Severe Storm Outlook Narrative (AC)
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075
ACUS11 KWNS 202047
SWOMCD
SPC MCD 202046
TXZ000-NMZ000-202315-

Mesoscale Discussion 0279
NWS Storm Prediction Center Norman OK
0346 PM CDT Fri Apr 20 2018

Areas affected...Eastern New Mexico...West Texas

Concerning...Severe potential...Watch unlikely

Valid 202046Z - 202315Z

Probability of Watch Issuance...20 percent

SUMMARY...A threat for large hail and wind damage may develop across
parts of eastern New Mexico and west Texas late this afternoon into
early evening. The threat is expected to remain isolated and weather
watch issuance appears unlikely at this time.

DISCUSSION...The latest surface analysis shows a 1002 mb low eastern
New Mexico with a dryline extending southward from the low into far
west Texas. Surface dewpoints to the east of the dryline range from
near 40 F at Clovis, NM to near 50 F at Midland, TX. In response to
surface heating, a narrow corridor of instability is analyzed by the
RAP from far west Texas extending northward into eastern New Mexico.
Visible satellite imagery shows developing cumulus along the
instability corridor with the most widespread cumulus located from
near Roswell, NM northward to near Tucumcari, NM. A weak capping
inversion is likely present but the cap should diminish over the
next couple of hours as surface heating continues and large-scale
ascent increases ahead of an approaching upper-level system in the
Four Corners region. This should allow for the initiation of
surfaced-based convection in east eastern New Mexico late this
afternoon.

The HRRR solution seems reasonable which develops a line of
thunderstorms oriented from north to south across far eastern New
Mexico and moves this line eastward into west Texas by early
evening. Regional WSR-88D VWPs and objective analysis show strong
deep-layer shear in place with 0-6 km shear estimated near 60 kt.
This combined with steep mid-level lapse rates on forecast soundings
may support strong updrafts capable of producing isolated large
hail. A wind damage threat will also be possible. Instability should
remain relatively weak and any severe threat should remain isolated.

..Broyles/Hart.. 04/20/2018

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LUB...AMA...MAF...ABQ...

LAT...LON   33500236 34410243 34880269 35020325 34950402 34720436
            34070435 32830409 31750382 31240362 30960337 30930271
            31440243 33500236




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