Area Forecast Discussion
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FXUS62 KRAH 190836
Area Forecast Discussion
National Weather Service Raleigh NC
336 AM EST Thu Jan 19 2017
High pressure will build over the region today. A wave of low
pressure is expected to move in from the southwest Thursday night
and Friday. This will be followed by a strong storm system for late
in the weekend.
.NEAR TERM /THROUGH TONIGHT/...
As of 335 AM Thursday...
Surface high pressure and an upper level ridge will be in control
for the day today. This will result in clear skies, slightly cooler
temperatures, and very little wind. High temperatures around 60
Cloud cover will begin to increase from the southwest this evening
as a southern stream system approaches. Precipitation chances will
increase for the western Piedmont after 6z and rain should begin
before 12z. Elsewhere should remain dry. Lows in the mid 40s.
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 335 AM Thursday...
Rain will continue across central NC on Friday as a disorganized
frontal system moves across the area. Rain will continue into the
late afternoon or early evening ending from west to east as it does
so. Total accumulations of rainfall are expected to be somewhere in
the neighborhood of a tenth to a quarter of an inch. Temperatures
will be dictated by cloud cover but warm air advection ahead of the
system will bring max temps up into the mid 60s across the south,
with upper 50s to low 60s across the north. Lows Friday night in the
upper 40s to low 50s.
.LONG TERM /Friday through Wednesday/...
As of 350 PM Wednesday...
The first wave of low pressure in the strengthening jet aloft
is forecast to dampen out Thursday night and Friday as it tracks
NE across the TN Valley to the mid-Atlantic coast. Likely POP
for rain expected, especially in the west and north for a period
late Thursday night and early Friday, with lesser chance POP in the
SE. QPF with the weakening system should be 0.25 or less in the NW,
with 0.10 or less SE. Skies should return to variably cloudy
Friday afternoon and evening between systems. Mild temperatures
will continue with lows in the 40s. Highs Friday in the 60s, except
upper 50s NW.
Friday night through Saturday...
The next system is forecast to approach from the SW late Friday
night and Saturday. The Gulf of Mexico is forecast to be wide
open as the flow between the high pressure off the SE coast and
the deepening upper storm out west increases from the south. A
leading warm front is expected to lift from the Gulf Coast states
northward into our region Saturday. Strong WAA and overrunning
will result in a large shield of rain that is expected to over-
spread much of our region late Friday night and Saturday. The
highest POP and QPF for now will be across the west and south
portions of the Piedmont Friday night, gradually spreading north
Saturday. Mild temperatures will become warmer in the SE later
Saturday as the warm front tries to lift into the region. It
appears it will have some In-Situ Damming resistance over
the Piedmont; however, there should be rather minimal damming
this time due to the lack of a strong enough high pressure
and/or dry air for evaporative cooling to support anything more
than some weak In-Situ Damming in the Piedmont Saturday.
There should still be some highs holding in the 50s NW, ranging
to 60s SE Saturday with rain likely.
Saturday night through Monday...
Heavy rain and the chance of thunderstorms the main hazards
for this period. Severe storms possible in the warm sector
by late Sunday.
The very potent mid/upper level system is expected to have the
potential to produce fairly wild weather conditions (warm and
stormy) for our region (for January standards). The main storm is
expected to strengthen as it lifts out of the FL Panhandle Sunday
toward our region Sunday night. A stronger warm front is forecast to
lift into our southeastern counties Sunday afternoon/night as the
surface low deepens. Widespread rain, some heavy is expected
Saturday night and Sunday. Temperatures should hold in the 50s
Saturday night, then reach into the 60s Sunday. The readings may
hold or come up even more Sunday night depending on the warm front
The main low pressure track is still uncertain and this will
play a role in our severe storms threat late Sunday and Sunday
night/Monday morning. Widespread rain should hold down the
instability. However, dew points are forecast to surge into the 60s
in the warm sector Sunday night. If this warm sector does surge into
the region (or a portion of the region), the likelihood of severe
weather will increase dramatically. There is still much uncertainty
with these details and they will be hashed out in later model runs.
For now, we will continue to carry periods of rain Sunday and Sunday
night. There will be a chance of thunderstorms, and severe weather
is possible. The timing would be late Sunday afternoon into Monday
morning (with the triple point low and cold frontal passage expected
Monday morning) ending the storminess.
We will broad brush the heavy rain and thunderstorm potential hazards
in the entire region - until the details become more certain in
Behind the front Monday, we will keep slight chance POP Monday,
with partly sunny skies returning. Very mild to warm air will
lead to some 70s for highs as CAA will be blocked by the Appalachians
(negatively tilted storm system lifts north of the region).
True CAA will likely lag the front until Monday night and Tuesday.
Even so, lows will be in the 40s. Highs are expected in the 60s
Tuesday (Pacific origin air mass).
A turn to colder weather is anticipated by recent model trends by
late next week.
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 120 AM Thursday...
VFR conditions across the area this morning will continue overnight
will clear skies and calm winds. Dewpoint depressions are high
enough that fog is not expected to be an issue tonight. VFR
conditions are expected to remain through the entirety of the TAF
Long term: Another system will move into the area later in the day
on Friday and could cause adverse conditions in the form of low
ceilings. Precipitation will also be possible. A series of
disturbances will keep weather unsettled through the weekend before
a more significant weather system moves in on Monday with the
potential for some strong thunderstorms.