Area Forecast Discussion
Issued by NWS Dodge City, KS

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FXUS63 KDDC 091659

1159 AM CDT Wed Jul 9 2014

...Updated Synopsis and Aviation sections...


On the synoptic scale this morning, mean ridging in the upper
troposphere was found across the western CONUS with mean troughing
across eastern North America. Across the central and northern Great
Plains, northwest flow was occurring in the mid/upper troposphere,
averaging 25 to 40 knots at 500mb from Kansas to North Dakota. Water
vapor loop showed the northwest flow was somewhat perturbed with a
shortwave disturbance moving southeast across the Dakotas. A smaller
scale feature could also be identified across central/eastern
Wyoming. There was an enhancement in mid level cloud and
thunderstorm activity ahead of these features across the southern
Nebraska Panhandle into the Sandhills of Nebraska late this morning.
At the surface, broad southerly flow was found from the western
Texas panhandle through far western Kansas and eastern Colorado to
western Nebraska. Surface lee troughing was weak across eastern
Colorado into southeastern Wyoming.


.SHORT TERM...(Today and tonight)

Well, this morning will start out with a few non-severe storms
moving up from Oklahoma, along and near a boundary layer axis
getting pushed north by a low level jet.  Both the NAM and ECMWF
models were showing a 25 to 35 knot 850mb jet from 12z-18z this
morning.  The existing 20 to 30 percent PoPs across out southeast
half seems appropriate, as the current activity in Oklahoma is
scattered at most.  Then this afternoon, the real show should start,
as a warm front advances east-northeast from New Mexico, and a upper
wave brings some cool air aloft over western Kansas.  The NAM model
is a bit more unstable than the ECMWF or GFS models, showing MuCape
values in the 1800-2200 J/kg by 00z across our northeastern half,
where as, at the same time the ECMWF model is showing 1200-1600
J/kg.  The respective Bulk Shear values were 22-25Kts for the NAM
and 20-23kts for the ECMWF model.  Thus, I have to agree with the
SPC Day 1 outlook for slight chances for severe storms across most
our our area.  Will add possible severe wording to the zones late
this afternoon and evening, and possibly as late as midnight.  My
first guess will be up to golf ball size hail and wind gusts to 70
mph, which will be reflected in the HWO.  I did not change the
forecast Highs today, figuring varying clouds conditions and with a
warm front advancing through, highs will end up with mid 90s
southwest to upper 80s northeast, near the Hays area.

Tonight will see that upper level trough migrating east, and the
precipitation will slowly end in the west.  The eastern zones will be
the last to have the thunderstorms clear to the east, probably just
after sunrise Thursday.  Minimum temperatures should fall into the
mid 60s to near 70 degree range.  Winds will start out south at 12
to 16 mph, but settle to around 9 to 11 knots toward Thursday

On Thursday, there may be a few storms in our eastern zones early,
but most of the day Thursday will be precipitation-free.  A long
southerly fetch of winds in the 15 to 20 mph range will bump up
maximum temperatures Thursday into the middle 90s to near 100F
degrees.  Not many clouds are expected in the afternoon, so full
sunshine will be in force.

.LONG TERM...(Thursday through Tuesday)

Thunderstorms are likely across portions of central Kansas early
Thursday morning as an upper level shortwave coming off the ridge
axis across the Colorado Rockies dips southeast across the Central
Plains. Increased convergence/forcing ahead of the advancing surface
trough along with ample low/mid level moisture will be enough to
support convection across central Kansas as the aforementioned
shortwave dives southeast across the region. Drier conditions
are then likely Thursday afternoon through Friday afternoon as
the upper level ridge axis shifts eastward across the Western
High Plains. Going into the weekend, medium range models indicate
the upper level ridge breaking down somewhat as it moves further
east into the Central Plains returning a southwest flow aloft to
portions of the Rocky Mountain Region. The GFS/ECMWF hint at H5
vort maxima ejecting eastward out of the Central Rockies providing
the focus for possible thunderstorms lee of the front range Friday
night into Saturday. Although the flow aloft will remain fairly
weak, forcing associated with a surface trough and enough
instability will exist to support thunderstorm development across
eastern Colorado late Friday afternoon with storms potentially
moving into western Kansas overnight through early Saturday.

Warmer temperatures are likely Thursday as a prevailing lee side
trough continues to influence a southerly flow across western
Kansas. This will enhance warm air advection into the area with
H85 temperatures climbing into the mid 20s(C) across central Kansas
to near 30C closer to the Colorado border. Highs will reach well
into the 90s(F) Thursday afternoon with similar highs expected
each day going into the weekend as upper level ridging moves out
of the Rockies across the Western High Plains.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)

The lee trough will continue to strengthen across eastern Colorado,
increasing the pressure gradient and resulting surface winds. Wind
speeds during the afternoon hours will range from 15 to 19 knots
with gusts in the mid to upper 20s knots out of the southeast. Winds
will decrease slightly during the overnight hours. At this time,
thunderstorm activity will not be included in any three of the
terminals (DDC, GCK, HYS) given low confidence of any thunderstorm
impacts. Thunderstorms will likely make an approach to GCK late this
evening, however more than likely in a weakening state (or even
completely dissolved by the time they reach GCK). Another overnight
cluster of thunderstorms will develop across central Kansas, but HYS
appears to be on the western edge of any of this activity with a
much higher probability of thunderstorms east of HYS overnight.


DDC  90  68  97  73 /  20  30  10  10
GCK  91  67  98  73 /  10  30  10  10
EHA  94  70  98  72 /  20  20   0  10
LBL  94  69  99  73 /  20  20   0   0
HYS  89  67  95  73 /  10  30  20  10
P28  90  69  96  75 /  20  30  20   0




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