sunday Outbreak"): 260
· March 21, 1952: 202
· June 8, 1953 (Flint, Mich., etc.): 142
· May 11, 1953 (Waco, Tex, etc.): 127
· Feb. 21, 1971: 121
· May 22, 2011 (Joplin, Mo...Mpls./St. Paul, Minn.): 117· May 25, 1955 (Udall, Kan., etc.): 102
· June 9, 1953 (Worcester, Mass.): 90
Top 10 deadliest Single Tornado:
· Mar. 18, 1925 (Tri-State Tornado): 695
· May 6, 1840 (Natchez, Miss.): 317
· May 27, 1896 (St. Louis, Mo.): 255
· Apr. 5, 1936 (Tupelo, Miss.): 216
· Apr. 6, 1936 (Gainesville, Ga.): 203
· Apr. 9, 1947 (Woodward, Okla.): 181
· Apr. 24, 1908 (Amite, La., Purvis, Miss.): 143
· Jun. 12, 1899 (New Richmond, Wisc.): 117
· May 22, 2011 (Joplin, Mo.): 116· Jun. 8, 1953 (Flint, Mich.): 115

Notice the dates of the events were all prior to advanced warnings systems such as radar and sirens until 2011.

This year alone across the US 481 persons have been killed by tornadoes. The last time fatalities from tornadoes was this high was in 1953 (519)

Tornado Outbreak Today:

Classic “tornado alley” outbreak appears in place for this afternoon and evening as strong jet stream structure ejects into the central plains. Strong surface low pressure will develop over OK with a very unstable warm sector pulling northward across the great plains with tremendous low level shear and instability. Shear values of 80-90kts coupled with CAPES values of 4000-5000 J/kg will for sure support destructive supercells with high potential for very large long tracked violent tornadoes. Outbreak should commence by mid afternoon across central OK and KS and then spread across N TX, AR, and MO overnight. SPC high risk is in place for much of OK and southern KS indicating the gravity of this potential outbreak. The amount of shear coupled with the forecasted instability mentioned above points to some really big tornadoes. Outbreak will continue on Wednesday across the mid MS Valley into the Ohio Valley or into greater population areas.

[srainhoutx]

Early HRRR data suggests a very rough afternoon/evening near OKC and Central/Eastern Kansas. Looks like a very active day ahead.

[srainhoutx]

With a high risk day for much of OK and KS, and mod down to DFW, I fully expect all the balloon sites in/near the high risk to have 18Z or 19Z balloon releases.

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 AM CDT TUE MAY 24 2011

VALID 241300Z - 251200Z

...THERE IS A HIGH RISK OF SVR TSTMS OVER PARTS OF OKLAHOMA AND
KANSAS...

...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK AREA
FROM N TX N/NEWD INTO PARTS OF AR AND MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE ABOVE AREAS
FROM S CNTRL TX THROUGH THE MID MS AND OH VLYS INTO NEW
ENGLAND...THE MID ATLANTIC STATES AND NC...

...SYNOPSIS...
...TORNADO OUTBREAK EXPECTED OVER PARTS OF THE SRN AND CNTRL PLNS
AND OZARKS LATER TODAY INTO TONIGHT...

POTENT UPR TROUGH NOW CROSSING THE FOUR CORNERS WILL FURTHER
STRENGTHEN AND EVOLVE INTO CLOSED LOW OVER THE CNTRL HI PLNS BY THIS
EVE AS ASSOCIATED BAND OF 75 KT MID LVL FLOW SWEEPS E/NE ACROSS THE
SRN PLNS. THE LOW WILL CONTINUE E INTO CNTRL KS TONIGHT/EARLY WED
AS THE SPEED MAX/VORT LOBE ROTATE NE ACROSS THE OZARKS. AT THE
SFC...LOW NOW OVER THE OK/TX PANHANDLES SHOULD UNDERGO SUBSTANTIAL
DEEPENING AS IT MOVES SLOWLY NE INTO S CNTRL KS THIS EVE...AND
CONTINUES N/NE INTO CNTRL KS OVERNIGHT. IN RESPONSE...FLOW AT ALL
LVLS SHOULD SUBSTANTIALLY STRENGTHEN OVER THE SRN HALF OF THE PLNS
AND OZARKS LATER TODAY THROUGH EARLY WED.

...SRN/CNTRL PLNS AND OZARKS LATER TODAY THROUGH TNGT...
SETUP STILL APPEARS FAVORABLE FOR SCTD STRONG TSTM DEVELOPMENT BY
ABOUT 21Z IN AREA OF STRONG SFC HEATING ALONG AND AHEAD OF DRYLINE
EXTENDING S FROM PANHANDLE SFC LOW. COMBINATION OF STRENGTHENING
WIND FIELD...DEEP EML...AND RATHER RICH BOUNDARY LAYER MOISTURE
ACROSS REGION WILL SUPPORT A FEW INTENSE SUPERCELLS. ARRIVAL OF
STRONG HEIGHT FALLS/UVV WITH AFOREMENTIONED VORT LOBE SHOULD FOSTER
MORE WIDESPREAD STORM DEVELOPMENT ALONG AND AHEAD OF DRY LINE A BIT
LATER IN THE DAY OR BY EARLY EVE.

ALTHOUGH SOME POTENTIAL WILL EXIST FOR POSSIBLE STORM
INTERFERENCE...ESPECIALLY WITH NWD EXTENT IN HIGH/MDT RISK
AREA...SETUP STILL APPEARS FAVORABLE FOR AT LEAST FEW LONG-LIVED
DISCRETE/SEMI-DISCRETE STORMS. GIVEN STRENGTH OF WIND FIELD AND
STRONG LWR TROPOSPHERIC VEERING DUE TO WWD POSITION OF SFC LOW AND
SLIGHT NEG TILT OF UPR VORT...POTENTIAL ALSO WILL EXIST FOR
LONG-LIVED STRONG TORNADOES...ESPECIALLY IN CNTRL/ERN/NRN OK.
WEAK W-E BOUNDARY NOW INVOF THE RED RVR SHOULD MOVE/REDEVELOP NEWD
LATER TODAY. THIS FEATURE MAY SERVE AS A SECONDARY FOCUS FOR STORM
DEVELOPMENT...AND/OR ENHANCE LOW LVL HELICITY...OVER PARTS OF
CNTRL/ER OK LATER TODAY.

WITH TIME THE KS/OK/N TX STORMS SHOULD EVOLVE INTO BROKEN LINE
SEGMENTS AND POSSIBLY A COMPLEX QLCS WITH EMBEDDED SUSTAINED
SUPERCELLS. THIS ACTIVITY SHOULD MOVE/DEVELOP RAPIDLY NE INTO PARTS
OF MO AND AR LATER THIS EVE THROUGH EARLY WED...WITH AN EXPANDING
THREAT FOR DMGG WIND IN ADDITION TO A CONTINUING RISK FOR
HAIL/TORNADOES. A PORTION OF THIS ACTIVITY...OR PERHAPS NEW
STORMS...MAY AFFECT THE LWR OH VLY REGION BY 12Z WED.

IN THE NEAR TERM...SLIGHTLY ELEVATED MCS WITH A THREAT FOR HAIL AND
POSSIBLY LOCALLY DMGG WIND EXPECTED TO CONTINUE E TO ESE ACROSS
CNTRL KS. OUTFLOW BOUNDARY FROM THIS FEATURE MAY SERVE AS
A FOCUS FOR STORM DEVELOPMENT IN CNTRL/ERN KS LATER TODAY.

...CNTRL APPALACHIANS INTO VA/NC NOW THROUGH THIS AFTN...
ONGOING LOOSELY-ORGANIZED MCS NOW OVER ERN KY/TN APPEARS TO BE
SUPPORTED IN PART BY UPR IMPULSE THAT CROSSED THE SRN PLNS
YESTERDAY. AS THE IMPULSE CONTINUES EWD AND BOUNDARY LAYER
DESTABILIZES AHEAD OF IT...CONDITIONS MAY BECOME FAVORABLE FOR
UPSCALE DEVELOPMENT INTO A N-S ORIENTED FORWARD-PROPAGATING MCS.
STRENGTH OF UNIDIRECTIONAL WIND FIELD AND STEEP LOW LVL LAPSE RATES
PER GSO 12Z SOUNDING SUGGEST GOOD LIKELIHOOD FOR DMGG WIND. OTHER
STRONG/SVR STORMS MAY FORM AHEAD OF THE MCS ALONG LEE TROUGH IN SE
VA/ERN NC.

...OH VLY TO MID ATLANTIC/NEW ENGLAND THIS AFTN...
ONGOING SHOWERS/SCTD TSTMS MAY BE JOINED POCKETS OF ADDITIONAL
DEVELOPMENT LATER TODAY AS AIR MASS DESTABILIZES ALONG/AHEAD OF COLD
FRONT ASSOCIATED WITH ERN CANADIAN UPR TROUGH. WHILE THE BELT OF
STRONGEST FLOW ALOFT WILL REMAIN S OF THE OH RVR...
AMPLE FLOW WILL EXIST FOR ORGANIZED STORMS THAT MAY POSE A THREAT
FOR LOCALLY DMGG WIND AND SVR HAIL.

..CORFIDI/SMITH.. 05/24/2011

[srainhoutx]

SPC expands High Risk abit further S into N Central TX and just NW of Ft Worth/Dallas area...

05242011 image1.gif

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1125 AM CDT TUE MAY 24 2011

VALID 241630Z - 251200Z

...THERE IS A HIGH RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER
PORTIONS OF SOUTHERN KS...CENTRAL AND EASTERN OK...AND NORTH CENTRAL
TX...

...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF CENTRAL AND NORTH
TX...MOST OF OK...MUCH OF CENTRAL/EASTERN KS...CENTRAL AND SOUTHERN
MO...AND NORTHWEST AR....

...THERE IS A SLGT RISK OF SVR TSTMS OVER A LARGE AREA FROM THE
SOUTHERN PLAINS...ACROSS THE MID MS/OH/TN VALLEYS...INTO THE MID
ATLANTIC STATES AND SOUTHERN NEW ENGLAND....

...AN INTENSE OUTBREAK OF TORNADOES AND WIDESPREAD SEVERE
THUNDERSTORMS IS EXPECTED LATER TODAY OVER PORTIONS OF KS/OK/TX...

...CENTRAL/SOUTHERN PLAINS...
MORNING SATELLITE LOOPS SHOW A VIGOROUS AND PROGRESSIVE MID/UPPER
LEVEL SHORTWAVE TROUGH OVER THE SOUTHERN ROCKIES. THIS FEATURE IS
FORECAST TO ROTATE RAPIDLY EASTWARD INTO THE PLAINS AND BECOME
NEGATIVELY-TILTED THIS EVENING. LATEST TCC PROFILER DATA SHOWS 90+
KNOT FLOW AT 6KM...INDICATIVE OF THE MID/UPPER LEVEL WIND MAX THAT
WILL NOSE INTO THE PLAINS THIS EVENING. MEANWHILE... SOUTHERLY LOW
LEVEL WINDS WILL MAINTAIN UPPER 60S AND LOWER 70S DEWPOINTS ACROSS
MUCH OF NORTH TX...OK...AND SOUTHERN/CENTRAL KS. BY MID AFTERNOON
THE DRYLINE WILL EXTEND FROM WEST-CENTRAL KS INTO WESTERN OK AND
WESTERN NORTH TX. STRONG HEATING AND RICH MOISTURE...COUPLED WITH
NEAR DRY-ADIABATIC MID LEVEL LAPSE RATES...WILL YIELD AN EXTREMELY
UNSTABLE AIR MASS WITH MLCAPE VALUES OF 4000-4500 J/KG.

PRESENT INDICATIONS AND LATEST OPERATIONS/MESOSCALE MODEL GUIDANCE
INDICATE THAT DISCRETE SUPERCELL THUNDERSTORMS WILL FORM ALONG THE
KS/OK DRYLINE BY MID AFTERNOON AND MOVE RAPIDLY NORTHEASTWARD WITH A
RISK OF A FEW TORNADOES AND VERY LARGE HAIL. EARLY IN THE
EVENT...THE GREATEST TORNADO THREAT WILL BE OVER KS AS STORMS
INTERACT WITH PRE-EXISTING OUTFLOW BOUNDARY AND BACKED LOW LEVEL
WINDS.

AS THE AFTERNOON PROGRESSES...CONTINUED HEATING AND LARGE SCALE LIFT
DUE TO APPROACHING UPPER TROUGH MAY LEAD TO MULTIPLE ROUNDS OF
CONVECTIVE DEVELOPMENT ALONG THE DRYLINE. THESE STORMS WILL ALSO
TRACK ACROSS THE HIGH RISK AREA DURING THE EVENING. LOW LEVEL WINDS
WILL BE STRENGTHENING...WITH ALL CONDITIONS FAVORING THE POTENTIAL
FOR LONG-TRACKED STRONG/VIOLENT TORNADOES AND VERY LARGE HAIL OVER
PORTIONS OF NORTH TX...CENTRAL OK...AND CENTRAL KS.

DURING THE LATE EVENING...STORMS ARE EXPECTED TO CONGEAL AND SPREAD
EASTWARD INTO PORTIONS OF MO/AR WITH AN ENHANCED RISK OF WIDESPREAD
DAMAGING WINDS AND HAIL.

...MID ATLANTIC STATES...
A CLUSTER OF THUNDERSTORMS IS ONGOING THIS MORNING OVER WESTERN VA.
THIS ACTIVITY IS EXPECTED TO INTENSIFY BY EARLY AFTERNOON AND SPREAD
EASTWARD TOWARD THE COAST BY EVENING. LOW LEVEL WINDS ARE
RELATIVELY WEAK. HOWEVER...40-50 KNOT MID/UPPER LEVEL WINDS AND
MLCAPE VALUES OF 2500-3000 J/KG WILL PROMOTE A RISK OF SEVERE STORMS
CAPABLE OF DAMAGING WINDS AND HAIL.

..HART/GRAMS.. 05/24/2011

05242011 day1otlk_1630.gif

[tireman4]

I have a bad bad bad feeling about this. Very bad....Sigh.

[srainhoutx]

This will likely be a PDS Watch a bit later...

MESOSCALE DISCUSSION 0925
NWS STORM PREDICTION CENTER NORMAN OK
1218 PM CDT TUE MAY 24 2011

AREAS AFFECTED...NW TX...WRN AND CNTRL OK

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 241718Z - 241845Z

STORM INITIATION IS EXPECTED ACROSS WRN OK AND NW TX OVER THE NEXT
HOUR. SUPERCELLS SHOULD RAPIDLY DEVELOP WITH A THREAT FOR LARGE HAIL
AND TORNADOES. A TORNADO WATCH WILL LIKELY NEED TO BE ISSUED BY 18Z.


SFC ANALYSIS SHOWS A 997 MB LOW IN THE NRN TX PANHANDLE WITH A
DRYLINE EXTENDING SWD FROM THE LOW ACROSS FAR WRN OK INTO WEST TX.
THE DRYLINE IS STARTING TO ADVANCE EWD WITH VISIBLE SATELLITE
IMAGERY SHOWING AN EXPANDING FIELD OF CUMULUS FROM I-40 IN WRN OK
SWD TO NEAR SAN ANGELO IN WCNTRL TX. AS FURTHER DESTABILIZATION
OCCURS THIS AFTERNOON AND THE CAP WEAKENS...RAPID CELL INITIATION IS
EXPECTED TO OCCUR ALONG THIS CORRIDOR. AS THIS OCCURS...A 50 TO 65
KT MID-LEVEL JET EJECTING NEWD TOWARD THE SRN PLAINS WILL CREATE
STRONG DEEP LAYER SHEAR PROFILES VERY FAVORABLE FOR SUPERCELLS. AS
STORMS INTENSIFY...VERY LARGE HAIL GREATER THAN 2 INCHES IN DIAMETER
WILL BECOME LIKELY. IN ADDITION...A 30 TO 40 KT LOW-LEVEL JET IS IN
PLACE ACROSS NW TX AND WRN OK. AS THIS FEATURE
STRENGTHENS...LOW-LEVEL SHEAR WILL BECOME VERY FAVORABLE FOR
TORNADOES. WITH 0-3 KM STORM RELATIVE HELICITIES INCREASING INTO THE
450 TO 600 M2/S2 RANGE...LONG-TRACK STRONG TORNADOES ARE EXPECTED TO
OCCUR LATE THIS AFTERNOON INTO EARLY THIS EVENING.

..BROYLES.. 05/24/2011

[tireman4]

All the folks that are on this forum from the DFW area, stay safe. This is ever changing and can get dangerous within minutes....

[srainhoutx]

All the folks that are on this forum from the DFW area, stay safe. This is ever changing and can get dangerous within minutes....

Ditto. We have a lot of folks outside of the Houston area viewing the forum now. Many never post, but do send pm's stating they are out there and are watching/reading our forum. Stay Safe folks in OK as well!

[tireman4]

Here they come...the first of the Watches...

SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 356
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM CDT TUE MAY 24 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

WESTERN AND CENTRAL OKLAHOMA
NORTHWEST AND NORTH-CENTRAL TEXAS

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL
1000 PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE
MILES EAST AND WEST OF A LINE FROM 45 MILES WEST NORTHWEST OF
PONCA CITY OKLAHOMA TO 25 MILES SOUTH SOUTHWEST OF FORT WORTH
TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 352...WW 354...WW 355...

DISCUSSION...TSTM INITIATION IS ANTICIPATED WITHIN THE NEXT HOUR OR
TWO ALONG THE DRYLINE FROM WRN OK INTO W-CNTRL TX. STRONG HEIGHT
FALLS/DYNAMIC FORCING FOR ASCENT ASSOCIATED WITH NEGATIVELY TILTED
MIDLEVEL TROUGH EMERGING INTO THE PLAINS SHOULD SUPPORT A RAPID
INCREASE IN STORM COVERAGE THROUGH THE AFTERNOON. WARM SECTOR AIR
MASS IS CHARACTERIZED BY A VERY MOIST BOUNDARY LAYER WITH DEWPOINTS
IN THE UPPER 60S TO LOWER 70S. WHEN COUPLED WITH STEEP MIDLEVEL
LAPSE RATES...ENVIRONMENT IS MODERATELY TO STRONGLY UNSTABLE WITH
MLCAPE VALUES OF 2500-4000 J/KG. DEEP-LAYER SHEAR STRENGTHENING TO
40-50 KT WILL PROMOTE RAPID SUPERCELL DEVELOPMENT WITH THE INITIAL
HAZARD BEING VERY LARGE HAIL. INITIAL VEER-BACK WIND PROFILE
OBSERVED IN CURRENT VADS/PROFILERS IS EXPECTED TO TRANSITION TO
LARGE CLOCKWISE CURVED HODOGRAPHS BY 00Z WHERE 0-1 KM SRH WILL
APPROACH 400-500 M2/S2. AS SUCH...EXPECT A RAPID INCREASE IN THE
THREAT FOR TORNADOES THIS AFTERNOON INTO EVENING...SOME OF WHICH
COULD BE LONG-TRACKED AND STRONG TO VIOLENT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 23035.