437 
FXUS64 KLUB 310714
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
214 AM CDT Sat Jul 31 2021

.SHORT TERM...
06Z upper air analysis indicates that the once well-defined 
mid/upper-level anticyclone is beginning to decay over the southern 
Great Plains as an amplifying, longwave trough digs into the Upper 
Midwest region with several subtle perturbations rotating through 
the main belt of larger-scale flow. At the surface, a diffuse trough 
was located across far eastern New Mexico, extending northward 
towards southeastern Colorado where lee cyclogenesis of a broad, 
1008 mb low is underway with a quasi-stationary front extending 
generally eastward along the 40th parallel. Strong, diabatic surface 
heating is expected today as temperatures soar into the lower 90s on 
the Caprock and to near 100 degrees in the eastern Rolling Plains 
with a deep, well-mixed boundary-layer extending up to ~3-km AGL. 
Isolated thunderstorms (single cells) will be possible this 
afternoon as subsidence decreases with the airmass being very weakly 
capped. A rogue wet-microburst cannot be ruled out, but in general, 
not expecting anything from the afternoon "show" if anything does 
develop.

The aforementioned front is forecast to near the CWA by this time 
tonight (01/~06Z), with the development of scattered thunderstorms 
expected as it moves equatorward. The advection of high theta-e 
inflow-layer air ahead of the front and weak, geopotential height 
falls should contribute to tall/sizable MUCAPE values approaching 
~2,000 J/kg across the southern TX PH with PWATs increasing to 
around 1.50-1.70", which exceeds the 99th percentile as per SPC 
Sounding Climatology on 01/00Z at the AMA RAOB site. The deepest 
cores will be capable of producing efficient rain rates per hour, 
and localized flash flooding will be possible as a result prior to 
sunrise Sunday. An isolated wind-damage event or two will be 
possible given the well-mixed sub-cloud layer ahead of the front, 
though the convective wind risk should be limited as large-scale 
forcing for ascent is displaced far to the east of the Texas High 
Plains. In short: the potential is increasing for yet another round 
of wetting rains across the CWA.

.LONG TERM...
Next week will start off with upper level ridging in the 
Intermountain West and troughing over the eastern CONUS. The eastern 
US trough will send a cold front through on Sunday morning. 
Initially, we will start out with good chances of precipitation 
in the immediate wake of the cold front on Sunday afternoon and 
evening. Precipitable water values will increase on Sunday after 
the front moves through, increasing to values on the order of 
125-150 percent of normal for early August. This will promote 
areas of heavy rainfall during this time period on Sunday. Beyond 
Sunday, precipitation chances become murky. The devil will be in 
the details as it usually is at these timescales under weak 
forcing aloft. It is difficult to pin down any time next week of 
better precipitation chances due to possible subtle disturbances 
rotating around the upper ridge. The cold front will likely plow 
through to the Gulf Coast. This will leave the South Plains under 
easterly to southeasterly low level flow with northwest flow 
aloft. This pattern will favor convection in the higher terrain of
New Mexico with much more uncertainty for West Texas. Even if 
precipitation does not manifest itself after Sunday, temperatures 
will, nonetheless, be cooler under the upslope low level flow. 
Afternoon temperatures are expected to be several degrees off of 
seasonal averages. By late in the week, the upper pattern looks to
break down as stronger troughing moves on shore in the Pacific 
Northwest.

&&

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

$$

09/01