U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 260041 
Storm Prediction Center ac 260040 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0640 PM CST sun Feb 25 2018 

Valid 260100z - 261200z 

..there is a marginal risk of severe thunderstorms along the 
central Gulf Coast... 

Scattered storms will occur through tonight across the central Gulf 
coastal states, and a few may produce locally severe wind gusts or a 
brief/weak tornado. 

..synopsis and discussion... 
As the right entrance region of the large-scale upper jet moves 
across the southeast, winds just off the surface will help increase 
moisture and instability for storms near and north of a stalled 
front, currently located from near Beaumont Texas eastward along the 
central Gulf Coast. The elevated storms are not expected to be 
severe, despite favorable lift and deep layer shear supportive of 
organized batches of storms, as lapse rates aloft do not appear to 
favor hail. However, near and south of the front, sufficient 
low-level turning of the winds with height and a moist air mass may 
allow for a few cells, and or small bows, capable of severe wind or 
a brief/weak tornado. The greatest threat appears to be from south 
central la across far southern MS, al, and the western Florida Panhandle 
tonight. The 00z lch sounding shows ample precipitable water and 
strong flow aloft, and is located near the front. Temperatures are a 
bit warmer farther east, further supporting a potential increase in 
storm intensity later this evening. 

.Jewell.. 02/26/2018 


Mesoscale Discussion

acus11 kwns 250600 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 250600 

Mesoscale discussion 0098 
National Weather Service Storm Prediction Center Norman OK 
1200 am CST sun Feb 25 2018 

Areas affected...Texas coastal plain 

Concerning...severe potential...watch unlikely 

Valid 250600z - 250730z 

Probability of watch issuance...5 percent 

Summary...some thunderstorm activity developing across the region 
could become fairly strong through the 2-4 am CST time frame. 
Overall, though, the severe weather potential seems limited, and a 
watch is not currently anticipated. 

Discussion...scattered thunderstorm development is underway near and 
ahead of the weak surface front advancing into the Texas coastal 
plain. This is being aided by forcing for ascent associated with 
another low-amplitude short wave impulse crossing the lower Rio 
Grande Valley, within the subtropical westerlies. Although 
southerly low-level flow across the region is generally modest, with 
speeds up to 30 kt generally confined to Upper Texas coastal areas, 
deep layer shear is strong. With layers of modestly steep lower/mid 
tropospheric lapse rates contributing to cape up to around 1000 j/kg 
(for moist boundary layer parcels with dew points in the upper 60s 
to near 70), some of these storms could be accompanied by some risk 
for severe hail into the 07-09z time frame. Eventually, upscale 
convective growth is possible along and just ahead of the front. As 
this occurs, the risk for hail probably will decrease, but a few 
locally strong wind gusts may accompany developing outflow. 

.Kerr/grams.. 02/25/2018 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 29389792 29819689 30329548 30699453 30749369 29739370 
29199540 28219685 28179780 29389792