Mar 21, 2019 0600 UTC Day 1 Convective Outlook
Updated: Thu Mar 21 05:56:40 UTC 2019 (20190321 1200Z Day 1 shapefile | 20190321 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20190321 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 18,322 1,020,909 Albuquerque, NM...Rio Rancho, NM...Farmington, NM...South Valley, NM...Los Lunas, NM...
Probabilistic Tornado Graphic
20190321 1200 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20190321 1200 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 13,751 934,855 Albuquerque, NM...Rio Rancho, NM...Farmington, NM...South Valley, NM...Los Lunas, NM...
Probabilistic Large Hail Graphic
20190321 1200 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 18,254 1,022,016 Albuquerque, NM...Rio Rancho, NM...Farmington, NM...South Valley, NM...Los Lunas, NM...
   SPC AC 210556

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1256 AM CDT Thu Mar 21 2019

   Valid 211200Z - 221200Z


   Isolated, marginally severe thunderstorms are possible over parts of
   northwestern to central New Mexico and extreme southwestern Colorado
   this afternoon.

   A high-amplitude upper-air pattern will prevail through this period,
   with a synoptic ridge moving slowly eastward from the Rockies across
   the Great Plains.  To its east, a strong shortwave trough now over
   Lake Michigan and IL will dig southeastward and strengthen, forming
   a closed 500-mb cyclone over WV and VA by 00Z.  This cyclone will
   phase somewhat with a weakening perturbation now located over the
   Mid-South region, before pivoting offshore and devolving to an
   open-wave trough late in the period.  West of the synoptic ridge, a
   negatively tilted synoptic-scale trough is apparent in moisture-
   channel imagery, from a position offshore of northern CA
   southeastward across much of CA to the northern Baja/northwestern
   Sonora region.  A closed cyclone should evolve in this trough during
   the day, over the Sierra Nevada and western Great Basin, with the
   associated 500-mb low located over southeastern NV by 00Z.  By
   22/12Z, the low should pivot across UT, while a basal shortwave
   trough crosses AZ.  Minor shortwaves will precede this feature,
   within the broad area of height falls impinging on the southern

   At the surface, a low south of ILM is expected to reach northeastern
   NC by the start of the period, then deepen and move across the
   Mid-Atlantic to southern New England by 22/12Z.  Associated
   deep-layer lift, with the approach of the eastern shortwave troughs,
   will contribute to thunder potential the first 2-3 hours of the
   period over eastern NC.  A low-level Pacific front -- initially over
   parts of AZ and Baja -- will move slowly to western NM by 00Z, then
   slowly cross northern/central NM overnight.

   ...NM, extreme southwestern CO...
   Isolated to scattered thunderstorms are expected to develop this
   afternoon in a corridor  from just east of the Four Corners across
   northwestern to central NM.  For a period of roughly 3-4 hours
   during mid/late afternoon, isolated large hail and severe gusts may

   Shots of large-scale DCVA/lift, related to shortwaves pivoting
   around the rim of the mid/upper cyclone, will move over the
   low-level frontal zone and across a narrow warm sector over the
   outlook area this afternoon.  In that sector, low-level theta-e
   advection and diabatic surface heating, beneath a regime of midlevel
   cooling, height falls and difluent cyclonic flow aloft, will
   contribute to an increasingly favorable thermodynamic environment
   for thunderstorms.  Surface dew points should increase through the
   30s and perhaps into the low 40s F, enabling MLCAPE 400-800 J/kg. 
   The buoyancy will develop atop well-mixed subcloud layers supporting
   strong/locally severe gusts, as well as maintenance of hail to the
   surface of the high desert and mountains in the outlook area. 
   Forecast soundings suggest effective-shear magnitudes 45-50 kt are
   possible, supporting at least transient supercell potential as well
   as organized multicell bands and clusters.

   Into south-central/southeastern NM and far west TX, potential
   becomes more isolated and uncertain, given the presence of weaker
   levels of deep-layer forcing, deep shear and low-level convergence. 
   Strong thunderstorms may develop over higher terrain of northern
   Chihuahua and far west TX after 00Z.  This activity would cross over
   a stabilizing boundary layer across far west TX, but also, a zone of
   elevated buoyancy and low-level moisture favorable for convection
   through this evening.  At this time the severe potential appears too
   conditional and low-end to place the already marginal outlook area
   farther southeastward.

   ..Edwards/Gleason.. 03/21/2019