Posted on 04/28/2014 10:15:49 AM PDT by halo66
MESOSCALE DISCUSSION 0451 NWS STORM PREDICTION CENTER NORMAN OK 1205 PM CDT MON APR 28 2014
AREAS AFFECTED...PORTIONS NERN LA...WRN/NRN MS...NWRN AL...SRN MIDDLE TN.
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 281705Z - 281900Z
PROBABILITY OF WATCH ISSUANCE...95 PERCENT
SUMMARY...TORNADO WATCH IS HIGHLY PROBABLE WITHIN NEXT HOUR ACROSS DISCUSSION AREA. SUPERCELLS ARE EXPECTED TO DEVELOP IN BKN/SW-NE BAND AND INTENSIFY THROUGH AFTN WITH A FEW SIGNIFICANT/LONG-TRACK TORNADOES POSSIBLE.
DISCUSSION...EARLIER CONVECTION HAS LEFT OUTFLOW/DIFFERENTIAL-HEATING BOUNDARY ALIGNED SW-NE ACROSS DISCUSSION AREA...BECOMING MORE DIFFUSE WITH SWWD EXTENT AT SFC. MEANWHILE VIS IMAGERY SHOWS EXPANDING POCKETS OF RELATIVELY CLOUD-FREE AREAS THAT WILL FOSTER SUSTAINED PERIOD OF INSOLATION AND QUICK SBCINH REMOVAL. MODIFIED RAOBS AND FCST SOUNDINGS OVER THIS CORRIDOR SUGGEST 1500-2500 J/KG MLCAPE WILL BUILD NEWD. IN THIS ENVIRONMENT...TSTMS ALREADY ARE DEVELOPING OVER NERN LA INVOF MLU...AND IF NOT ALREADY SFC-BASED...MAY BECOME SO SHORTLY. ADDITIONAL CONVECTION IS LIKELY TO FORM NEWD ACROSS MS INTO SRN MID TN AND NWRN AL AS AIR MASS THERE DESTABILIZES IN NEXT 2-3 HOURS. DEEP-LAYER AND LOW-LEVEL SHEAR EACH ARE FAVORABLE AND WILL REMAIN SO...WITH 50-70 KT EFFECTIVE SHEAR MAGNITUDES. EFFECTIVE SRH SHOULD INCREASE THROUGH AFTN TO AROUND 300 J/KG...AND VWP ALREADY SHOW 300-500 J/KG OF 0-3 KM SRH OVER NERN MS.
..EDWARDS/THOMPSON.. 04/28/2014
This area is also being monitored for an upgrade to a High Risk...
Prayers for the folks in those areas.
.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1141 AM CDT MON APR 28 2014
.UPDATE......SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON AND EVENING...
...SIGNIFICANT FLOODING POSSIBLE MONDAY INTO EARLY TUESDAY...
.UPDATE...NOT MANY UPDATES MADE TO GOING FORECAST AS SEVERE
WEATHER OUTBREAK REMAINS ON TRACK FOR LATE THIS MORNING AND
ESPECIALLY INTO THIS AFTERNOON AND EVENING WHERE STRONG AND POSSIBLY
LONG TRACK TORNADOES COULD OCCUR. CAUTION IS HIGHLY ADVISED FOR
THIS POTENTIALLY LIFE THREATENING AND DANGEROUS SITUATION.
.DISCUSSION...INITIAL LEAD S/WV RESPONSIBLE FOR THIS MORNINGS ACTIVELY
IS LIFTING NE AWAY FROM THE REGION RESULTING IN A WEAKENING TREND OF
THAT ACTIVITY. HOWEVER, A CYCLONICALLY CURVED H5-H3 JET STREAK IS
OBSERVED ON WV CHANNELS...REGIONAL VAD WIND PROFILES AND IN NWP
SURGING INTO THE NW DELTA AND THE ARKLAMISS AT THIS HOUR. THIS
SIGNATURE COUPLED WITH NEAR 2000 J/KG SBCAPE IS ALREADY INITIALIZING
ACROSS THE DELTA REGION WITH THE THIS NEXT AND MORE POTENT ROUND OF
SEVERE WEATHER EXPECTED FOR THE REGION. 0-1 KM ESRH REMAINS NEAR
200M2/S2 PER MESOANALYSIS AS OF 16Z BUT NWP SUITE SUGGESTS STEADILY
INCREASING LOW LVL SHEAR VALUES TOWARDS 300M2/S2 AND POSSIBLY HIGHER
THROUGH THE EARLY AFTN AND EVENING WHERE WORRISOME 0-1 KM EHI AND
STRONG TORNADO PARAMETERS VALUES INDICATE HEALTHY ENVIRONMENT CAPABLE
OF SUPPORTING SOME STRONG AND POSSIBLY LONG TRACK TORNADOES. SPC SSEO
UPDRAFT HELICITY SIGNALS SUGGEST THAT GREATEST RISK FOR THESE
TORNADOES COULD BE ACROSS NORTH CENTRAL AND NORTHEAST MISSISSIPPI
EXTENDING ALONG THE NATCHEZ TRACE CORRIDOR TOWARDS THE JACKSON
METROPLEX MID TO LATE AFTERNOON INTO THE EVENING. A COUPLE OF ROUGE
STORMS COULD ALSO DEVELOP SOUTH OF I-20 AND WITH LESS COMPETITION FOR
RESOURCES AND POTENTIALLY NON-BLOCKED INFLOW COULD BE TROUBLESOME.
THE TRENDS OF LOCAL WRF AND THE HRRR ECHO SPC SSEO HELICITY SIGNALS
THAT WHAT SEMI-DISCRETE STORMS DEVELOP WILL BE CAPABLE OF STRONG
ROTATING UPDRAFTS. NAM BUFR SOUNDINGS FOR JACKSON FOR MID AFTN
SUGGEST 0-3 SRH VALUES NEAR 500 M2/S2 WITH THIS ENVIRONMENT LIKELY IN
PLACE ALONG THE TRACE CORRIDOR. GRAPHICS HAVE BEEN UPDATED TO
REFLECT THIS HIGHER RISK AREA.
UPDATES ARE OUT AND AN UPDATED AVIATION DISCUSSION CAN BE FOUND
DIRECTLY BELOW. /ALLEN/
Hmmmmmmmmmm
comin this a’way
SE TN...
I have a dear friend in St. Louis and a cousin in OK.
Not to mention all our beloved FReepers in those areas!
PRAYERS UP!
SE TN should see more of a threat during the late evening/nighttime time frame. Doesn’t look like threat for strong tornadoes exists there...more of a wind/hail threat.
Be safe! You have our prayers.
SEL8
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 108
NWS STORM PREDICTION CENTER NORMAN OK
1240 PM CDT MON APR 28 2014
THE NWS STORM PREDICTION CENTER HAS ISSUED A
* TORNADO WATCH FOR PORTIONS OF
NORTH AND NORTHWEST ALABAMA
NORTHEAST LOUISIANA
CENTRAL AND NORTHEAST MISSISSIPPI
SOUTHERN MIDDLE TENNESSEE
* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1240 PM UNTIL
900 PM CDT.
...THIS IS A PARTICULARLY DANGEROUS SITUATION...
* PRIMARY THREATS INCLUDE...
NUMEROUS TORNADOES EXPECTED WITH A FEW INTENSE TORNADOES LIKELY
WIDESPREAD LARGE HAIL EXPECTED WITH ISOLATED VERY LARGE HAIL
EVENTS TO 3 INCHES IN DIAMETER LIKELY
SCATTERED DAMAGING WIND GUSTS TO 70 MPH LIKELY
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH OF HUNTSVILLE
ALABAMA TO 10 MILES SOUTH OF NATCHEZ MISSISSIPPI. FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU8).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
&&
DISCUSSION...SURFACE-BASED STORMS ARE BEGINNING TO DEVELOP FROM NE
LA INTO W CENTRAL MS...WITH ADDITIONAL DEVELOPMENT EXPECTED NEWD
TOWARD NE MS/NW AL AS CLOUDS CLEAR AND THE LOW LEVELS DESTABILIZE.
A COMBINATION OF MODERATE INSTABILITY /MLCAPE NEAR 2000 J PER KG/
AND STRONG DEEP-LAYER VERTICAL SHEAR WILL SUPPORT A BROKEN BAND OF
SUPERCELLS...WHILE SOME INCREASE IN LOW-LEVEL SHEAR IS EXPECTED THIS
AFTERNOON FROM CENTRAL MS INTO NE MS/NW AL...UP TO A RESIDUAL
OUTFLOW BOUNDARY IN SRN MIDDLE TN. SOME OF THE SUPERCELLS WILL BE
LONG-LIVED AND CAPABLE OF PRODUCING STRONG/LONG-TRACK TORNADOES...AS
WELL AS VERY LARGE HAIL.
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 24035.
...THOMPSON
Already tornado warnings from storms that just exploded...
Feel bad for those without access to shelters.
I this modern age, we have such good advance notice, but still occasional disasters like last night.
Very true...you would just hope that people will pay attention to these situations a little more...
You’d think with half the populace walking around with their nose in a cellphone screen, nobody would be surprised by a tornado these days.
I agree...but for some Facebook is like a drug! Don’t have time to check to see what that warning is that came across on your phone...
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