MESOSCALE PRECIPITATION DISCUSSION 0090
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
607 AM EDT SUN APR 02 2017

AREAS AFFECTED...CENTRAL TX

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 021006Z - 021506Z

SUMMARY...STEADILY INCREASING ASCENT PARAMETERS PROVIDES MODEST
ISENTROPIC ASCENT/SLOW MOVING/REPEAT THUNDERSTORM ENVIRONMENT FOR
POSSIBLE LOCALIZED FLASH FLOODING THREAT BEFORE LARGER MCS.

DISCUSSION...PRECURSORY TO THE STRONGEST ASCENT/LIFT WITH LARGE
MCS COMPLEX UPSTREAM...SYNOPTIC PARAMETERS HAVE BEEN STEADILY
INCREASING ALLOWING FOR INCREASING CONVECTION CAPABLE OF HIGHLY
EFFICIENT RAINFALL PRODUCTION.  GOES-EAST AND 16 WV AND AMVS
DEPICT SPLIT JET STRUCTURE WITH INCREASING SPEED MAX TRACKING
ACROSS S TX AT THIS TIME ALONG WITH STRENGTHENING N-S JET ACROSS
THE TX PANHANDLE SUPPORTING DUAL LEFT ENTRANCE AND RIGHT EXIT
DIVERGENCE AND BROAD SCALE ASCENT ACROSS CENTRAL TX.  WHILE
GREATEST ASCENT REMAINS UPSTREAM WITH LARGE MCS OVER SW TX/EDWARDS
TO KINNEY COUNTY...THIS BROAD ASCENT COUPLED WITH STRENGTHENING
LLJ HAS LEAD TO FEEDER BAND CONVECTIVE LINES WITHIN THE WARM
SECTOR INDICATIVE OF THE VERY MOIST/UNSTABLE LOW LEVEL
ENVIRONMENT.  CURRENTLY LOW LEVEL HEIGHT FALLS IS EXPANDING 850-7H
TROF NORTHEAST UNDER THE SPLIT JET WHICH ALSO ALIGNS FAIRLY WELL
WITH OVER NIGHT OUTFLOW BOUNDARY THAT EXTENDS FROM ROUGHLY GDJ TO
LZZ TO JUST SE OF JCT PER 09Z SFC ANALYSIS AND RADAR MOSAIC.  VWP
OF 40-45 KTS 85-7H FLOW GENERALLY INTERSECTS THIS BNDY/TROF
SUPPORTING THE FOCUS FOR DEEPER CONVECTIVE INITIATION AS NOTED BY
RADAR/INCREASED LIGHTNING AS WELL AS COOLING TOPS SPROUTING OUT OF
THE LARGER CIRRUS CANOPY IN GOES-16 EIR LOOP.  RELATIVELY
STATIONARY TROF AND ADDITIONAL SURGES OF ISENTROPIC ASCENT WITHIN
THE AREA OF CONCERN MAY POSE LOCALIZED LARGER TERM FLASH FLOODING
THREAT ASSOCIATED WITH THE MODERATE RAIN RATES OF 1.0-1.25"/HR
COULD PERSIST AHEAD OF THE APPROACH OF LARGER MCS/HEIGHT
FALLS/UVVS TOWARD 12-13Z WHEN RATES SHOULD INCREASE TO 2"/HR OR
GREATER WITH DEEPER ASCENT/HEIGHT FALLS ASSOCIATED WITH THE MCS.


GALLINA

ATTN...WFO...EWX...FWD...SJT...

ATTN...RFC...WGRFC...

LAT...LON   32659786 32579669 31719673 30979715 30479765
            30019835 30299922 31389907