Area forecast discussion
National Weather Service Fort Worth Texas
116 PM CDT Thursday may 23 2013
Aviation...
morning MVFR ceilings/visibility continues to improve at all taf
sites and expect all sites to be VFR by 19z. Scattered cumulus will
persist through the afternoon with clouds temporarily clearing
with the loss of surface heating this evening. Expect MVFR to IFR
conditions to return to all taf sites overnight/Friday morning.
Conditions should be slightly better Friday morning due to
stronger surface winds. All low ceilings/fog should lift and
scatter between 17 and 18z Friday morning.
Am becoming a bit more concerned about the potential for
thunderstorms towards morning at the metroplex taf sites as per
the 06z run of the Texas tech WRF. Am not confident enough to add
mention of thunder or impacts to this taf package since most of
the storms should be west of the terminals...but may introduce in
later updates as new model data becomes available.
The outflow boundary from storms to the north this morning has
stalled and winds have turned back to the east/southeast. Expect
south to southeast winds through Friday morning at speeds between
6 and 13 knots.
79
&&
Update...
expanded the morning probability of precipitation southward due to expected continuation
south of the thunderstorm in southern Oklahoma. This storm should
slowly weaken with time with the loss of the nocturnal low level jet.
However...MUCAPES across the area are near 3000 j/kg which could
keep the activity alive despite the loss in lift. May have to do
an additional update to place probability of precipitation in the forecast further south
if the storm continues to hold together.
Hampshire
&&
Previous discussion... /issued 312 am CDT Thursday may 23 2013/
warm advection within the low level southeast flow is increasing dew
points throughout most of Texas this morning...and low level
moisture will remain in place for the next several days. A weak
warm front is located this morning near the Red River and convection is
starting to form in southern OK. Northwest flow aloft should advect the
storms over northeastern counties this morning.
Precipitation forecast over the next few days is quite difficult due
to model differences in handling the weak forcing and determining
the locations where storms will occur. The weak ridging over Texas
is not strong enough to produce a subsidence inversion to cap off
convection and model pop solutions for our area range from dry to
storms across much of North Texas. This uncertainty will last through
the weekend. Should models begin to converge on a solution...the
low probability of precipitation currently forecast will need to be raised for the areas
where the precipitation becomes more likely.
There is some consensus among the guidance which suggests that
convection will break out near the dry line in West Texas this
afternoon...with some sort of mesoscale convective system moving south and spreading east
Thursday evening into the overnight hours. Confidence is higher
in the southward moving mesoscale convective system than the convection spreading
east...so I have slight chance probability of precipitation in the forecast. The
convection may initially affect northwest counties...expanding
overnight to affect much of the northern half of the North Texas
area on Friday.
The process may repeat itself Friday evening...with low probability of precipitation
lingering in the northern half Saturday and across northern
counties through Sunday morning...highly dependent on where
convection does form and evolve into an mesoscale convective system...and what direction
it moves.
With south flow continuing through the week...temperatures will
remain seasonable with afternoon highs in the 80s/90s and morning
lows in the upper 60s/70s. Afternoon highs are highly dependent
on where and to what extent convection occurs.
In the extended...the European model (ecmwf) and GFS suggest that an upper trough
will move into the Great Basin by Thursday...extending south to
northern Mexico. This system has the potential to produce
convection next Thursday and Friday...and I added low probability of precipitation to the
grids for those two days. 84
&&
Preliminary point temps/pops...
Dallas-ft. Worth, Texas 87 72 86 71 85 / 20 20 20 10 20
Waco, Texas 90 73 88 69 87 / 10 10 10 10 10
Paris, Texas 83 68 81 69 82 / 40 20 20 10 20
Denton, Texas 86 70 84 70 83 / 20 20 20 10 20
McKinney, Texas 85 70 85 70 84 / 30 20 20 10 20
Dallas, Texas 87 73 88 72 87 / 20 20 20 10 20
Terrell, Texas 88 71 87 70 87 / 20 20 20 10 20
Corsicana, Texas 90 71 89 70 87 / 10 10 10 10 10
Temple, Texas 90 72 87 69 86 / 10 10 10 10 10
Mineral Wells, Texas 91 71 86 70 84 / 10 20 20 20 20
&&
Forward watches/warnings/advisories...
none.
&&
$$
79/85
