Mesoscale Discussion 418

Issued

Apr 19, 2016, 3:48 PM CDT (20:48 UTC)

Expired

Apr 19, 2016, 6:15 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

20%

The Altus AFB radar (KFDR), 26 km from the middle of the area, began a volume at 20:49 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

792 
ACUS11 KWNS 192049
SWOMCD
SPC MCD 192048 
OKZ000-TXZ000-192315-

MESOSCALE DISCUSSION 0418
NWS STORM PREDICTION CENTER NORMAN OK
0348 PM CDT TUE APR 19 2016

AREAS AFFECTED...PORTIONS OF SWRN/S-CNTRL OK...AND NW TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 192048Z - 192315Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ORGANIZING CONVECTIVE CLUSTERS OVER THE TX S PLAINS ARE
FORECAST TO SPREAD EWD THROUGH THE REMAINDER OF THE AFTERNOON INTO
THE EVENING...AND WILL BE CAPABLE OF PRODUCING ISOLATED/MARGINAL SVR
WIND/HAIL. WW ISSUANCE IS UNLIKELY.

DISCUSSION...A RECENT WATER VAPOR LOOP IMPLIES A LOBE OF ASCENT
GLANCING PARTS OF THE TX PANHANDLE AND TX S PLAINS. THIS IS
ENCOURAGING CONTINUED TSTM DEVELOPMENT IN PROXIMITY TO A SFC
BOUNDARY ANALYZED NE/SW FROM N OF CHILDRESS TO S OF PLAINVIEW. TO
THE E...THIS BOUNDARY IS WAVY -- EXTENDING GENERALLY EWD/NEWD ACROSS
OKLAHOMA -- AND MESONET OBSERVATIONS SUGGEST IT LIES FROM NEAR
MANGUM TO NORMAN.

MEANWHILE...WIDESPREAD MULTI-LAYERED CLOUD DECKS ON EITHER SIDE OF
THE BOUNDARY HAVE BEEN ERODING. THIS HAS GIVEN WAY TO FILTERED
INSOLATION...CONTRIBUTING TO DIABATIC SFC-LAYER HEATING AND RECENT
NWD EDGING OF THE BOUNDARY IN PARTS OF SW/CNTRL OK. SFC DEWPOINTS IN
THE LOWER 60S COMBINED WITH STEEPENING LOW-LEVEL LAPSE RATES NEAR/S
OF THE BOUNDARY ARE YIELDING SBCAPE AROUND 500-1000 J/KG DESPITE
MODEST MID-LEVEL LAPSE RATES. THIS WILL BE SUFFICIENT FOR SUSTENANCE
OF ONGOING W TX CONVECTION...GIVEN 40-50 KT OF MID-LEVEL WSWLY FLOW
SAMPLED BY THE LBB VWP -- LIKELY ENHANCED BY THE IMPULSE-RELATED
ASCENT LOBE. INCIPIENT WARM-ADVECTION-DRIVEN CONVECTION IS PRESENTLY
DEVELOPING SSW/S OF CHILDRESS...AND WILL HAVE THE POTENTIAL TO MERGE
WITH ALREADY-ESTABLISHED CONVECTIVE CLUSTERS.

THROUGH LATE AFTERNOON...UPSCALE GROWTH -- WITH NWD DEVELOPMENT --
OF THE AFOREMENTIONED CONVECTION IS EXPECTED...GIVEN CONTINUED
DESTABILIZATION OF RELATIVELY MOIST INFLOW. RESULTANT ACTIVITY
SHOULD SPREAD EWD THROUGH THE EVENING...WITH ISOLATED INSTANCES OF
MARGINALLY SVR HAIL/WIND POSSIBLE. HOWEVER...THE OVERALL LIMITED
DEGREE OF BUOYANCY...AND WEAK LOW-LEVEL FLOW...SUGGEST THAT ANY SUCH
POTENTIAL WILL BE LIMITED. HOWEVER...CONVECTIVE TRENDS WILL CONTINUE
TO BE MONITORED.

..COHEN/HART.. 04/19/2016

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

ATTN...WFO...FWD...OUN...SJT...LUB...

LAT...LON   33490115 34430023 35119889 35279770 35069720 34439728
            33449854 32990036 33490115

Mesoscale Discussions in Texas, 2016Mesoscale Discussions in Oklahoma, 2016Every mesoscale discussion in 2016

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.