Scientific Forecaster Discussion

Return to Local Conditions & Forecast
Area forecast discussion 
National Weather Service Omaha/valley NE
1126 PM CDT Thursday Apr 24 2014

Short term...(tonight through sunday)
issued at 310 PM CDT Thursday Apr 24 2014

The primary forecast concern is the chance for thunderstorms and possible
severe weather from late Saturday through Sunday.

The 500 mb chart from 12z this morning showed a broad area of height
falls extending from the Dakotas southward into Texas. Strongest
falls were noted in two over North Dakota and another
over the Texas Panhandle. Some precipitation...mainly light...has lingered
over the southeast part of the forecast area today. This should be
out of the area by 6 PM or so and will not include in tonights
forecast. Skies should be clear to partly cloudy overnight with lows
in the upper 30s and lower 40s. Some fog may occur due to wet ground
from recent rain and light winds.

Dry weather is expected Friday with fairly light winds northern
zones and modest winds south. Expect highs from 75 to 80. A low
level jet should develop Friday night...with some increase in
850 mb moisture. Best bet for any storms though appears to be
across eastern Kansas or western Missouri. Decided to keep a
slight chance of thunderstorms near the Kansas and Missouri borders for
Saturday...but it appears that chances are better Saturday night.
Models show 850 mb dewpoints rising to around 10 degrees c or more
by 00z Sunday...with surface based cape values 2000-3000 j/kg
(gfs) or even higher from the NAM (3500 j/kg). Believe the GFS is
handling this better and that the NAM is just too dry with quantitative precipitation forecast
Saturday night. Have probability of precipitation from 30 to 60 percent due to the
unstable airmass...warm front to the south and diffluent flow

Closed low at 500 mb will still be back over The Four Corners region
at 00z Sunday...but should move to near the Colorado/Kansas/Nebraska
border region by 18z Sunday. The severe threat on Sunday seems a bit
higher than Saturday...but timing and details on this are still
to be worked out. Surface based cape values may be a little lower
Sunday but still appear adequate for mini supercells along the low
level convergence zone that will be moving through the area.

Long term...(sunday night through thursday)
issued at 310 PM CDT Thursday Apr 24 2014

It appears that drier air will work in from the southwest by Sunday cut back rain chances for at least the southwest part
of the area. Precipitation may be still ongoing in the northeast half of
the area Sunday evening.

Confidence on the exact details of what will happen next week is
low...but it does look at least somewhat unsettled. Deep moisture
and strong instability will probably be lacking the
severe weather threat does not appear high. The middle level flow
will become more meridional and more blocky. Temperatures...
especially highs...will be below normal to much below normal.
Precipitation chances will be mainly 20 to 50 percent...and hopefully all
of the precipitation will remain in liquid form.


Aviation...(06z tafs for kofk...klnk and koma.)
Issued at 1125 PM CDT Thursday Apr 24 2014

Although patchy fog cannot be ruled out near the MO river early
Friday morning...chances still appeared too low to mention in 06z
tafs and thus VFR conditions are expected at taf sites through
26/06z. Some middle clouds could move across eastern nebr late tonight
into middle Friday morning as a weak low pressure moves into eastern
nebr. The low could also provide a period of gusty SW winds to
koma and klnk by Friday afternoon...but the track of the low will create a
variable and changeable wind forecast for kofk.


Oax watches/warnings/advisories...


Short term...Miller
long term...Miller