janetjanet998

not the main show yet but new watch

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 230

NWS STORM PREDICTION CENTER NORMAN OK

810 AM CDT WED APR 27 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

NORTHERN ALABAMA

NORTHERN MISSISSIPPI

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 810 AM UNTIL

200 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.

\DISCUSSION...STORMS DEVELOPING ACROSS NRN MS THROUGH NRN AL ARE

EMBEDDED WITHIN VERY STRONG VERTICAL SHEAR PROFILES WITH LARGE

HODOGRAPHS. AS THE ATMOSPHERE DESTABILIZES...POTENTIAL WILL EXIST

FOR TORNADOES...DAMAGING WIND AND LARGE HAIL.

clear pockets in between the complexes over TN and breaks in tghe clouds ahead of the first one

expect new development over LA soon and move into central MS then AL

storms over N MS now becoming almost surface based and now TOR warned..

old complex may move into VA/ NC/SC later as airmass destabilzes as they cross the mountains

OH valley may have a few tornadoes...

then the big show over MS/AL later

This is very april 3-4 1974 like in that regard, with possible multiple bands of storms producing tornadoes at the same time

new RUC has the best paramters I ever recall seeing even at 20% reduction

again we have to add on the stuff from yesterday evening and over night too

...THERE IS A HIGH RISK OF SVR TSTMS TODAY INTO EARLY TONIGHT FOR NE

MS...CENTRAL/NRN AL...NW GA...SE TN...

..THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK

FROM

NRN/CENTRAL MS TO SRN AL...NW GA...MIDDLE/ERN TN...WRN SC...WRN

NC...WRN VA...AND ERN KY...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE N CENTRAL GULF COAST

TO THE OH VALLEY/APPALACHIANS AND NY...

--DANGEROUS TORNADO OUTBREAK IS EXPECTED FROM LATE MORNING INTO LATE

EVENING ACROSS THE TN VALLEY REGION--

..SYNOPSIS

AN INTENSE MIDLEVEL SHORTWAVE TROUGH AND ASSOCIATED 100 KT 500 MB

JET WILL PIVOT EWD FROM TX/OK THIS MORNING TO LOWER MS/TN VALLEY

REGION BY THIS EVENING...AND CONTINUE NEWD TO THE CENTRAL

APPALACHIANS OVERNIGHT. THE PRIMARY SURFACE CYCLONE WILL DEVELOP

NEWD FROM WRN AR THIS MORNING TO WRN KY/SRN INDIANA BY THIS

EVENING...AND THEN CONTINUE NEWD TO THE LOWER GREAT LAKES OVERNIGHT.

A TRAILING COLD FRONT AND REMNANT DRYLINE FEATURE WILL SWEEP EWD

ACROSS THE ARKLAMISS THIS AFTERNOON...PROVIDING A FOCUS FOR SEVERE

STORM DEVELOPMENT. GIVEN THE PRESENCE OF VERY STRONG WINDS

THROUGHOUT THE TROPOSPHERE AND AN INFLUX OF RICH MOISTURE FROM THE

GULF OF MEXICO...THE ENVIRONMENT WILL BE FAVORABLE FOR A DANGEROUS

OUTBREAK OF FAST-MOVING TORNADIC SUPERCELLS AND EMBEDDED BOW ECHOES

TODAY INTO EARLY TONIGHT.

..MS/AL/TN/KY/GA AREA THROUGH TONIGHT

THE REMNANTS OF AN INTENSE OVERNIGHT MCS /INCLUDING EMBEDDED

SUPERCELLS AND BOWS/ IS WEAKENING OVER NE AL AND MIDDLE TN AS OF

SUNRISE. OTHER ELEVATED THUNDERSTORM DEVELOPMENT IS UNDERWAY TO THE

W FROM NE LA INTO SE AR/NRN MS. SOME FORM OF THIS ELEVATED

CONVECTION WILL LIKELY PERSIST THROUGH THE DAY WHILE SPREADING ENEWD

OVER NRN MS INTO WRN/MIDDLE TN. S OF THIS ACTIVITY AND IN THE WAKE

OF THE EARLIER MS/AL MCS...IT APPEARS THAT THE WARM SECTOR WILL

RECOVER QUICKLY DURING THE MORNING/EARLY AFTERNOON IN RESPONSE TO

CLOUD BREAKS AND STRONG LOW-LEVEL SLY FLOW. A RESERVOIR OF 70-72 F

BOUNDARY LAYER DEWPOINTS FROM SRN LA TO SRN AL WILL SPREAD NWD IN

THE WAKE OF THE MORNING STORMS...BENEATH THE REMNANTS OF STEEP

MIDLEVEL LAPSE RATE PLUME SPREADING EWD FROM TX/LA. SURFACE HEATING

WITHIN THE MOIST WARM SECTOR WILL BOOST MLCAPE VALUES TO 2500-4000

J/KG ALONG AND S OF THE REMNANT OUTFLOW BOUNDARY...AND REDUCE

CONVECTIVE INHIBITION BY ABOUT MIDDAY. THIS WILL ALLOW THE

DEVELOPMENT OF SCATTERED-NUMEROUS WARM SECTOR SUPERCELLS ALONG

CONFLUENCE BANDS E OF THE COLD FRONT/DRYLINE BY EARLY AFTERNOON.

THE VERTICAL SHEAR ENVIRONMENT WILL BECOME VERY FAVORABLE FOR

TORNADIC SUPERCELLS...CHARACTERIZED BY LONG/CURVED HODOGRAPHS WITH

EFFECTIVE BULK SHEAR IN EXCESS OF 70 KT AND EFFECTIVE SRH OF 300-600

M2/S2 IN THE UNSTABLE WARM SECTOR. GIVEN THE EXPECTATION OF SEVERAL

HOURS OF DISCRETE SUPERCELL DEVELOPMENT IN THE WAKE OF THE MORNING

STORMS...A VERY MOIST BOUNDARY LAYER...THE STRONG INSTABILITY...AND

INTENSE VERTICAL SHEAR...THE SCENARIO APPEARS FAVORABLE FOR MULTIPLE

LONG-TRACK SUPERCELLS WITH THE POTENTIAL TO PRODUCE INTENSE/DAMAGING

TORNADOES IN THE HIGH RISK AREA.

..AR NEWD TO THE LOWER OH VALLEY TODAY

ALONG THE PATH OF THE MIDLEVEL TROUGH AND SURFACE CYCLONE...THERE

WILL BE A FOCUS FOR ADDITIONAL SEVERE THUNDERSTORM DEVELOPMENT LATER

TODAY. THE DEGREE OF INSTABILITY IS IN QUESTION GIVEN THE IMPACTS

OF OVERNIGHT AND ONGOING CONVECTION FARTHER TO THE SE. STILL...ANY

CLOUD BREAKS WILL ALLOW DESTABILIZATION BENEATH COOL MIDLEVEL

TEMPERATURES...IN AN ENVIRONMENT OF STRONG DEEP-LAYER SPEED SHEAR.

DAMAGING WINDS/HAIL AND A COUPLE OF TORNADOES WILL BE POSSIBLE WITH

ANY CLUSTERS IMMEDIATELY IN ADVANCE OF THE SURFACE LOW.

..UPPER OH VALLEY TONIGHT

THE PRIMARY SURFACE CYCLONE AND STRONG KINEMATIC PROFILES ARE

EXPECTED TO REACH THE UPPER OH VALLEY EARLY TONIGHT. THE MAGNITUDE

OF WARM SECTOR INSTABILITY IS IN QUESTION GIVEN WIDESPREAD

CONVECTION ONGOING AND EXPECTED TO THE SOUTH. HOWEVER...VERY STRONG

LOW-LEVEL SHEAR IN A MOIST ENVIRONMENT COULD SUPPORT A FEW TORNADOES

WITH EMBEDDED BOWS AND SUPERCELL STRUCTURES.

..THOMPSON/COHEN.. 04/27/2011

The Tornado outbreak of april 26-27th continures and will likely all day..with rounds of tornadic storms.

for those of you just waking up things went nuts over MS last night,, about 70 tornado warnings issued since midnight

several supercells formed within the heavy precip field with many confrimed tornadoes..many towns got hit..damage reports still flowing in...injuries reported,,mobile home parks hit

one supercell was insane with extreme couplet and hurricane like eye with strong north and south feeder bands with storm motions of 60-70mPH this was at about 3am..not good

the tornado count will really rise as many damage reported now listed as wind damage say possible tornado

This April 26-27, 20011 outbreak may have tornadoes then the superoutbreak, but of course if you take the superoutbreak and out in todays world there would likley be closer to 225 tornadoes then 148

There was a 36 hour outbreak that actually had more then the 148 a few years ago..the date escapes me at this moment but that was out over the open plains

in this case coming up only luck will keep the death toll out of the dozens

a silver lining of all the outbreaks latley is that people may be paying more attention

freak..

north system has 1000 CApE to work with..south 3000

For now I am ok keeping all three in one. Monday-Tue-Wed will likely be three moderates in a row, possibly a high on Wed at some point. All three days have regions with significant potential although Tue/Wed look to be potentially very dangerous.

I just started a new thread for monday as you were typing that.. I don';t care..delete it if you wish

http://www.americanwx.com/bb/index.php/topic/17617-monday-april-25th/

12z NAM coming a little more NW for Mondays event..but cloudy/rainy warm sector..still cape around 1500

looks decent

perhaps keep this thread for monday..but then spin one off for tuesday and/or weds?

also nam a little more se for weds at 12z

Memphis NWS for WEDS

SOMETHING INTERESTING OF NOTE...GFS

STRONG TORNADO PARAMETER IS AROUND 20 WHICH IS PRETTY

UNPRECEDENTED /1 OR 2 IS CONSIDERED HIGH/.

18z gfs much stronger with the monday low 994 mb in western MO by 00z tuesday and aorund 991 in western IL by 06z

puts STL in corsshairs again

12z gfs

holy moly

may 2003 had 543 tornadoes, a record

I do believe the top 10 are all May or June

I'm not sure what the monthy record is for april..but we may smash that if trends continue