U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 221728 
Storm Prediction Center ac 221727 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1227 PM CDT Mon Apr 22 2019 

Valid 231200z - 241200z 

..there is a slight risk of severe thunderstorms from far southeast 
New Mexico into portions of western...central and North Texas... 

Severe thunderstorms capable of producing isolated large hail and 
wind damage are expected across parts of southeast New Mexico and 
Texas on Tuesday afternoon and evening. Additional strong storms may 
produce isolated gusty winds and small hail from northern Kentucky 
into southwest Pennsylvania Tuesday afternoon and evening. 

..southern High Plains and vicinity... 

A cutoff low centered over northwest Mexico/southern Arizona will 
migrate east/southeast toward the Rio Grande Valley/southern rockies 
by Wednesday morning. A weak surface low/frontal wave will extend 
east/northeast from southeast nm into southern MO during the 
morning, and the front will only slowly sag southward through the 
evening before advancing southward more quickly overnight. Ahead of 
the front, southeasterly low level flow will advect Gulf moisture 
north/northeast across much of Texas into southern OK. Low to mid 60s 
dewpoints beneath 7-8 c/km lapse rates and 40+ kt effective bulk 
shear will support supercells along/ahead of the front. Storms are 
expected to develop during the afternoon and increase in coverage 
during the evening as ascent increases across the Southern Plains. 
Initial storm development is expected near higher terrain of western 
Texas and southeast nm. Isolated convection will likely be ongoing on 
the cool side of the front across the Texas South Plains/Panhandle into 
western OK at the beginning of the period. As the cold front becomes 
reinforced by this activity and the warm sector destabilizes during 
the afternoon, additional storms are expected to develop across the 
Permian Basin northeastward into North Texas. This convection may 
remain discrete initially but should transition into bowing line 
segments during the evening. As the cold front surges southward 
during the nighttime hours, convection may become undercut and 
severe threat should diminish after 06z. Any cells that remain 
discrete Tuesday afternoon/evening will pose a threat for large hail 
and damaging winds. As convection takes on more linear modes, the 
hail threat should diminish. 

..northern Kentucky into southwest PA... 

A northern stream shortwave trough will move across the Great Lakes 
and toward the mid-Atlantic and southern Ontario/Quebec on Tuesday. 
This will bring a band of enhanced mid-to-upper level flow across 
portions of the mid/upper Ohio Valley vicinity. Modest low level 
moisture (mid/upper 50s f dewpoints) beneath 6.5-7.5 c/km midlevel 
lapse rates will be adequate for weak destabilization (500-1000 j/kg 
mlcape) by afternoon ahead of an eastward progressing cold front. A 
few strong storms will be possible along the front and a few 
strong/locally damaging wind gusts and small hail could accompany 
these stronger cells into early evening. 

..maximum risk by hazard... 
Tornado: 5% - slight 
wind: 15% - slight 
hail: 15% - slight 

.Leitman.. 04/22/2019