Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/13/18
Area Forecast Discussion
National Weather Service Birmingham AL
703 PM CST Mon Feb 12 2018
For 00Z Aviation.
Quite a bit of moisture located in the lowest 8k ft, with much
drier conditions aloft. It appears there is a bit more convergence
around 925mb, right in the moisture zone. Additionally, a weak low
at 850mb was located just north of the area. This was all
collocated with a fairly tight overall moisture gradient. RAP
analysis has some weak MUCAPE in this zone too. Therefore,
increased rain chances for the remainder of the afternoon and into
the evening hours centered on I-59. Rain amounts should be light
but think there is a good chance it measures. Expect this area of
light showers to diminish in coverage overnight.
Previous short-term discussion:Through Tonight.
Cloudy skies will continue overnight due to a stalled out surface
front over southeast Alabama and southwest flow aloft. Showers
have been developing along the I-20 corridor this afternoon,
mainly west of I-65. The rain has been forming along an zone of
weak convergence between 925 mb and 850 mb. This zone of convergence
will become oriented more north to south as a wedge develops over
Georgia and shifts into east Alabama. Overall expect areal coverage
of showers to diminish this evening, possibly becoming more of the
drizzle variety. Temperatures have remained in the 40s across
north Alabama this afternoon due to cloud cover and rain. Expect
temperatures will hold steady or even rise slightly across the
north as warm air advection increases aloft.
Tuesday through Monday.
Ridging at 850mb slides eastward into Northern Florida on Tuesday
as the surface high pressure builds in across the Coastal Mid-
Atlantic. This will set up a cold air damming pattern resulting in
a backdoor cold front moving into Central AL. Each new model run
has trended drier with this front, so have only mentioned a slight
chance for showers. In all likelihood, the only noticeable impact
from this backdoor front is moderation of the high temperatures
in the eastern portions of the state on Tuesday afternoon.
A wedging pattern sets up later Tuesday into Wednesday with the
ridging remaining in place to our south and east and an elongated
trough through the Northern and Western portions of the CONUS.
Models continue to show a convergent moisture axis stretching
through North MS, North AL, and into TN. Our northern counties could
see some increased rain chances with this boundary early Wednesday
through Thursday. The GFS and EC disagree on how long this moisture
axis remains with the ECMWF drying it out earlier on Thursday.
Have kept at least chance PoPs in the north on Thursday to account
for the wetter GFS solution.
Late Thursday into Friday, a surface low moves through the
Midwestern States and stretches a cold front southwestward through
the MS River Valley. This front will push south-southeastward into
Central AL sometime on Friday, but models are still carrying about a
6-12 hour difference in timing, which isn`t unusual this far out.
The GFS is quicker and pushes the front and any rain chances out of
the area by Saturday morning, but the Euro keeps the frontal passage
slower and rain lingers into Saturday. Therefore, I`m keeping at
least slight chance PoPs into Saturday to account for the slower
ECMWF. The forecast for later Saturday through Monday becomes
uncertain with models hinting at another front pushing southward
into the area. The timing hasn`t been consistent with model runs, so
in coordination with all neighboring offices, we`ve decided to keep
PoPs in the 35-45% range for now. If models become more consistent
with the frontal timing, we could see an increase in those PoPs in
00Z TAF Discussion.
Low level moisture remains high throughout the period. Varying
lifting mechanisms will be in place and the ceilings should hold
tight. The forecast consists of IFR/MVFR ceilings and some vis
restrictions of at least MVFR. SHowers and light drizzle are
possible overnight with lesser rain chances on Tuesday.
Light northerly winds are expected with ceilings becoming IFR
before 06z for most locations. These ceilings should hold until at
least 15z before slowly rising to MVFR. Winds swing around to the
east and southeast on Tuesday but remain rather light.
A cold front has stalled near the I-85 corridor. Moist conditions
will continue through tonight along with patchy light rain.
Mostly cloudy skies will prevail through the week, along with a
chance of showers. The best rain of rain will be across the
northern half of Alabama. Overall, no fire weather concerns due to
lighter winds, high relative humidities, and good overnight
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 42 60 50 63 57 / 80 20 30 60 50
Anniston 46 61 50 65 58 / 70 20 20 40 40
Birmingham 43 64 53 66 60 / 50 20 30 50 40
Tuscaloosa 42 66 55 68 61 / 30 10 30 40 40
Calera 44 66 53 67 59 / 40 20 20 30 30
Auburn 51 63 51 67 58 / 20 20 20 20 20
Montgomery 50 69 54 70 60 / 30 20 20 20 20
Troy 52 69 54 71 59 / 20 20 20 10 10
Area Forecast Discussion
National Weather Service Duluth MN
534 PM CST Mon Feb 12 2018
Issued at 529 PM CST Mon Feb 12 2018
Updated aviation section for the 00Z TAFs below.
.SHORT TERM...(This evening through Tuesday)
Issued at 223 PM CST Mon Feb 12 2018
Increasing clouds and a chance for some light snow will be the main
focus for tonight. A positively-tilted shortwave trough will
eventually make its way across Montana and the Dakotas this evening
and overnight. Ahead of the wave, surface high pressure will make
its way across the Great Lakes, which will enhance southerly
return flow and warm air advection (WAA) behind it. This WAA will
bring some chances of light snow, mainly from the Brainerd Lakes
region, northeast towards the Minnesota Arrowhead region. Model
guidance disagrees somewhat regarding the amount of QPF this WAA
will generate, but the RAP soundings indicate some decent
dendritic snow growth, along with some better isentropic lift
within the dendritic snow growth layer. I decided to increase the
PoPs/QPF from the previous forecast to account for the dendritic
snow growth, but capped the QPF to two-hundredths or less of an
inch through the overnight period. In all, one-half inch or less
of snow will be possible for portions of the Northland through
Tuesday morning. The increased cloud cover should keep the wind
chills elevated enough to keep from reaching Wind Chill Advisory
criteria. Overnight lows will still be on the chilly side, with
temps between 0 and 10 below zero.
The mid-level shortwave will eventually arrive Tuesday morning, but
some drier air will lead to diminished chances of snow, with any
lingering precipitation winding down by the afternoon. Skies are
expected to become mostly sunny as well by the late
morning/afternoon hours. South to southwest winds look to be pretty
gusty Tuesday as stronger low-level winds develop along the mid-
level trough. 850 mb level winds are progged to reach between 40 to
50 knots. Both the 12.12z NAM and GFS model soundings indicate
boundary layer mixing to reach up to 900 mb, so some stronger
momentum transport is expected. Wind gusts could reach between 20 to
25 mph by Tuesday afternoon. Thanks to the WAA, temperatures Tuesday
will be much warmer compared to today, with highs in the lower to
middle 20s across the area.
.LONG TERM...(Tuesday night through Monday)
Issued at 223 PM CST Mon Feb 12 2018
The extended period will feature big temperature swings and an
absence of any strong storm systems.
Warm air advection will continue Tuesday night into Wednesday but we
expect most of the region to remain dry. It`s possible more stratus
will develop Tuesday night into Wednesday than is currently expected
and some drizzle/freezing drizzle would then be possible. However,
based on the amount of dry air in place initially we will continue
with the dry forecast. We expect highs Wednesday in the mid thirties
to around forty. The warm temperatures will be short lived as a cold
front will sweep through the region Wednesday night. There will be a
chance for light snow with the front and colder air Wednesday night
into Thursday but accumulation is expected to be less than an inch.
Northerly winds will continue to draw colder air into the Northland
Thursday with lake effect snow possible along portions of the South
Shore, mainly in the snowbelt of Ashland and Iron Counties. Some
accumulation will be possible there late Wednesday night into
Thursday night before winds back to more westerly. Highs Thursday
will be 10 to 25 degrees colder than Wednesday and range from 10 to
15 above in far northern Minnesota to the mid to upper twenties over
Friday will be dry with highs in the teens. Temperatures will then
moderate into the weekend as warm air advection develops ahead of a
low pressure system. Highs Saturday and Sunday will range from the
mid twenties to mid thirties for most areas. There may be some light
snow on Saturday with the warm air advection with chances increasing
Sunday as the low nears the Northland. Although heavy snow looks
unlikely with this low, some light snow accumulation and possibly a
wintry mix will be possible.
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 529 PM CST Mon Feb 12 2018
VFR to begin with, but MVFR possible as snow showers traverse
through the area tonight. Minor accumulations expected at most TAF
sites and potentially an IFR vsby restriction in the heavier
showers. Most guidance went VFR, but opted to go with MVFR due to
the nature of snow showers to quickly drop vsbys. LLWS may become
an issue towards the end of the TAF period as stronger winds move
overhead after 10Z.
.PRELIMINARY POINT TEMPS/POPS...
DLH -3 24 16 36 / 20 30 0 0
INL -10 23 15 35 / 30 20 0 10
BRD 0 25 15 37 / 40 10 0 0
HYR -4 26 16 39 / 10 10 10 0
ASX -1 29 19 40 / 10 20 0 0
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
937 PM CST Mon Feb 12 2018
Temperatures and dew points have been running at least a few degrees
cooler than our current forecast across areas where clear skies have
lasted a bit longer over our northern and northeastern counties.
Therefore, we have retrended our temperatures and dew points based on
current observational and model trends, decreasing low temperatures
tonight across most of the region to the mid to upper 30s for our
northern counties and lower to mid 40s elsewhere. Our northern
counties will most likely not see temperatures decrease any further
tonight and may even see them come up a degree or two as low clouds
continue to build back in from the south and east. Patchy fog that
develops mainly over the southeastern half of the region and the low
clouds should keep temperatures down tomorrow, so we decreased high
temperatures slightly for tomorrow as well in agreement with trends
from the last several model cycles.
.PREV DISCUSSION... /ISSUED 535 PM CST Mon Feb 12 2018/
00Z Aviation forecast below.
BKN-OVC 3500-5000 foot deck prevails across western half of the CWA
along with patches through the I-35 corridor. There is also an MVFR
deck 1500-2500 feet just northeast of AUS as well as down across the
Coastal Plains. HRRR and CONSShort guidance suggests the MVFR deck
building back into the AUS area 01Z-03Z and into the SAT area
03Z-05Z. Ceilings should then gradually lower into IFR category
06Z-08Z. Should also see -DZ and BR developing along the I-35
corridor closer to daybreak and then continuing through much of the
day, also resulting in MVFR visibility. Just west of the I-35 TAF
sites guidance suggests LIFR conditions Tuesday morning across the
eastern Hill Country. Farther west, the MVFR ceilings are expected to
develop at DRT 11Z-13Z. NE-E winds around 5 kts overnight at AUS and
SAT and SE 5-10 kts at DRT.
PREV DISCUSSION... /ISSUED 237 PM CST Mon Feb 12 2018/
SHORT TERM (Tonight through Tuesday Night)...
No hazards expected through tomorrow as moisture return flow begins
overnight allowing for low clouds and areas of fog to develop along
with scattered drizzle and light rain showers.
Temperatures this afternoon continue to struggle to warm in areas of
thicker clouds over the Coastal Plains and the Rio Grande Plains. The
bisection of the I-35 corridor and the Hill Country has left some
spots warming into the mid 50s while others remain in the upper 30s
to low 40s. The Hill Country will be the warmest area today as they
will see the most solar insolation. Northeast to east winds persist
across South-Central Texas as surface high pressure axis extends
southwest across the Mississippi River Valley.
Surface winds will remain northeasterly through Tuesday but flow in
the H85 and higher layers will become SE and veering with height to
the SW/W. Isentropic upglide over the remnant cool surface layer
will prompt light drizzle, fog, and low clouds to develop early
Tuesday morning. With the influx of moisture, temperatures will
remain near steady overnight in the low to mid 40s. Confidence is
high in scattered drizzle to light rain showers through out the day
Tuesday and thus the basis for higher rain chances. However,
accumulations will be quite minimal with only a few hundredths of an
inch likely for areas along and east of the I-35 corridor.
LONG TERM (Wednesday through Monday)...
A continuation of drizzle, light rain, and foggy mornings is expected
into Thursday along with a nice warm up with highs into the 60s and
even 70s/80s by Thursday afternoon. A big change is expected Friday
and Saturday as a cold front sweeps through the area, giving us the
best chance for widespread rain. Rain chances look to continue
however into late weekend and early next week as well. Will need to
monitor early to mid next week as a stronger system could result in
stronger thunderstorms across NE/E portions of the area.
By mid-week, a surface high pressure system will be anchored across
the subtropical Atlantic in conjunction with a H5 ridge over the
Gulf of Mexico. This pattern will provide excellent funneling of
higher moisture content into the region. Morning lows will increase
Wednesday and Thursday. Lows Thursday will only be in the upper 50s
to low 60s given the higher surface dewpoints expected. A strong cold
front is advertised to move through the region Friday per GFS and
ECMWF. Stronger dynamics look to stay north while adequate isentropic
upglide occurs up and over the front Saturday into Sunday. Highs on
Friday will be highly dependent on frontal timing that afternoon.
Despite the high moisutre content, instability appears to be weak on
Friday and this will limit heavy rain and thunderstorm potential with
the frontal passage.
Moisture will quickly return by late Sunday in association with a
strong surface low developing in the Southern Plains. Showers and
thunderstorms look to be possible again next Tuesday in a more
unstable regime. Pockets of stronger thunderstorms and heavy rain
could occur with this system based on current projections. Stay
tuned for more details as the week and weekend progress.
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 37 50 48 66 60 / 30 40 30 30 20
Austin Bergstrom Intl Airport 36 49 48 66 60 / 30 40 30 30 20
New Braunfels Muni Airport 39 54 49 66 59 / 30 40 30 30 20
Burnet Muni Airport 36 50 46 68 59 / 10 40 30 30 10
Del Rio Intl Airport 44 57 48 70 57 / - - 10 10 10
Georgetown Muni Airport 36 49 47 67 60 / 20 40 30 30 10
Hondo Muni Airport 43 56 50 67 58 / 20 30 30 30 10
San Marcos Muni Airport 38 49 48 66 60 / 30 40 30 30 20
La Grange - Fayette Regional 39 52 51 68 62 / 30 50 30 30 20
San Antonio Intl Airport 41 53 50 67 60 / 30 30 30 30 20
Stinson Muni Airport 42 54 50 67 60 / 30 30 30 30 20
Area Forecast Discussion
National Weather Service Jackson MS
933 PM CST Mon Feb 12 2018
Updated for evening discussion.
Minor changes have been made during this evening update. Hi-Res
models have shied away from light rain chances late tonight,
higher probability persist tomorrow morning in the southwest
region. Some patchy fog in the southeast region may develop in
early morning hours where sufficient moisture lingers, however it
won`t be a problem for travel.
Overall it will be a cloudy night with low temperatures in the
lower 40s in the majority of the region with the exception of the
Northern Delta. Clear skies have remained further north and have
had temperatures already drop into the mid-30s, however those
overcast conditions to the south will roll in and radiation
cooling will diminish. /SKH/
Prior discussion below:
Tonight through Tuesday:
Latest RAP and satellite imagery showed southwest flow aloft with
some anafrontal warm advection patchy light rain decreasing from
west to east. With strong cold advection in place temperatures
were slow to rise with readings into the 40s for mid afternoon.
For tonight, CAM guidance pushes the patchy light rain out of the
region by this evening. Clouds will decrease across the northwest
during the evening before filling back in after midnight.
Overnight lows will be from the lower 30s northwest to the middle
40s southeast. For Tuesday we will get some isentropic lift which
will bring some showers over our western areas during the morning
and develop east during the day. Pwats will increase to 1.6
inches. It will be warmer on Tuesday with highs from the lower 50s
northwest to the middle 60s southeast./17/
Tuesday night through the coming weekend:
Unsettled conditions look to continue for the foreseeable future,
but at least temperatures should generally trend warmer. In fact,
readings may average 20 degrees above normal by Thursday and at
least a few locations will probably experience a maximum
temperature that day touching the 80 degree mark.
This warming trend will also be quite evident across the region on
Wednesday, but there will also likely be a good deal of showers
and embedded thunderstorms through at least the first half of the
day over northern zones, coincident with the warm front lifting
back north through the region. This precipitation will probably
start Tuesday night with the latest ECMWF model suggesting the
best northward Gulf of Mexico moisture transport up into the
Arklamiss Delta could prompt some heavy downpours and rumbles of
thunder up there. As of this juncture we do not anticipate any
hazardous weather issues Tuesday night into Wednesday, but we will
certainly be closely monitoring trends in heavy rain potential
(especially considering the recent regional heavy rains and
associated nearly-saturated soils).
But by Wednesday night into Thursday the warm front and the bulk
of synoptic lift in the troposphere will likely have focused to
the north and northwest of our region. Lots of low clouds and even
some isolated showers should continue, but we do expect at least
partial sunshine by Thursday afternoon.
But the good weather Thursday will not last through Friday.
Another cold front will arrive from the northwest through the
day, dropping temperatures quickly and bringing rain showers and
maybe a few isolated thunderstorms. The air mass coming in the
wake of this front should not be as cold as the current air mass,
but it will nonetheless feel a little chilly considering the
anomalous warmth the day prior.
Unfortunately, confidence is increasing that this frontal zone
coming in on Friday will hang up in the vicinity of our region
through the coming weekend. Of course this spells clouds and
pockets of showers when southern stream disturbances (which are
anticipated) move overhead the wavering baroclinic zone in the
00Z TAF discussion:
The cold advection stratus event continues over the ArkLaMiss with
widespread MVFR to IFR category ceilings expected to persist
through Tuesday at all locations. Some temporary clearing may take
place in the GLH/GWO area this evening before lower stratus
redevelops and expands again. Vsby may also be reduced by BR/DZ
during the overnight and early morning, especially over southern MS.
By Tuesday afternoon, there could be sufficient mixing to erode
the stratus a little more than today, but this is still
questionable given the strength of the near-sfc inversion. /EC/
.PRELIMINARY POINT TEMPS/POPS...
Jackson 41 55 54 75 / 13 17 28 38
Meridian 41 55 53 74 / 16 17 25 34
Vicksburg 39 53 51 75 / 10 27 30 40
Hattiesburg 43 60 59 76 / 9 14 15 23
Natchez 41 56 55 75 / 6 31 24 27
Greenville 35 48 46 69 / 4 25 70 70
Greenwood 37 52 50 73 / 5 21 58 69
Area Forecast Discussion
National Weather Service Midland/Odessa TX
510 PM CST Mon Feb 12 2018
See 00Z aviation discussion below.
MVFR CIGs are currently being observed well southeast of MAF, but
are expected to surge northward tonight. There is quite a bit of
uncertainty on if they will reach MAF, spread farther west, or
even come in lower than currently indicated with some forecast
soundings showing CIGs possibly at BKN004-008. Therefore will keep
the previous forecast in place and reevaluate at the next TAF
.PREV DISCUSSION... /issued 245 PM CST Mon Feb 12 2018/
WV imagery shows the upper-lvl trough that made landfall on the OR
coast yesterday is now over nrn NV, putting West Texas and Southeast
New Mexico under SW flow aloft. At the sfc, return flow has
resumed, and thicknesses are forecast to increase thru Thu. As
such, after another cool day today, temps should climb to right
around normal Tue afternoon, then ramp up to unseasonably warm
Wed/Thu, w/temps feeling more like late May than mid Feb. Along
w/the warmup, continued return flow will advect Gulf moisture into
the area, w/50F+ dewpoints creeping into the lwr Trans Pecos by late
Meanwhile, the upper trough over NV is forecast to jog SW, to just
off the SoCal coast by 06Z Wed. It is here, similar to yesterday`s
runs, that the models begin to diverge on solutions. The GFS wants
to lag offshore, while the Canadian and other models open, move
east, and phase into SW flow aloft. However, all models dig a
secondary trough out of the PacNW that intercepts the first. Again,
the GFS holds back, while the other models depict an eastward
progression. As the trough moves east, it is set to push a strong
cold front into the FA by 12Z Fri, taking temps well-blo normal by
As the trough moves east, large-scale ascent ahead of the trough,
combined w/the approaching RR quadrant of an upper jet, could kick
off -SHRA over the NW zones as soon as Wed night. Chances increase
thru Friday, when ensembles increase a swath of PWAT over the region
to near 4 std devs above normal, making this the best chance for
significant rainfall over West Texas and Southeast New Mexico in
quite some time. As for frozen precip, model soundings are
considerably moistened up thru the column compared to yesterday,
bringing the possibility of a changeover to snow in some locations
Fri night. W/warm days ahead, if it does happen, little
accumulations are to be expected attm. Warm noses could
significant;y alter things, as well. For now, we`ll not get too
detailed, as things will change between now and then.
Precip should taper off Sat, w/a warmup in temps to back above-
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 28 62 37 78 / 0 0 0 0
Carlsbad 25 63 35 76 / 0 0 0 0
Dryden 32 63 39 71 / 0 0 0 0
Fort Stockton 33 67 42 79 / 0 0 0 0
Guadalupe Pass 35 64 44 70 / 0 0 0 0
Hobbs 24 62 35 74 / 0 0 0 0
Marfa 27 70 33 77 / 0 0 0 0
Midland Intl Airport 31 63 37 77 / 0 0 0 0
Odessa 31 64 38 76 / 0 0 0 0
Wink 28 65 34 76 / 0 0 0 0
Area Forecast Discussion
National Weather Service Blacksburg VA
844 PM EST Mon Feb 12 2018
High pressure to the northwest will move east across New England
tonight and wedge south into the Carolinas overnight and
Tuesday. Rain will then spread back into the region Wednesday as
the next in a series of disturbances moves northeast along the
Appalachians. Another cold front will arrive from the northwest
by the end of the week with added rain chances in store.
.NEAR TERM /THROUGH TUESDAY/...
As of 840 PM EST Monday...
Forecast remains quite uncertain in regards to light precipitation
overnight including ptype given drier air aloft overtop a developing
wedge that will gradually cause added low level cooling late given
easterly flow. Latest Hires solutions remain uncertain in regards
to northward extent of any light rain or drizzle but at least
show spotty amounts southern half by daybreak. This just as low
level cold advection will be sinking southwest toward the southern
Blue Ridge where current temperatures remain well above freezing.
Latest forecast soundings do continue to show a cold nose aloft,
around 3000 feet and above where freezing rain/drizzle could
occur overnight with levels lowering espcly heading up into the
New River/Roanoke Valley region by early Tuesday. However forecast
amounts remain very light/spotty and should only cause light elevated
icing along the Parkway including east facing slopes mainly after
midnight. Thus hanging onto earlier forecast of passing spotty
rain/drizzle developing south in the next few hours. This before
perhaps trending toward more pockets of freezing drizzle late
as precip slips northward into already colder air in place.
Otherwise no headlines given uncertainty and more elevated
nature to any icing with clouds filling in at least southern
half including very low pops for now. Did bump up lows across
the southern third where clouds likely to limit falls until the
combo of weak cold advection and light precip help cool the low
levels by morning. May even see colder values after 12z pending
precipitation coverage as appears Tuesday morning will be when
the center axis of the wedge and spotty rain coincide.
Previous discussion as of 255 PM EST Monday...
A strong area of high pressure centered over the western
Atlantic will continue to block/slow down weather features from
moving eastward into tonight. The high pressure will weaken some
and eventually move south Tuesday, allowing the weather pattern
to become more progressive.
A wave of low pressure tracking along a stalled front across
the coast of NC/VA has move offshore this afternoon. The chance
for showers will diminish as dry northerly flow increases going
into this evening. A strong surface high pressure (1045 mb)
centered over New England will wedge south overnight into
Tuesday. This wedge will bring cooler air (upper 20s to mid 30s)
into the region by Tuesday morning. Models have a Theta-E ridge
over the region with the boundary north towards DC. This
Theta-E ridge and weak isentropic lift will bring a chance for
light precipitation to the area Tuesday. The 12Z GFS has light
precipitation falling in the morning (midnight to noon), while
the NAM is later after sunrise into the afternoon. HRRR also
brings precipitation into the area after midnight and keeps it
through the day. So, the chance for precipitation look good,
especially areas south of 460, however amounts will only be a
couple of hundredths of an inch. With morning surface
temperatures ranging in the upper 20s to mid 30s, precipitation
type will consist of rain, drizzle and/or freezing rain. Some
flurries are possible north of hwy 460. Ground temperatures
across the area are warm enough to not have any ice problems on
roadways. Any ice (glazing) will be on elevated surfaces such as
vehicle, decks and trees, therefore no headlines are expected
at this time. Temperatures will warm above freezing during the
afternoon for areas inside the wedge, however they will not make
it out of the 40s. Areas outside of the wedge
(Bluefield/Mountain Empire) will warm into the 40s.
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 255 PM EST Monday...
Cool high pressure will be situated from off the Northeast
coast southwest to over central North Carolin Tuesday evening.
Some lingering onshore moisture may keep a low threat of rain in
place early in the southeast but most of the models have the
area dry. Should see some clearing early in the foothills, but
next warm frontal boundary/advection of moisture starts shifting
northeast toward the TN valley by Wed morning and overall
looking at a chance of rain that day, with best chance staying
from far Southwest Virginia into Southeast West Virginia, with
less threat in the NC piedmont.
Upper heights build but remain fairly zonal and fast with
moisture shifting a little further north by Thursday though best
axis of lift and moisture convergence will be situated from TN
northeastward toward the eastern Ohio Valley such that our
mountains will see the higher pops Wed night-Thursday night. At
the moment rainfall amounts are not amounting to too much, with
higher rainfall totals staying west of the Appalachians along
better upper forcing and low level warm advection ahead of storm
system in the central Plains.
Tuesday night starts off chilly with high pressure in place
though clouds may offset the colder temps. Lows will range from
the lower to mid 30s in the Alleghanys/Greenbrier to the
piedmont, with lower to mid 40s out toward Chilhowie and along
the NC/TN mountains, where warm advection kicks in late.
Thinking non-diurnal trend with temps warming late in the west.
Wednesday clouds and rain chances will keep temps down some but
warm advection will at least push highs toward 60 degrees. So
for those heading out for Valentines, take an umbrella.
Mild temps for mid February Wed night and even warmer Thursday,
but clouds may limit this. After lows in the upper 40s to lower
50s Wed night, look for highs Thursday in the mid 60s to lower
Lows again Thursday night, will be mild from the upper 40s to
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 120 PM EST Monday...
Active pattern across us into the weekend, though not
completely wet either. Appears models have frontal boundary
shifting southeast through us Friday with a fast west-east upper
flow. As the front takes on more of a west-east orientation it
will slow/stop across the Gulf Coast States and Southeast. The
ECMWF gives it enough of a push thanks to sharper trough over
the Canadian Prairies into the Great Lakes, so may see the
deeper moisture nudge south of our forecast area by late
Saturday into Saturday night. Meanwhile the GFS slows it faster
keeping threat of precip around Saturday over the southern half
of the forecast area, and given orientation of the upper flow,
leaned toward this solution. Colder air chasing the moisture may
bring a changeover to snow/snow shower mainly along and west of
the Blue Ridge by late Friday night into Saturday morning.
High pressure situates itself over the Carolinas and mid-
Atlantic Sunday, but will start to see return flow aloft as
western trough ejects eastward into the Desert Southwest,
turning the flow southwest over us and sending moisture our way.
Looking at a warm front lifting northward across the TN and Mid
MS Valley Sunday evening into the Great Lakes Monday. Some
spillover of precip will likely overrun this boundary and make
for a cloudier Monday with a chance of rain. If the precip
arrives early enough Monday a wintry mix could occur, but models
overall are keeping it milder.
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
As of 615 PM EST Monday...
Nose of dry air has sliced low clouds in two this evening with
sub-VFR across the far western sections around KBLF and over
the southeast at KDAN. Expect some of this drying to perhaps
provide for brief improvement in flying conditions west with
low cigs likely lingering south before perhaps edging back north
along the Blue Ridge overnight. This will create quite a
variation in cigs from IFR/LIFR at KBLF and MVFR around KDAN
with more scattered clouds elsewhere to start.
Latest short term guidance remains inconsistent in exactly how
far north lower cigs will advance overnight per drier air, with
trend toward keeping VFR outside of the far southwest through
morning. This likely too optimistic given development of the
wedge so including more clouds and at least VFR cigs south of
KLWB overnight. In addition, spotty light precipitation is
possible, but confidence is low on timing/location and whether
or not any even affects the TAF sites. Latest HRRR/GFS models
still have light precipitation starting as early as midnight,
before shifting north along the southern Blue Ridge, and then
across southern sections toward daybreak Tuesday. Thus may
include a period of -DZ espcly around KDAN late.
The surface high shifts east on Tuesday with the wedge lingering
despite some drying aloft under increasing warm advection just
above the surface inversion. This may tend to trap lower cigs
espcly southern and western sections for much of the day although
any precipitation looks quite light and spotty. However still
low confidence on the expanse of sub-VFR cigs, but appears most
sites will see some improvement to VFR by late in the afternoon.
Extended Aviation Discussion...
As the high/wedge moves east of the area by Wednesday, another
disturbance will track from the south central U.S. toward the
Mid-Atlantic with more rain and sub-VFR ceilings. Another front
may also bring widespread rainfall and sub-VFR ceilings to the
area by Friday. Brief drying behind this front may bring a
return to VFR on Saturday as high pressure again wedges in from
the north over the weekend.