National Weather Service Raw Text Product

959 
FXUS62 KRAH 200737
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
237 AM EST Tue Feb 20 2024

.SYNOPSIS...
Surface high pressure centered over the Northeast states will extend 
southwestward through the Carolinas through mid week. A storm system 
will cross the Mid Atlantic region late Thursday through Friday. 
High pressure will build over the Southeast states for the weekend.

&&

.NEAR TERM /TODAY THROUGH TONIGHT/...
As of 150 AM Tuesday...  

Dry and quiet day, but with some high clouds. The surface high 
currently centered over the Northeast states will continue to extend 
to the SSW through central NC, and as this will be topped by light, 
dry, and diffluent 925-850 mb flow from the NE and N, our low levels 
will stay quite dry today. A rather strong mid-upper level low can 
be seen clearly on GOES IR and layer WV imagery spinning over the MO 
Bootheel currently, and this feature is expected to track SE, 
passing just to our SW and S but still bringing an area of high 
clouds over the region today, from late morning through the 
afternoon, leading to several hours of milky sunshine. This slightly 
reduced insolation for a period of time should equate to slightly 
cooler highs today compared to yesterday. Today's low level CAA from 
the Northeast ridge will also cut a few meters off low level 
thicknesses today as compared to yesterday, but they won't be far 
from normal. Expect highs of 53-60, near to a degree or so below 
normal. As the upper low continue moving SE and exits off the GA/FL 
coast tonight, skies should become fair to mostly clear, and with 
light surface winds after sundown, radiational cooling conditions 
will be decent, favoring chilly lows of 25-32. -GIH

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 220 AM Tuesday...

The weak upper low sitting over the NC Outer Banks early this 
morning and the upper low passing to our SW today will congeal into 
a baggy closed low and trough over and off the Mid Atlantic and 
Southeast coast Wed, maintaining a deep dry flow from the N and NW 
from just off the surface trough the mid-upper levels, while narrow 
surface ridging hold across central NC. As the mid-upper trough 
slowly pushes further offshore through Wed night and the upstream 
mid-upper level ridging begins to build into our area from the W, a 
warm frontal zone aloft with an attendant band of moist upglide at 
around 300-310K will shift ENE into and through western and north 
central NC Wed night, resulting in an increase in mostly high clouds 
after midnight. But most of the night will be fair to mostly clear, 
esp from the Triangle to the S and E. With very little change in 
either air mass or advection pattern Wed as compared to today, we 
should again see highs of 53-60. Expect lows of 28-38 with light and 
variable surface flow gradually becomes southerly, esp in the W, as 
the surface ridge loses its grip on our area and we become 
increasingly under the influence of prefrontal WAA Wed night. -GIH

&&


.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 237 AM Tuesday...

Upper level flow will become increasingly zonal through the day 
Thursday as a potent shortwave trough sweeps across the southern 
CONUS. Meanwhile, another trough will dive southward from the 
northern Plains Thursday afternoon, with its attendant cold front 
approaching the western slopes of the Appalachians Thursday night. 
Across NC, clouds will increase through the day Thursday, as will 
temperatures. Highs should reach the low to mid 60s area-wide, 
followed by a mild night in the upper 40s to lower 50s.  Precip with 
the front is likely to hold off until late Thursday night/early 
Friday morning when the best upper forcing arrives across NC. By 
that time, moisture transport should be maximized with PW's in the 
1.00 - 1.25 inch range. Nearly 75-80 members of the grand ensemble 
show precip chances reaching a peak during the early morning hours 
on Friday, with numerous members (60-70) carrying precip into the 
mid/late morning hours as well. This certainly makes sense and is in 
line with previous forecast thinking. Rainfall amounts don't look 
overly impressive, with most ensemble forecasts in the 0.25 to 0.50 
range area-wide. There could also be a rumble of thunder coincident 
with FROPA Friday afternoon when a narrow band of pre-frontal 
surface-based instability on the order of 250 J/KG is realized but 
widespread strong/severe storms aren't anticipated. Temperatures 
Friday should reach the mid to upper 60s. Post-frontal lows will 
fall into the upper 30s to lower 40s. 

Saturday will see northwest flow aloft across NC, and there are an 
increasing number of ensemble members suggesting a fast moving post-
frontal shortwave trough sweeping through the area. While the 
passage of an upper trough is possible, precip chances look 
relatively slim. Post-frontal BL drying Friday night should scour 
out an appreciable amount of moisture and aside from an increase in 
cloud cover late morning into the afternoon (and some breezy 
northwest winds), the trough should have minimal sensible weather 
impacts. Behind this trough, dry weather should prevail Sunday into 
Monday as the flow gradually backs to zonal on Sunday and 
southwesterly on Monday. Temperatures will retreat into the 50s on 
Saturday, then gradually moderate into the 60s Sunday and 70s on 
Monday.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
As of 1240 AM Tuesday...

Confidence is high that VFR conditions will persist across central 
NC for the next 24 hours. An upper level disturbance diving through 
the Southeast states will bring a batch of mid and high level clouds 
across the region today, mainly from late morning through mid 
afternoon, however cloud bases will be well into VFR range. Surface 
winds will be mostly light from the NE and E, except 6-10 kts from 
14z to 23z. 

Looking beyond 06z Wed, there is a chance of sub-VFR cigs (most 
likely IFR) at RWI 09z-14z Wed morning, but otherwise VFR conditions 
will hold through at least Wed evening. We'll have another chance 
for sub-VFR conditions early Thu morning, again mainly at RWI, but 
they can't be ruled out at RDU/FAY as well. Sub-VFR conditions with 
rain chances and gusty winds are expected areawide Thu night through 
much of Fri. VFR conditions should return late Fri through Sat. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...Hartfield
SHORT TERM...Hartfield
LONG TERM...Leins
AVIATION...Hartfield