Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion 
National Weather Service Springfield MO 
707 am CDT Monday may 20 2013 


Short term...(today and tonight) 
issued at 254 am CDT Monday may 20 2013 


On going convection across the region and the potential for 
another round of severe weather this afternoon and into early 
Tuesday morning remained the focus for the forecast. 


Ongoing thunderstorms across the Ozarks this morning will bring 
a period of heavy rainfall to portions of southeastern Kansas and 
the Ozarks as storms develop and move over the same location 
through sunrise. Some lingering showers or convection may remain 
over the area through the morning though some clearing should 
occur late in the morning and into the afternoon. 


The upper low will continue to shift slowly east across the 
northern plains as another jet maximum swings across the southern 
periphery of the again...negatively tilting system. This will 
combine with a slowly veering low level jet to allow for the 
potential for quickly developing thunderstorms to initiate across 
eastern Kansas and eastern Oklahoma. A fairly strong low level jet 
will be developing across southern Oklahoma as the entrance 
region of the upper level jet moves over the Ozarks during the 
afternoon. This will provide ample lift once again for the 
development of severe thunderstorms. The one concern will be the 
dry line. It has currently retreated fairly far west over western 
Oklahoma. Where the storms initially develop...likely as 
supercells once again...will depend on how far east the dry line 
makes it before the deep lift from the jet streak and low level 
jet moves over the region. Storms may develop as far west as 
Wichita to Tulsa to somewhere near the Missouri and Kansas state 
line. This will have enormous consequences in what type of severe 
weather the Ozarks will experience. Some short term Ann local 
models suggest that the storms develop farther west and move 
through the region as a qlcs or squall line with embedded 
mesovortices. It is also possible that a weak to moderate cap 
holds the storm development farther east which would suggest that 
supercells may be the initial Mode. 


Additional concerns for the afternoon and tonight will be the 
numerous outflow boundaries left over from tonight convection. This 
also includes the residual boundary that storms are moving along 
this morning. 


Models continue to indicate that the storms will ultimately begin 
to train across the region. This could be in the form of training 
supercells or heavy rainfall producing storms with embedded severe 
thunderstorms. In either case...the storms will be working with a 
very moist air mass again Monday with precipitable water values in 
the 1.5 to 1.75 inch range. This in conjunction with storms moving 
over the same areas will likely lead to flooding across the 
Ozarks. This looks to remain focused along the Interstate 44 
corridor. 


Despite the type of storms or the Mode in which they move over the 
region...there remains the potential for large hail...damaging 
winds...flooding rains...and tornadoes. 


Long term...(tuesday through sunday) 
issued at 254 am CDT Monday may 20 2013 


For Tuesday...models continue to struggle with the timing of the cold 
frontal passage. The upper level low will remain over the northern 
plains with the potential for severe thunderstorms to develop once 
again during the day. The primary area of concern looks to be 
focused along and south of Interstate 44...but with the differing 
model solutions...the potential for thunderstorms remain across 
the all of the Missouri Ozarks. The main concern with this 
convection would be hail and heavy rainfall leading to additional 
flooding after several days of heavy rains. 


The upper low will finally be on the move to the east on Thursday 
as an upper level ridge shifts over the area for the end of the 
week and into the weekend. Models do continue to indicated several 
short waves moving over the ridge with a limited potential for 
some showers and thunderstorms. 


&& 


Aviation...(for the 12z tafs through 12z Tuesday morning) 
issued at 658 am CDT Monday may 20 2013 


Showers and thunderstorms were impacting portions of the Ozarks 
region this morning however...the storms should remain north of 
area aerodromes into this afternoon. MVFR to VFR ceilings will 
give way to VFR flight conditions by 14-15z and remain VFR into 
later in the afternoon. Thunderstorms are expected to impact the 
regions terminals after 20-12z with the potential fro MVFR to 
periods of IFR flight conditions. Will monitor the latest 
conditions through the afternoon and evening and modify the flight 
forecast as needed with the latest information. Otherwise...expect 
strong to severe thunderstorms to impact the region late this 
afternoon and overnight. 


&& 


Sgf watches/warnings/advisories... 
MO...Flash Flood Watch from this evening through Tuesday morning for 
moz055>058-066>071-077>083-088>098-101>106. 


Flash Flood Watch until 10 am CDT this morning for moz055>058- 
066>070-077>081-088>095-101>103. 


Kansas...Flash Flood Watch from this evening through Tuesday morning for 
ksz073-097-101. 


Flash Flood Watch until 10 am CDT this morning for ksz073-097- 
101. 


&& 


$$ 


Short term...Hatch 
long term...Hatch 
aviation...Hatch