[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 010454
SWOMCD
SPC MCD 010453 
ALZ000-MSZ000-LAZ000-ARZ000-TXZ000-010600-

MESOSCALE DISCUSSION 0471
NWS STORM PREDICTION CENTER NORMAN OK
1053 PM CST THU MAR 31 2005

AREAS AFFECTED...NRN/CNTRL LA EWD ACROSS CNTRL/SRN MS

CONCERNING...SEVERE THUNDERSTORM WATCH 116...117...

VALID 010453Z - 010600Z

A NEW TORNADO WATCH WILL BE ISSUED SOON TO REPLACE WW 116/117.

AS OF 0435Z...REGIONAL RADAR IMAGERY SHOWED BOW ECHO BECOMING BETTER
DEFINED S OF SHV WITH A GENERAL EWD MOTION OF AROUND 40 KTS. LATEST
MESOANALYSIS SUGGESTS THAT THIS FEATURE IS NEARLY COINCIDENT WITH
MAIN SURFACE LOW...AND THAT EXTRAPOLATION WILL TAKE IT N OF
RETREATING WARM FRONT INTO INCREASINGLY STABLE AIR MASS FOR
SURFACE-BASED PARCELS. 3-HR PRESSURE TENANCIES INDICATE CORRIDOR OF
LOCALLY STRONGER FALLS FROM THIS LOW EWD INTO CNTRL MS
/JAN/...LIKELY INDICATING IT/S EVENTUAL TRACK OVERNIGHT.

ATTENDANT WARM FRONT CONTINUES TO SLOWLY LIFT NWD WITH SURFACE WIND
INCREASING FROM THE SE AT POE THIS PAST HOUR. FARTHER E...PERSISTENT
AND WIDESPREAD CONVECTION ACROSS SERN LA INTO SRN MS WILL LIKELY
IMPEDE NWD MOVEMENT OF THIS BOUNDARY AT LEAST TO SOME DEGREE
OVERNIGHT.

GIVEN THAT MAIN UPPER SYSTEM STILL IS DIGGING OVER WRN PORTIONS OF
TX/OK...SYNOPTIC SYSTEM IS STILL NOT IN PHASE WITH SURFACE WARM
SECTOR AND AS A RESULT...SURFACE LOW HAS SHOWN LITTLE OR NO
DEEPENING. GIVEN MODERATE INSTABILITY AND SUFFICIENT DEEP-LAYER
SHEAR...SUPERCELLS AND/OR BOWING STRUCTURES WILL REMAIN POSSIBLE E
OF SURFACE LOW AND ALONG ATTENDANT BAROCLINIC ZONES. FT. POLK VWP
HAS INDICATED AN INCREASE IN LOW-LEVEL SHEAR OVER THE PAST HOUR AND
LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THAT THIS TREND WILL
CONTINUE OVERNIGHT. THUS...ISOLATED TORNADO THREAT SHOULD INCREASE
ACROSS WARM SECTOR OVERNIGHT...IN ADDITION TO A CONTINUED THREAT OF
DAMAGING WINDS AND LARGE HAIL.

..MEAD.. 04/01/2005

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BMX...MOB...JAN...LIX...LCH...SHV...HGX...

33059391 32938832 30578838 30789486 

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