Area Forecast Discussion
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FXUS64 KLUB 181646 AAA
AFDLUB

Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
1046 AM CST Sat Feb 18 2017

.UPDATE...
Layer of stratus with some dense fog in our eastern zones is
proving more resilient than originally thought. Extrapolation from
satellite and METAR trends syncs well with the latest high res
guidance in keeping cool and moist ENE winds intact through early
afternoon. This will only delay the erosion of low clouds and
keep high temps at least 5 degrees cooler than previously
advertised. Fog-wise, some thinning of the previously dense fog
is noted in the city of Childress and at the airport, but the new
concern is how fast tonight`s round of fog may develop as much
richer moisture advection unfolds.

&&

.PREV DISCUSSION... /issued 521 AM CST Sat Feb 18 2017/

AVIATION...
IFR conditions have moved into KCDS early this morning with
easterly winds drawing moisture into the area. Conditions are
expected to improve to VFR after daybreak. Easterly winds across a
larger area early Sunday morning may bring in additional low CIGS
and fog by daybreak on Sunday. Furthermore, a low level jet
forming tonight may bring LLWS to all TAF sites.

PREV DISCUSSION... /issued 433 AM CST Sat Feb 18 2017/

SHORT TERM...
A highly amplified trough will move inland from the west coast today
and will be in control of our weather for the next few days. High
level clouds will begin to spread over the region today. And though
there will be a slight increase in thicknesses for today, these high
clouds may limit afternoon temperatures a few degrees below
guidance. The approaching upper level trough will cause a surface
response with winds swinging around to the east-southeast this
evening and overnight which will begin to draw up low level moisture
from the Gulf of Mexico where surface dew points are currently in
the 60s. Initially, this will result in greater and more widespread
chances of low stratus and fog for Sunday morning.

LONG TERM...
There do not appear to be significant changes with the two main
events of the long term period: a trending lower chance for
thunder Sunday, and a still solid looking very windy day Thursday
along with possible dust and fire weather potential.

The very amplified and hopeful (for rain or thunder) looking
upper trough will be approaching through the southern Rockies
Sunday. A significant portion of the energy will be taking a
northeast track through the Four-Corners into east-central
Colorado Sunday evening. Solutions agree that a notable arm of
potential vorticity will swing northeast through the southern high
plains around midday Sunday. Flow in lower levels already will be
veering by early in the day, however, and prospects for retaining
significant moisture are less. The latest TTU WRF run is one of
few still developing convection over the high plains, and it
appears modest with this at best. We have trimmed further the
slight chance mention on the Caprock, and also lowered chance
levels a bit over much of the Rolling Plains. The lower level
drying will cause an even more conditional chance than previously
expected. Further drying will sweep in behind this vorticity arm
late Sunday, scouring majority of the remaining moisture. Over the
Rolling Plains where modest instability appears may hang on until
arrival of the vorticity lobe and a dryline, this allows for
slightly higher conditional probabilities.

For Thursday, solutions continue to indicate significant mid level
energy rolling out of the central Rockies into the central high
plains, with the strong wind corridor from the central Panhandle
into the South Plains. We continue to populate the grid forecast
with higher wind speeds, about midway between the Superblend and
ConsMos solutions. This would translate to a solid Wind Advisory
day on the Caprock, potentially near high wind levels over the
extreme southwest Panhandle. Current forecast speeds are edged
slightly higher than previously. Of course we are holding on to
the blowing dust mention as well, though this nay be somewhat
alleviated by cultivating of farm land in the days ahead. And our
Rangeland Fire Threat Index pulses up to levels 6 and 7 with
current forecast winds and humidity, so this may need further
addressing in the coming days. For now, continued mention of wind
and fire threats in the Hazardous Weather Outlook is appropriate.

Otherwise, height rises Monday and Tuesday will lead to warming,
southwest flow increasing Wednesday will lead to a breezy day and
also probably the warmest day ahead, and then behind the wind
storm a cold front should drop highs for Friday. RMcQueen

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

93



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