FXUS62 KRAH 271416

Area Forecast Discussion
National Weather Service Raleigh NC
1010 AM EDT Mon Mar 27 2017

A warm moist southerly flow will hold over the area through 
Wednesday. An upper level trough will cross the region beginning 
late tonight through Tuesday, bringing unsettled weather. A backdoor 
cold front will drop southward through the area late Wednesday 
through Wednesday night. Another storm system will cross the area 
Thursday night and Friday. 


As of 1010 AM Monday...

The band of light showers was slowly weakening and dissipating over 
the eastern Piedmont and northern Coastal Plain late morning. 
Rainfall this morning has been generally less than a tenth of an 
inch with this band. We will update the weather and POP grids to 
indicate scattered showers closer to the Interstate 95 corridor with 
a few isolated showers possible over the western Piedmont through 
around 18Z. This afternoon, it appears that a lull in showers will 
occur, supported by current data and by the Hi-Res convection 
allowing models, as the focus for storms will shift well to our west 
over the Tennessee Valley with the next short wave trough. This 
trough will set off strong to severe thunderstorms over TN/AL this 
afternoon and evening with weakening storms likely advancing into 
the NC mountains tonight. Before that time, a few showers/isolated 
thunderstorms may develop this afternoon - with a low chance POP 
warranted into the Triad region. 

Satellite data indicated some breaks developing over much of the 
Piedmont, with stratus confined to the NW Piedmont and Foothills. 
This is expected to burn off by early afternoon. Partly sunny skies 
will lead to increased mixing with SSW winds 10-15 mph. Highs should 
warm into the 70s to near 80 in the Sandhills. Readings in the N and 
E Piedmont and N Coastal Plain may be tempered a few degrees due to 
the slower clearing. 

Tonight, increasing POP later over the western third of the region 
with the convective threat increasing. Otherwise, very mild SW flow 
and at least partly cloudy skies will lead to lows around 60 (15-20 
degrees above normal). 


As of 330 AM Monday...

Tuesday and Tuesday night low pressure currently over the Arklatex 
area will track north of the area through the mid-Atlantic states 
and bring a very weak cool front with it. Maybe a bit better chance 
for thunder Tuesday afternoon, especially in the central and eastern 
portions of the forecast area as instability look a little better 
than on Monday afternoon and low-level lapse rates remain very 
steep. The proximity of the low to the north will provide upwards of 
25-30 kts of bulk shear to work with. As a result SPC, currently has 
the forecast area in a marginal risk for severe thunderstorms. While 
damaging wind should remain the primary threat, some better CAPE 
values aloft could result in some small hail. 

Temperatures will continue to be in the upper 70 to low 80s across 
the forecast area on Tuesday afternoon with lows in the mid 50s.


.LONG TERM /Wednesday through Sunday/... 
As of 205 AM Monday...

Wed-Thu: Behind the departing shortwave through, the mid level ridge 
axis will shift eastward over the Southeast through Thu, although by 
Thu it will be deamplifying as the next mid level low tracks through 
the central CONUS. NC will remain in the warm sector for much of 
Wed, as the backdoor front holds to our north until late in the day, 
when energy dropping into the polar low SE of the Canadian Maritimes 
helps drive the cool dense surface high pressure area southward into 
NC, with the front dropping through NC NNE to SSW Wed evening/night 
and settling south of the forecast area by Thu morning. Expect 
partly to mostly sunny skies Wed with flat cumulus beneath the warm 
layer focused around 700 mb. The low levels will cool/stabilize Wed 
night with increased moisture pooling around 900-800 mb, so expect 
cloudy skies, thickest in the west where moist isentropic upglide 
will be deepest. While a uniform northeasterly low level flow into 
the area will set up behind the front, the 850 mb anticyclone will 
shift off the Carolina coast, resulting in increasing 850 mb winds 
and strengthening moist overrunning atop the cool stable pool Thu, 
most evident over the NW CWA. Will keep skies mostly cloudy to 
cloudy with a chance of light rain or drizzle in the W from late Wed 
night through Thu. Highs Wed from lower 70s NE to around 80 SW. Lows 
45-55 NE-SW Wed night as cooler air pushes into the NE. Highs Thu 
from mid 50s NW to the mid 60s SE within a wedge regime. 

Thu night through Fri night: A volatile period as another strong mid 
level shortwave moves from the central Plains through the Miss 
Valley and Ohio Valley before crossing the Mid Atlantic region. At 
the surface, models depict the primary surface low tracking NE over 
or just south of SE MI through Fri, while the front to our south 
shifts back northward as a warm front, and a triple-point low forms 
over SW VA. While we would normally be skeptical about the complete 
passage of a warm front through NC immediately following a wedge 
regime, the parent high is rather weak and progressive and may be 
unlikely to put up much of a fight, so will depict a northward surge 
of higher dewpoints through much of the forecast area (excluding the 
far NW) on Fri. The primary low will then track up the St. Lawrence 
Valley Fri night while filling, as the triple-point low crosses WV 
and N VA and becomes the primary low near or just off the Delmarva 
peninsula, with W-to-E cold frontal passage through central NC. In 
terms of sensible weather, given the improving mechanisms to force 
ascent including mid level DPVA, strengthening upper divergence, and 
increasing 850 mb moisture transport, expect numerous showers and 
thunderstorms starting Thu night, peaking in coverage and intensity 
Fri, then exiting to our east Fri night as the mid level trough 
moves off the coast. A few strong storms are possible Fri, although 
the DPVA will have weakened a bit by the time the trough gets here, 
and we're lacking the instability and strong kinematics that might 
prompt greater concern. Lows Thu night mid 40s to low 50s, highs Fri 
62-72, and lows Fri night 49-55.

Sat-Sun: Weak modified surface high pressure builds in behind the 
front with another rough of shortwave ridging in the wake of 
Friday's trough and ahead of the next system moving from the Four 
Corners into the S Plains. Expect dry weather and partly cloudy to 
mostly clear skies. Thicknesses are projected to stay a bit above 
normal through the weekend, so expect highs from around 70 to the 
mid 70s. -GIH


As of 1010 AM Monday...

24 Hour TAF Period: Generally VFR CIGS expected this afternoon, with MVFR 
CIGS and VSBYS with showers/isolated thunderstorms expected to spread
eastward into the region after 06Z/tonight. Lower IFR CIGS with showers
likely between 06Z-12z/Tue, especially at KINT/KGSO/KRDU. This 
should spread into the KFAY and KRWI areas Tuesday. A return to VFR 
conditions is expected Tuesday night and Wednesday, with the exception 
of IFR to LIFR fog and stratus potential during the early morning Wed. 

Long term: A storm system is expected to push into the region Thursday
night and Friday with showers, low CIGS, and fog.






National Weather Service Glossary of Abbreviations
Back to forecast page
Expanded Version (without abbreviations)

Units: English | Metric

Find the Weather for any City, State or Zipcode, or Country:

U.S. State List | Severe Weather | Tropical Storms | Ski Conditions
United States | Canada | Central America | South America | Asia | Europe | Australia | Africa | Islands

Weather Underground

© Copyright 2017
The Weather Company, LLC