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Area forecast discussion 
National Weather Service Fort Worth Texas
258 am CST Sat Jan 31 2015

Discussion...
as I write this an area of virga sits over western counties
moving northeast at 25 miles per hour. An occasional rain drop may make it
to the surface...but the 00z sounding showed very dry air between
750 and 950 mb. It will take a bit of precipitation to moisten this
layer. As a result...although precipitation onset timing has changed
little...I have decreased quantitative precipitation forecast since a good portion of our
expected rain will evaporate as it moistens this layer. Many
areas will now struggle to get a quarter inch out of this
system...with a bit more than a third of an inch possible in the
northwest and northern counties.

The precipitation should also shut off faster Sunday as the accompanying
cold front dries out the lower levels. Better precipitation chances are
now confined to the southeastern half of north/central Texas after
noon.

The upper low prognosticated to sweep east across coastal Texas Tuesday
night into Wednesday has its track shifted a bit farther
north...and low probability of precipitation have been adjusted a bit north as well. I
would not be surprised to see the track shift back south again
tomorrow...that seems to be the pattern with this system. At any
rate...with the trough passage another cold front will sweep
south across the area. GFS and European model (ecmwf) generate quantitative precipitation forecast behind this
front...but moisture is limited to below the inversion and this
would appear to be drizzle rather than showers or rain.

Temperatures will remain seasonably cool...with Wednesday likely the
warmest day of the week with highs in the upper 50s/low 60s. 84



&&

Aviation...
/issued 1136 PM CST Friday Jan 30 2015/
VFR will prevail through tonight with ceilings near fl150 and light
east/southeast winds. Middle and upper level moisture will continue to
increase overnight with ceilings dropping to near fl100 Saturday
morning. A very dry layer of air will persist between 5-10
thousand feet through morning which means precipitation aloft will
be primarily virga with turbulence likely below fl100. Any rain
drops that can survive the trip through the dry air and reach the
surface will be few and far between with no impacts to aviation
operations...so will leave rain out of tafs until late afternoon
and evening when dry air is finally worked through and column
saturates. Just some periods of light rain is expected at taf
sites Saturday night...with amounts light. Some scattered showers
with brief moderate rainfall will hold off until frontal passage Sunday
morning.

Below 5000 feet...moist return flow will organize and bring MVFR ceilings
into the taf sites from SW to NE during the afternoon hours. Ceilings
should continue to lower to IFR early to middle Saturday evening with
the aid of rainfall and continued low level moist/warm advection.
Winds will become more southeasterly and increase to 10-15kt by
sunset...becoming more southerly Saturday night. It is possible
LIFR ceilings may occur after 6z...but this possibility is too low to
include in dfw extended taf at this time.

Tr.92





&&

Preliminary point temps/pops...
Dallas-ft. Worth, Texas 55 48 57 29 44 / 60 90 60 10 5
Waco, Texas 55 51 61 32 47 / 60 80 70 10 5
Paris, Texas 54 44 55 27 42 / 40 90 70 10 5
Denton, Texas 53 45 54 28 44 / 70 90 60 10 5
McKinney, Texas 55 46 56 28 43 / 60 90 70 10 5
Dallas, Texas 55 48 58 30 44 / 60 90 60 10 5
Terrell, Texas 56 49 59 30 44 / 50 90 70 10 5
Corsicana, Texas 56 51 61 31 45 / 50 80 70 10 5
Temple, Texas 56 52 63 33 48 / 60 70 70 10 5
Mineral Wells, Texas 52 46 53 28 46 / 90 80 40 10 5

&&

Forward watches/warnings/advisories...
none.

&&

$$

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