X
Xenesthis
Guest
Chicago, IL...Houston, TX...Columbus, OH...Memphis, TN...New Orleans, LA...
Forecast Discussion
SPC AC 201254
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0754 AM CDT Sat May 20 2017
Valid 201300Z - 211200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MS
RIVER VALLEY TO THE OH VALLEY...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH TX...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM TX TO THE
MIDWEST AND WV/VA/NC...
...SUMMARY...
Strong to severe thunderstorms will be possible ahead of a cold
front from south-central Texas into the lower-to-middle Mississippi
and Ohio Valleys, especially this afternoon and evening. Isolated
damaging wind gusts and hail will be the most common threats.
...Synopsis...
Within a semi-amplified pattern, a closed trough centered over the
central High Plains early this morning will continue to shift
northeastward toward the Upper Midwest through tonight. A cold front
will move east-southeastward across the Midwest, lower and middle MS
River Valley, Ark-La-Tex and parts of east/south TX, with much of
today's thunderstorms and severe risk focused ahead of this front.
...Lower/mid Mississippi Valley to Tennessee Valley/Ohio Valley...
An extensive corridor of linearly organized pre-cold frontal
convection extends early this morning from southern IL southwestward
into AR/western TN toward the Ark-La-Tex region and other parts of
east TX. Related convective outflows will continue to focus
additional storm development to the east/southeast of these
early-day storms, with other line/outflow-preceding convection
likely to increase especially this afternoon within a moist and
weakly capped air mass from portions of LA/MS/AL northward into the
OH Valley.
The strongest forcing for ascent/vertical shear related to the
upstream synopsis-described trough will tend to lag the
aforementioned outflow and downstream corridor of peak diurnal
destabilization. Even so, steepening low-level lapse rates and
moderate buoyancy combined with gradually strengthening of
deep-layer southwesterly winds will support relatively
well-organized linear segments capable of mostly wind damage.
Somewhat stronger deep-layer/low-level shear will exist across the
OH River Valley vicinity including IN/western OH, particularly near
a northward-shifting warm front. This may be conducive for a few
supercells ahead of the upstream linear convection/outflows with
somewhat greater possibilities for hail and a tornado or two aside
from what should be a more prevalent damaging wind risk.
Farther west, a few lower-topped thunderstorms may develop near the
east/southeastward-moving front across the middle/upper MS River
vicinity and Ozarks by late afternoon. However, given pre-frontal
trajectories emanating from convectively overturned air, any severe
potential near the front is currently expected to remain limited
later this afternoon into evening.
...South-central Texas...
Scattered strong to severe thunderstorms have been common through
the overnight/early morning hours across parts of the Concho
Valley/Edwards Plateau vicinity in areas along/north of a
southward-sagging cold front. These storms may continue
east-southeastward today, while additional storm development occurs
near the front this afternoon/early evening within a strongly
unstable environment. For additional short-term information, see
Mesoscale Discussion 798. Given ample instability, strong
mid/high-level westerlies atop the frontal zone will support the
possibility of supercells and organized clusters capable of mainly
large hail and severe-caliber wind gusts.
...Parts of VA/NC...
A few strong to severe thunderstorms could develop this afternoon in
vicinity of a backdoor cold front, where a moderately unstable
environment could yield pulse-type thunderstorms capable of locally
damaging winds.
..Guyer/Jewell.. 05/20/2017
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
CURRENT UTC TIME: 1530Z (10:30AM), RELOAD THIS PAGE TO UPDATE THE TIME
Forecast Discussion
SPC AC 201254
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0754 AM CDT Sat May 20 2017
Valid 201300Z - 211200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MS
RIVER VALLEY TO THE OH VALLEY...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH TX...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM TX TO THE
MIDWEST AND WV/VA/NC...
...SUMMARY...
Strong to severe thunderstorms will be possible ahead of a cold
front from south-central Texas into the lower-to-middle Mississippi
and Ohio Valleys, especially this afternoon and evening. Isolated
damaging wind gusts and hail will be the most common threats.
...Synopsis...
Within a semi-amplified pattern, a closed trough centered over the
central High Plains early this morning will continue to shift
northeastward toward the Upper Midwest through tonight. A cold front
will move east-southeastward across the Midwest, lower and middle MS
River Valley, Ark-La-Tex and parts of east/south TX, with much of
today's thunderstorms and severe risk focused ahead of this front.
...Lower/mid Mississippi Valley to Tennessee Valley/Ohio Valley...
An extensive corridor of linearly organized pre-cold frontal
convection extends early this morning from southern IL southwestward
into AR/western TN toward the Ark-La-Tex region and other parts of
east TX. Related convective outflows will continue to focus
additional storm development to the east/southeast of these
early-day storms, with other line/outflow-preceding convection
likely to increase especially this afternoon within a moist and
weakly capped air mass from portions of LA/MS/AL northward into the
OH Valley.
The strongest forcing for ascent/vertical shear related to the
upstream synopsis-described trough will tend to lag the
aforementioned outflow and downstream corridor of peak diurnal
destabilization. Even so, steepening low-level lapse rates and
moderate buoyancy combined with gradually strengthening of
deep-layer southwesterly winds will support relatively
well-organized linear segments capable of mostly wind damage.
Somewhat stronger deep-layer/low-level shear will exist across the
OH River Valley vicinity including IN/western OH, particularly near
a northward-shifting warm front. This may be conducive for a few
supercells ahead of the upstream linear convection/outflows with
somewhat greater possibilities for hail and a tornado or two aside
from what should be a more prevalent damaging wind risk.
Farther west, a few lower-topped thunderstorms may develop near the
east/southeastward-moving front across the middle/upper MS River
vicinity and Ozarks by late afternoon. However, given pre-frontal
trajectories emanating from convectively overturned air, any severe
potential near the front is currently expected to remain limited
later this afternoon into evening.
...South-central Texas...
Scattered strong to severe thunderstorms have been common through
the overnight/early morning hours across parts of the Concho
Valley/Edwards Plateau vicinity in areas along/north of a
southward-sagging cold front. These storms may continue
east-southeastward today, while additional storm development occurs
near the front this afternoon/early evening within a strongly
unstable environment. For additional short-term information, see
Mesoscale Discussion 798. Given ample instability, strong
mid/high-level westerlies atop the frontal zone will support the
possibility of supercells and organized clusters capable of mainly
large hail and severe-caliber wind gusts.
...Parts of VA/NC...
A few strong to severe thunderstorms could develop this afternoon in
vicinity of a backdoor cold front, where a moderately unstable
environment could yield pulse-type thunderstorms capable of locally
damaging winds.
..Guyer/Jewell.. 05/20/2017
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
CURRENT UTC TIME: 1530Z (10:30AM), RELOAD THIS PAGE TO UPDATE THE TIME
