Area Forecast Discussion
Issued by NWS Goodland, KS

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 47 48 49 50

000
FXUS63 KGLD 240839
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
239 AM MDT Fri Mar 24 2017

.UPDATE...
Issued at 1023 PM MDT Thu Mar 23 2017

Have been seeing a few reports with gusts right around 50 kts in
isolated locations well removed from precipitation...and with 59
kts measured at McCook airport wind gusts are becoming more
significant. Being that a lot of these gusts are not associated
with convection, so think widespread High Wind Warning warranted
for a few hours even though higher gusts remain spotty and depend
on localized mixing down of LLJ.

UPDATE Issued at 644 PM MDT Thu Mar 23 2017

A Blowing Dust Advisory has been issued for the next few hours for
the counties south of I-70 and along and west of Hwy 27; in
Colorado and Kansas. There was a dust plum observed via
satellite. Dust was verified from a spotter and the Burlington, CO
ASOS site.

&&

.SHORT TERM...(This afternoon through Friday)
Issued at 339 PM MDT Thu Mar 23 2017

Early afternoon WV imagery and RAP analysis shows a trough becoming
negatively tilted near the Four Corners Region. SW diffluent flow
extends across the plains ahead of this upper trough. At the surface
lee trough is deepening with a trough axis near our northern CWA
and a dry line and possible warm front just south of our CWA.

This afternoon-evening: Mesoanalysis shows weakening CIN and axis of
2500 J/KG SB CAPE east of CO state line. Axis of 50-75 kt effective
bulk shear extends along the CO border. As cap is weakening we are
beginning to see CU field developing along and east of surface low
pressure. Short range guidance (RAP/HRRR) are showing thunderstorm
initiation along CO border within the hour, and increasing
coverage/possible mergers through the early evening. Shear profiles
at least within the effective layer are linear in nature, however as
LLJ increases around 00Z we may see low level veering (particularly
along warm front/trough axis) which could allow super cell
development. Greater concern will be for large hail and damaging
winds (particularly damaging winds due to high storm bases and
dry air masses). DCAPE values are already in the 1000-1500 J/KG
range. Due to the very high shear environment and possibility for
dry air entrainment/precip loading (based on moisture profiles)
raises the possibility for isolated gusts in excess of 80 mph.

Late tonight-Friday: Upper low closes off and deepens and is showing
by guidances to track near southern Kansas border (there are
variances). As has been the case guidance shows best precip coverage
across our NW CWA where occlusion/deformation zone sets up and
moderate to heavy rainfall will be possible. Wet bulb profiles on
GFS/ECMWF are borderline on rain/snow mix, however in our far west
we should see a change over in the 09-15Z time frame and a mix can`t
be ruled out in counties adjacent to CO border. I couldn`t rule out
moderate snow accumulations in our far west, however ground
temperatures are very warm and I am unsure how persistent the
snowfall would be. NAM is a cold outlier, but it should be noted it
shows the possibility for predominately snow spreading into NW
Kansas/SW Nebraska (similar conditions to eastern CO). GFS and ECMWF
do show temperature profiles cooling over NW KS during the day as
upper low transitions east, but this is separated from main precip
axis in the west.

It is worth noting that unless we see showers/isolated thunderstorms
fill in near upper low center, our southeast CWA may not receive any
precipitation Friday due to a dry slot moving from the southeast to
northwest. I trended PoPs down for those locations.

Regarding Wind/Winter Weather Highlights: Mixed layer winds should
support at least 60 mph along and west of the CO state line late
tonight and Friday (west to east progression in winds increasing). I
have less confidence in winds furthest east towards Hwy 83 and SW
Nebraska due to position on main wind max. I went ahead and upgraded
watch to High Wind Warning, but could see the counties east and
north remaining just below criteria. Where snow occurs (more likely
west) these winds should combine to crease blowing snow/near
blizzard conditions. Confidence was lower in the east due to better
consistency with GFS/ECWMF. I was also unsure of duration of
possible white out conditions, so decision was made to issue Winter
Weather Advisory for our eastern Colorado counties. We will need to
monitor trends, and make adjustments as necessary.

.LONG TERM...(Monday through Thursday)
Issued at 239 AM MDT Fri Mar 24 2017

The main story during the extended period is rain chances due to a
potentially strong system heading towards the Plains midweek.
Temperatures remain near to above normal for much of the region.

The period starts out dry on Monday with an upper ridge between
Sunday`s departing wave and the incoming system to the west. A warm
day with highs in the low/mid 60s is anticipated.

A deep upper trough develops over the west coast and moves into the
desert southwest Monday night. The trough closes off and tracks east
across northern Texas and Oklahoma through Thursday. This system
brings rain shower chances to the region Monday night through the
end of the period. Wednesday night and Thursday, chances are
confined to the southern and eastern portions of the area as weak
ridging builds in behind the exiting system. There are still
discrepancies with how this system will evolve and precipitation
chances depend on its track. Will continue to monitor.

Temperatures cool off slightly Tuesday through Thursday, with highs
in the upper 50s to low 60s. Lows stay in the 30s throughout the
extended.


&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1129 PM MDT Thu Mar 23 2017

Showers and thunderstorms will move across the area for the rest
of the night in advance of incoming storm system. Mvfr conditions
will develop at both sites through 12z. Precipitation will become
more widespread after 12z. From 12z to into the evening hours,
mvfr with occasional ifr conditions are expected. Winds will shift
to the north and northeast and increase into the 20 to 35 knot
range with gusts up to 50 knots, mainly at Kgld. Around 00z the
winds will decrease to near 20 knots with some gusts up to 30
knots.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...High Wind Warning from 6 AM MDT /7 AM CDT/ this morning to 6 PM
     MDT /7 PM CDT/ this evening for KSZ001-002-013-014-027-028-
     041-042.

CO...High Wind Warning until 6 PM MDT this evening for COZ090>092.

     Winter Weather Advisory until noon MDT today for COZ090>092.

NE...NONE.
&&

$$

UPDATE...JRM
SHORT TERM...DR
LONG TERM...JBH
AVIATION...BULLER



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