Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Goodland Kansas
531 am MDT Sat Apr 18 2015
issued at 458 am MDT Sat Apr 18 2015
Update to forecast has been sent out for issuance of dense fog
advisory for the central portion of the County Warning Area...where less than 1sm
visibilities has appeared. Will be in effect through the middle morning
hours. No other changes at this time.
Short term...(today through Monday night)
issued at 237 am MDT Sat Apr 18 2015
Across the forecast area this morning....clear to partly cloudy
conditions over the southern half of the area...while for the
northern half mostly cloudy to cloudy skies persist with the last of
the overnight precipitation lifting out of the area into central
Nebraska. As with yesterday morning do expect areas of fog to
develop...burning off by the middle morning hours.
For the rest of today on through the evening hours...the tri state
region is expected to see yet another round of rain shower/thunderstorm with severe
potential after 18z. Much of the County Warning Area has been put under slight risk
for severe weather by the Storm Prediction Center. Upper low/trough
remains over the eastern portions of The Rockies...while surface
boundary remains over the region. This entire complex will finally
shift through the day...moving over the County Warning Area overnight. Some model
difference in placement of system by Sunday morning...but overall
trend is mainly east of area.
This movement eastward through the day will shift the focus for best
potential for severe weather more over eastern zones as upper lows treks
eastward. Have concentrated higher pop trend towards that area base
Don low track later today into tonight. With the slight risk tag for
the County Warning Area...have again put in enhanced wording for the area for large
hail...damaging winds and heavy rainfall. Some localized amounts
near/under any thunderstorms could see an inch or more rainfall...as
seen over past couple days.
Going into Sunday...reprieve in sight for the County Warning Area as precipitation expected
to wind down from this system from west to east...with eastern zones
seeing highest potential quantitative precipitation forecast from exiting wrap-around moisture.
Expect another round of fog to develop and burn off by middle/late
morning. Model trend leans toward a late afternoon end to any
-rw. A shortwave does work off of The Rockies Sunday night into
Monday night...but placement of surface ridge just east of shortwave
will keep chances for precipitation confined to mainly eastern Colorado on
the order of a few hundredths of an inch. Going with some patchy fog
Monday morning despite intro of cooler/dry air brought about by
surface ridge from the north-northwest.
Temperatures in the short term will trend down overall with the exit of
clouds/moisture and arrival of cooler airmass. Looking for highs
today to mainly be in the 60s...warmest west due to lack of early
clouds with drier air wrapping into area. 50s for Sunday into
Monday. Overnight lows will start off mainly in the u30s to l40s
Sat night...then shift downward into the u20s to middle 30s...coldest
in eastern Colorado.
Long term...(tuesday through friday)
issued at 225 am MDT Sat Apr 18 2015
The long term forecast period starts with an upper level ridge
building into the High Plains region with mild temperatures in the
middle 60s to lower 70s and mostly dry conditions. The GFS and Canadian
models indicate weak middle level shortwave troughs that will move
through the tri state area...which could spark some afternoon
showers and thunderstorms through the extended forecast period.
However...the best chances for precipitation to return to the area
is when another large upper level disturbance approaches the Central
Plains from the west Thursday and Friday with increasing jet lift.
Surface based cape between 1000 and 1500 j/kg are present through
the vertical profile Thursday afternoon and evening ahead of a
surface cold front...which will likely bring another round of
stronger thunderstorms to the tri state area. Upper level energy
diminishes on Friday once the cold front pushes through the Central
Plains...however isolated thunderstorms are still possible Friday
afternoon an into the overnight hours.
Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 531 am MDT Sat Apr 18 2015
IFR down to vlifr conditions in dense fog through 15z...visibility
1sm or less and ceilings down to vv001 at times. After 15z...mix of
VFR/MVFR conditions with 4-6sm in -rw/fog with -tsra possible
after 20z this afternoon...through 02z Sunday. Ceilings bkn050-100.
Winds varible through 16z then east-southeast 5-10kts...becm northerly by 07z-
10z Sunday 10-20kts.
Kansas...dense fog advisory until 9 am MDT /10 am CDT/ this morning for