259
FXUS64 KLUB 231839
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
139 PM CDT Sun Jun 23 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Monday)
Issued at 139 PM CDT Sun Jun 23 2024

A non-zero chance of isolated convection will exist for the extreme
southwestern Texas Panhandle late this afternoon into the evening.
Mid-level moisture was still prevalent rotating around the ridge
although most activity will be confined to eastern New Mexico and
into the central and northern Texas Panhandle. Upper level ridging
will continue to linger over central Texas and slowly drift westward
through Monday centering over El Paso by Monday afternoon. This will
act to shunt the mid-level moisture farther to the north rotating
around the ridge and eliminate any chances of isolated convection
for Monday afternoon. A slight increase in heights/thickness values
on Monday will result in a small bump in temperatures upwards as
well.

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 139 PM CDT Sun Jun 23 2024

Mid/upper-level ridging will continue to amplify into Tuesday as a
barotropic low located west of Baja California rotates eastward and
as a more-amplified, baroclinic, mid/upper-level trough digs into
the Pacific Northwest. The net response of these features emerging
towards western North America will result in an anticyclonically-
curving, 250 mb jet streak over the central Rocky Mountains with its
right exit-region nosing into the TX PH by late Tuesday. At the
surface, diffuse troughing extending to the south of a lee cyclone
in eastern Colorado/western Kansas will maintain slightly backed
flow during the afternoon hours as intense insolation causes high
temperatures to soar into the upper 90s across the Caprock and
breach 100 degrees in the Rolling Plains. Heat indices may approach
105 degrees across portions of the Rolling Plains on Tuesday. (Heat
Advisory criteria are temperatures or heat indices between 105-109
degrees for the Rolling Plains.) Weak, mid-level, shortwave
perturbations translating about the apex of the ridge; in addition
to MLCINH becoming completely eroded beneath a tall, skinny EML,
will support the potential for thunderstorms across the extreme
southwestern TX PH and farther southwestward into the South Plains.
Low PoPs have been maintained for Tuesday evening across these
locales as it remains unclear how far east thunderstorm initiation
will occur in eastern New Mexico. Steering flow magnitudes between
10-15 kt will also result in slow-moving storms, with the mean
convective movement governed by propagation effects from merging
cold pools before chances for storms wane early Wednesday morning.

Wednesday is forecast to be the hottest day of the work week as
geopotential heights rise to near 596 dam in the mid-levels, with
850 mb temperatures nearing 30 deg C. Surface temperatures are
forecast to approach 102-104 degrees across the eastern portions of
the Rolling Plains while near 99-100 degrees towards the edge of the
Caprock Escarpment. Heat index values between 105-108 degrees are
forecast for the eastern Rolling Plains (i.e., Childress County
southward into Stonewall County), which is within Heat Advisory
criteria. The blended temperatures have been maintained and are
slightly below the statistical guidance envelope, and this is due to
the potential effects of evapotranspiration from lush vegetation.
However, area-averaged forecast soundings do indicate a well-mixed
boundary-layer developing while dewpoints remain within the middle
60s by peak heating. If hotter temperatures are realized, then heat
indices could approach 110 degrees for portions of the eastern
Rolling Plains on Wednesday afternoon. Farther west, temperatures
are forecast to peak in the upper 90s across the Caprock Escarpment
amidst the dampened, southeasterly breeze; and renewed chances of
late-afternoon and evening thunderstorms remain intact across the
northwestern South Plains into the extreme southern TX PH as the
core of the subtropical ridge begins to rotate eastward. Very warm
temperatures are expected on Tuesday and Wednesday morning, too,
especially across the Rolling Plains where lows near 80 degrees are
forecast, further contributing to the heat stress.

Towards the end of the week and into next weekend, the amplitude of
the subtropical ridge will dampen due to the progressive wave
pattern along the 49th parallel, with the center of the 250 mb
anticyclone rotating into eastern Texas or perhaps farther east.
Global NWP guidance remains in agreement with the longitudinal
extension of the subtropical ridge as it phases with an another
amplified ridge over the North Atlantic. PoPs have been maintained
for this forecast package; however, uncertainty exists with where
the fetch of monsoonal moisture will be positioned by next weekend
and one can expect adjustments to these PoPs until then. Otherwise,
hot and breezy conditions are forecast through the end of the period
as surface troughing and return flow persist across the entire CWA
with temperatures remaining in the middle-upper 90s by next weekend.

Sincavage

&&

.AVIATION...
(18Z TAFS)
Issued at 1208 PM CDT Sun Jun 23 2024

VFR will prevail through the TAF period.

&&

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

$$

SHORT TERM...01
LONG TERM....09
AVIATION...01