Area Forecast Discussion
Issued by NWS Goodland, KS

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FXUS63 KGLD 181212

Area Forecast Discussion
National Weather Service Goodland KS
612 AM MDT Mon Sep 18 2017

.SHORT TERM...(Today through Wednesday night)
Issued at 310 AM MDT Mon Sep 18 2017

The primary short term forecast concern is the possibility of
critical fire weather conditions on Tuesday afternoon.

Fog will persist across much of the forecast area early this
morning with localized visibilities occasionally less than one
mile. Fog should dissipate by 16Z with skies clearing by mid day.

The zonal flow aloft today will turn more southwesterly as the low
pressure area moving through the Pacific Northwest moves into the
northern Great Basin area on Tuesday. The lead cyclonic
circulation is the expanding upper low pressure area swings into
south central Canada while a secondary lobe begins diving
southward along the west coast. The lead low lobe sweeps a short
wave trough through the northern extent of the forecast area
Tuesday evening. The short wave trough encourages a deepening
surface low pressure area over eastern Wyoming and extending as a
surface trough into eastern New Mexico to move across the
forecast area Tuesday evening with a cold front pushing through
the area by late Tuesday evening.

In the downslope southwest surface flow ahead of the surface
trough, gusty winds are expected Tuesday afternoon with a wind
shift to follow during the evening. Warmer than average high
temperatures will be in middle 80s to middle 90s with relative
humidity values dropping into the lower teens across mainly the
western sections of the forecast area.

On Wednesday, high temperatures will cool briefly into the 70s and
lower 80s as a cooler high pressure area moves quickly through the
region before temperatures warm again later in the week.

.LONG TERM...(Thursday through Sunday)
Issued at 224 AM MDT Mon Sep 18 2017

An active pattern will take shape as we head into the end of next
week. Thursday will remain quiet as a deep trough develops to our
west, slowly moving eastward toward the CWA. A surface cold front
will push through the region late Friday, stalling out just east of
our area. This will provide a focus for thunderstorm development
Friday through Sunday. There is generally good agreement between the
GFS, ECMWF, and CMC regarding this solution with only a few temporal
differences. The GFS continues to be the coldest and most
progressive model with the other two remaining a bit slower.

Regarding Saturday, there will be an axis of higher instability as
CAPE climbs into the 1500 to 2000 J/Kg range during the afternoon.
Given a favorable shear profile and a stationary boundary as a
focus for development, we can expect a chance of strong to severe
thunderstorms during the afternoon on Saturday. Additionally, PW
values will exceed 1.25" with some areas exceeding 1.50" within
the Friday through Sunday time frame, mainly east of the
Kansas/Colorado border (GFS Sounding). This combined with the slow
moving boundary will increase our risk of flash flooding across
the region, especially in our eastern counties. This type of setup
commonly favors training of storms over the same areas.

Thunderstorms remain in the forecast for Sunday as the surface
boundary moves slowly eastward. The trough remains to our west, even
with the progressive GFS model, with a series of H7 shortwaves
propagating along the eastern portions of the H5 feature. We could
still see a few strong storms on Sunday as instability will remain
in place mainly for our eastern counties. PW values, although lower
than Saturday, will remain well over one inch for much of the
eastern two thirds of the CWA.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 450 AM MDT Mon Sep 18 2017

Conditions at GLD through 14Z will be intermittently VLIFR to
LIFR with ceilings between 200-500 ft AGL and visibilities of 1
mile occasionally dropping to less than 1/2 mile with fog.
Conditions between 14-16Z will transition through IFR to MVFR as
ceilings and visibilities improve to VFR as temperatures warm
following sunrise. Clear skies and light winds are expected after

Conditions at MCK will be intermittently LIFR to IFR through 15Z
due mainly to low ceilings. MVFR conditions are expected between
15-17Z as ceilings begin to raise with VFR conditions and clearing
skies after 17Z.


Issued at 310 AM MDT Mon Sep 18 2017

The potential for critical fire weather conditions is looking more
likely on Tuesday afternoon. Afternoon high temperatures in the
mid 80s to mid 90s and relative humidity values between 13-15
percent across the western 2/3s of the forecast area are expected.
Breezy southwest winds will also be noted ahead of a deepening
surface trough that moves across the forecast area during the
early evening on Tuesday followed by a cold front late Tuesday
evening. A Fire Weather Watch has therefore been issued for
Tuesday afternoon.


KS...Fire Weather Watch Tuesday afternoon for KSZ001-002-013-014-027-

CO...Fire Weather Watch Tuesday afternoon for COZ252>254.

NE...Fire Weather Watch Tuesday afternoon for NEZ079-080.



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