Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 261325 CCA
Area Forecast Discussion...CORRECTED
National Weather Service Goodland KS
725 AM MDT THU MAY 26 2016
Issued at 723 AM MDT Thu May 26 2016
Update issued to the forecast to mainly remove mention of fog as
any fog currently is located near the front which continues to
lie south of the cwa. Adjusted pops for the morning to remove any chance
wording down to slight chance until storms begin to occur as the
day progresses. Best chances right now still look near the NW
corner where boundary from earlier this morning is still firing up
convection. No other changes at this time.
.SHORT TERM...(Today through Saturday night)
Issued at 405 AM MDT Thu May 26 2016
Main forecast issue is severe weather through tonight with secondary
issue of a continued active pattern into the weekend. Satellite
showing an amplified and blocky pattern from the Pacific into
eastern North America. Complicated surface pattern with stalled
front not too far to our south and east...anchored to low over
southeast Colorado. A secondary surface trough and/or remnant
outflow boundary that has moved into our area.
At jet level...models underdoing the winds a little over our area at
this time. At mid levels...models started out well and close to each
other. Would have to give a slight edge to the Canadian and Nam.
Models tended to initialize to warm with the Canadian the closest of
the larger scale models. Hires models and Ecmwf seem to be doing
well at the surface.
Overall a difficult and problematic forecast, especially in the
first 24 hours, due to poor model agreement from the
hires/convective allowing models all the way up the larger scale
output, and also poor model depiction of reality/current trends.
Today/tonight...models overpredicting precipitation/convection this
morning with the hires/convective allow models the worst. This is
also tied as to where the models put the synoptic boundaries,
especially the boundary to our south. Overall trend for this morning
has been to reduce the amount of morning convection and also have
the front further south this morning. Do have pops in their this
morning but may be too high. Models have also cut back on the amount
of fog and followed that trend.
Models to varying degrees pull the front back rapidly to the north
this afternoon. In general the models by late afternoon have the
front draped across the center of our area from southwest to
northeast. Rather strong and closed off upper system approaches from
the southwest this afternoon with mid level lift moving over the top
of the front. With the mean flow from south to the north would
expect the greatest chance to be along and north of the front which
means the northwest half.
The trend of having the highest pops in the northwest half to two
thirds looks to continue tonight. However, mesoscale influences
could change that. Locations along and north of the front look to
have the best chance for tornadoes. What appears to be certain is
very large hail due to very steep lapse rates. Also have a little
bit of concern of heavy rainfall due due to the storm motion forcing
being PERPENDICULAR to the front.
Based on the position of the front, how the cloud cover is this
morning, and how fast the convection develops this afternoon,
high temperatures may end up much cooler than I have them.
Friday/Friday night...Model trends have been to have closed off
system moved through slower and a little further south. This creates
a unique scenario. During this period we have wrap around showers
and thunderstorms on the west side of the system and stronger
thunderstorms and possible severe storms underneath and ahead of
the circulation. Tended to raise pops. Pops decrease during the
night. High temperatures may need to be cooled more from what I
have in there.
Saturday/Saturday night...highly uncertain period. Some indication
we may be drier than what I have in there. However, there looks to
be plenty of shortwaves moving through and kept a slight chance in
there which may have to be adjusted. High temperatures will be
.LONG TERM...(Sunday through Thursday)
Issued at 223 AM MDT Thu May 26 2016
At the start of the extended the upper level pattern is setting up with
a longwave trough moving eastward, out of the Pacific Northwest,
and deepen as it moves over the High Plains towards the end of the
period. On the surface, models are showing a low pressure system
developing, over the High Plains, and moving towards the
northwest with its associated front passing through the area
later in the week.
Chances for convective activity persist across the region throughout
the extended period as instability will be high on Sunday through
Tuesday and moisture return from the southeast. Followed by the
above mentioned pressure system at the end of the period. At this
time, severe weather threat looks low as there seems to be a lack of
a highly sheared atmosphere.
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 529 AM MDT Thu May 26 2016
Very uncertain forecast due to model differences and poor handling
of current radar/surface observation trends. For Kgld...until the
mid to late afternoon hours vfr conditions are expected.
Thunderstorms will beging to affect the site this afternoon into
the early overnight hours. At this time expect possible mvfr
conditions with thunderstorms. Between 06z and 12z ifr/lifr
conditions will develop.
For Kmck...until the mid to late afternoon hours vfr conditions
are expected. At that time thunderstorms should begin affecting
the site and cause mvfr conditions until aroun 09z. At that
time...ifr conditions will develop.