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Area forecast discussion
National Weather Service Cheyenne Wyoming
1107 PM MDT sun Apr 20 2014
Short term...(this evening through Tuesday night)
issued at 311 PM MDT sun Apr 20 2014
Convection developed right on time this afternoon. No longer
expecting much in the way of thunder. Upper dynamics are weak at
best with relatively limited moisture. Also soundings suggest
vertical growth is limited by middle level warm layer...so mainly
looking at short showers the rest of today. Could be a random
lightning strike here or there but the best chance for any
lightning will be near the mountains where upslope component may
be just enough for slightly stronger convection...and even that
will be remote. No threat for severe weather today or tonight.
Once the daytime heating is lost...showers will rapidly die off
Less chance for shower activity tomorrow. There may be enough low
level convergence along the Laramie range for some middle to late
afternoon showers. Otherwise light winds and mild temperatures
for the start of the work week.
Things start to get more interesting Tuesday. Upper level trough
will be moving inland off the West Coast. Models showing a tongue of
low level moisture streaming into the Nebraska Panhandle ahead of
the upper level trough with surface dew points in the middle 40s.
Should be enough low level moisture for some thunderstorm
activity. Shear profiles indicate the potential for some stronger
storms. Tough to say the severe threat at this time but with winds
aloft so strong and limited cape values...storms that do develop
could quickly get ripped apart by the strong shear.
Will also have to keep an eye on synoptic driven winds in the
west. Models showing 700 mb winds increasing to 50-60 kts by
Tuesday evening. Could see near High Wind Warning type winds
across western portions of Carbon and far west Converse counties.
Long term...(wednesday through sunday)
issued at 245 PM MDT sun Apr 20 2014
A rather progressive pattern will continue over the region this
period with a couple of upper troughs affecting the area. The
first will pass across the County Warning Area Wednesday but wind will be the main
weather brought by this system with the upper low moving well
north of the County Warning Area. A few showers will still occur mainly over the
mountains cooler Wednesday then remaining mild Thursday and Friday with a
short upper ridge passing across late Friday. Next upper system
will then begin to affect the County Warning Area Saturday bringing a better
chance for rain and some high elevation snow by late in the
day...continuing Sunday as the system becomes negatively tilted as
it moves over the Rocky Mountain area.
Aviation...(for the 06z tafs through Monday afternoon)
issued at 1107 PM MDT sun Apr 20 2014
Latest surface analysis was showing the weak surface boundary
passing through the southern Panhandle. This feature is helping
clear out the clouds especially in the Panhandle. A ridge axis will
push across the region...with winds becoming more light and
variable. Southeast winds should commence east of the Laramie range
Monday afternoon...but should remain light.
issued at 255 PM MDT sun Apr 20 2014
Showers will quickly die off across the area this evening with the
loss of daytime heating. A cold front will push across the area
this evening making for a slightly cooler day east of the Laramie
range Monday. A few light rain showers possible along the Laramie
range Monday afternoon otherwise dry for Monday. Another chance
for showers and thunderstorms is possible on Tuesday...with strong
gusty winds possible Tuesday night through Thursday.