Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 191104
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
604 AM CDT Wed Apr 19 2017

.SHORT TERM...(Today through Friday)
Issued at 359 AM CDT Wed Apr 19 2017

88D mosaic showing elevated convection mainly over the southern CWA
along deep moisture convergence axis extending from s-cntrl Neb into
southern IA. Trends over the last few hours indicate thunderstorm
activity will continue pushing eastward through the CWA during
the early morning hours before exiting the area toward late
morning.

For today...surface low centered over eastern CO will gradually lift
into eastern Neb/western IA later this afternoon allowing stalled
boundary currently extending along Neb/KS border to lift
northward as a warm front into central IA. Meanwhile, trailing
cold cold will be advancing southward through Neb. A moisture rich
environment...PWS 1.75"...will be in place allow for quick
destabilization...MLCAPES 1500-200 J/kg...during peak heating
hours. Storms are progged to fire on edge of CAP late this
afternoon with development expected generally along/south of I-80
on nose of 0-3km lapse rates coincident to axis of strengthening
boundary layer theta-E convergence.

Instability/deep layer shear will favor supercell development over
the southern CWA. Environment will be prime for large hail given
very steep mid-layer lapse rates atop moist boundary layer. In
addition...SRH should be adequate to pop off a few tornadic storms.
However...RAP13 hodographs show a more favorable environment to
produce tornadic storms will be found just east of the CWA/northeast
of the surface low where sfc-6km shear/ML SRH/instability will be
most prevalent. Storm activity should be coming to a close then
toward midnight.

Dry and bit cooler conditions expected heading into this weekend.

.LONG TERM...(Friday night through Tuesday)
Issued at 359 AM CDT Wed Apr 19 2017

GFS/CMC/ECM pcpn chances appear minimal during the extended periods
with better chances mainly north of the CWA with highs generally in
the mid 60s and lows in the mid 40s.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 603 AM CDT Wed Apr 19 2017

A broad swath of low-level moisture flux and warm advection has
resulted in episodic shower and thunderstorm activity early this
morning, a trend which should continue into mid morning. A surface
warm front situated near the NE-KS border as of 11z will develop
north today with MVFR to IFR ceilings affecting the TAF sites to
around midday. By mid afternoon, strong to severe storms are
expected to develop ahead of a surface low and along a cold front,
generally in a corridor from KOMA to LNK. This activity will shift
east of the area by evening with winds veering to northwest with
the passage of the cold front.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&

$$

SHORT TERM...DEE
LONG TERM...DEE
AVIATION...Mead



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