Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

FXUS63 KOAX 271840

Area Forecast Discussion
National Weather Service Omaha/Valley NE
140 PM CDT FRI MAY 27 2016

Issued at 117 PM CDT Fri May 27 2016

With variable clouds and spotty showers and thunderstorms
today...temperatures are warming through the 60s into the 70s. The
forecast soundings show the atmosphere is uncapped...thus with
heating and increased lift as the h5 trough migrates into the
Plains...will see shower and thunderstorm coverage increase. The
theta-e axis is focused over south central Nebraska...and there
has been some clearing and heating over southeast Nebraska.
Instability is best over Kansas. There is the hint of a 35kt 0-3km
bulk max this afternoon near the kansas border and with the
heating and better moisture returning there...storms that develop
in this region may be strong to severe.


.SHORT TERM...(today through Sunday)
Issued at 350 AM CDT Fri May 27 2016

Will go ahead and cancel the flash flood watch that was scheduled to
expire at 12z. Some streams in southeast Nebraska and southwest Iowa
have seen flooding...but it does not appear that widespread high
rainfall amounts will occur this morning. The main forecast
concerns will be in regards to thunderstorm chances...potential
severe storms and rain amounts through Saturday.

Large scale pattern features a mid tropospheric trough from Manitoba
down into the four corners region. Water vapor imagery early this
morning showed one closed low over eastern Colorado and another in
northern North Dakota. Highest precipitable water values and 850 mb
dewpoints (10-17 degrees C) were down across Kansas and Missouri.
Surface analysis was fairly complex due to outflow from numerous
thunderstorm complexes earlier in the night...but primary low was
over northwest Oklahoma. A weak front seemed to extend from another
low in northern South Dakota to western Kansas and then down to the
low in Oklahoma. Dewpoints in our area were in the mid 50s to lower
60s. Storm chances will linger into Saturday evening...then we may
get a dry period from later Saturday night into Sunday morning.
Timing of this will be tied to the progression of the Colorado
closed low lifting up toward Minnesota by midnight Saturday night.
By that time...a shortwave trough will be over southern California
with a stronger trough moving toward the Pacific Northwest.

Today...overall coverage of showers and storms should be fairly
low with main complex near the Kansas/Missouri border as of
0835z. Some recent runs of the high resolution convection allowing
models...including the experimental HRRR...develop storms again by
late this afternoon over southeast Nebraska and southwest Iowa. If
confidence of that happening...with heavy rain....increases then
we may need a new flash flood watch for that area. Day 1 SPC
outlook seems fine with better parameters for organized severe
storms mostly to our southwest.

.LONG TERM...(Sunday night through Thursday)
Issued at 350 AM CDT Fri May 27 2016

Pattern then turns active again early next week as 500 mb trough
moves toward our area. The GFS and ECMWF are in fair agreement...
showing a closed low forming in the northern plains. But the ECMWF
is more progressive...and prefer a solution closer to a blend. At
least for now it seems that rain chances will be lower in the
later part of the week.


.AVIATION...(18Z TAFS for KOMA...KLNK...KOFK through 18Z Saturday)
Issued at 117 PM CDT Fri May 27 2016

variable vfr/mvfr cigs for this afternoon and tonight with some
spotty showers and thunderstorms. Showers and thunderstorms should
increase in coverage late this afternoon and this evening with
increasing lift and heating. Did include a tempo mention in the
forecast at koma and klnk as a first guess and a prob30 at kofk.
As the h5 low migrates eastward. Shower and thunderstorm chances
will continue into Saturday.


.OAX Watches/Warnings/Advisories...


LONG TERM...Miller
AVIATION...Zapotocny is the U.S. government's official web portal to all federal, state and local government web resources and services.