Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/22/19
Area Forecast Discussion
National Weather Service Albuquerque NM
548 PM MDT Fri Jun 21 2019
.AVIATION...
00Z TAF CYCLE
Wildfire smoke from southern Arizona will move into central New
Mexico this evening and continue into the overnight hours. The
Woodbury fire is not quite as active compared to this time yesterday
but areas of visibility will likely be restricted to between 5 and 8
miles in FU across much of central New Mexico overnight. Breezy to
locally windy conditions will redevelop late Saturday morning,
dispersing the smoke.
33
&&
.PREV DISCUSSION...312 PM MDT Fri Jun 21 2019...
.SYNOPSIS...
Very dry, warm, and breezy weather will continue through Saturday
with areas of smoke likely around parts of central and western New
Mexico. An unseasonably cool weather system will shift through
northern New Mexico late Saturday through Sunday and usher in well
below normal temperatures for late June. A few showers and storms
are possible over the Four Corners region and the northern mountains
late Saturday afternoon. A few of these storms may become strong with
hail, high winds, lightning, and brief rainfall. Temperatures on
Sunday will be 10 to 20 degrees below normal. High pressure will
develop over New Mexico through next week with warmer temperatures
again. The chances for showers and storms will increase each day next
week as moisture begins trickling northward into the area.
&&
.DISCUSSION...
The latest water vapor imagery shows deep layer southwest flow in
place over the southwest CONUS with very dry and hot conditions.
Smoke plumes from several fires over NM and AZ are beginning to
increase with southwest winds gusting up to 35 mph, temps in the 80s
and 90s, and humidity values in the single digits. The latest HRRR
smoke guidance shows another round of smoke moving into NM tonight
before dissipating quickly Saturday morning. An Air Quality Alert
has been issued again but for a larger area than last night.
An unseasonably deep upper level trough entering the Great Basin
today will move into the Four Corners Saturday and continue to force
dry southwest flow over most of NM. Max temps will trend cooler over
the far northwestern half of the state where mid level moisture will
also begin increasing along an approaching cold front. Guidance is
still consistent with showers and storms developing on the frontal
boundary shifting southeast by late Saturday afternoon. Model
moisture and instability does favor a few dry storms across the
northwest with wetter cells closer to the CO border and within the
higher terrain. Winds in the ABQ metro area will likely crank for an
hour or two Saturday evening as the cold front moves in aided by
convective outflow from the northwest. Meanwhile, a weak back door
boundary will begin sagging into northeastern NM where a few light
showers are also possible Saturday night.
Temperatures on Sunday will be remarkably cool with highs 10 to 20F
below normal for late June. Very dry air moving into the area behind
the upper level trough with strengthening surface high pressure will
lead to very chilly overnight lows for Monday morning. Near-freezing
temps are possible in many northern and western valleys. Temps will
rebound Monday with upper level high pressure building north into the
region. Overnight lows will remain chilly for northern and western
NM Monday night where strong radiational cooling takes place. High
temps will continue trending warmer into Tuesday.
Low level moisture will begin advecting northwestward into NM by late
Tuesday while upper level high pressure continues building over the
region. Each afternoon and evening through the end of next week will
feature more coverage of showers and storms as moisture deepens over
the southeastern half of the state.
Guyer
&&
.FIRE WEATHER...
...RED FLAG WARNING IN EFFECT FROM NOON TO 7 PM FOR AREAS ALONG AND
SOUTH OF INTERSTATE 40 DUE TO STRONG WINDS, LOW HUMIDITY, AND AN
UNSTABLE AIRMASS...
...DRY LIGHTNING POSSIBLE SATURDAY...
Breezy to windy conditions will subside in lower elevations through
the early evening with some ridge tops and exposed slopes keeping
some periodic gusts (but still less than this afternoon). Overnight
RH recovery will be considerably better tonight, but still only
rising to 30 to 40 percent in many central NM zones through early
Saturday morning. Smoke from AZ wildfires will also bring in haze
and low visibility to much of central NM tonight. Winds will also
shift direction in the northeastern quadrant of NM tonight as a weak
front sags in.
With the couplet of troughs aloft moving into UT and CO on Saturday,
breezy to windy conditions will persist into NM with cooler
temperatures feeding into the state. Concerns for marginally
critical fire weather will be focused to the east central plains
Saturday afternoon, but at this time the duration and spatial
coverage of critical winds appears to be too low for any Red Flag
highlights. Will continue to monitor this closely as high Haines
indices are also pegged over this area, too. Also worth mentioning,
a few showers and thunderstorms will attend/precede the latter
trough progression. These could be fairly high-based with extensive
evaporation beneath cloud bases and hence the potential for some dry
lightning in north central to northwestern zones. These drier storms
would also induce gusty and erratic winds of their own on local
scales.
With the aforementioned troughs passing into the plains by Sunday,
wind directions in NM will veer a bit more west or northwesterly
with breezy conditions still lingering. Mostly dry conditions will
also prevail with cooler than average temperatures (by 5 to 15
degrees).
Into next week, as a new dome of high pressure aloft builds over NM
temperatures will gradually rise closer to normal. Beneath the
ridge, low layer moisture will begin intruding the eastern plains
zones, periodically attempting to filter into central zones.
52
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM MDT this evening for the following
zones... NMZ105>109.
&&
$$
52
Area Forecast Discussion
National Weather Service Denver/Boulder CO
832 PM MDT Fri Jun 21 2019
.UPDATE...
Issued at 830 PM MDT Fri Jun 21 2019
There is still pretty decent coverage of showers and thunderstorms
across the CWA at this time. Upstream satellite and radar
pictures show that the northwestern CWA stands the best chance of
continue convection for a few more hours. There is less upstream
for the southeast CWA. The latest models keep good chance of
showers going for the western and northern CWA much of the
overnight period. Will make some adjustments to the pop, sky and
weather GFE grids accordingly. I allowed the Severe Thunderstorm
Watch to expire at 8 PM MDT.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 300 PM MDT Fri Jun 21 2019
An unseasonable, deepening and occluding upper low over northern
Montana is extending a trough into the Great Basin. Numerous
showers and thunderstorms are occurring in the warm conveyor belt
across Northwestern Colorado ahead of the 100 kt jet. Looking at
visible satellite, the more stable air over northern Colorado has trapped
waves in it, while below I-70 shows the more bubbling cumulus
field denoting the instability. Only really expecting severe storm
activity in this area, and perhaps slightly further north into
Arapahoe County due to the east-northeast storm movement. HRRR has
consistently been showing a swath of updraft helicity starting in
Elbert County east into central Lincoln County. This would match
up well with the best dewpoints. Expect the current storm activity
over Douglas County to continue pushing east-northeast through
the rest of the afternoon. Elsewhere across the plains, showers
and weaker thunderstorms will continue through the afternoon and
into the evening. A stronger push from the north will increase the
coverage of rain showers and lower clouds as well through
tonight. Then coverage is expected to decrease from the east into
the early morning as flow aloft increases out of the south and
upslope decreases. Over the mountains, snow continues to fall and
accumulate over elevations of 9000 feet or so. Snow will likely be
seen falling to elevations as low as 7500 feet, but there
shouldn`t be much accumulation if any. The band of snow showers
will be sinking south to lower snow amounts falling over zone 31,
so having the advisory end by morning seems good, with another 2
to 4 inches likely to fall this evening and overnight.
The jet will continue the SW to NE oriented band of snow further
south on Saturday over the Front Range mountains. Another 1 to 4
inches are expected to fall during the day tomorrow. The upper
trough will move into eastern Utah, with high surface pressure
over the Great Plains keeping some stability over the plains.
However, with enough moisture still in the area and the jet
nearby, will continue to see a showers and cooler day tomorrow
across the plains.
.LONG TERM...(Saturday night through Friday)
Issued at 300 PM MDT Fri Jun 21 2019
The broad summary for the extended forecast is a transition from
a cold springlike storm system containing widespread showery
precip over to a more seasonal pattern as a warm and dry stable
ridge of high pressure begins to build into the region Monday into
late next week.
Starting with Saturday night, the coldest piece of the melt-day
storm system begins to the enter the northern and central portion
of the state as the base of the elongated and positively tilted
trough bottoms and begins to pull eastward. This is the time frame
when the last impulse of mountain snowfall arrives as a 70-80kt
jet rounds the bottom of the trough over the OK panhandle placing
the CWA under the left exit region of this feature. Across the
lower elevations, a moist adiabatic sounding develops and remains
in place into early Sunday with easterly flow up to 700mb. The
ending of the Winter Weather Advisory for the higher mountains
looks on track for 12z Sunday.
Early Sunday, temperature guidance runs have come in a bit colder
and are nudging into record low territory for Sunday morning. The
record low for June 23rd in Denver is 43 degF, so keeping current
grid temps in the lower to mid 40s is still on track despite the
likelihood of early morning cloud cover and scattered showers.
Later in the day, models are fairly synced with the timing of the
exit of the trough around midday as QG fields bring a sharp
gradient of subsidence over the state by late afternoon Sunday.
The NAM is quickest to bring this subsidence in. Forecast
soundings and cross sections still indicate a moist adiabatic
profile up to 300mb thru 18Z as cold northerly flow is in place
behind the exiting trough. This will likely keep orographic rain
and snow showers going trough Sunday afternoon across the
mountains with snowfall over the highest ranges especially on
northwest and north aspects. Across the plains Sunday afternoon,
will expect a mostly cloudy scene especially in the morning with
enough surface heating to provide mixed layer capes in the 200-800
J/kg range. So, will likely see the unsettled weather continue
into Sunday evening with scattered showers and fast moving weak
thunderstorms in northwest flow aloft.
As we head into late Sunday night and early Monday, NAM surface
fields indicate light westerly surface flow, so not expecting
widespread overnight post-storm fog at this time for Monday
morning but can`t rule out some patchy dense fog in low lying
areas. At this time, forecast soundings and cross sections begin
to declare an end to the wintery and cold springlike episode as
the atmos drys out and brisk northwest flow develops. By midday
Monday, the beginning of a prolonged warmer and dryer period
ensues. Hints of a weak ridge axis over AZ and UT begins to
develop across the Great Basin as the cold, precip producing
trough moves out onto the Great Lakes and Ohio Valley region.
By early Tuesday, the stable ridge becomes more amplified but with
good daytime heating, isolated showers and weak storms should
develop over the higher terrain and push out onto the plains.
Across the plains, soundings are mostly dry and V shaped, so
isolated gusty weak storms will be the rule in the afternoon and
early evening. For Wednesday, the ridge axis becomes aligned over
the central US. At this point, medium range models indicate
subtropical moisture drawing northward into the southern and
central Rockies and central US plains in typical summerlike
fashion under the dominant ridge centered over TX and Gulf south.
This pattern persists into Friday while supplying enough moisture
each afternoon for isolated showers and storms to fire off the
higher terrain and push out onto the plains. With the dominant
ridge holding firm over the southern portion of the US and
warm/dry stable flow aloft persisting off the eastern Pacific,
Thursday looks to provide the first 90 degF day of the season. No
significant pattern change for Friday with temps holding above
seasonal average with isolated afternoon storms.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 830 PM MDT Fri Jun 21 2019
The low level winds at DIA still are still easterly this evening.
Models have them going southeasterly before 06Z but never
becoming true drainage anytime overnight. Overall it is pretty
difficult for overnight winds not to go to drainage, however the
pressure gradient in place may keep them a but east of due south
overnight. Concerning ceilings, models show them to be BKN-
OVC025-040 all night into Saturday. Upstream radars picture show
showers and a few thunderstorms should continue off an on over DIA
for the next 2 or 3 hours.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM MDT Sunday for COZ033-034.
Winter Weather Advisory until 6 AM MDT Saturday for COZ031.
&&
$$
UPDATE.......RJK
SHORT TERM...Kriederman
LONG TERM....Fredin
AVIATION.....RJK
Area Forecast Discussion
National Weather Service Charleston SC
1012 PM EDT Fri Jun 21 2019
.SYNOPSIS...
A stationary front will remain across the region through this
weekend. High pressure is expected to build over the Southeast
U.S. early next week. A cold front is forecast to slowly move
across the Coastal Plain Wednesday into Thursday.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Regional radar composite shows an impressive late-evening MCS
moving across the Tennessee Valley. This feature is outpacing
much of the mesoscale guidance tonight, which is not unusual for
these features. Both the RAP and H3R are now showing some form
of the MCS and its associated wind shift moving into the western
zones by daybreak and offshore shortly thereafter. RAP
instability profiles show a fairly sharp noctural instability
gradient setting up along the Savannah River all the way up into
the South Carolina Upstate so it seems reasonable the MCS will
continue to propagate to the southeast as moist, unstable air
feeds into it from the south. Per coordination with neighboring
WFOs, pops were increased slightly to 20-30% and a shift wind
shift was populated into the hourly wind grids for the late
evening update.
It does not appear at this time that the MCS will pose a
significant wind threat far to the southeast, especially as it
approaches during the typically unfavorable diurnal minimum.
However, this will ultimately be governed by mesoscale
processes such as cold pool maintenance. Gusty winds could still
occur with an isolated damaging wind gust being possible across
the far interior, especially over areas that saw wind damage
with Thursday`s severe weather event.
Lows will range from the mid 70s inland to around 80 at the
coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
A very complicated forecast for Saturday. IR satellite data shows a
very large Mesoscale Convective System (MCS) tracking across the Mid
West this afternoon. Short-term guidance indicates that the MCS will
reach the southern Appalachians late tonight. It is suspected that
the convection will gradually dissipate in the wake of the
mountains. However, remnant showers and isolated thunderstorms
should survive to the Coastal Plain during the early daylight hours.
I will highlight the timing and placement of the convection with
slight chance PoPs until 10 AM. The rest of the morning into the
early afternoon, the forecast will remain free of convection across
the area. Forecast soundings indicate a low-level inversion around
850 mb during the morning and forecast to mix out by the mid-
afternoon, this inversion should keep the boundary layer capped
during the morning.
Debris clouds are expected to dissipate by mid-day, strong
insolation should occur through mid-afternoon. High temperatures are
forecast to range generally in the mid 90s away from the coast. The
high temperatures combined with dewpoints in the mid 70s should
result in heat index values between 105 to 109 across the coastal
and most inland areas from late morning through the afternoon. A
Heat Advisory has been issued from late morning until 6 PM.
The hot temperatures combined with dewpoints in the low to mid 70s
should result in CAPE values between 2500-3000 J/kg Saturday
afternoon, per forecast soundings. In addition, wind profiles are
forecast to become unidirectional with shear increasing to around 25
knots. Models indicate that a second MCS will cross the mountains
during the Mid-day. The mountains should disturb the cold pool, with
a cold pool sliding SE across GA. The arrival cold pool should
trigger new convection, likely organizing into multicell lines. The
storm structure and moderate values of DCAPE should support damaging
wind gusts with the stronger cells. The severe risk should occur
during the late afternoon into the evening. The region has been
highlighted with a slight risk for severe thunderstorms.
Sunday and Monday, the mid ridge axis is expected to ripple over the
region. The environment should support scattered to isolated diurnal
thunderstorms each day. Hot temperatures and dewpoints in the low to
mid 70s are forecast to result in heat index values around 105
across the coastal counties each afternoon.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Weak troughing will prevail across the Southeast. The typical
afternoon/evening showers/thunderstorms are expected.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR. Gusty winds likely by mid-morning once the morning
inversion breaks. A large mesoscale convective system (MCS) is
expected to develop across parts of Georgia into South Carolina
tomorrow, which could push through the area late in the
afternoon or early evening. Timing is a bit uncertain, but tstm
impacts are possible at both KCHS and KSAV by the end of the 00z
TAF period. Will not include a mention at either terminal at
this time given any impacts will be very late and timing is
still uncertain.
Extended Aviation Outlook: Brief flight restrictions are possible in
afternoon/evening showers/thunderstorms.
&&
.MARINE...
Tonight: Southwest winds will prevail through the night. A sharp
wind shift to the west could occur just after daybreak as the
remnants of a MCS move into the coastal waters. This wind shift
could pose a risk for isolated wind gusts in excess of 30 kt,
mainly where isolated convection lingers. Mariners are urged to
remain alert for potential impacts just after daybreak.
Sunday through Wednesday: Winds/seas are expected to remain
below Small Craft Advisory criteria. A front will remain nearly
stationary across the area through this weekend. High pressure
will gradually build across the waters early next week. Wind
directions will vary from day to day, keeping the development of
swells limited.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from 10 AM to 6 PM EDT Saturday for GAZ099>101-
114>119-137>141.
SC...Heat Advisory from 10 AM to 6 PM EDT Saturday for SCZ042>044-
047>052.
MARINE...None.
&&
$$
Area Forecast Discussion
National Weather Service Dodge City KS
544 PM CDT Fri Jun 21 2019
...Updated aviation section...
.SHORT TERM...(This evening through Saturday)
Issued at 1213 PM CDT Fri Jun 21 2019
An outflow boundary from morning storms has stalled out along the
highway 56 corridor...given the cooler stable air I lowered
afternoon highs north of this boundary while keeping temps to the
south closer to the mid to upper 90s.
Looking towards this evening another shortwave will propagate from
northeast Colorado into northwest Kansas. The setup will bring a
cold front into western Kansas through the overnight. Storms will
likely propagate along the cooler 700 mb temps in northwest Kansas
into south central Nebraska as much of our area will see 700 mb
temps warm to 15-17 (C) which would keep us plenty capped even
with the cold front passing through.
Some short term models are suggesting saturation and low clouds
developing behind the cold front around sunrise (5 am- 8 am)
which may produce patchy to areas of fog mainly from Dodge City to
Hays where winds should be lighter initially.
Saturday the main question is how far south and east the cold
front moves through the area...as areas along and east of the
front will have a severe weather and flooding risk. As you would
expect all the models have different ideas how far east the front
goes but the general idea is that it will stall somewhere east of
a Dodge City to Hays line. Dew points ahead of the front will
increase through the day with good moisture from the south. By
late afternoon a shortwave is expected to move into western
Oklahoma where storms will start to break out along the front and
train north and eastward. PW values of 1.25-1.75 in. in this area
will suggest this time frame as the start of a flash flooding risk
with the higher risk of flooding during the night Saturday.
Severe risk will also be present along the front with hail and
wind.
.LONG TERM...(Saturday night through Friday)
Issued at 144 PM CDT Fri Jun 21 2019
A second round of thunderstorms will develop Saturday night in the
front range of the Rockies with a large upper trough moving into
central Colorado and a shortwave rotating around the low. Some
models think the heavy rain will spread into northwest and north
central Kansas while I noticed the latest 39 hr RAP wanted to take
the heavier rain further south. Nonetheless I think areas in our
southeast could see two rounds of heavy rain which will keep the
flash flooding risk there into Sunday morning.
The upper level trough/low slowly moves eastward into Sunday and
long term models are suggesting a pretty cool day with northerly
winds, clouds, and periodic rain showers/storms. We may only see
highs in the 70s. Trough should be out of the region by Monday
morning.
For early next week we transition from a zonal to a ridge pattern.
The main uncertainty is if we will be under the ridge or on the
northerly extent of the ridge. Long term models seem to think that
we will still be having some shortwaves and decent moisture
riding the ridge which could give us some scattered storm chances
most notably Wednesday and Thursday. However what does seem more
certain is a stretch of 90 degree weather for much of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 542 PM CDT Fri Jun 21 2019
A cold front that will move through western Kansas during the
overnight which could produce some post frontal low clouds,
especially for DDC and HYS from 11Z-15Z. Winds will increase out
of the northeast to 15-25 kts as the cold front moves through the
area. Cloud ceilings should fall for all TAF sites mainly to MVFR
with some IFR conditions as post frontal stratus develops.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 84 59 77 / 0 20 50 20
GCK 62 81 56 76 / 0 10 50 10
EHA 61 82 55 76 / 0 0 40 10
LBL 66 85 60 77 / 0 10 50 10
HYS 63 74 57 73 / 10 10 70 20
P28 73 92 69 83 / 10 40 60 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from Saturday afternoon through Sunday morning
for KSZ066-080-081-089-090.
&&
$$
SHORT TERM...Tatro
LONG TERM...Tatro
AVIATION...Hovorka_42
Area Forecast Discussion
National Weather Service Grand Forks ND
959 PM CDT Fri Jun 21 2019
.UPDATE...
Issued at 956 PM CDT Fri Jun 21 2019
Rain continues to move east across eastern North Dakota and into
parts of far western Minnesota. Little to no thunder has been
observed or is expected tonight. Mostly light rain showers, but a
few localized areas of moderate to heavy rainfall has been
reported.
UPDATE Issued at 649 PM CDT Fri Jun 21 2019
The window for severe weather appears to be closing with
instability never making in far into North Dakota and the best
shear continues to be out over the western half of North Dakota.
Still expect rain showers with some isolated thunderstorms this
evening in eastern North Dakota. Some rain showers may make into
northwest Minnesota as well later this evening into overnight but
many of the CAMs have rain coverage diminishing as it crosses over
the Red River Valley.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 317 PM CDT Fri Jun 21 2019
Data indicates that the time period of severe weather if it would
occur will be brief and may well be in the eastern part of BIS
CWA in the 22z-01z period. Considerable cloud cover and showers
are developing in central ND ahead of the surface trough/front and
upper low forcing. There is a narrow zone of partial clearing
trying to occur from Aberdeen NNW to about Ashley, Edgeley ND.
This zone per HRRR, RAP and other models is in the zone with the
mostly likely chance for destabilization and dew pts reaching
63/65 and capes reaching 1500-2000 j/kg for a brief time late
aftn. HRRR reflectivity and Updraft Helicity fcsts indicate this
area as well as showing some signals for severe storms. But this
zone is rather narrow and as storms move away form this area past
01z the instability drops quickly toward the Red River valley with
general showers/t-storms the result.
Chance for showers/t-storms later tonight will diminish as the
surface front/trough dissipates as it moves into Minnesota
Saturday will see drier airmass spread thru central ND into DVL
basin. Best sunshine in that area but will need to watch for a few
t-storms along eastern edge of this drier airmass over parts of E
ND. Farther east the main low level moisture corridor will be over
western Minnesota and therefore higher rain chances Saturday for
areas along and east of the Red. No severe risk.
.LONG TERM...(Saturday night through Friday)
Issued at 317 PM CDT Fri Jun 21 2019
Showers will end in NW/WC MN Saturday evening.
Sunday to Tuesday...
Much of the long term is dominated by the large upper-level low
tracking into Canada. For the day on Sunday, models are in good
agreement regarding the low, which will be located in eastern
Saskatchewan and slowly move further to the northeast. Guidance
suggests moisture advection from the south, which helps to keep the
pattern active with showers and thunderstorms.
Wednesday through Friday...
As the low continues to track into northern Manitoba, meridional
flow aloft continues over the area. Models are in agreement that
ridging will take place over the area for the day on Wednesday,
leading to continued warming. This heating, combined with embedded
shortwaves, shows the possibility of stronger thunderstorms.
Uncertainty still exists at this point, but any initiated convection
could have an unstable environment given by moisture content and
daytime heating. To end the week, look for the ridging to steepen
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 649 PM CDT Fri Jun 21 2019
Light to moderate rain this evening at KDVL and as rain showers
pass through. This area of rain will move east into the KGFK,
KFAR, and KTVF terminals later this evening into the overnight.
Generally expecting rain, but a thunderstorm could be in the
vicinity of a terminal this evening with the most likely location
being at KFAR. VFR conditions falling to MVFR during rain showers
with a chance of IFR if a thunderstorm approaches. Some gusty
winds continue at all terminals with some gusts in the the 20 to
25 knot range. Winds should lessen late this evening into the
overnight.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...NC
SHORT TERM...Riddle
LONG TERM...Lynch/BSW
AVIATION...NC
Area Forecast Discussion
National Weather Service Hastings NE
631 PM CDT Fri Jun 21 2019
.SHORT TERM...(Tonight)
Issued at 252 PM CDT Fri Jun 21 2019
12Z upper and satellite water vapor imagery showing a large upper
low situated over MT/ID/WY with overall troughing over the Rockies.
Meanwhile ridging was noted to the east over the MS river valley
with troughing over the east coast. Decent 30-80 meter 500 mb
height falls ahead of the western low pressure. Meanwhile at the
surface, low pressure was noted in far northeast MT with a cold
front extending into the central Dakotas and Neb and then curling
west into CO. Another surface low was sitting over southern KS, just
southeast of DDC at 17Z with a warm front stretching east and a dry
line dropping south. Dewpoints were in the low/mid 70s along and
south of the warm front compared to mid 30s behind the dry line.
The question for late this afternoon and into the overnight involves
the chance for precipitation once again. CAMs are showing a couple
of possibilities, one being along the front beginning in the
northwest part of the CWA late this afternoon and continuing into
the evening. Doesn`t appear to be a lot in terms of mid/upper level
forcing to help this along but convergence along the front may be
sufficient for at least isolated activity. Instability not off the
charts but models are progging 1500-2000 j/kg of ML-CAPE, while
deep layer shear currently running about 40 kt. As of 19Z, GOES
East Day Cloud Phase Distinction RGB product is showing convective
initiation in central SDak along the front and this may be
unzipping into north central Neb. Possible convection will need to
overcome some CIN in our CWA especially further south. A second
area of concern is to our west, northeast CO and western KS. HRRR
is once again popping convection here and then sliding it ENE into
our CWA sometime just prior to or after midnight. Each of the runs
today have been consistent in weakening these storms as they move
towards us, although the 17Z run does show one storm maintaining
its strength as it moves in between 06 and 08Z tonight. For now
will keep higher Pops in the NW early and then continue throughout
most of the CWA with possible storms moving in from the west.
.LONG TERM...(Saturday through Friday)
A chance of showers and isolated thunderstorms continues
for the weekend as the upper low remains to our west. The surface
cold front should push into southwest to northeast KS and stall out.
We may see off and on post frontal precip but the far better chance
for severe and heavier rain should remain to our southeast. That
said, will need to monitor the frontal position as it may end up
close enough to the southeast CWA to result in severe storms.
By Monday morning then 500 mb trough axis will finally push east of
us with ridging building in from the west. For the rest of the work
week and possibly into next weekend a more summer like pattern
prevails with the ridge holding steady from the desert southwest
into the Plains. Expect highs to be much higher with upper 80s to
lower 90s the norm. Rain chances become much less likely although
not totally zero as we end up in the "ring of fire" pattern with
weak waves rotating around the ridge. The question then becomes,
does any storm activity move over us, or is it further north and
east.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Saturday)
Issued at 631 PM CDT Fri Jun 21 2019
There will be a chance for thunderstorms this evening and
overnight. How widespread they will be is to be determined, and so
have only included a VCTS at this time. Will amend as necessary.
The front is not far to the northwest of the terminals and have
brought gusty north winds in, in the next hour or so. MVFR to IFR
ceilings are possible during the day tomorrow with northerly
winds.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...Ewald
LONG TERM...Ewald
AVIATION...Billings Wright
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1055 PM EDT Fri Jun 21 2019
.SYNOPSIS...
Showers and thunderstorm activity will return this weekend and
persist off and on through much of next week. Near seasonable
temperatures are expected to prevail through the next seven days.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 11pm EDT Friday: Upstream convective system is currently in
Eastern TN and is expected to reach the TN border and parts of
Northeast Georgia in the next couple hours, with a severe
thunderstorm watch in effect for the western part of the CWA where
CAPE is elevated.
A Mesoscale Convective Complex (MCC) has developed atop the ridge
over northern Missouri, and convection driven by the associated cold
pool continues to run eastward into southern Illinois, with
additional activity developing over south-central MO. These features
will become the main players in our forecast for the upcoming
nighttime period. Corfidi vector steering flow should drive the
system mainly eastward toward the Appalachians, but with additional
south flank development expected as the cold pool encounters better
instability there. The convection-allowing models have converged on
a solution with more of a direct hit of the MCS on the southern
Appalachians overnight. The HRRR has the system arriving the fastest
(circa 05Z) and surviving east of the mountains through 08Z or so.
The NAMNest and national hi-res solutions are a touch slower, with
varying decay as the system traverses the higher terrain and
encounters stabler air. Given the latest solutions, will feature
more solid chances over the NC mountains for the overnight hours,
and advertise isolated to scattered coverage eastward through the
lower piedmont. The HWO wording has been beefed up accordingly for
mountain areas.
Saturday is a major question mark for the timing and coverage of the
next round of MCS activity, especially in light of the early morning
passage of the decaying MCS late tonight. There are some features
that suggest the afternoon timing will be favored. First, the region
just east of the central CONUS flat ridge, mainly over the lower
Ohio Valley and surrounding areas, will provide a prime area of
genesis for further MCS activity through Saturday. This appears tied
more strongly to weak upper shortwaves or MCVs moving down the east
side of the upper ridge and this activity would time out toward
Saturday afternoon. Also, a boundary will be in place across the
forecast area through the day on Saturday, and peak afternoon
instability will lead to maintenance of the passing MCS, if one
forms. All told, will feature a peak of coverage (likely northwest
to solid chance southeast) for the afternoon hours. The latest Day 2
Slight Risk Outlook looks well placed, with some 3000+ muCAPE likely
south of the stalled boundary. This too will be talked up in the HWO
for mainly wind potential.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
As of 200 PM EDT Friday: The forecast area will remain on the east
side of a mid level ridge axis on Saturday night and Sunday. This
position in the flow looks to be active with convective complexes
moving through and some local development of storms also possible
both periods. A few of the storms may be severe per the SPC Day 2
outlook.
The ridge axis will move across the area Sunday night and east of
the area on Monday. This will lead to a quieter period Sunday night
and most of Monday. A mid level trough moving across the Great Lakes
states is expected to activate a front moving across the Tennessee
Valley on Monday afternoon. Some of this activity will move into the
mountains during the late afternoon hours.
The forecast for Sunday will feature highs in the upper 80s to lower
90s in the Piedmont and mid 80s in the mountain valleys. The overall
pattern suggests that debris cloudiness and possible leftover
convective boundaries may have an impact on these readings. We may
have to make some adjustments once the timing and location of storms
become more clear.
With less cloudiness and the ridge overhead, Monday looks to be the
hottest day of the week. We expect highs in the lower to middle 90s
in the Piedmont and in the mid to upper 80s in the mountain valleys.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 200 PM EDT Friday: A potent upper trough is expected to lift
northeast into the Great Lakes states Monday evening driving a
rapidly weakening cold front through the region sometime Monday
night or Tuesday morning. A few showers and thunderstorms will be
possible with the front.
Moisture will decrease slightly for the middle of next week so the
chance of showers and thunderstorms will be lower than this weekend
which is closer to climo. Temperatures will be near or slightly
above climo.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Very weak pressure gradient in post-frontal
regime is giving generally light northerly to northwesterly winds,
with a few gusts still seen that will fairly quickly die-out
diurnally. Skies are also mostly clear at the moment as moisture has
been shunted southward with the front. These good VFR conditions
will likely change early Saturday morning as the remnants of an MCS
cross over the Southern Appalachians. This is expected to give a
period of a few hours of scattered showers to the region, and
possibly some thunder. By Saturday afternoon, front lifts back
northward bringing increasing moisture, clouds, and chances for
afternoon thunder with it for Saturday afternoon. Timing of showers
in the TAFs was derived from the HRRR model and other cams. Latest
radar has upstream MCS, currently over western KY and TN, a little
ahead of schedule.
Outlook: A more diurnally-driven convective pattern is expected
Sunday through Tuesday, with some mid-week drying possible. Mainly
daybreak restrictions will be possible each day, aside from any
thunderstorms.
Confidence Table...
03-09Z 09-15Z 15-21Z 21-00Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% High 100%
KHKY High 100% High 100% High 95% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% 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...None.
SC...None.
&&
$$
SYNOPSIS...SW
NEAR TERM...HG/WJM
SHORT TERM...SW
LONG TERM...SW
AVIATION...WJM
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
916 PM CDT Fri Jun 21 2019
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Rest of tonight:
A decaying MCS has propagated southeast through the Mid Mississippi
Valley & Mid-South, producing widespread wind damage as it moves
through. Overall this complex continues to become more cold pool
& outflow dominant over northern Mississippi & should become less
robust as it propagates southward. Model CAM suite doesn`t have a
good handle on this complex. Main updates to the going forecast
were to add some PoPs for areas in north-northeast Mississippi
(i.e. from around Grenada across to Lowndes County and Golden
Triangle) as there is some potential for some rain chances to
sneak into our area. Some light rain or an isolated storm can`t be
ruled out. There is high instability but with increasing
subsidence inversion & forcing off to the north & east, think
potential is very limited in any more organized convection
potential. We may still struggle to get much convection or rain at
all, but wanted to account for anything that could sneak into the
area. Updates are out or will be coming out shortly. /DC/
Prior discussion below:
Tonight and Saturday: Mid afternoon surface analysis had a 1020mb
high ridging across the Florida peninsula and across the northern
Gulf of Mexico. This was resulting in very moist air from the Gulf
move up across our CWA and maintain mid to upper 70 dew points
while temperatures climb through the lower 90s and into the mid
90s. This was resulting in heat index values between 105 and 110.
A Heat Advisory was expanded earlier to include the whole CWA til
7PM. Satellite and RAP analysis also indicated a mid level ridge
across our CWA from the south. This combined ridging surface and
aloft has led to an inversion noted on regional soundings this
morning that has continued to limit convection over our area.
Local radars were showing the first hints of isolated shower
development near Highway 84. Isolated showers and thunderstorms
will remain possible perhaps as far north as Interstate 20 through
early evening but will dissipate rapidly with the loss of daytime
heating. Although tonight will be dry, it will be very warm and
humid. Morning lows will be above normal in the mid 70s at most
locations. Ridging surface and aloft will continue to dominate
Saturday. A little greater mixing is expected which will result in
slightly lower peak heat index values. Still, with temperatures
climbing back into the low to mid 90s along with lower 70 dew
points, heat index values will be around 105. Wl carry a "limited"
for heat stress areawide in our HWO.
Saturday night through Thursday: The ridging aloft will shift east
Sunday as troughing deepens over the central CONUS. Wl maintain
surface ridging from the southeast that wl preserve our moist
airmass. There will likely be pockets across the CWA that the
peak heat index value approach 105 again. Most of the CWA will
remain dry but rain chances will return to the west by Sunday
afternoon that may provide some relief from the heat. Rain chances
will increase from the west Sunday night into Monday. Models
differ on the strength of the upper level trough and associated
cold front but agree that our next best chance for widespread rain
will be on Monday. The upper level trough axis will shift east of
Mississippi Tuesday but the stalled front looks to linger over
our CWA and provide a focus for convection through Tuesday. Our
region looks to remain in a weakness between mid level ridging
from the east and from the west through Friday. Depending on how
far south the weak cold front stalls before returning north or
washing out, at least diurnally driven chances for rain will
continue for most of our CWA through Friday. Slightly cooler than
normal temperatures are expected Monday and Tuesday with a slow
warming trend through the end of the week. Otherwise, warmer than
normal morning lows will continue through Friday. /22/
&&
.AVIATION...
00Z TAF discussion:
VFR conditions are occurring this afternoon and should prevail
through the evening. MVFR to patchy IFR ceilings should develop
after 09Z tomorrow and lift by 15-16Z. VFR conditions expected
after that. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 76 94 73 92 / 3 5 6 10
Meridian 76 94 72 95 / 4 5 11 8
Vicksburg 77 94 74 93 / 4 7 4 13
Hattiesburg 76 95 73 94 / 4 5 3 10
Natchez 77 93 74 93 / 4 5 3 16
Greenville 77 94 75 92 / 3 8 10 15
Greenwood 76 93 75 93 / 2 10 9 9
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
DC
Area Forecast Discussion
National Weather Service North Platte NE
817 PM CDT Fri Jun 21 2019
.UPDATE...
Issued at 813 PM CDT Fri Jun 21 2019
Radar continues to show weaker cells across the west at this time
and primary cell over the north central exited southeast Wheeler
County. Convection to increase in coverage toward midnight as a
series of disturbances moving through flow carry showers and
thunderstorms northeast through daybreak Saturday.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 330 PM CDT Fri Jun 21 2019
Two areas for potential severe weather this afternoon and tonight.
The first is up across ncntl Nebraska where the Pacific cold front
has slowed allowing for moisture convergence, pooling and
destabilization. SPC mesoanalysis suggested 1500 J/KG of CAPE with
no cap or inhibition. Winds aloft at 500 mb are strong at 30-35kts
which would support supercells. A 50 percent POP is in place in this
area tonight for scattered thunderstorms, a few which could become
strong or briefly severe. Large hail would appear to be the
primary concern.
The second potential area for severe weather is across swrn Nebraska
but this area is post-frontal with northwest sfc winds. The SPC
mesoanalysis would suggest the area farther south near Dodge City
might be more favorable for storm development. Meanwhile, the HRRR
shows storms firing on the Palmer divide in ecntl Colorado this
afternoon which track east, generally remaining south of Nebraska
this evening. POPs tonight across swrn Nebraska less than 50
percent suggesting scattered storm coverage.
The rest of the forecast area tonight, Saturday and Saturday night
is operating on a showers/isolated thunderstorm chance as cooler
more stable air is in place or will overtake the area Saturday and
beyond. An upper level low is predicted to develop across Nebraska
this weekend which would support showers and isolated thunderstorms.
The cold air aloft is impressive with h500mb temperatures dipping to
-15C. The temperature forecast then follows the cooler bias
corrected guidance blend for highs in the 60s and 70s and lows
in the 40s and 50s.
.LONG TERM...(Sunday through Friday)
Issued at 330 PM CDT Fri Jun 21 2019
The extended forecast continues on track and the models are in good
agreement building an upper level ridge into New Mexico, ern Colo,
KS and Nebraska. Winds aloft at 500mb weaken to less than 20kts
Tuesday night signaling a summer pattern. There is still an
isolated thunderstorm chance Wednesday and beyond but storms will be
brief and likely become outflow dominant.
Rain chances diminish Sunday afternoon as an upper low lifts into
ncntl Nebraska. Temperatures warm Monday and increase throughout the
week. A check on moisture suggests the rich moisture across KS and
the South will move north through the Missouri river basin and
remain mostly east of western Nebraska. The models show a steady
rise in dew points to the mid and upper 60s across wrn Nebraska by
Wednesday. The concern with the dew points is that the 70-plus dew
points across the South will creep west into wrn and ncntl
Nebraska.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 615 PM CDT Fri Jun 21 2019
Post frontal conditions are expected across all terminals through
the 00z TAF cycle. The front has hung up just east of a KBBW to
KONL line where one stray thunderstorms has developed. Into the
overnight we expect a general increase in showers and
thunderstorms across the outlook area. Heavy rainfall may reduce
visibility in the strongest storms withe MVFR or lower ceilings.
We anticipate that the activity will taper off early Saturday
morning. Overall forecast confidence is strong, though short fused
updates to the forecast may be needed depending on convective
trends.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Keck
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Jacobs
Area Forecast Discussion
National Weather Service Louisville KY
1018 PM EDT Fri Jun 21 2019
.Forecast Update...
Issued at 1020 PM EDT Fri Jun 21 2019
Have been waiting to see evidence of a wake low, with south to
southeast winds behind the active convection we had earlier. It`s
starting to show on the Kentucky Mesonet with a band of
southeasterly winds from western KY to Owen county. SDF gustied to
25 knots. Have updated the grids for this as well as will be
cancelling the watch for the rest of the counties very shortly.
Issued at 740 PM EDT Fri Jun 21 2019
Will be clearing some counties from the watch as the main line
pushes through the region. We could see some redevelopment of storms
behind it, but they likely would be elevated. Seeing good progress
of the merger of the two lines of storms as they move into our BWG
counties. Line closer to SDF does not look as intense, again as it
moves into the drier surface air. Latest RAP mesoanalysis shows the
instability gradient right along the line where our downstream watch
box is.
Issued at 620 PM EDT Fri Jun 21 2019
Northern side of the storm line is fairly healthy, despite moving
into a less favorable environment. Decided to go ahead and expand
the watch eastward, and with plenty of instability still to work
through in southern KY, expect a better chance of severe weather all
the way to the Lake Cumberland region this evening. Do have an odd
shaped eastern extent, mostly because of the geography of the
counties.
Issued at 420 PM EDT Fri Jun 21 2019
Seeing the north/south oriented part of the line entering the Wabash
now start to weaken with regard to lightning and cloud tops and a
lack of wind/wind damage reports. The southern part of that line is
becoming more robust however, with cellular activity showing some
much colder cloud tops on latest IR imagery. Will follow this part
of the line downstream into our forecast area and after coordination
with SPC decided on a watch. Kept the Louisville metro out of this
watch...given that weakening line.
A second MCS is moving in from southeast MO and we will have to
watch to see how that interacts with the first line. Models have
been pegging that part of the line to stay stronger farther into our
area later this evening, but expect the first wave to stabilize the
lower levels. We can readjust the watch area later as we see how
that interaction plays out.
&&
.Short Term...(This evening through Saturday)
Issued at 315 PM EDT Fri Jun 21 2019
...Strong to Severe Storms Likely This Evening Through Tonight...
A complicated forecast is in store for the short term. Regional
radars and GOES-satellite reveal two distinct MCSs across central IL
and central MO at this hour. These MCSs are riding along a warm
front and instability gradient which is beginning to advect into our
region. These MCSs should continue to follow along the front and
begin to take a dive to the southeast here soon.
The latest high-res models have not handled the MCS in central IL
very well. Most have had it weakening significantly as it progresses
eastward, however, it has managed to maintain itself longer than
what they predicted. It is noteworthy that over the last 30-60
minutes, cloud tops have started to warm, lightning activity has
decreased, and radar imagery doesn`t look as impressive compared to
earlier in the day. Additionally, appears the severe potential with
the MCS has been at a minimum over the last hour, as observations in
the path of it have generally reported sub-severe winds. This may be
due to a frontal inversion that has kept the strongest winds from
mixing down to the surface. As this MCS approaches our region, the
northern portion of the MCS should remain sub-severe, though it`s
tough to say whether or not southern portions of the line will be
capable of sporadic severe winds when it arrives since theoretically
there should be less CIN in those areas with it being in close
proximity to the warm front. Based on some rough timing estimates,
think this line will begin entering our CWA (Dubois County, IN)
around 21z, and then arriving to the Louisville/Bowing Green Metro
areas around 22z-00z, and then arriving to the Lexington metro area
by 00z-02z, if it holds together.
The second MCS over MO is the one more likely to produce our severe
weather based on the latest high-res guidance. This second MCS will
be on the heels of the first, so we may see a slight break in the
action, but it should quickly fill in. The warm front/instability
gradient will continue to advect eastward into our region out ahead
of the second MCS, which will aid in destabilizing the atmosphere
even more. The big caveat to severe weather potential in our region
is if the first MCS slows the advancement of the warm front and
stabilizes the atmosphere ahead of the second MCS. Given that most
guidance weakens the first MCS in central IL significantly and does
not have it impacting our region, they result in a more unstable
atmosphere ahead of the second MCS in MO, so they may not have the
best portrayal of environmental conditions. Still, given the
consistency in guidance to destabilize things quickly ahead of the
second MCS, and a 30-40kt LLJ pumping in moisture/higher theta-E air
from the southwest, will continue to advertise likely severe weather
across the region, with the highest chances generally along and west
of the I-65 corridor. Damaging straight line winds will be the most
likely threat with the line, though brief isolated tornadoes will be
possible within bowing segments and embedded mesovortices.
The potential for yet another MCS (#3) could occur after midnight,
bringing additional showers/storms and potential severe weather. We
may finally start to dry out late tomorrow morning into the
afternoon. Confidence in this third MCS remains low, but is
something to watch. Given that our area will experience multiple
rounds of heavy rainfall, and most area creeks/rivers/streams are
still running high, will go ahead and put out a flash flood watch
for much of southern Indiana and central Kentucky. This watch will
run through tomorrow morning, but it may need to be expanded in time
through the weekend if confidence increases in additional rounds of
rain.
.Long Term...(Saturday night through Friday)
Issued at 325 PM EDT Fri Jun 21 2019
Saturday Night - Monday...
An active weather pattern looks to continue through early next week.
Saturday night a weak sfc boundary over the area combined with upper
level shortwave activity and plenty of instability will provide
focus for showers and storms. Strong storms are possible Sat
evening before the environment becomes more elevated later Sat
night into Sun morning.
After a morning storm complex on Sun, we should see a break in
convection for a large chunk of the day with an upper level ridge
axis passing through. However, plenty of instability is expected to
build Sun afternoon and could kick off scattered showers and storms
especially along any left over boundaries from morning storms.
Scattered showers and storms will likely continue into Sun night.
Monday an upper level trough and cold front will approach the
region. This should bring a better chance for showers and storms
and possibly a more organized threat for some of those to be strong
to severe with bulk shear values of 25-35 kts and CAPE values of
1500-2500 j/kg. The cold front passage is expected Mon evening.
Temperatures will be in the 80s for highs Sun/Mon with Sun being the
hotter day under the upper level ridge. Low temps should range
through the upper 60s to low 70s.
Tuesday - Friday...
A few showers/storms may linger over east central KY on Tues before
the area goes dry. A period of mainly dry weather is expected Tues-
Fri as upper level ridging builds in over the southern U.S. A few
small chances for diurnally driven storms may exist during the
afternoon/evening hours each day next week, but mainly dry weather
is anticipated. A slow warm up is expected with temps starting in
the mid 80s for highs on Tues and increasing to the upper 80s to
around 90 for highs by the end of the work week.
&&
.Aviation...(00Z TAF Issuance)
Updated at 735 PM EDT Fri Jun 21 2019
Line of storms approaching SDF/BWG this hour. Will see gusty winds
at both terminals as those storms move through. Thunder will last an
hour or two behind this line as it continues heading southeast. Will
watch for redevelopment overnight, but confidence in individual
locations is fairly low. Will have a longer period of vicinity
showers and probably some brief periods of thunder into the morning
hours as a low-level jet tries to establish itself.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...Flash Flood Watch through Saturday morning for INZ076>079-083-
084-089>092.
KY...Flash Flood Watch through Saturday morning for KYZ023>036-
038>042-045>049-053>057-061>067-070>078-081-082.
&&
$$
Update...RJS
Short Term...DM
Long Term...AMS
Aviation...RJS
Area Forecast Discussion
National Weather Service Morristown TN
953 PM EDT Fri Jun 21 2019
.DISCUSSION...
Large bowing MCS continues to work east across Middle TN and
southcentral/southeast KY this evening. Out ahead, a warm front
and consequent swly moisture advection continue to move into the
TN Valley at this time. Thus, am expecting continued elevated CAPE
levels regionwide, with the most unstable regions along/west of
the I75 corridor tonight. The primary threat tonight will be
damaging winds along/ahead of the passing MCS, some gusts as high
as 60-70mph are expected. Also, backed flow out ahead of the
front could enhance localized llv helicity, therefore a few
embedded tornadoes cannot be ruled out. All said, looking at a
stormy night across east TN and southwest VA/NC with timing as
follows. Latest HRRR runs favor intrusion of the bowing line
across the Plateau by 11PM, then moving east/southeast approaching
the I75 corridor by around midnight, before moving further east
across the I81 corridor into the foothills/mountains closer to the
2AM timeframe. Severe Thunderstorm Watch 419 continues through
2AM.
As for the fcst, tweaked pops to align with current coverage
westward, as well as latest CAMPOP trends over the next 3-4 hours.
No other sig changes needed/made with this update.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 73 90 73 89 / 80 50 30 30
Knoxville McGhee Tyson Airport, TN 70 87 70 87 / 80 50 50 50
Oak Ridge, TN 70 87 70 87 / 80 50 50 30
Tri Cities Airport, TN 63 82 65 83 / 80 50 60 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&
$$
CDG
Area Forecast Discussion
National Weather Service Nashville TN
1014 PM CDT Fri Jun 21 2019
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Will be clearing the last row of counties in the next 10 min or
so. mostly light rain showers continue with a few embedded heavier
showers and isol tstms. We are still looking at another possible
system moving down as we move toward sunrise. Latest Hrrr data,
note that this model handled the last system rather well,
indicates that the next system will be knocking on the door around
12z. Day 2 outlook does indicate a slight risk for our eastern
half with a marginal risk elsewhere. However, much of the
atmosphere is already worked over so this next event should not
come close to rivaling what have experienced over the last several
hours.
Will double check those temps and make sure they are on track.
updated zones will follow.
&&
.AVIATION...
00Z TAF DISCUSSION.
MCS on its way to the mid state at this hour. Should begin to feel
the impact near CKV within the next 2-3 hours. Most areas will get
20-30 kt winds with gusts between 30 and 40kts. Isolated to
scattered area will reach and perhaps surpass severe limits. The
showers and tstms will traverse the entire mid state with the
activity reaching the BNA area between 1z and 3z and then CSV
between 3z and 6z. Some decrease in low level forcing will occur
by the time the complex reaches the CSV area. However, Momentum,
couple with available convective fuel will allow the severe
potential and high winds to continue.
Another system could potentially roll through around sunrise. This
second system looks a bit iffy at this time however. Otherwise,
should be relatively quiet aft 15z.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......21
AVIATION........21
Area Forecast Discussion
National Weather Service Pueblo CO
908 PM MDT Fri Jun 21 2019
.UPDATE...
Issued at 903 PM MDT Fri Jun 21 2019
Expired watch 217, will keep watch 220 in place until 11 pm for
Kiowa County. Storms have weakened somewhat as of 9 pm, though
still getting some fairly strong outflow gusts (61 kts at KLHX)
along Highway 50, well south of the storm cores.
UPDATE Issued at 812 PM MDT Fri Jun 21 2019
Extended Svr Tstorm Watch 217 until 9 pm to account for storms
currently moving through the county. Main threat looks to be
severe wind, as organized updrafts seem to be quickly disrupted by
deepening nly flow, though some marginally severe hail may still
be possible.
UPDATE Issued at 533 PM MDT Fri Jun 21 2019
Updated forecasts to add severe thunderstorm watch 420 to Kiowa
County, as activity farther northwest may brush by later this
evening with front dropping south. Even had a run of the HRRR with
storms farther south near Lamar, though latest run has backed
off, keeping everything from Kiowa County northward, so will await
further developments before extending watch south.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 305 PM MDT Fri Jun 21 2019
...Active weather pattern over the next 24 hours with severe
thunderstorms for the plains and snow for the mountains...
Front has been slow to lift back northward across southern CO today
allowing surface dew points to stay in the 50s and even around 60
across the far eastern plains. This has allowed sfc based CAPE
values to creep up over 1000-2000+ J/kg across the southeast plains
though stout cap has kept thunderstorms from initiating across
southern portions of the area. It will be a different matter for El
Paso county as high res models continue to show thunderstorms
initiating over the Pikes Peak region and moving eastward through
the afternoon and early evening. Impressive deep layer shear is in
place and once instability is realized (1000-1500 J/kg) should see
isolated supercell thunderstorms develop along the Palmer Divide and
move eastward. Am somewhat concerned that higher dew points farther
south could lead to an increased severe threat for one tier of
counties farther south (including Crowley and Kiowa and possibly
Pueblo)...but HRRR has been solid on keeping the majority of the
stronger activity across El Paso, Lincoln, Douglas and Elbert
counties. NAMNest has trended southward with Kiowa county getting in
on the action towards 02-03z. For now, Severe thunderstorm watch is
already in place for El Paso county through 8 PM.
Across the remainder of the mountains should see shower and
thunderstorm activity increase as energy in the base of the upper
trof axis rotates through western CO. Snow levels will drop
overnight down to 10.5kft...with an inch or two of snow possible
across the higher elevations of the Sawatch and Mosquito ranges
overnight. Amounts appear too light at this point to warrant any
Winter weather highlights.
Meanwhile, cold front will blast through the southeast plains this
evening with gusts up to 50 mph possible behind the front,
especially where enhanced by convective outflows from the north.
Could see a strong storm or two develop along/behind the front this
evening, but again high res models do not look too excited about
this potential with HRRR keeping activity to the north. Low levels
cool and saturate with showers developing behind the front after 06z
which continue into the morning hours.
Saturday looks like a typical Day 2 Severe weather set up with
upslope flow across the plains. Cool and stable conditions can be
expected through the morning...but with strong forcing from the
upper trof swinging through, should see sufficient cooling aloft for
scattered thunderstorms to develop over the mountains which move off
into the adjacent plains during the afternoon. Deep layer shear
will be sufficient for a severe potential but CAPE may be the
limiting factor. SPC Day 2 outlook has Marginal threat for severe
thunderstorms tomorrow which still looks good given the uncertainty.
Best bet to see severe thunderstorms would be the I-25 corridor and
lower eastern slopes of the southeast mountains where elevated
heating is most likely to break the cap. Raton ridge area and
southern portions of the southeast plains will also be another risk
area. Large hail and damaging winds will be the primary storm
threats, though an isolated tornado would not be out of the question
if we can get rid of the CIN. Will also need to monitor burn scars
closely for a flash flood threat...though certainty is too low at
this point to go out with a flash flood watch. -KT
.LONG TERM...(Saturday night through Friday)
Issued at 305 PM MDT Fri Jun 21 2019
Saturday night-Sunday night...Latest models remain in decent
agreement of an unseasonably strong upper trough lifting out across
the Rockies through the day Sunday, though still indicate some
differences on how far south the associated wrap around
precipitation will be across eastern Colorado on Sunday. At any
rate, should see scattered to numerous showers and storms across the
higher terrain Saturday afternoon spreading north and east across
the I-25 Corridor through the far southeast Plains Saturday night.
With strong lift associated with the passing system, storms could be
on the strong side through the evening, with locally heavy rain and
hail possible. Latest guidance continues to indicate snow levels
falling to around 9,000 feet through early Sunday morning,
supporting a few inches of accumulating snow across the higher
peaks, mainly above 10,000 feet across the central mountains and the
Pikes Peak massif. With moderate northwest and subsidence developing
behind the passing trough on Sunday, believe the best chances of
lingering showers and storms will be north and east of the Highway
50 Corridor on through the day on Sunday. With the unseasonably cool
system moving across the region, overnight lows look to be in the
the 30s and 40s across the area Saturday night and Sunday night,
with the potential for near freezing temperatures in the San Luis
Valley Sunday night/Monday morning. Highs on Sunday will continue to
be well below seasonal levels in the 60s and 70s across the Plains
and mainly 40s and 50s across the higher terrain.
Monday-Friday...A warmer and drier weather pattern remains in the
offing as a large ridge of high pressure is forecast to build into
the Rockies through the beginning of the week and then becomes
entrenched across the Rockies into the end of next week. This will
bring steady warming with temperatures back to and slightly above
seasonal levels, with more isolated diurnal convective activity.
There may also be the potential for convection along a dryline
wavering across the far southeast Plains through the middle of the
week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 305 PM MDT Fri Jun 21 2019
Isolated to scattered thunderstorms will be most likely to affect
the central mountains and Pikes Peak region this afternoon with the
potential for hail and damaging winds at KCOS. Most of the high res
models keep activity just north of the KCOS terminal. Cold front
will drop through KCOS and KPUB by 01z with gusts to around 40-45
kts possible with Fropa. KPUB is more likely to remain dry through
the evening. Low clouds will fill in and lower across the plains
after 06z with the potential for -SHRA and MVFR to IFR conditions
towards morning. Clouds will persist through the morning before
breaking with a better chance of afternoon thunderstorms after 20-
21z.
For KALS...will see gusty southwest winds continue into early
evening before winds decrease overnight. Southwest winds will pick
up again on Saturday though will not be as gusty as today`s.
Conditions will remain VFR. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT
Confidence in the above aviation forecast discussion is
moderate.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...DS
NEAR TERM...AMS/DS
SHORT TERM...PW
LONG TERM...PW
AVIATION...DS/JH
Area Forecast Discussion
National Weather Service Tallahassee FL
850 PM EDT Fri Jun 21 2019
.UPDATE...
Forecast remains on track this evening with just only very small
isolated storms lingering that will dissipate over the next hour
or two.
&&
.PREV DISCUSSION [718 PM EDT]...
.NEAR TERM [Through Tonight]...
The main concerns this evening will be scattered thunderstorms
and elevated heat indices/apparent temperatures.
A weak surface trough was located invof the I-10 corridor, in
addition to a sea-breeze front in the southeast big bend, both
serving as triggering mechanisms for showers and scattered
thunderstorms. The 18Z TAE RAP sounding indicated Mixed Layer
CAPE over 3k J/kg and Precipitable Water values near 1.9 inches.
Mid-level lapse rates were around 7C/km and Downdraft CAPE was
over 1.2k J/kg. The potential for robust convection is there
given these indices, however Bulk Shear Shear (0-6 km) of only
around 10 knots and a cap around 700 hPa will limit both the
coverage and intensity of thunderstorms. At this time, highest
precip potential in the chance category will be near I-10 into
the big bend through early tonight. A couple pulse-type severe
thunderstorms are possible with damaging wind the main threat.
Turning our attention to the heat, apparent temperatures/heat
index values as of late afternoon were elevated across the
region, with values within a couple degrees of 105, but just
shy of heat advisory criteria at most locations, which is 108
degrees. With temperatures near maximum values for the day
and dew points beginning to fall, heat indices should begin
to decrease, and the current forecast reflects this thinking.
Another warm and humid night is in store with a slight chance
of a shower and low temperatures generally in the middle 70s.
.SHORT TERM [Saturday Through Sunday Night]...
Deep layer ridging and dry air will cover much of the Tri-State
region through the weekend. The main exception will be across
south-central Georgia where scattered showers and storms will be
more likely as an upper level wave links up with lee troughing.
Otherwise, highs will climb into the middle and upper 90s with
heat indices well over 100 degrees.
.LONG TERM [Monday Through Friday]...
Multiple shortwaves are forecast to move across the northern Gulf
Coast next week. These waves will all superposition over the
eastern GOMEX and then retrograde as a TUTT later in the week.
The result will be a week of unsettled weather, with higher than
average rain chances. High temperatures should remain in the lower
90s which is near normal.
.AVIATION...
[Through 00Z Sunday]
Convection has wound down for the evening and VFR conditions should
continue for the next few hours. Around 06-09Z, MVFR cigs are
expected to develop and could linger over the region into the late
morning-early afternoon hours on Saturday. Tomorrow afternoon
chances for thunderstorms are 30% or less at all TAF sites, so no
TSRA included in this TAF package. Light to moderate southwest winds
are forecast through the period.
.MARINE...
Winds and seas are forecast to remain below headline levels over
the next several days. As is typical this time of year, expect
upticks in winds and chop near the coast each afternoon.
.FIRE WEATHER...
Drier conditions and below average rain chances are forecast
over the next few days. Hazardous fire weather conditions are
not expected, however.
.HYDROLOGY...
Low rain chances will result in no flooding concerns through early
next week. By Tuesday, the pattern will shift to a wetter regime
with widespread rainfall totals of 1-3" forecast through the end
of next week.
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 76 94 74 96 74 / 10 20 10 10 0
Panama City 78 88 79 89 78 / 10 10 10 0 0
Dothan 76 94 73 95 73 / 20 30 10 10 0
Albany 76 93 74 94 74 / 20 30 20 20 10
Valdosta 75 94 73 96 74 / 20 20 20 10 0
Cross City 75 91 74 93 74 / 0 10 10 10 0
Apalachicola 79 89 77 90 78 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until midnight EDT /11 PM CDT/ tonight for
Coastal Bay-Coastal Franklin-Coastal Gulf-South Walton.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...Nguyen
NEAR TERM...LF
SHORT TERM...Harrigan
LONG TERM...Harrigan
AVIATION...Nguyen
MARINE...Harrigan
FIRE WEATHER...Harrigan
HYDROLOGY...Harrigan