U.S. Severe Weather Forecast (Convective Outlook)

Day Three

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Storm Prediction Center ac 191929 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0229 PM CDT Tue Mar 19 2019 

Valid 192000z - 201200z 

..no severe thunderstorm areas forecast... 

severe thunderstorms are not expected through early Wednesday. 

..20z update... 

The ongoing forecast is on track and changes are not needed. See the 
previous discussion below for more details. 

.Leitman.. 03/19/2019 

Previous discussion... /issued 1129 am CDT Tue Mar 19 2019/ 

..Florida Keys vicinity... 
A few thunderstorms will be possible across The Straits of Florida 
through the afternoon. 

..southern rockies... 
A shortwave trough over the Black Hills will move south into Kansas 
through 12z Wednesday. Scant boundary-layer moisture amid steep 
low/mid-level lapse rates in conjunction with Post-frontal upslope 
flow along the adjacent High Plains may aid in isolated thunder 
occurrence during the late afternoon to early evening. 

A shortwave trough will approach the California coast through early 
Wednesday. The onset of mid-level height falls should overspread the 
Central Valley and western Sierra Nevada this evening where limited 
buoyancy might support a few thunderstorms. Otherwise, very isolated 
thunder may accompany the trough as mid-level lapse rates steepen 
near the central/southern coast in the early morning. 

..eastern Kansas/western Missouri... 
A thunderstorm or two cannot be ruled out across the region this 
afternoon near an advancing surface low and front, although 
worst-case thermodynamic profiles will likely remain only marginally 
conducive for lightning generation. Thus, a very low 
coverage/probability (10 percent or less) of thunderstorms is 
currently perceived. 


Mesoscale Discussion

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sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 152340 

Mesoscale discussion 0222 
National Weather Service Storm Prediction Center Norman OK 
0640 PM CDT Fri Mar 15 2019 

Areas affected...parts of central Maryland....southeastern 
Pennsylvania...northern New Jersey...southeastern New York 

Concerning...severe potential...watch unlikely 

Valid 152340z - 160145z 

Probability of watch issuance...5 percent 

Summary...a narrow line of storms may be accompanied by some risk 
for potentially damaging wind gusts through about 8-9 PM EDT across 
the northern mid Atlantic coast region, mainly west and northwest of 
the greater Philadelphia and New York City metropolitan areas. 

Discussion...an evolving narrow line of generally low-topped 
thunderstorm activity appears to have formed within Lee surface 
troughing, in response to an area of enhanced mid/upper forcing for 
ascent and and lower/mid tropospheric cooling spreading to the east 
of the Allegheny Mountains. The latest rapid refresh suggests that 
a secondary surface low may be in the process of forming across the 
northern mid Atlantic coast region into southern New England by this 

Peak boundary layer cape appears limited to around 500 j/kg or so, 
and should begin waning with the onset of radiational surface 
cooling during the next couple of hours. So current vigorous 
convective intensities are not anticipated to be particularly 
long-lived. However, strongly sheared, 40-50 kt mean southwesterly 
flow in the convective layer could still support some increase in 
potential for damaging convective gusts through 00-01z, before 
storms begin to weaken. 

.Kerr/Hart.. 03/15/2019 

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


Latitude...Lon 40457579 41477391 41337356 40917368 40207481 39467617 
39347667 39497699 39707688 40457579