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223
FXUS62 KRAH 190715
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
313 AM EDT Wed Jun 19 2024

.SYNOPSIS...
High pressure will remain over the Mid Atlantic and Carolinas
through much of this week. Moisture will increase across the area
late this week into this weekend, bringing some increased rain
chances to the Sandhills/Southern Coastal Plain.

&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 313 AM Wednesday...

Water vapor imagery this morning continues to highlight the
anomalous mid-level ridge anchored over the eastern seaboard.  At
the sfc, latest analysis depicted a 1026 mb high off the Delmarva
coast. Sfc dewpoints across central NC remain in the lower to mid
60s (the plume of higher dew points > 70 has largely been displaced
well to our north and west).  The MIMIC-TPW satellite has remotely-
sensed PWAT of 0.5 to 1 inch across central NC, with a swath of
drier air over the north Atlantic retrograding towards the eastern
seaboard.  This drier air will continue to advect into our area
today promoting largely dry conditions and good mixing of dew points
later this afternoon. The HRRR and NamNest do simulate some isolated
decaying showers moving onshore and possibly reaching our far
eastern areas later this afternoon.  However, given the anomalous
dry air in place, highly doubtful that any of these showers measure.
While temperatures will again max in the upper 80s to lower 90s
under ely sfc flow, heat indices will remain well under advisory
criteria. Still, given the persistent hot temperatures this past
week, make sure to practice heat safety if spending considerable
amount of time outside.
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&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
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As of 313 AM Wednesday...

The anomalous mid-level ridge will de-amplify a bit Thursday as the
center of the anticyclone retrogrades over the southeast. The sfc
high will remain anchored offshore, positioned to continue light
esely flow and a steady stream of drier air across central NC (PWAT
remains ~70 to 80 % below normal Thursday). As such, max temps will
remain near 90 and heat indices will remain under criteria as dew
points once again mix out into the lower 60s. Void of lifting
mechanism and moisture, expect another dry weather day on Thursday.
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&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 200 PM Tuesday...

The anomalously strong upper level anticyclone will be centered over
the mid-Atlantic on Thu, then slowly drift westward to over the TN
Valley Thu night. The high will remain over the TN/mid-MS Valley Fri
into Sat before migrating further westward through the southern
Plains to the Desert Southwest over the weekend as a northern stream
trough tracks eastward through the Great Lakes and into the
Northeast. The trough should progress eastward through the Northeast
and mid-Atlantic Mon/Mon night. At the surface, somewhat flat high
pressure off the East Coast will drift slowly southward Thu and Fri,
while still ridging westward into the area. As the surface
wave/inverted trough associated with the weak low aloft moves inland
over FL/GA Thu/Fri, a warm front will slowly creep northward toward
central NC. By Sat, any lingering, ely/nely flow and relatively dry
air associated with the ridge will be gone and the now sely/sly
return flow around the high will result in an influx of warm, moist
air into the area from the Atlantic. Southerly/swly flow will then
dominate through Sun night/Mon, when trough strengthens over the
area ahead of an approaching cold front moving through the OH
Valley. There continue to be significant differences between the
medium-range guidance wrt this front, so it remains unclear whether
it will impact central NC or not, and when.

Temperatures: The big weather story continues to be the potential
heat risk this weekend into early next week. Initially under the
upper level high on Thu, the position of the surface high/ridge Thu
and Fri may help keep temps/apparent temps down across central NC.
However, as that ridge breaks down and the high aloft retreats
westward, central NC will be under the influence of nwly flow and
subsidence aloft and sely/southerly return flow at the surface,
resulting in increasing low-level thicknesses and surface dewpoints.
The result will be an increasingly hot forecast through the weekend
into early next week. For now, Sun appears to the the hottest day,
with highs in the mid to upper 90s and heat index values in the 100-
104 range across the eastern Piedmont, Sandhills, and Coastal Plain
regions of central NC. Highs on Sat and Mon should also top out in
the mid to upper 90s with heat index values mainly in the 94-101
range. There will also be limited relief from the heat overnight
from Sat night through Mon night, with temps struggling to dip below
70 degrees.

Precipitation: Since any rain associated with the area of low
pressure expected to move westward and inland over FL/GA on Fri/Sat
should remain south of central NC, the forecast remains dry through
at least Saturday. Showers and storms could develop Sun/Mon with the
trough extending from the Northeast through the mid-Atlantic and
Carolinas, however the models disagree on the chances and potential
coverage.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
As of 216 AM Wednesday...

VFR conditions will prevail through the 24 hr TAF period as dry high
pressure remains anchored just off the Carolina coast. Light ely sfc
flow will continue through the period.

Outlook: VFR and dry conditions should persist through Saturday.
Moisture and the chance for showers will return late this weekend,
especially near KFAY/KRDU/KRWI.

&&

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

&&

$$

SYNOPSIS...Leins
NEAR TERM...Luchetti
SHORT TERM...Luchetti
LONG TERM...KC
AVIATION...Luchetti