Area Forecast Discussion
Issued by NWS Hastings, NE

Home | Current Version | Previous Version | Text Only | 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 44 45 46

FXUS63 KGID 280548

Area Forecast Discussion
National Weather Service Hastings NE
1248 AM CDT TUE JUN 28 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 329 PM CDT Mon Jun 27 2016

Another day, another chance of thunderstorms across the region. Up
to this point, outside of some isolated stuff, it`s been a
pretty quiet day across the CWA. More activity to our east and
west. Not a lot of change aloft, upper air and satellite data
continue to show zonal/low amplitude northwesterly flow in place,
sitting between broad ridging over the Rockies and a trough
swinging through the Great Lakes region. Though subtle, satellite
showing a shortwave disturbance embedded in the main flow moving
through eastern WY. At the surface, obs showing a couple of
boundaries affecting the CWA. One draped just south of the NE/KS
state line, the other located closer to I-80. In between the 2 is
more northeasterly (at times gusty) winds and dewpoints in the
lower/mid 60s. On the other side, more easterly/lighter winds and
dewpoints mainly in the 50s. SPC meso page showing gradually
eroding capping over the area, with a better instability axis
located over the High Plains and closer to the MO River. Through
the rest of this afternoon, while the better forcing is still off
to the west, thunderstorm chances remain in place across the CWA.

Expecting activity over the High Plains to continue to expand in
coverage through the rest of the day as that disturbance continues
to push east, with the main concern being with its evolution
through the overnight hours. Recent models runs showing a
general southeastward movement to the activity through tonight
along the better convergence of the increasing (20-30kt) LLJ,
though also show the main instability axis (while waning with
time) remaining over the High Plains. Can`t completely rule out
thunderstorm chances at any particular part of the CWA, but the
best chances look to continue to be over west-southwesterly half.
Depends on the model, some are more aggressive with the areal
coverage than others. Instability/shear parameters keeps the
concern for strong/severe thunderstorms remains in place overnight
in place, will keep mention going in HWO.

Looking at tomorrow, have some slight chance pops continuing into
the morning hours, but for the remainder of the day, confidence is
on the lower side. Inherited a dry forecast for the afternoon
hours, some keep scattered activity around all day, others show
activity off to the west of the CWA. Decided to keep that dry
mention going. At the surface, winds across the area look to once
again be east/southeasterly (10-15 MPH), as high pressure builds
into the upper midwest and low pressure remains over the Rockies.
Didn`t make any significant changes to forecast highs, which are
in the mid 80s for most locations.

.LONG TERM...(Tuesday night through Monday)
Issued at 329 PM CDT Mon Jun 27 2016

Similar to today, thunderstorms are expected to develop during the
afternoon hours on Tuesday over the High Plains, as yet another
shortwave disturbance is riding around the edge of the ridge. The
better chances for us remain in the Tuesday evening/overnight
hours. Some models continue to show things being a bit different
than today, with a northward shift to the activity, starting out
more over SD/NE vs NE/CO/KS (like today). Already had likely PoPs
going in the forecast over portions of the CWA and felt those
handled things well for now, though did adjust the area of those
higher PoPs a bit. Models showing a stronger LLJ developing
(compared to tonight), with better placement of instability over
the area, and sufficient deeper layer shear is expected to be in
place to keep the threat for severe weather going. As we get into
Wednesday, confidence in just how much lingering activity is still
around through the morning hours is low, but the best chances
would be across the southern third or so of the CWA. Have a
noticeable drop in PoPs for the afternoon hours, though some
models suggest there won`t be much around post 12Z.

Not going to go into a lot of details regarding the forecast for
Wednesday night through Monday, could basically copy/paste the
general story in from the past few days. Upper level flow remains
progressive, northwesterly to more zonal at times, embedded
shortwave disturbances periodically affecting the area. Do have
PoPs in every period of this time frame, because it`s difficult at
this point to have much confidence in removing PoPs due to
timing/location differences, not because we`re expecting a multi-
day rainout. Too early to pin down severe potential, but it will
be a concern.

As far as temperatures go, forecast calls for near-normal to
perhaps slightly below normal highs through this time frame.
Generally mid 80s for highs through Thursday, perhaps a bump up
into the upper 80s for Monday. Forecast lows remain in the 60s.


.AVIATION...(For the 06Z KGRI/KEAR TAFS through 06Z Tuesday night)
Issued at 1248 AM CDT Tue Jun 28 2016

General overview:
While confidence is relatively high that VFR ceiling/visibility
will prevail through the period (although could foresee a low-end
VFR ceiling for a time), confidence in the timing/likelihood of
potential thunderstorm activity is solidly below average.

Right off the bat this morning, a small area of thunderstorms is
ongoing roughly 30 miles south/southeast of the terminals, but at
least in the next few hours, this is not expected to be a factor.
IF (a "big if") storms were to affect KGRI/KEAR during the
period, this would in theory be most favored during the 12z-18z
time frame. However, confidence is still too low at this time to
even introduce a generic "vicinity" (VCTS) mention. Obviously
amendments will be made as necessary.

Surface wind:
Not accounting for any possible thunderstorm outflow effects,
sustained speeds should average under 12kt for most of, if not the
entire period, with direction generally transitioning from
northeast early this morning, to southeast through much of the


.GID Watches/Warnings/Advisories...


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