April 28/29 U.S east coast tornadoes



Supercells formed along the east coast of the USA in North and South Carolina and Suffolk VA.  200 people were injured and one fatality reported, although it is not know if the tornado was the cause of this.  The storms were low topped - meaning their height was around 30,000 feet.   The tornado was rated possibly EF3  There has been sever damage to houses and cars and areas. Here's some US links to view photos and videos of the tornadoes.

 http://www.wavy.com/Global/story.asp?S=8239023&nav=23iidhDw

http://www.wavy.com/


April 21-22 2008 scenario

Conditions are good for widespread thunderstorms in respective areas, but there is also the possibility of severe thunderstorms with very large hail and the expectation with increased CAPE at 1,000j/kg the likelihood of supercells with tornadoes is possible today or tomorrow US time (21/22nd)  There are favorable conditions with a developing jet stream, the latest synopsis from the Storm Prediction Centre explains it all - a bit technical - but fairly straightforward of sorts and just included for your information.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NRN OK/SERN-ERN KS/WRN-NRN MO TO FAR SRN IA... ...SYNOPSIS... MODELS REMAIN CONSISTENT SHOWING LARGE UPPER LOW/TROUGH IN THE NWRN U.S./SWRN CANADA WILL EVOLVE INTO AN ELONGATED POSITIVE TILTED TROUGH WITH TWO SEPARATE CLOSED LOW CENTERS...1) ONE DEVELOPING NEWD INTO CENTRAL CANADA...AND 2) SECOND LOW SHIFTING SLOWLY SWWD OFF THE PAC NW COAST. A LEAD WEAK IMPULSE IS EXPECTED TO TRACK ENEWD INTO THE WRN GREAT LAKES REGION TODAY...WHILE A STRONGER AND FAST MOVING SHORT WAVE TROUGH MOVES FROM THE GREAT BASIN TO THE CENTRAL HIGH PLAINS BY 22/00Z...AND THEN NEWD INTO THE UPPER MS VALLEY TONIGHT. IN THE LOW LEVELS...COLD FRONT ATTENDANT TO LEAD IMPULSE AND CENTRAL CANADA CLOSED LOW WILL SPREAD EWD ACROSS UPPER MS VALLEY THIS FORECAST PERIOD...WITH SRN EXTENT SPREADING SSEWD INTO NWRN MO TO NWRN OK BY LATE THIS AFTERNOON. ..

.SRN PLAINS TO LOWER MO VALLEY REGION... 00Z GFS/NAM HAVE COME INTO BETTER AGREEMENT WITH THE MOVEMENT OF THE COLD FRONT SSEWD THROUGH THE SRN PLAINS THIS AFTERNOON. THIS BOUNDARY IS EXPECTED TO EXTEND FROM THE TX PANHANDLE NEWD THROUGH NWRN OK TO ERN KS/NWRN MO TO CENTRAL IA BY LATE AFTERNOON. MEANWHILE...A DRY LINE WILL MIX EWD INTO WRN OK AND CENTRAL TX THIS AFTERNOON BEFORE RETREATING WWD SOME TONIGHT. SWLY LOW LEVEL FLOW LOCATED OVER THE WARM SECTOR THIS MORNING IS FORECAST TO BACK TO SLY DURING THE AFTERNOON IN RESPONSE TO APPROACH OF GREAT BASIN SHORT WAVE TROUGH. THIS WILL RESULT IN NWD MOISTURE RETURN WITH SURFACE DEWPOINTS IN THE MID 60S SPREADING ACROSS MUCH OF OK AND WRN AR EAST OF THE DRY LINE...WHILE UPPER 50S DEWPOINTS REACH INTO CENTRAL PARTS OF IA ALONG COLD FRONT. SWLY FLOW LOCATED ABOVE THE BOUNDARY LAYER WILL MAINTAIN A STRONG EML ATOP THE MOISTURE RETURN...WITH STEEP MID LEVEL LAPSE RATES CONTRIBUTING TO MODERATE INSTABILITY WITHIN THE WARM SECTOR FROM THE SRN PLAINS NEWD INTO SRN/ERN KS TO WRN MO. THIS EML IS EXPECTED TO CAP THE WARM SECTOR FOR MUCH OF THE AFTERNOON AND LIKELY PRECLUDE SURFACE BASED TSTM DEVELOPMENT UNTIL THE ARRIVAL OF FORCING FOR ASCENT WITH SHORT WAVE TROUGH MOVING NEWD THROUGH THE CENTRAL PLAINS THIS EVENING. HOWEVER...GIVEN DEGREE OF INSTABILITY /MUCAPES APPROACHING 2500 J/KG/...DEEP LAYER SHEAR AROUND 40 KT AND CONVERGENCE AT THE TRIPLE POINT..

.THE POTENTIAL FOR AT LEAST ISOLATED TSTM DEVELOPMENT MAY OCCUR LATE THIS AFTERNOON /AFTER 21Z/. IF STORMS DEVELOP DURING THAT TIME FRAME...ISOLATED SUPERCELLS WOULD BE LIKELY WITH ATTENDANT THREATS FOR A FEW TORNADOES AND LARGE HAIL...SOME VERY LARGE...GIVEN THE FAVORABLE THERMODYNAMICS AND KINEMATICS. OTHERWISE...AS THE SHORT WAVE TROUGH TRACKS NEWD THROUGH THE CENTRAL PLAINS TO UPPER MS VALLEY THIS EVENING/OVERNIGHT...TSTMS SHOULD DEVELOP NEWD ALONG THE COLD FRONT INTO ERN KS/WRN MO AND IA. ALTHOUGH STRONGEST DEEP LAYER SHEAR SHOULD REMAIN OVER THE POST FRONTAL ENVIRONMENT TONIGHT...MORE SUBSTANTIAL MOISTURE RETURN INTO SERN KS/WRN MO COMBINED WITH MODEST DEEP LAYER SHEAR SHOULD SUPPORT THE POTENTIAL FOR STRONG TO SEVERE TSTMS. ...ERN OK/AR/SRN MO MAINLY TONIGHT... LOW LEVEL WINDS ARE EXPECTED TO VEER TO SWLY TONIGHT AS GREAT BASIN SHORT WAVE TROUGH TRACKS N OF THIS REGION TOWARD THE UPPER MS VALLEY. TSTMS SHOULD DEVELOP WITHIN WAA REGIME...WITH ELEVATED INSTABILITY UP TO 1000 J/KG AND EFFECTIVE BULK SHEAR AROUND 30 KT SUPPORTING A FEW STRONGER STORMS PRODUCING HAIL.


 Arkansas/Oklahoma tornadoes with possible severe outbreak 10 April 2008

There have been three reports thus far today of tornado touchdowns.  Strongest wind gust 65kts and largest hail thus far 2". There have been several areas with wind damage, downed trees and some structural damage, but the tornadoes have not caused too much concern due to their location.  The map below shows the risk areas, a moderate risk is quite worrying in any chaser's view.

There is very strong wind shear with the system moving through, some winds are averaging between 60 - 120mph at different heights - just perfect for supercells to rotate in.  There are still tornado watches in place.





Latest warning issued 10 April 2008:

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 183

NWS STORM PREDICTION CENTER NORMAN OK

805 PM CDT WED APR 9 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF 



WESTERN ARKANSAS

SOUTHEAST OKLAHOMA

NORTHEAST TEXAS



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 805 PM

UNTIL 300 AM CDT.



TORNADOES...HAIL TO 2 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 45 STATUTE

MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF FORT

SMITH ARKANSAS TO 35 MILES SOUTH SOUTHWEST OF DE QUEEN ARKANSAS. 

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 179...WW 180...WW

181...WW 182...



DISCUSSION...SCATTERED INTENSE/SUPERCELL THUNDERSTORMS ARE MOVING

EASTWARD ACROSS EASTERN OK INTO WESTERN AR.  THESE STORMS ARE IN

REGION OF STRONG ASCENT AHEAD OF SUB-SYNOPTIC SURFACE LOW.  VERY

STRONG WIND FIELDS AND MODERATE INSTABILITY SHOULD MAINTAIN THE RISK

OF LARGE HAIL...DAMAGING WINDS...AND TORNADOES FOR SEVERAL HOURS.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 24035.

         Video of tornado: http://www.youtube.com/watch?v=V5THCsnxRVQ
        Commentary of severe weather outbreak outlook here : http://www.youtube.com/watch?v=VTsCFHYVlhU&feature=related

          News footage from reporter:  http://youtube.com/watch?v=SQmld4mG3Tw&feature=related

          More news coverage: 
http://www.wsbtv.com/news/15611659/detail.html

Atlanta tornado photos!!!

Courtesy of Weather.com - here's first photos of the actual storm at night with the tornado visible by lightning and damage photos to the city.  Notice the structure of the storm - text book!   The tornado is hidden and this is why you should never chase supercells up close at night.

http://www.weather.com/newscenter/slideshow/atltornado1.html?from=hp_main_tab3

Storm Prediction Centre's report on this event here and you can bookmark this site yourself if you want to visit the SPC regularly.

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



Highly experienced US chaser, Verne Carlson  has an awesome invention to capture video of tornadoes and thunderstorms from the air, a remote aircraft aptly named the Wicked Witch3.  This is the link to his storm blog website that shows images that the aircraft relays back to him by video and Verne's reports .  This site should be viewed regularly during the next few months as the tornado season kicks in.

http://stormchaserco.blogspot.com/2008/04/best-ww3-flights-yet.html