[BNAWX] Severe Storm Outlook Narrative

[EMWIN Server]

ACUS11 KWNS 010612
SWOMCD
SPC MCD 010612
TNZ000-ALZ000-KYZ000-ILZ000-MSZ000-MOZ000-ARZ000-LAZ000-010815-

MESOSCALE DISCUSSION 0226
NWS STORM PREDICTION CENTER NORMAN OK
1212 AM CST THU MAR 01 2007

AREAS AFFECTED...LOWER OH VALLEY INTO MID SOUTH AND LOWER MS VALLEY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 010612Z - 010815Z

SEVERE POTENTIAL...INITIALLY IN THE FORM OF SEVERE HAIL FROM
ELEVATED TSTMS...IS EXPECTED TO EVOLVE INTO A THREAT OF MORE
SURFACE-BASED STORMS CAPABLE OF TORNADOES...DAMAGING WINDS AND
SEVERE HAIL THROUGH THE EARLY MORNING HOURS.  CONVECTIVE TRENDS WILL
BE MONITORED FOR POSSIBLE WW/S/.

SCATTERED TSTMS HAVE RECENTLY DEVELOPED AS OF 0530Z FROM PORTIONS OF
NRN AR EWD THROUGH WRN TN AND NRN MS.  WATER VAPOR IMAGERY AND SHORT
TERM MODEL GUIDANCE SUGGEST THAT THERE IS A WEAK IMPULSE MOVING
THROUGH THE ARKLATEX WHICH MAY...IN PART...BE CONTRIBUTING TO THIS
DEVELOPMENT.  HOWEVER...BROAD LOW-LEVEL WARM/MOIST ADVECTIONS ARE
LIKELY THE PRIMARY FORCING MECHANISMS BASED ON REGIONAL VADS/VWPS.
EXPECT THESE PROCESSES TO CONTINUE...EVEN STRENGTHEN...OVERNIGHT AS
MAIN LLJ AXIS DEVELOPS EWD THROUGH THE LOWER/MID MS VALLEY EWD INTO
THE TN AND OH VALLEYS.

SURFACE OBSERVATIONS INDICATE THAT ERN EDGE OF PRIMARY SURFACE
MOISTURE AXIS EXTENDS FROM UNO SWD TO BVX TO HEZ WITH DEWPOINTS
COMMONLY IN THE 40S TO LOWER 50S E OF THIS LINE.  AS SUCH...RUC
FORECAST SOUNDINGS INDICATE THAT MUCH OF THIS INITIAL CONVECTIVE
ACTIVITY IS ROOTED IN AN ELEVATED MOIST LAYER /800-900 MB/.
MODESTLY STEEP LAPSE RATES OF 7-7.5 C/KM ATOP THIS MOIST LAYER ARE
CONTRIBUTING TO MUCAPES OF 500-1000 J/KG...SUPPORTIVE OF A FEW
ELEVATED SEVERE STORMS CAPABLE OF HAIL.

LATEST RUC/NAM GUIDANCE SUGGESTS THAT RAPID AIR MASS DESTABILIZATION
WILL OCCUR OVERNIGHT THROUGH THE OZARK PLATEAU REGION EWD THROUGH
THE LOWER MS VALLEY INTO MID SOUTH AND LOWER OH VALLEY.  AS THIS
OCCURS...A GRADUAL EVOLUTION FROM ELEVATED TO SURFACE-BASED STORMS
WILL OCCUR...NAMELY FROM SW TO NE ACROSS DISCUSSION AREA.  THE
INCREASING INSTABILITY COUPLED WITH THE PRESENCE OF RELATIVELY
STRONG LOW AND DEEP-LAYER SHEAR INDICATE THE LIKELIHOOD OF
SUPERCELLS CAPABLE OF DAMAGING WINDS...LARGE HAIL AND TORNADOES.
THIS IS ESPECIALLY THE CASE FOR ANY STORMS THAT CAN BECOME ROOTED IN
MOISTENING BOUNDARY LAYER.

..MEAD.. 03/01/2007

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

ATTN...WFO...OHX...BMX...HUN...PAH...MEG...JAN...LSX...LZK...SGF...

34779280 35859309 36519283 37219171 37789057 38068964
37808863 36998759 35908739 34638766 33778815 33378863
32948944 32729078 32959200

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