Turner Downs Forecast Discussion

FXUS62 KRAH 190222

National Weather Service Raleigh NC
922 PM EST Mon Jan 18 2021

High pressure will build across the area early Tuesday morning.
Another cold front will move across the Mid-Atlantic states and the
Carolinas late Tuesday into early Wednesday with high pressure
building in again on Wednesday.


As of 922 PM Monday...

Evening water vapor imagery depicts weak westerly flow aloft in the
wake of a departing trough earlier in the day. The stratocu that
developed across the area during the afternoon hours dissipated
after sunset as expected, with only a few clouds remaining along the
NC/VA border. Despite the clear/mostly clear skies across the
region, temps have only dropped into the mid 30s as of 02Z, owed in
large part to lingering BL mixing and 5-8kt surface winds.

For the rest of the night, temps will continue to fall into the
mid/upper 20s, then remain mostly steady for the rest of the night
as high clouds associated with a weak upstream trough will move into
the area. This shortwave trough is moisture starved and won`t bring
about any precip to the area, and should be of minimal impact
outside of dealing with the overnight temperature forecast. Overall
the forecast for this evening is in great shape, only made minor
adjustments based on observational trends and incoming 00Z model


As of 150PM Monday...

A strong westerly flow develops on Tuesday with a band of 100kt
winds at 500 mb stretching from the OH Valley toward the VA
coast. An approaching upper level trough drops into the OH
Valley on Tuesday night. Pockets of mid and high level moisture
will move across the region during the period resulting in
variably skies but dry conditions. A period of mid level clouds
is expected on Tuesday morning and early afternoon before
relaxing a bit. Another round of high level clouds will move
into the region on Tuesday night before shifting east early
Wednesday. Low level thickness values will moderate a bit on
Tuesday with the axis of coldest air located over the northwest
Piedmont on Monday shifting east toward the northern Coastal
Plain on Tuesday. Highs should moderate an average of 3 to 6
degrees on Tuesday and range in the lower to mid 50s with a few
upper 50s possible across the Sandhills and southern Coastal
Plain. Lows on Tuesday night will be moderated by clouds cover
and the mixing ahead of the approaching trough. Lows should
range in the 30s. -Blaes

As of 300 PM Monday...

Cold front will exit the area bringing clear skies in the afternoon
and overnight with high temps in the upper 40s in the north and low
50s in the south. Wednesday night temperatures will drop into the
upper 20s low 30s. Thursdays weather becomes more unsettling as a
short wave will move into the region from the southeast. Moisture
from the Deep South will advect north and eastward and spread
throughout the region. It is difficult to time exactly as when the
onset will occur Thursday morning but with most of the moisture not
arriving till late afternoon any precipitation falling in the early
morning/sunrise hours could be of wintry mix as temperatures will be
below freezing in portions of the Northern Piedmont. Wintry mix will
not last long and after daybreak, all precipitation will be falling
as liquid. Highest PoPs are Thursday night into Friday morning with
southern half of CWA continuing to have slight pops through the
afternoon Friday. A break from one system to the next, weekend
temperatures will be near normal with highs in the upper 40s and low
50s. The start of next week an upper level ridge will help move a
series of disturbances from the west bringing our next chance of
unsettling weather for the beginning of the work week.


As of 620 PM Monday...

High confidence in VFR conditions for the 24-hour TAF period. Skies
have cleared with loss of daytime heating. Some mid and high-level
clouds will stream in during the overnight and tomorrow afternoon
from the west in advance of a cold front moving through early
Wednesday. The gusty winds that were present earlier this afternoon
have died down and this should continue through the overnight with
winds out of the west-southwest around 5 knots. Southwest winds
tomorrow will be around 10 knots with gusts to 15 knots with high
pressure to our south.

Outlook: A cold front tracks through central NC early Wednesday
morning. In advance of the cold front, there could be a brief period
of LLWS (prior to 12Z Wed) as low-level winds approach 30 knots
above a stable surface layer, as well as VFR ceilings. Otherwise,
VFR conditions expected to persist through Thursday. Another cold
front and mid-level disturbance advances through late Thursday and
Friday, bringing potential for sub-VFR ceilings and light





NWS RAH Office Area Forecast Discussion