Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/19/19

Area Forecast Discussion

National Weather Service Amarillo TX

 622 PM CDT Fri Oct 18 2019

.AVIATION...
00Z TAF Cycle

VFR conditions are expected at all three TAF sites through 00Z
Sunday. Southwest to west winds 10 to 20 knots with gusts to near
30 knots will become northwest and north and increase to around 15
to 25 knots and 20 to 30 knots with gusts near 30 to 35 knots
after 02Z to 04Z Saturday. The north winds are expected to
diminish to around 5 to 15 knots after 13Z to 17Z Saturday.

Schneider

&&

.PREV DISCUSSION... /Issued 408 PM CDT Fri Oct 18 2019/

.SHORT TERM...Tonight and Saturday...
Some high-based cumulus is evident in satellite imagery at this time
over south-central and southeast Texas Panhandle.  This area fits
well with RAP analysis of higher theta-e values from surface through
700 mb.  With modest low-level moisture flux convergence expected to
continue into this evening, in areas along and east of surface trof,
will maintain isolated showers and thunderstorms across eastern half
of forecast area through this evening.  Threat for severe
thunderstorms is low, but brief gusts above 50 MPH may occur due to
forecast DCAPE values of 1000 to 1600 J/kg.

Cold front currently moving into northwest Kansas expected to sweep
through the Oklahoma and Texas Panhandles this evening, clearing
southeast Texas Panhandle by midnight.  Winds will abruptly shift to
northwest and north with frontal passage.  Gusts of 30 to 40 MPH
expected for about 3 to 4 hours following frontal passage, with
strongest values expected over northern sections.

Saturday expected to be sunny with high temperatures mainly in the
lower- to mid-70s, close to seasonal norms.  Light to moderate north
winds in the morning will trend to east and south by late afternoon
as post-frontal high pressure ridge departs to our east and lee trof
takes shape across eastern New Mexico.

Cockrell

LONG TERM...Sunday through Friday...
Current satellite analysis and the 12Z AMA upper air sounding have
the area under zonal flow today. This is due to a broad trough over
the area and much of the western CONUS with a jet maxima of about
150 kts just off the coast of British Columbia at H2. By Sunday
afternoon this H2 trough will deepen over the Rocky Mountains, with
the axis running from the Saskatchewan Province down into New
Mexico. This will put the area under southwest flow in the left
entrance region of a 120 knot jet at H2 on the downstream side of
the trough by Sunday evening.

By Sunday morning, an H5 low pressure will close off, lee side of
the Rockies over eastern Wyoming into western Nebraska and South
Dakota. The highest jet maxima of around 85 kts will be entering the
H5 trough axis over central Colorado. By 1 PM Sunday, the H5 low
pressure strengthens over South Dakota as it moves east. At the
surface, a cold front will push through, entering the northwest CWA
between 10 AM and 2 PM. This will cause the day time high forecast
to be a bit tricky depending on the actual timing especially in the
northwestern CWA. Winds are expected to be 20 to 30 knots ahead and
just behind the front. Fire weather conditions are a concern in the
northwest as fuels are dry and the RH will drop to around 10
percent.

Monday and beyond, the CWA will come under NW to zonal flow allowing
for things to be quiet for a few days with temperatures just
slightly above normal. Will have a gradual warm up into the mid 70s
at least for the southern Texas Panhandle by Wed. A shallow cold
front is expected to come through Wednesday night into Thursday
morning. The GFS has a second push of much colder air Thursday night
into Friday with much of the northwestern CWA dropping below
freezing in the overnight hours. Also, the GFS has precip, most
likely snow in the northwestern CWA, Thursday night into Friday
morning. The GFS has greater coverage in precip chances over the
area, while the Euro only has a small area in the far northwest CWA.
The Canadian is dry. Even with freezing temperatures overnight for
the northwest and mid 30s elsewhere, the GFS is the only model
depicting below freezing 850 mb temperatures at this time. Friday is
still seven days away but will have to watch and see what the models
do with this system as the week goes on.

Hoffeditz

FIRE WEATHER...
Elevated to critical fire weather conditions are expected Sunday
afternoon mainly for the northwestern Combined Oklahoma and Texas
Panhandles. An approaching cold front Sunday will allow
temperatures ahead of it to warm into the 70s. This cold front
will enable strong west winds in front of it, and bring even
stronger winds behind it for a short while. Sustained winds in the
northwest CWA will be 25 to 30 mph gusting up to 40 at times. Dry
fuels in the northwest combined with strong winds will also be
accompanied by low relative humidities. Fire starts will be more
likely ahead of the front in the warmer temperatures. However, if
a fire is going as the front passes, the winds shift and the wind
speeds will create a dangerous situation. As the timing of the
front is key to fire weather conditions and the low confidence for
the timing of the front will hold off on any highlights for now.

Hoffeditz

&&

.AMA Watches/Warnings/Advisories...
TX...None.
OK...None.

&&

$$

11/99