NASA - National Aeronautics and Space Administration

Forecast Based on

• on satellite
• current surface observations
• 00 UTC ETA
• 00 UTC NGM
• 09 UTC MAPS/RUC
• MRF
• 12z ECWMF

Synopsis

A broad trough with numerous embedded shortwaves from the Rockies to
the Central Plains is controlling the weather over the area. At the surface,
an inverted surface trough has formed to the lee of the Rockies with a warm front
extending from a low in southwestern Texas to the upper Ohio valley. A strong
low level jet is associated with this trough and is pumping Gulf air into central
Texas on up to the Red River. An east/west dryline on the Red River Valley will
turn counter-clockwise through the day. Strong convection will spring up along
this boundary with severe thunderstorms becoming more likely into the late afternoon
and evening. Tornadoes may occur. Convection occurred in southwestern Kansas last
night, but the state will not receive any more precipitation.

Prog Discussion

A shortwave over the central Plains is producing mid and high level
clouds. As this shortwave exits the region to the northeast, an associated surface
low will track across Kansas. Upstream there is a shortwave over southern CA/western
AZ border that will rotate around and deepen the the 500 mb trough. This shortwave
will drive convection along a front which will connect from a surface low in the
northern Plains to a low that is moving eastward across Texas. Both high and mid
level cloudiness will prevail today and tomorrow.

48 hour Forecast:

12z 21 Apr - 00Z 22 Apr: High and mid level cloudiness. As the surface low progresses
across Kansas, the wind will shift from southerly to northernly in the late afternoon.
Speeds of 15 kts. Highs in the low 70s.

00Z 22 Apr - 12Z 22 Apr: Partly cloudy and cool. Low in the 40s. Northwesterly winds
of 15 kts.

12z 22 Apr - 12Z 23 Apr: Partly cloudy and cool. Highs in the mid 50s. Decreasing
winds during day.

Extended Range Discussion:

12z 23 Apr - 12Z 24 Apr: Amplifying trough will progress eastward leaving KS and OK
on the backside of the trough by Wednesday morning. Depending on the speed of trough,
ridge cirrus could be spilling over by Tues, but more likely on Wed. Daytime high in
the mid 60s.

Walker and Mace