SWOMCD
SPC MCD 151435
TXZ000-151730-
MESOSCALE DISCUSSION 0316
NWS STORM PREDICTION CENTER NORMAN OK
0935 AM CDT THU APR 15 2010
AREAS AFFECTED...PORTIONS S-CENTRAL TO W-CENTRAL TX.
CONCERNING...HEAVY RAINFALL
VALID 151435Z - 151730Z
POTENTIAL IS INCREASING FOR EPISODIC RAIN RATES 1-2 INCHES/HOUR
BEGINNING S OF I-10 AND SW OF I-37...THEN SPREADING NWD OVER SRN/WRN
HILL COUNTRY AND EDWARDS PLATEAU WITH TIME.
MOISTURE CHANNEL IMAGERY INDICATES MID-UPPER LOW MOVING NWD ACROSS
RIO GRANDE INVOF DRT...CORROBORATED WITH SIMILARLY MOVING VORTEX
EVIDENT IN REFLECTIVITY DATA OVER SRN VAL VERDE COUNTY AS OF 14Z.
STG LOW-LEVEL MOISTURE TRANSPORT REGIME WILL PERSIST E THROUGH SE OF
THAT CIRCULATION...WITH SUSTAINED/30-40 KT SELY LLJ EMANATING FROM
NWRN GULF. SOURCE-LAYER MOISTURE IS NOTHING UNUSUAL FOR THAT AREA
GIVEN SEVERAL COMMON MEASURES -- E.G. GPS AND SOUNDING PW AROUND
1.5-1.75 INCHES...SFC DEW POINTS UPPER 60S F...MEAN MIXING RATIO
12-14 G/KG...AND ANALYZED 925-850 MB DEW POINTS AROUND 15 AND 12 DEG
C RESPECTIVELY. HOWEVER...AIR MASS IS NEARLY SATURATED THROUGH DEEP
LAYER...WITH LIKELIHOOD OF BOUNDARY LAYER DESTABILIZATION. THIS
MOISTURE CONTENT SHOULD BE SUFFICIENT TO SUPPORT AT LEAST PERIODIC
HEAVY RAIN RATES ABOVE 1 INCH/HOUR GIVEN PRESENCE OF PROLONGED
LOW-LEVEL CONVERGENCE AND ISENTROPIC LIFT...AND MODIFIED RAOBS AND
MODEL SOUNDINGS THAT INDICATE LIKELIHOOD OF MIXTURE OF EFFICIENT
WARM-CLOUD PROCESSES AND DEEP TSTMS. IN ADDITION...MERGERS OF
CONVECTION ALONG NERN PERIPHERY OF PRIMARY/INITIAL RAIN AREA WILL
ENHANCE RATES LOCALLY. DIABATIC HEATING OF INFLOW LAYER WILL BE
GRADUAL DUE TO EXTENSIVE CLOUD COVER...BUT WHEN COMBINED WITH THETAE
ADVECTION...SHOULD OFFSET WEAK LAPSE RATES ALOFT...INCREASE MLCAPE
ABOVE 500 J/KG OVER SRN HILL COUNTRY AND RAISE BUOYANT LAYER TO NEAR
TROPOPAUSE...IN SUPPORT OF DEEP PRECIP GENERATION IN AREA OF
SUSTAINED/DEEP ASCENT. ELEVATED WAA CONVEYOR ALSO WILL SUPPORT AT
LEAST ISOLATED HEAVY RATES WITHIN BROADER/LONG-LASTING PRECIP SHIELD
NWWD AS FAR AS ERN PERMIAN BASIN AND SRN CAPROCK AREAS OF W TX.
..EDWARDS.. 04/15/2010
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CRP...EWX...SJT...LUB...MAF...
LAT...LON 28379875 30070002 31760181 32480191 33030145 31019923
29429848 28379875
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment