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Area forecast discussion
National Weather Service Fort Worth Texas
304 am CST Fri Dec 6 2019

Short term...
/today and tonight/

As of early this morning, a cold front continues to move through
the area and is positioned from near Sherman to Alliance to
Comanche. Temperatures are still in the mid 50s, but northwest
winds are invading the area and are gusting to near 30 kt across
our northwest counties. The center of the surface low is located
across far southeast Oklahoma and this will continue to move off
to the east through the morning allowing colder air to filter into
the region. Despite strong forcing for ascent associated with a
passing shortwave, limited moisture has resulted in only widely
scattered light rain showers mainly well off to the north and
east. We'll keep pops out of the forecast through the morning
hours. Some lower cloud cover could persist mainly east of I-35
into the afternoon hours.

Northwest winds will gradually become more northerly today, but
will stay up into the 15 to 20 mph range. Temperatures will likely
remain in the low/mid 50s along the Red River with lower 60s to
the south behind the front. Another digging trough approaching the
West Coast of the U.S. Will mean that the southern branch of the
jet stream will be positioned over the southwest U.S. This should
result in an increase in high cloud cover, especially later in the
day.

By tonight, we'll remain within the shallow cool airmass with a
weakening northerly flow. There will be some moisture just above
the shallow frontal inversion and as winds above the surface
become more easterly overnight, some lower cloud cover could
spread back westward toward the I-35 corridor. While no
precipitation is expected, the increased cloud cover will impact
overnight lows. Lows will drop to near freezing across our
northwest counties, while areas from I-35 eastward are likely to
remain in the 40s.

Dunn

&&

Long term...
/Saturday Onward/

Synopsis: after a relatively benign week, a return to a more
active pattern is in store for next week. Temperatures will be
near to a little below normal, along with increased rain chances.
Still, widespread hazardous weather appears unlikely at this
time.

We will start off the forthcoming weekend with upper-level
ridging. This will mean milder temperatures by Sunday (saturday
will still be cool owing to Friday morning's frontal passage), and
rain-free conditions. A subtle shortwave trough will pass across
Oklahoma on Sunday, but the only impact on our sensible weather
will be slightly increased cloud cover (and even then, only high
clouds).

Heading into the work week, global models are in good agreement
that a deep mid-tropospheric trough will dig into the interior
Continental U.S.. this should help to drive a cold front across north and
central Texas during the day Monday. Rain showers should develop
along and ahead of the front, with a few thunderstorms possible
across parts of central Texas where low-level moisture will be
more abundant. Rain will persist into Monday night as positive
differential vorticity advection over the region continues to
promote vertical ascent. While temperatures will fall behind the
front, the freezing line should still be well to our north up in
northern Oklahoma or even southern Kansas, thus winter weather
will not be a concern. Rain should taper off during the day
Tuesday as the upper-level trough axis shifts to the east, and
upper-level heights rise. Cool temperatures can be expected on
Tuesday, with highs struggling to get out of the 50s. Breezy north
winds will keep wind chills in the 40s all day. Tuesday night
will be the coldest night of the week, with lows likely to be in
the 30s across the entire County Warning Area. A light freeze
appears likely for areas north and west of Dallas/Fort Worth (with
the urban core of the metroplex itself likely remaining just
above freezing).

We should get a brief break in the rain on Wednesday, before
another deep upper-level trough swings into the western and
central Continental U.S. On Thursday. At least low rain chances will exist on
Thursday and into Friday along yet another surface cold front, but
with moisture content being a bit lower, and some run-to-run model
disagreements, we have opted to keep pops in the slight chance to
chance categories at this time.

37

&&

Aviation... /issued 1119 PM CST Thu Dec 5 2019/
/06z tafs/

Concerns and challenges: timing wind shift and veering surface
winds to the northwest and frontal passage...then wind speeds after 12z Friday.

A cold front, extending from a surface low near ksps continues to
move through kabi/ksps/kokc areas at this hour. This feature was
moving progressively southeast just in advance of a potent mid level
impulse over northwest OK toward the Red River valley at 05z. Frontal passage still
appears to be around 09z at dfw Metro terminals, then 11z-12z at
Waco and across central Texas. Otherwise, the one big change was to
remove MVFR cigs, as better saturation on the frontal inversion
within the 925mb layer will likely stay across southeast OK/East Texas into Arkansas
and la. Northwest winds will increase to between 15-20 mph by mid morning
with gusts 25-30 knots possible through early afternoon, before
decouple later in the afternoon allows for surface winds to veer
northerly and drop to around 10 knots or below by nightfall Friday
evening.

No precipitation is expected due to very dry low-mid levels, but
there will be plentiful cirrostratus off and on throughout the day
Friday into Friday night. Some spotty altostratus or altocumulus
may occur as well, but regardless, any cigs will be VFR category.

05/

&&

Preliminary point temps/pops...
Dallas-ft. Worth 59 40 60 46 70 / 0 0 0 0 0
Waco 65 40 63 45 72 / 0 0 0 0 0
Paris 60 39 59 43 64 / 0 0 0 0 0
Denton 57 35 59 45 70 / 0 0 0 0 0
McKinney 59 37 59 45 68 / 0 0 0 0 0
Dallas 61 40 60 46 70 / 0 0 0 0 0
Terrell 62 39 62 45 69 / 0 0 0 0 0
Corsicana 63 42 62 45 69 / 0 0 0 0 0
Temple 64 41 63 45 73 / 0 0 0 0 0
Mineral Wells 58 34 59 43 71 / 0 0 0 0 0

&&

Forward watches/warnings/advisories...
none.

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