Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1223 AM CDT Tue Mar 12 2019 Valid 121200Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN HIGH PLAINS... ...SUMMARY...
Severe thunderstorms with wind damage, a few tornadoes and isolated large hail are expected to develop across parts of the southern High Plains this afternoon and evening. The wind-damage threat may affect areas as far east as central Texas after midnight. ...Eastern New Mexico/West and Central Texas...
An upper-level low will move across the southwestern U.S. today as south-southwesterly mid-level flow remains in place across the southern High Plains. At the surface, a Pacific cold front will move across the upper Rio Grande Valley as a powerful low pressure system gathers strength across eastern Colorado. A corridor of maximized low-level moisture is forecast to take shape across far West Texas extending northward into southeast New Mexico, where a pocket of moderate instability appears likely to develop by afternoon.
Convection will first initiate in central New Mexico this afternoon as large-scale ascent associated with the upper-level low spreads eastward. As low-level convergence becomes enhanced along and ahead of the front, surface-based thunderstorms are forecast to initiate across southeastern New Mexico. These storms will move eastward and likely congeal into a squall line by early evening. A linear MCS is forecast to move eastward across west Texas during the evening. RAP forecast soundings along the instability axis near Midland this evening show MLCAPE near 2000 J/kg, veering wind profiles with height, strong deep-layer shear and steep mid-level lapse rates.
This environment should be favorable for supercells. A few tornadoes, wind damage and isolated large hail will be possible with supercells from southeast New Mexico into far West Texas late this afternoon.
This potential should shift eastward into West Texas by early evening as storms congeal into a squall line. A tornado threat will continue with the squall line with embedded rotating cells and bow echoes. However, the greatest threat is forecast to be with damaging wind gusts along the leading edge of the line. A 30 percent wind-damage probability has been introduced across southeast New Mexico and West Texas along the expected track of the squall line. The squall-line and wind-damage threat should continue eastward into west-central Texas during the mid to late evening, gradually diminishing during the overnight period. ..Broyles/Dean.. 03/12/2019 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
Tuesday, March 12th, 2019 3:06 AM MDT.
Area Forecast Discussion National Weather Service Albuquerque NM 306 AM MDT Tue Mar 12 2019 .SYNOPSIS... A very active weather pattern will unfold over the next several days as a potentially historic storm takes shape over New Mexico today through Wednesday. Rain and thunderstorms will expand in coverage today over the entire area. A few storms over eastern New Mexico may become severe today and tonight with large hail, damaging winds, frequent lightning, minor flooding, and even a couple tornados. Meanwhile, colder air will move into western New Mexico this evening and transition rain over to snow into the lower elevations. Heavy snow is expected after midnight over much of northern and western New Mexico, especially west facing slopes. Snow will likely continue into Wednesday while winds begin to rip across the state. Widespread strong to potentially damaging winds are possible from the Rio Grande Valley eastward through the eastern plains Wednesday afternoon. Temperatures will be much colder through Thursday with additional snowfall possible over the Sangre de Cristo Mountains. && .DISCUSSION... A highly complex weather scenario is evolving over the area as a potentially historic late winter storm system intensifies across NM through Wednesday. The most challenging aspect is the timing and placement of rain to snow over northern and western NM tonight and Wednesday as cold air moves into the area on potentially widespread damaging winds. The storm system will undergo bombogenesis as it shifts east onto the high plains Wednesday. The H5 low center will deepen to near 528dm while the associated surface low deepens to near 971mb. But first, deep layer southerly flow ahead of the system will advect record moisture into NM today with abundant instability leading to widespread showers and thunderstorms. Several storms are likely to become severe over the east central and southeast plains today with large hail, damaging wind, frequent lightning, minor flooding, and even a couple tornados possible. SPC has elevated the severe risk to "Enhanced" for parts of southeastern NM. Once the severe aspect of this storm shifts east, the focus will be winter weather and high winds over a large part of the state late tonight into Wednesday. High snow levels today will lower quickly tonight as the core of the deepening upper low crosses the area and moist, unstable upslope flow begins over the northern and western high terrain. Guidance has been very consistent with a secondary piece of energy shearing into the back side of the departing low Wednesday and Wednesday night. The combination of strong winds, colder temperatures, snow, and blowing snow will make for nasty winter weather conditions, therefore a winter storm warning has been expanded over a good chunk of northern NM and the Southwest Mts. 700mb winds on the back side of the upper low are near 75 kt over eastern NM with a very intense surface pressure gradient. MOS wind output is higher than several forecasters in the office have ever seen which elevates the seriousness of a potentially widespread damaging wind event Wednesday afternoon and evening. High wind watches will remain intact for now across central and eastern NM however it is very likely that warnings are forthcoming soon. Once the intense low shifts east onto the Great Plains a back door cold front will move southwest into northeastern NM while a broad upper level trough remains in place over northern NM. This set up will allow snow to continue over the Sangres through Thursday. Guyer
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