Area Forecast Discussion
Issued by NWS Hastings, NE
FXUS63 KGID 231755
Area Forecast Discussion
National Weather Service Hastings NE
1255 PM CDT THU JUN 23 2016
.SHORT TERM...(Today and tonight)
Issued at 438 AM CDT Thu Jun 23 2016
Aloft: Subtropical high pres was parked over the Srn 1/3 of the
CONUS with the main belt of Westerlies over the Nrn 1/3. A low
amplitude ridge extended from WY/MT N into Canada. A closed low
was just off the Pac NW. This low has been dropping SSE and will
move onshore into WA/OR tonight. This will force some modest
amplification as wavelengths shorten. The ridge will move over the
Nrn Plains tonight.
Surface: The weak cool front that moved thru yesterday morning
was over Srn KS into the OK/TX panhandles. Canadian high pres has
dropped into the Dakotas. This high will drift SE into the upr
Midwest. Meanwhile...this front will remain quasi-stationary
along the KS/OK border most of today...but begin lifting back N
across KS as a warm front tonight. This as lee cyclogenesis occurs
tonight over MT. The front should still be just S of the fcst
area by dawn Fri.
Today: Overall should average p/cloudy due to cloud debris from
yesterdays tstms upstream over CO. One small cluster of tstms has
cont`d thru the night over SW KS. High-res models with explicit
convection apparently are keying on outflow and the remnant
convectively-generated vort max associated with this cluster to
initiate other storms as early as midday over S-cntrl KS. There is
a slight chance the Nrn fringe of this activity could brush parts
of Rooks/Osborne/Mitchell counties...but it`s doubtful. Most of
the tstm activity will remain over Srn KS...close to the front and
Tonight: More storms will fire W and S of the fcst area late this
afternoon and eve...and that will send more cloud debris into the
fcst area. So expect p-m/cloudy. Can`t rule out a little tstm
activity...mainly over S-cntrl KS.
The low-lvl moisture plume associated with the front will
gradually begin to advect NW back into the fcst area this
afternoon and tonight...with WAA intensifying as a 30 kt low-lvl
jet develops. Increasing 850 mb dwpts may still not be enough as
fcst soundings show substantial CIN will remain. But if saturation
occurs around 700 mb after 3 AM tonight...that could result in a
few elevated tstms with 1000 J/kg of CAPE available.
Deep layer shear (1-6 km) will be weak (around 20 kts) this
afternoon and weaken further to 10-15 kts tonight. That will
result in very slow storm movement and poor storm organization and
life times...limiting the svr threat.
Given this environment...we`ll run with hail up to the size of
nickels and gusts up to 50 mph associated with any tstms that
develop over N-cntrl KS late this afternoon/eve. Elsewhere...no
strong or svr tstms expected.
Fcst confidence: average thru tonight. Believe we are probably
too high with the probability of precip (PoP) thru tonight...
especially over S-cntrl Neb. This is the main weakness in this
fcst. The 00Z EC ensemble probabilities for at least .10" QPF in
24 hrs are greatest along and S of I-70. 03Z SREF probs have the
.LONG TERM...(Friday through Wednesday)
Issued at 407 AM CDT Thu Jun 23 2016
There could be some leftover convection on Friday morning from a
nocturnal MCS as some models continue to indicate this. Although
we will be mostly in the warm sector as a warm front will have
returned and probably moved east of most of the CWA, we could re-
fire along the boundary, especially east/northeast by Friday
By Saturday, there is good agreement that a trough with a closed
low will travel from the northern Rocky Mountains into the
northern plains near the Canadian border. This will drag a cold
front into the CWA by Saturday afternoon/evening and with decent
bulk shear by late June standards, could give us a shot at some
severe weather, and an enhanced shot at some rain.
This front may hit a snag and could hang out just south/southeast
of the CWA for a few days and may actually move back north a bit,
and give us more chances of rain, which we definitely need. Also,
we will be within northwest flow with several probable
perturbations and jet streak induced rain chances to give us a
shot at rain for most of the extended forecast.
Temperatures will continue to be generally above normal until
early next week, but not as much above normal as temperatures have
recently been, with highs generally in the 80s/90s, and possibly
cooling off to near or slightly below normal in the lower/mid 80s
for Tuesday through Thursday, with an especially good shot of rain
coming Tuesday night as the nearly stationary boundary will be
nearby, along with a nearby upper level jet streak and developing
.AVIATION...(For the 18Z KGRI/KEAR TAFS through 18Z Friday afternoon)
Issued at 1255 PM CDT Thu Jun 23 2016
Confidence is fairly high in VFR visibility/ceiling through the
period, with the main question mark being whether thunderstorm
activity might become an issue mainly during the latter half.
A few models are hinting at the possibility of a lower-end VFR
ceiling this evening or even a brief MVFR ceiling toward Friday
morning, but will officially stick with VFR for now.
Confidence is rather high in dry/storm-free conditions through the
first half of the period, but at least some hit-and-miss/isolated
activity is probably not out of the question during the latter
half. However, confidence in any such activity directly affecting
the terminals simply remains too low to even justify a "vicinity"
mention at this time.
Surface winds will gradually veer from generally easterly this
afternoon to more southeasterly as the period goes on. Sustained
speeds the vast majority of the time should average under 12kt,
except for slightly higher speeds by late Friday morning/early