Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX
FXUS64 KFWD 211157 AAB
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
557 AM CST Sat Jan 21 2017
VFR conditions prevail currently at the major airports but
abundant moisture near the surface and light winds have led to
areas of dense fog over the last hour or so. Fog and low cigs
extend from just east of Temple to Palestine northward to Canton.
A few locations southeast of Dallas have also reported lower
visibilities over the last few minutes. Low level flow is out of
the southwest so we don`t anticipate a strong westward surge in
low cigs/vis through the morning. At this time...will leave the
mention of any fog or low clouds out of the current TAFs.
Otherwise...a strong upper trough is expected to swing through the
Southern Plains this evening. This system is already causing
surface pressures to fall across the region and this will
eventually lead to increasing winds through late this afternoon.
In addition...strong forcing will spread across North Texas today.
While the low levels (with the exception of the near surface
layer) are very dry...there is ample moisture in the mid levels.
Extensive mid level cloud cover is expected today and the strong
forcing will likely squeeze out some scattered showers through the
evening hours. This is already being observed on area radars.
While most of this precipitation is not currently hitting the
ground...there should be an increase in scattered showers and
possibly a few thunderstorms through the day today. The main
concern with these will be increased air turbulence to aircraft
and strong downburst winds. Even the lightest of precipitation
into the drier low level air will be sufficient for strong
downdrafts. TAFs will continue with VCSH through much of the day
Later tonight...as the upper trough moves east...winds will become
more westerly then northwest by Sunday morning. There is also the
possibility of some wrap around low clouds and will address this
with a BKN025 in the extended portion of the DFW TAF from 12-16Z
Quick update to include the Dense Fog Advisory, which is in effect
until 10 AM for locations south and east of a Terrell to Marlin to
Killeen line. Stratus and fog continues to surge northward early
this morning, and several sites are now reporting visibilities of
a half mile or less. Depending on trends, it`s possible we`ll need
to add a county or two to the north of the current advisory area
as the morning progresses.
.PREV DISCUSSION... /ISSUED 341 AM CST Sat Jan 21 2017/
Our energetic and active weather pattern continues today with
several interesting features to watch. The first is an area of
low clouds and fog which is percolating across the Hill Country
early this morning. Southwesterly winds in the lowest few thousand
feet will continue to advect this into our region over the next
few hours. Have added in patchy fog wording roughly south and east
of a Bonham to Rockwall to Killeen line, and areas of fog south
and east of a Canton to Corsicana to Temple line as this stratus
deck surges northeastward. We`ll be holding off on issuing a dense
fog advisory for the time as it`s still a bit unclear if the 20
kts of flow just off the surface will help keep things
sufficiently mixed enough to preclude widespread dense fog.
Out to our west, pressure falls have commenced across the Texas
Panhandle early this morning, heralding the nascent stages of
surface cyclogenesis as the nose of a 120+ kt jet streak is
overspreading the state. Surface low pressure will rapidly
materialize this afternoon and the race eastward across southern
Oklahoma tonight. As this low progresses eastward, the pressure
gradient will tighten which will result in the development of
breezy west to southwest winds later this morning and afternoon.
In addition, forecast soundings to our west indicate the
development of what should become a very deeply mixed atmosphere.
Momentum transfer output from BUFKIT soundings indicate the
potential for mixing down some 35-40 kts of flow locked up just
above 800 mb by this afternoon. While statistical guidance does
not concur, almost all available high-resolution guidance appears
to be keying in on this signal, indicating strong winds/gusts
materializing this afternoon and evening. It`s possible that cloud
cover ultimately limits the amount of mixing, but given enough of
a signal from guidance, we`ve gone ahead and hoisted a Wind
Advisory for our far western row of counties (Young, Stephens,
Eastland, Comanche, and Mills) from 1 PM to 6 PM.
The next focus is on precipitation chances this afternoon and
tonight. While moisture is in short supply--PWATS are generally
running about a half inch or less--abundant lift from this
approaching system will likely be able to squeeze out whatever
little moisture is available. There may be a few showers this
morning, but better chances will arrive later this afternoon and
this evening. Given the aforementioned deep inverted-V profiles,
any shower/storms will be capable of producing strong and gusty
downburst winds, although widespread severe-caliber wind gusts are
not anticipated at this time. Precip chances will decrease from
west to east late tonight. As this low clears our area on Sunday,
we`ll be left with dry weather through next week.
As this low departs, strong winds are once again in the cards, and
we will likely need another Wind Advisory--this time for much if
not all of the area--late tonight and into Sunday. We will defer
judgment on this to the dayshift, however.
Temperatures will moderate into the 70s on Monday and Tuesday
before a reinforcing cold front sends temperatures back into the
50s on Wednesday where they will likely remain to close out the
rest of the week.
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 70 48 63 43 67 / 30 30 10 0 0
Waco 73 49 64 40 71 / 30 20 5 0 0
Paris 68 46 60 42 62 / 20 50 20 0 0
Denton 70 46 62 39 66 / 30 30 10 0 0
McKinney 69 47 62 41 65 / 30 40 10 0 0
Dallas 71 48 63 43 68 / 30 30 10 0 0
Terrell 70 47 63 43 66 / 30 40 10 0 0
Corsicana 74 48 64 43 68 / 30 30 10 0 0
Temple 74 49 65 42 72 / 30 20 5 0 0
Mineral Wells 72 46 62 40 71 / 30 20 5 0 0
Dense Fog Advisory until 10 AM CST this morning for TXZ121-122-
Wind Advisory from 1 PM this afternoon to 6 PM CST this evening