RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sun Apr 21 17:48:02 UTC 2019.
No Mesoscale Discussions are in effect as of Sun Apr 21 17:48:02 UTC 2019.
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1119 AM CDT Sun Apr 21 2019
Valid 211630Z - 221200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE THIS
AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF THE CENTRAL PLAINS...
...SUMMARY...
Marginally severe hail or wind is possible across parts of the
central Plains this afternoon and evening, mainly from northern
Kansas into Nebraska.
...Central Plains late this afternoon into tonight...
A series of low-amplitude midlevel troughs will eject
east-northeastward from NM/CO to the mid MO Valley, downstream from
an amplifying trough over the lower CO Valley. Modest low-level
moisture return is underway from the western Gulf of Mexico to the
southern/central Plains. The moistening will occur beneath a warm
elevated mixed layer, and much of the warm sector will remain capped
through the period. Strong surface heating/deep mixing and
low-level ascent from near a lee cyclone along the CO/KS border
northeastward along a cold front into NE should support thunderstorm
development this afternoon/evening. MLCAPE of 500-1000 J/kg with
steep low-level lapse rates and DCAPE greater than 1000 J/kg will
favor high-based, multicell storm clusters capable of producing
isolated severe outflow winds and marginally severe hail late this
afternoon into early tonight.
..Thompson/Squitieri.. 04/21/2019
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1237 PM CDT Sun Apr 21 2019
Valid 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN HIGH PLAINS LATE MONDAY AFTERNOON INTO MONDAY NIGHT....
...SUMMARY...
Widely scattered severe thunderstorms may produce large hail and
isolated wind damage across parts far east-central New Mexico into
the Texas South Plains and southwestern Oklahoma late Monday
afternoon through the overnight hours.
...Synopsis...
A weak upper ridge over the southern Plains will suppress convection
for much of the day due to a strong cap in the 850-700 mb layer.
Further north, a shortwave trough will migrate eastward across the
Upper Midwest and Great Lakes. A cold front will extend
southwestward from a surface low over western IA into the OK/TX
Panhandle vicinity early Monday. As the low and cold front shift
east, an area of thunderstorms will move across IA into southern WI
and northern IL. This activity is not expected to be severe, but
some small hail and gusty winds are possible.
The northern section of the cold front will advance eastward into
the mid-MS Valley by Tuesday morning while the southern portions of
the front remains more diffuse, extending from east-central NM into
central OK at the end of the period. The slow-moving front will be
a focus for thunderstorm develop across the southern High Plains by
late afternoon into the overnight hours when a western upper trough
ejects eastward across the southwestern deserts toward the southern
Rockies. Falling heights and cooling temps aloft will aid in
maintaining modestly steep lapse rates. Weakening of the capping
inversion is forecast by late afternoon/evening as stronger forcing
for ascent and modest moisture advection ahead of the front become
sufficient for development of a few surface-based storms. Modest
effective bulk shear around 25-30 kt will result in loosely
organized clusters/semi-discrete cells which may tend to become
bowing segments as they interact/organize along the surface front.
Damaging wind gusts and large hail will be the main concern with
storms from eastern NM through the Texas South Plains into southwest
OK.
...MAXIMUM RISK BY HAZARD...
Tornado: 2% - Marginal
Wind: 15% - Slight
Hail: 15% - Slight
..Leitman.. 04/21/2019
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1155 AM CDT Sun Apr 21 2019
Valid 211700Z - 221200Z
...CRITICAL FIRE WEATHER AREA FOR NORTHEAST NEW MEXICO...
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN NEW MEXICO
AND WEST TEXAS...
No changes have been made for this update. Please see the previous
discussion for further details.
..Wendt.. 04/21/2019
.PREV DISCUSSION... /ISSUED 0126 AM CDT Sun Apr 21 2019/
...Synopsis...
An upper-level trough located over the lower Great Basin will slowly
migrate southward throughout the forecast period. Mid-level flow
along the southern periphery of this system will be marginally
enhanced, allowing persistent west-southwesterly winds of 35-45 kt
to overspread much of the Southwest into the southern High Plains.
At the surface, lee cyclogenesis will occur along the central High
Plains, with an area of low pressure developing in western Kansas by
mid-day and strengthening throughout the afternoon. A dryline will
extend south of the low and propagate eastward throughout the
afternoon.
...Southwest into the southern High Plains...
Elevated to critical fire-weather conditions will develop west of
the dryline across portions West Texas, southern and northeastern
New Mexico and far southeastern Arizona. During the afternoon,
sustained winds of 15-25 mph will develop, gusting to 35 mph, while
RH values fall into the teens and single digits over a widespread
area. A minor expansion was made to the elevated area across
portions of the Texas Panhandle to account for a more eastward
progression of the dryline than indicated previously in the
guidance. Elsewhere, the elevated and critical areas have been
maintained and confined based on limited fuel receptiveness and
availability.
...Please see www.spc.noaa.gov/fire for graphic product...
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