Wind Advisory 27, NWS Greenville-Spartanburg, SC

024 
WWUS72 KGSP 300237
NPWGSP

URGENT - WEATHER MESSAGE
National Weather Service Greenville-Spartanburg SC
937 PM EST Sun Dec 29 2019

NCZ033-048>053-058-059-062>064-301045-
/O.CON.KGSP.WI.Y.0027.000000T0000Z-191230T1100Z/
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-
Including the cities of Banner Elk, Newland, Luck, Waynesville, 
Tuckasegee, Rainbow Springs, Kyle, and Highlands
937 PM EST Sun Dec 29 2019

...WIND ADVISORY REMAINS IN EFFECT UNTIL 6 AM EST MONDAY ABOVE
3500 FEET...

* WHAT...Southwest winds 20 to 30 mph with gusts up to 55 mph.

* WHERE...The North Carolina mountains above 3500 ft, especially
  in the central and southwest mountains.

* WHEN...Until 6 AM EST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
257 PM EST Sun Dec 29 2019

.SYNOPSIS...
A cold front will cross the region from the west late tonight and
Monday morning. Dry and cool weather will return behind the front
Monday night and should last through mid week. Another storm system
arrives at the end of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 230 PM EST Sunday: A large occluded low pressure system over
the center of the Country, will bring a cold front in from the west
late tonight. Ahead of the front, persistent deep-layer isent lift
is keeping cloudy skies and areas of light rain showers across the
FA. Guidance generally agrees that moisture will be a little more
shallow as we head into the evening, making the better PoPs more
confined to the southerly upslope areas of the Escarpment. Temps are
quite mild, considering the overcast skies, and will not drop much
tonight, as WAA ramps up further with a 50-60 kt southwesterly LLJ.

As the front crosses the TN Valley and enters the Southern
Appalachians, there looks to be about 300-500 J/kg of MUCAPE with a
narrow frontal band of convection. The Smokies and southern NC
mountains may have some thunder as the line pushes in, and a nonzero
chance of severe winds (Day 1 Convective Outlook has a marginal
risk). From there, confidence in any deep-layer CAPE is low. Both
the NAM and GFS fcst soundings show a lingering mid-lvl inversion,
which may cap convection around 700-650 mb. Also, the main lobe of
vorticity that will pivot NE thru the large upper low will remain
west of the area, so the front will not be strongly forced in the
mid and upper levels. With that said, the strong LLJ will supply
some theta-e to likely support at least a little CAPE as the line
crosses the FA. Will mention slgt chc to chc thunder thru most of
the area overnight. The LLJ will likely produce advisory-level gusts
in the high terrain of the NC mountains. But with strong WAA, this
likely will not impact locations below about 3500 ft, so will hoist
a wind advisory for elevations above 3500 ft from 6 PM this evening
to 6 AM Monday. One other issue we continue to monitor, is any
excessive rain/flood threat. The trends continue to be lower, as the
frontal precip should be fairly narrow, and fast-moving. Only
expecting 1-1.5" of additional QPF in the SWLY upslope areas, and
generally 0.25-0.5" elsewhere.

The front, and associated band of convection, should cross the area
during the pre-dawn hours, reaching the I-77 corridor by around 12z.
At that point, the line may start to gain more instability to work
with, but will probably be exiting to our east by the time it may
pose much of a severe threat. The Day 2 Convective Outlook has a
marginal risk well to our east over the Raleigh area. Skies should
start clearing out rapidly during the mid-to late-morning, and while
CAA starts to ramp up, thicknesses will be slow to fall. So most of
the area will have another warm day. It will be breezy, but not
expecting anything near advisory criteria behind the front.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 210 pm Sunday: Dry and generally seasonably cool conditions
can be expected through the short term, as surface high pressure
oozes into the southeast quadrant of the country. Clouds should more
or less be limited to the TN border areas, where persistent W/NW
flow will act on an increasingly shallow layer of moisture. Temps
are forecast to be within a couple of degrees of climo through the
period.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
As of 220 pm Sunday: Global model guidance is in rather good
agreement that a highly amplified pattern, with a deep central U.S.
trough and potent southern Conus short wave likely bringing active
weather to the Southeast by the end of the week. However,
differences in the details persist, especially regarding timing,
with the ECMWF exhibiting differences of as much as 12 hours with
the GFS. The two models are in agreement that precip probability
will ramp up with warm frontal activation during the day Thu.
However, while the GFS quickly sweeps a cold front and moisture east
of the area by Friday afternoon, the ECMWF does not do so until
early Saturday. The official forecast will feature pops increasing
to categorical by Thu evening, then due to the inherent uncertainty,
only trending slowly down through Thu night and Friday, with token
chances lingering into Fri night. One potential key item that
guidance does agree on is a relatively late start to precip chances
on Thu, such that p-type concerns stemming from any cold air
lingering in mtn valleys should be minimal.

Otherwise, the potential for mountain northwest flow snow showers
will exist on the back side of this storm system into the weekend,
although that is also a subject of some controversy as the global
models do not agree on how quickly the next short wave trough will
begin impacting the East, and therefore on how long northwest flow
will be in place in the wake of the late week system. For now, token
20-30 pop will be featured through much of the weekend, mainly
across the TN border zones.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Sites are starting out mainly IFR, with some
MVFR at KAVL and KCLT. But with another round of more widespread -
SHRA, expect some reduction in cigs and vsby again thru the aftn
hours. As a cold front approaches, a strong LLJ will enter the area
tonight, and this may help lift cigs a bit overnight, while
widespread -SHRA continues. There may be some LLWS concerns, late
tonight, but there is expected to be just enough mixing to preclude
a mention in any of the TAFs. A line of more intense -SHRA, with a
chance for embedded TSRA will cross the area in the 09-15z time
frame from west to east. Will mention PROB30 for TS at all sites
except KHKY. SW winds should become gusty overnight thru Monday
morning. Skies should start improving quickly after the front passes
mid-to-late morning.

Outlook: VFR conditions will prevail across the area starting by
Monday aftn through midweek as dry high pressure returns behind the
front. Moisture from the next system may start to return on Thursday.

Confidence Table...

            20-02Z        02-08Z        08-14Z        14-18Z
KCLT       Med   70%     Med   73%     High 100%     High  90%
KGSP       High  93%     Med   75%     High  81%     High 100%
KAVL       High  88%     High  87%     Med   79%     High 100%
KHKY       High  89%     High  83%     Med   77%     High  93%
KGMU       High  91%     High  80%     Med   78%     High 100%
KAND       Med   77%     Low   52%     High  81%     High 100%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Wind Advisory above 3500 feet from 6 PM this evening to 6 AM
     EST Monday for NCZ033-048>053-058-059-062>064.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...ARK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...ARK

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
537 AM EST Sun Dec 29 2019

GAZ017-018-026-028-029-NCZ035>037-056-057-068>072-082-501>510-
SCZ004>014-019-301045-
Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-Davie-
Catawba-Rowan-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union-
Caldwell Mountains-Greater Caldwell-Burke Mountains-Greater Burke-
McDowell Mountains-Eastern McDowell-Rutherford Mountains-
Greater Rutherford-Polk Mountains-Eastern Polk-Greater Oconee-
Greater Pickens-Greater Greenville-Spartanburg-Cherokee-York-
Anderson-Abbeville-Laurens-Chester-Greenwood-
537 AM EST Sun Dec 29 2019

This Hazardous Weather Outlook is for northeast Georgia, the western
Piedmont and foothills of North Carolina, and upstate South Carolina.

.DAY ONE...Today and tonight.

A few thunderstorms are possible late tonight and early Monday
morning. Some of the storms will have heavy downpours and occasional
cloud-to-ground lightning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-NCZ062>065-SCZ001>003-301045-
Rabun-Macon-Southern Jackson-Transylvania-Henderson-Oconee Mountains-
Pickens Mountains-Greenville Mountains-
537 AM EST Sun Dec 29 2019

This Hazardous Weather Outlook is for northeast Georgia, western
North Carolina and upstate South Carolina.

.DAY ONE...Today and tonight.

A cold front will approach the mountains today and will cross the
region late tonight and early Monday morning. A few thunderstorms are
possible ahead and along the front. Some of the storms will have
heavy downpours, strong gusty winds, and occasional cloud- to- ground
lightning. Rainfall amounts may exceed two inches over areas which
received excessive rainfall during the past week. Localized minor
flooding will be possible along smaller streams and low lying areas.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-048>053-058-059-301045-
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-
537 AM EST Sun Dec 29 2019

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Today and tonight.

A cold front will approach the mountains today and will cross the
region late tonight and early Monday morning. A few thunderstorms are
possible ahead and along the front. Some of the storms will have
heavy downpours, strong gusty winds, and occasional cloud-to-ground
lightning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

PM