Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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218
FXUS63 KOAX 252049
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
349 PM CDT Sun Jun 25 2017

.SHORT TERM...(Tonight through Wednesday)
Issued at 348 PM CDT Sun Jun 25 2017

Several impulses rotating around base of eastern U.S. long wave
trough creating streaks of light precipitation across central
plains this afternoon. So far, precipitation has remained north
and south of forecast area, but current WV loop picking up another
impulse dropping southward from northern plains and associated
weak boundary. CAM and synoptic models all depicting precipitation
development, though are not consistent with timing, location and
coverage. Instability looks weak, so broadbrushed slight to low
chance PoP -SHRA across forecast area overnight. Otherwise,
another cool night, as even though surface flow briefly becomes
southerly, showers and evap cooling will mitigate.

Showers, clouds and low level cool advection will delay return to
seasonal temperatures again on Monday.  Some downslope warming
across western CWA may counter cooling behind front. Lower
temperatures a tad across southeast part of CWA, where I think
showers and clouds will be more persistent. Precipitation moves
east and south of area by evening.

Upper ridging builds over area on Tuesday, and will allow
temperatures to rebound to seasonal values in the low-mid 80s.
Ridging short-lived as Manitoba shortwave flattens mid-level flow
by Tuesday evening. Lee cyclogenesis will ramp up low level flow,
and help to draw moisture back into area. For now, Tuesday looks
dry, but storms developing along frontal boundary in high plains.
Per instability and shear parameters, storms likely will congeal
into MCS that will into area Tuesday night.


.LONG TERM...(Wednesday night through Sunday)
Issued at 348 PM CDT Sun Jun 25 2017

Remnants of MCS will impact area Wednesday. Lingering boundary
across southeast Nebraska and southwest Iowa will set the stage
for additional convective development on Wednesday afternoon.
There looks to be a brief reprieve Wednesday night into Thursday
with narrow band of large scale subsidence in wake of short wave
moving across northern plains. Reprieve is short, as yet a more
potent short-wave drops out of Saskatchewan/Manitoba Thursday
afternoon into Friday. Long wave trough remains quasi-stationary
over central/northern plains through Sunday. Deterministic models
having consensus issues with solution/evolution, with GEFS
depicting quite a bit of spread. As such precipitation timing and
location variable, and for now accepting consensus solution.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1223 PM CDT Sun Jun 25 2017

VFR conditions through the period. Northwest winds at 12 to 18
knots at KOMA will diminish by 21z. Otherwise, there will be 30
percent chance of showers at KOMA/KLNK in the 14-18z period.


&&

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

$$

SHORT TERM...Fortin
LONG TERM...Fortin
AVIATION...DeWald



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