Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
1248 PM EST Wednesday Jan 28 2015
high pressure extending from the Great Lakes to the Gulf Coast
will build east across the area tonight and move offshore
Thursday. A cold front will move across the region Thursday night.
A few showers may occur ahead of the front. Dry high pressure
will return Friday and Saturday.
Near term /through tonight/...
cold high pressure extending from the Great Lakes to the Gulf
Coast will build east into our area this afternoon. Subsidence
associated with the ridge will keep skies clear. Early afternoon
readings in the low/middle 40s are well on the way to highs in the
middle 40s north to lower 50s south.
The area of high pressure will be overhead tonight. Expect strong
net radiational cooling with lows ranging through the 20s given
near calm wind and dry airmass. The local radiation technique
indicated 24 degrees at cae and 23 at ags. The normally
cooler/sheltered locations could dip into the upper teens.
We may see high clouds increasing towards dawn as the upper
ridge axis shifts east of the area. If these clouds are dense
enough they could hold temperatures up a few degrees.
Short term /Thursday through Saturday night/...
a series of upper impulses will dive southeast across the east Continental U.S....in a
general northwest flow aloft. Surface high pressure axis will be in place
over our forecast area (fa) early Thursday...and will quickly
weaken and shift to our south and east during the day as a cold
front approaches. The front will move through Thursday night with
limited moisture to work with and dry low level air in place ahead
of it. Models continue to indicate minimal precipitation chances...slight
chance of light rain or sprinkles at best. Behind the front...dry
cold Canadian high pressure will build in Fri/Sat.
Long term /Sunday through Wednesday/...
GFS/European model (ecmwf) in good agreement this time period...and both are slightly
slower with the approach of the next system. Closed upper low over
the SW Continental U.S. Will shift south into northwest mex...while northern stream
trough digs over the central Continental U.S. Sunday and shifts east into the east
Continental U.S. Monday. This will lead to a developing surface low near the middle
to lower miss valley Sunday which shifts NE into New England Monday.
Latest GFS/European model (ecmwf) not indicating much in the way of a low near the
Gulf Coast. This farther north track of the low will inhibit
formation of significant persistent wedge over our forecast area. So will trend
higher on temperatures sun. Rumble of thunder may also be possible late
sun/sun nt to accompany the likely probability of precipitation. Models bring front through
early Monday...with high pressure building in Monday into Tuesday. Both
GFS/European model (ecmwf) stall the front to our south with a new wave forming along
bringing moisture back into our region Tuesday nt or Wednesday.
Aviation /18z Wednesday through Monday/...
VFR conditions will occur through the taf period.
Dry air mass will provide clear skies this afternoon. Could see high
clouds increasing around dawn on Thursday as the upper ridge axis
shifts east of the taf sites. Surface high pressure will cross the
area this afternoon and tonight then move offshore Thursday afternoon
as a cold front approaches from the west. Northerly winds 5 to 10
knots this afternoon...becoming near calm around sunset. Southerly
winds increasing to around 10 knots Thursday afternoon. The air mass
will remain too dry for overnight fog.
Extended aviation outlook...brief restrictions possible Thursday
night as a cold front crosses the region. Ceiling/visibilities restrictions
possible Sunday as moisture returns ahead of a low pressure