485 
FXUS64 KLUB 201119
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
619 AM CDT Mon Sep 20 2021

.AVIATION...
VFR next 24 hours. A cold front will move into the area around
mid-afternoon bringing winds around to the north at KCDS first
followed by KPVW and KLBB a few hours later. Expect hot and bumpy
thermal turbulence today with most normally aspirated aircraft 
unable to climb high enough to find smooth air after 18Z. Check 
density altitude. There is a ~10pct chance of thunderstorm 
development east of a LBB to CDS line late this afternoon. 
Underflight of showers/virga not recommended due to threat of 
strong downburst winds.


&&

.PREV DISCUSSION... /issued 306 AM CDT Mon Sep 20 2021/ 

SHORT TERM...
A shortwave trough will traverse the central and northern plains 
today. The morphology of the trough tends to suggest a double-
shot of energy. That is, an initial front followed by a secondary 
surge of cooler/drier air hours later. The trough axis is progged 
to deepen somewhat over the next 24 hours which will help 
reinforce the cooler airmass driving it southward. Subsident 
compression of the frontal boundary combined with westerly 
downslope winds will allow temperatures to get quite toasty this 
afternoon. The dryline should race east after sunrise making it to
our eastern counties by mid-day. By mid-afternoon, a cold front 
should be arriving in our northeast which will set up a triple- 
point in the Rolling Plains late this afternoon. There will be 
scant little moisture to work with though forecast soundings do 
suggest at least some potential for virga and perhaps a dry 
thunderstorm closer to the triple point itself. All in all, the 
prospects for measurable rain at the surface are pretty 
meager...certainly below mentionable levels. However, any virga 
that develops will have the capability of producing strong 
downburst winds given the inverted V soundings anticipated. Wind 
gusts to 55 mph, and possibly higher, seem legit if we can get the
precipitation processes going aloft. Honest thunderstorm 
development is certainly possible to our southeast late this 
afternoon and evening. The front will bring cooler lows (55- 65) 
tonight but it will take that second frontal surge on Tuesday to 
make it feel a lot more like fall.

LONG TERM...
By Tuesday morning the aforementioned cold front will be well south 
of the forecast area. The surface pressure gradient will remain 
tight across the region Tuesday morning and early afternoon 
keeping northerly winds breezy and bringing in the secondary 
surge of cooler/drier area. Temperatures will be much cooler
on Tuesday with high temperatures in the 70's on the Caprock and 
lowers 80's off of the Caprock. By Tuesday night surface high 
pressure will settle across the southeastern Texas Panhandle 
bringing light winds and clear skies to the region. This will 
allow for excellent cooling conditions across the higher terrain 
of the forecast area and a few upper 30's would be possible in the
typically cool spots with 40's and lower 50's possible elsewhere.
By Wednesday, upper level ridging will begin to expand across the
Desert Southwest although height rises will not be all that 
impressive. This means that temperatures will only slowly warm 
each day through the end of the week. The upper level pattern 
becomes more uncertain this weekend as models struggle with a 
cutoff low over southern California due to differences in the strength
and location of a shortwave moving across the Pacific Northwest. 
However, these differences won't impact the forecast area too much
until early next so dry conditions and gradually warming 
temperatures can be expected through the weekend. /WCI

&&

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

$$

26/58/26