Post by Briella - Houma on Apr 21, 2014 13:34:15 GMT -6
MESOSCALE DISCUSSION 0376
NWS STORM PREDICTION CENTER NORMAN OK
0225 PM CDT MON APR 21 2014
AREAS AFFECTED...PARTS OF CENTRAL AND N TX
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 211925Z - 212130Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...SEVERE RISK IS GRADUALLY INCREASING ACROSS CENTRAL TX
ATTM...AS CONVECTIVE INITIATION IS EXPECTED TO BEGIN OVER THE NEXT
HOUR OR SO. WW ISSUANCE MAY BE REQUIRED.
DISCUSSION...LATEST VISIBLE SATELLITE IMAGERY SHOWS CU FIELD
INCREASING ACROSS THE CENTRAL TX VICINITY /SE OF SJT-NE OF
JCT/...NEAR THE ADVANCING COOL FRONT WHERE HEATING OF THE MODESTLY
MOIST BOUNDARY LAYER HAS YIELDED A ZONE OF 1500 TO 2000 J/KG
MIXED-LAYER CAPE. THOUGH LARGE-SCALE ASCENT APPEARS RELATIVELY WEAK
AND THUS DEVELOPMENT IS NOT EXPECTED TO BE EXPLOSIVE...STORMS --
ALREADY ONGOING OVER THE HIGHER TERRAIN OF NRN MEXICO -- ARE
FORECAST TO INITIATE ACROSS PARTS OF CENTRAL TX IN THE NEXT HOUR OR
SO. WITH TIME...DEVELOPMENT SHOULD SPREAD NEWD ALONG THE FRONT
TOWARD THE DFW METROPLEX...WHERE HEATING/DESTABILIZATION IS BEING
HINDERED A BIT BY LINGERING CLOUD COVER.
AS STORMS INITIATE...LOCAL UPDRAFT ORGANIZATION IS EXPECTED GIVEN
STEEP LAPSE RATE ENVIRONMENT IN CONJUNCTION WITH AMPLE SHEAR /AIDED
BY AROUND 30 KT WLYS AT MID LEVELS/. WHILE MODEST LOW-LEVEL FLOW
AND RELATIVELY HIGH CLOUD BASES SHOULD LIMIT TORNADO
RISK...POTENTIAL FOR LARGE HAIL IS EVIDENT ALONG WITH RISK FOR
LOCALLY DAMAGING WINDS -- WHICH SUGGEST POSSIBILITY THAT WW WILL BE
REQUIRED.
