Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/22/18
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
533 PM MDT Mon May 21 2018
.AVIATION...
00Z TAF CYCLE
Upper low to drift to near KLAS by 22/18Z with a moist low level east
to west flow continuing over most of NM. Mts occasionally obscured in
sct to nmrs showers and tstms contining from the Contdvd to the
Pecos Valley with a few storms containing hail and wind gusts to
around 50kt. This activity with isold strong to severe storms to
shift farther into the eastern plains by 03Z and persist thru 10Z if
HRRR is correct. Areas of MVFR to IFR cigs/vsbys in br and
preciptation will also obscure terrain from the east slopes of the
central mt chain to the TX border. Improving conditions at 22/15Z
with showers and storms breaking out from the central mt chain
eastward aft 22/18Z.
&&
.PREV DISCUSSION...326 PM MDT Mon May 21 2018...
.SYNOPSIS...
An upper level low pressure system stalled over the Great Basin will
interact with abundant low level moisture already in place for
scattered to numerous showers and thunderstorms east of the
continental divide tonight. Storms will then return mainly along and
east of the central mountain chain Tuesday through Wednesday, then
across southeast areas Thursday; however, coverage will trend
downward each day as the upper low lifts northeastward across the
northern mountains and drier air filters over New Mexico from the
southwest. There is a risk of severe thunderstorms across central and
eastern areas for the remainder of this afternoon and into the
evening, then again across the east on Tuesday afternoon and evening.
With the drier air will come warmer temperatures with highs reaching
above normal areawide during the latter half of the week.
&&
.DISCUSSION...
The closed upper level low pressure system stalled over the southern
Great Basin has created favorable dynamics for severe thunderstorms
over central parts of the forecast area this afternoon. The risk of
severe storms will spread onto the eastern plains this evening, then
return to eastern areas on Tuesday afternoon and evening. Storms
will be capable of producing over 1 inch of rain, large hail and
damaging winds.
The upper low will weaken as it lifts northeastward across the
northern Rockies through mid week, steering drier air over NM from
the southwest in the process. There will be a notable downtick in the
coverage of showers and thunderstorms, especially in the west where
dry weather will return on Tuesday. Storms along and east of the
central mountain chain will become spottier and their wetting
footprints will decrease through mid week, with dry weather pretty
much areawide again on Friday.
During the coming weekend another upper level low pressure system
will move through the Great Basin from the west strengthening wind
and potentially increasing fire weather concerns over portions of New
Mexico. There will also be a risk of dryline thunderstorms across the
far eastern and especially southeastern plains each afternoon and
evening.
44
&&
.FIRE WEATHER...
Showers and storms with locally heavy rainfall have developed along
and east of the Cont Dvd this afternoon. This activity will spread
eastward across the Rio Grande Valley and into the eastern plains
through tonight. Meanwhile, much drier southwest flow has already
spread into far western NM today. This drier air will move east
toward the Rio Grande Valley Tuesday with breezy to locally windy
conditions. Widespread marginal critical fire weather is likely
along and west of the central mountain chain for several hours
Tuesday afternoon. Meanwhile, more showers and storms with locally
heavy rainfall will impact eastern NM.
Drier air will spread even farther east into central NM Wednesday as
an upper level trough lifts across the Great Basin. The coverage of
marginal critical fire weather however will decrease as relatively
lighter winds are expected for central and western NM. Eastern NM
will remain in the deeper moisture where showers and storms with
locally heavy rainfall continue.
A ridge will build over NM Thursday through Saturday and allow
temperatures to warm above normal for the entire area with very dry
air and light winds. Multiple days of single digit min humidity is
likely again for central and western NM with poor to fair overnight
recoveries.
Guyer
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Glasgow MT
721 PM MDT Mon May 21 2018
.DISCUSSION...
Evening Update: A few thunderstorms have developed along a narrow
surface boundary running north to south across western Valley and
Garfield counties. Thunderstorms are mainly forming over the
higher terrain in this area, primarily the Larb Hills. As storms
move off of the terrain and off of the surface boundary, they are
quickly weakening. Any of these storms does have the potential to
produce small hail, gusty winds up to 30 or 40 mph, and fairly
frequent lightning. Currently we do not expect large hail or
severe winds, and certainly not widespread. As the boundary
slowly moves eastward, storms may begin to develop a little
further east than they currently are, but after sunset the chance
for storms should decrease. A few showers will not be out of the
question, however. With the update I mainly blended forecast pops
with the SREF, ConsShort, and HRRR models as they seemed to have
the best handle on the convection this evening.
Hickford
Afternoon Update (2pm MDT): Generally the narrative from the
morning forecast remains intact, as well as the forecast in
general. The main updates were to the precipitation forecast in
the near and short terms, needing to account for current trends in
the convection that has formed in the vicinity of the Little
Rockies. Otherwise, no other major changes were made to the
forecast for the afternoon.
Bigelbach
PREVIOUS DISCUSSION: Expect a relatively warm and dry weather day
across northeast Montana for the most part. An upper level
shortwave will approach this afternoon from the west. Dynamic
forcing will enhance ascent, especially across upslope terrain
areas upstream of the CWA. That said, expect any convection to
spill into the western zones by this evening. Nam Bufkit forecast
soundings nicely show a little instability, and CAPE as high as
500 J/kg near Jordan this afternoon and evening. At this time,
little in the way of 0-6 km shear should prevent stronger storms,
but brief heavy downpours, as well as breezy conditions may
accompany some of the multicellular structures that evolve across
the area tonight.
While afternoon and evening convective activity will again be
possible on Tuesday, right now the focus is on Wednesday and
Thursday as being the most active. An upper shortwave trough and
associated vorticity maxima over northern Wyoming will lift into
southern and central Montana on Wednesday and eventually eastern
Montana by Thursday. Meanwhile, expect surface low pressure to
track well southeast of the CWA into the Plains during this time.
Low and mid level moisture will increase ahead of this shortwave,
and forecast Bufkit soundings show a more pronounced nice veering
wind profile with increasing levels of 0-6 km sheer across
locations within the CWA. Nice inverted V sounding in the low
levels in the southeast zones in particular in the presence of low
level shear suggest wind potential with any convection. While
models show in excess of 1000 J/kg surface-based CAPE over these
locations on Thursday, any elevated convection over complex
terrain and across portions of the CWA may be sustained well into
the evening hours. In short, will be closely monitoring Wednesday
and Thursday for at least an isolated stronger or possibly severe
storm over portions of NE Montana, and if anything, with
precipitable water values between 1.00" and 1.50" do think locally
heavy rainfall may result as well.
The forecast beyond the midweek was trended toward consensus model
blends given the usual spread in guidance at larger time scales
and lower predictability of mesoscale features. Early indications,
however, suggest a building ridge over the western U.S. with
warmer and dry weather conditions. Maliawco
&&
.AVIATION...
Flight Category: VFR.
Synopsis: A weak disturbance is spreading scattered shower and
isolated thunderstorm activity over the sites. Tomorrow
afternoon, some of these showers could gain strength and some
isolated thunderstorm activity may impact aviation operations if
such storms were to pass over the airfield(s).
Wind: Expect generally light and variable winds overnight, except
under showers and thunderstorms where winds may become erratic and
gusty. Winds tomorrow will increase to around 7-12 kts out of the
north- northeast. If any thunderstorms pass over the sites
tomorrow, expect gusty and erratic winds.
Bigelbach / Hickford
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
weather.gov/glasgow
Area Forecast Discussion
National Weather Service Hastings NE
612 PM CDT Mon May 21 2018
.SHORT TERM...(This evening through Tuesday)
Issued at 208 PM CDT Mon May 21 2018
The area of surface high pressure has shifted southeast of the
forecast area, and we`ve begun to see southerly winds increase
behind it. Remnant low to mid-level moisture has allowed for some
fair-weather cumulus to develop which should dissipate this
evening.
A chance for thunderstorms continues tonight in association with
a low-level jet that is forecast to set up in the area. There
still are some substantial differences between models on the
location of this feature, though. The model consensus is that the
best convergence and threat for thunderstorms will be along our
northern and eastern counties, but I also included some slight
PoPs further south as the NAM and HRRR try to bring some weakening
convection into our western counties late this evening. All that
being said, I expect that the large majority of the area will stay
completely dry overnight.
This week`s warmup gets underway on Tuesday as a large upper low
over the southwest CONUS puts us into consistent south to
southwesterly flow at the surface and aloft. There is another
chance for thunderstorms Tuesday evening through the overnight,
but like tonight, considerable difference remain on placement of
the LLJ and resulting convection. At this time, most of the models
tend to favor areas to the north of us for any thunderstorm
development.
.LONG TERM...(Tuesday night through Monday)
Issued at 208 PM CDT Mon May 21 2018
Off and on thunderstorm chances continue Wednesday through Friday
as the upper low slowly lifts out of the Southwest. Most of the
time will be dry, but we really can`t rule out thunderstorms on
any given day. Highs Tuesday through Friday are expected to range
from the mid 80s to low 90s each day.
We will see a pattern shift to more northwest flow and ridging
into Saturday, which should lead to mostly dry Memorial Day
weekend. That said, this forecast does now include a slight chance
for showers and storms on Sunday as the next upper low tracks a
little faster across the Rockies. Even so, the overwhelming
majority of Memorial Day weekend looks dry and pleasant with highs
in the 80s and 90s.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 609 PM CDT Mon May 21 2018
Overall its VFR conditions through the forecast with a couple of
caveats. First, low level jet sneaks into area overnight and have
include LLWS in the KEAR TAF. With the low level jet and warm
advection, models generate sporadic showers and isolated
thunderstorms overnight. Not strong location consensus but close
enough for inclusion of VCTS in the KEAR TAF for now.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...Mangels
LONG TERM...Mangels
AVIATION...NOAA/NWS/Moritz
Area Forecast Discussion
National Weather Service Wilmington OH
1021 PM EDT Mon May 21 2018
.SYNOPSIS...
Showers and thunderstorms will remain possible across the region
until a cold front moves through Tuesday afternoon and evening.
High pressure will build in to bring dry conditions for mid to
late week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Showers and thunderstorms are continuing to work slowly east
across the area late this evening. Do expect to see a gradual
weakening trend over the next few hours as we continue to lose
the diurnal enhancement. Nonetheless, these storms have been
producing locally heavy rainfall and we have numerous boundaries
still floating around out there. The last few runs of the HRRR
have been consistently hanging on to things a bit longer into
the overnight hours so decided to go with a short fused FFA for
an axis across central portions of our fa to account for this.
Given the expected weakening trend though, would think the
threat will decrease as we progress through the early morning
hours.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Showers and thunderstorms may start to redevelop along a pre-
frontal trough in the morning across southeastern counties.
Additional activity will develop through the day as a cold front
approaches. Scattered showers and thunderstorms will occur
until the front crosses the area in the afternoon and evening.
Cannot rule out some stronger updrafts that could be capable of
strong to damaging wind gusts. High pressure will start to build
in later Tuesday night with a drier air mass.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
The long term will open up with rather pleasant weather as surface
high pressure centers over Michigan. The upper level trough axis
will be centered over eastern Canada with the best ageostrophic
convergence located from Michigan to central Ohio.
Wednesday afternoon 1000/850 MB thicknesses are forecast to be
around 1390 M which would support high temperatures only around 80
degrees. Wednesday night into Thursday the broad upper level low
that was over the western United States will open up and head east.
The wave will then impinge on the upper level trough axis pushing
the corresponding surface high pressure east as well. This means
high temperatures will start to recover Thursday (even though
temperatures will likely remain above normal through the long term)
into the lower 80s. 850 MB temperatures remain rather steady while
1000/850 MB thicknesses only slightly increase.
Friday a weak mid-level ridge will form over Tennessee with an upper
level low over the Gulf of Mexico. GFS forecast soundings at KCVG
even show a weak subsidence inversion from the mid-level ridge at
this time and with PWATs forecast to be around 1.25" Fridays highs
could again approach 10 degrees above normal for this time of year
(mid 80s with some upper 80s southwest).
Saturday into Sunday gulf moisture surges north with the cold front
now forecast to remain well north of the ILN forecast area. Even
with the front remaining well north of the area, above normal PWATs
and weak PVA from the upper level low will allow shower and
thunderstorm chances to return to the area Saturday and continue
through Monday.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
The main line of showers and storms extending from southeast
Indiana into west central Ohio has been making a very slow
eastward push over the last several hours. The airmass out ahead
of this is still unstable and we are seeing some isolated to
scattered showers and storms beginning to develop in those area.
As a result, will allow for a period of showers and
thunderstorms at all of the TAF sites through the rest of the
evening hours. As we begin to lose some of the diurnal
enhancement and some weak mid level energy pushes eastward, we
should see an overall weakening trend in the coverage and
intensity through the night, but will hang on to a VCSH through
a good part of the overnight hours to account for any lingering
activity. There are some indications that some MVFR cigs may
develop late tonight into Tuesday morning, especially at the
northern TAF sites. A cold front will push east across the area
through the day and this will lead to some additional scattered
shower and thunderstorm activity later Tuesday morning and into
the afternoon hours. Will cover this threat with a VCSH at this
point.
OUTLOOK...No significant weather expected.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Flash Flood Watch until 6 AM EDT Tuesday for OHZ045-046-
052>056-062>065-071>073-078>081.
KY...Flash Flood Watch until 6 AM EDT Tuesday for KYZ092-093-
095>099.
IN...None.
&&
$$
SYNOPSIS...
NEAR TERM...JGL
SHORT TERM...
LONG TERM...Haines
AVIATION...JGL
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1112 PM EDT Mon May 21 2018
.UPDATE...
Issued at 1112 PM EDT MON MAY 21 2018
A few showers linger in the far east and also dot the west. A
cluster of storms is currently moving north northeast across
north central Kentucky. The eastern flank of these storms may
brush the Bluegrass counties between 12 and 1 am; however, would
imagine that a weakening trend would continue, given the air mass
in place. The latest HRRR trends support this as well. As such,
will hold onto a few more showers through midnight, with mainly
dry conditions expected through dawn. Mid-level clouds are
relenting generally along and west of I-75, but another batch is
creeping in from southeastern Tennessee. This should help keep
the fog from becoming too dense overnight. Forecast lows in the
low to mid 60s look on track. Mainly tweaked a few sites based on
the observational trends. Updates have been sent.
UPDATE Issued at 855 PM EDT MON MAY 21 2018
Only a few cluster of showers across the area, as multiple
traversing outflow boundaries have scoured out the majority of
the available CAPE across most of eastern Kentucky. Will hang onto
thunder for a few more hours, before a lull takes place through
the first half of the overnight. Upstream, more organized
convection may lend some influence towards dawn, and will maintain
some scattered showers working back into the area from the
northwest. Will reevaluate this along with the lows and fog with
the next update. For now, mainly freshened up the temperature,
sky, and POPs based on the latest trends in observations,
satellite, and radar. Updates have been sent.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 418 PM EDT MON MAY 21 2018
Showers and thunderstorms will continue to drift north this
afternoon into early this evening, producing brief periods of
locally heavy rainfall as they initially develop and merge with
additional cells in a summertime-type environment. Small hail will
be possible with initial updraft surges, while downburst wind gusts
to 40-50 mph may also be possible as these collapse. Have not seen
as high of coverage farther west into the Bluegrass region at this
time, farther displaced from a weak surface kink and any topographic
influence. Will see preexisting storms off to the south approach and
interact with cold pools/outflow boundaries to provide additional
lift here, with instability and storm coverage dissipating near and
after sunset.
A weakening upper trough approaching the Great Lakes and
accompanying surface low just off to its southeast will continue to
lift northeast, keeping eastern Kentucky firmly in the warm sector.
May see some shower activity linger into tonight across the
Bluegrass region nearer to a frontal boundary moving into the Ohio
Valley and associated remnant outflow boundaries from earlier
convection. Most locales should remain dry as earlier precipitation
leads to fog development even outside of valleys through the night
into Tuesday morning.
Broad/weak troughing overhead Tuesday along with a continued sultry
airmass will promote quickly developing showers/storms during the
morning. These will increase in coverage with diabatic heating
through the afternoon as a cool front makes closer approach toward
the lower Ohio Valley. While deep layer shear will be a tad stronger
compared to today, this combined with weaker instability does not
suggest much if any uptick in storm severity. Cell mergers and
initial pulses may briefly produce heavy rain and small hail
again, along with gusty downburst winds to perhaps 40 mph. Rain
chances will continue Tuesday evening and night as the front
enters Kentucky and provides greater low level forcing. Fog will
once again be in play given the recently wet ground, at least
during the early overnight prior to arrival of somewhat drier air.
.LONG TERM...(Wednesday through Monday)
Issued at 300 PM EDT MON MAY 21 2018
The extended will feature alternating periods of wet and dry
weather across eastern Kentucky. The period should begin with rain
exiting the area on Wednesday, as a trough of low pressure aloft
pushes off to the east of the area. Wednesday night through
Thursday night should be dry, as a ridge of high pressure sets up
across the region. Another area of low pressure is then forecast
to push through over the weekend, bringing more rain chances to
the area from Friday afternoon through the end of the upcoming
weekend. The best chance for thunderstorms will be during the
afternoon and evening hours. Temperatures will continue to run
above normal, with daily highs in the low to mid 80s and nightly
lows in the low to mid 60s expected for most locations. Valley fog
will also be possible each day during the late night and early
morning hours.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 855 PM EDT MON MAY 21 2018
Will hold onto VFR conditions through 06z, as convection wanes,
and mainly a mid-level debris deck is left behind. Some clearing
will work in from the southwest overnight, with some patchy fog
expected. Have gone MVFR at most TAF sites, with IFR or worse
expected at SJS, as they saw more significant rainfall earlier.
Have kept it VFR at JKL, with a light wind remaining on the
ridges. Another round of scattered convection will threaten once
again on Tuesday. Winds will remain light through early Tuesday
morning, before increasing to around 5 kts out of the southwest.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GUSEMAN
LONG TERM...AR
AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Melbourne FL
955 PM EDT Mon May 21 2018
.UPDATE...
Widespread precip tapered off to isolated light rain showers a
little after sunset across just about all of the area. Local radars
show spotty showers continuing upstream over the Atlantic, with much
higher coverage and intensity of precip over the Keys/Straits and
offshore south Florida. Local RAOB and DRWP data show SE to SSE flow
in the surface to 2KM layer, which supports at least some onshore
component to marine shower motion, especially farther south along
the Treasure Coast. Some redevelopment is likely given the favorable
setup aloft, high PWAT air mass in place, an approaching nocturnal
marine instability cycle. have trimmed POPs back to 20 north and
interior, trending up to 40 for the Treasure Coast. Min temps near
70/L70s once again.
&&
.AVIATION...VFR most areas. MVFR to local IFR VSBYs (possibly MVFR
CIGs as well) near 2-3SM/BKN025 in showers overnight, with the best
chance along the MLB-SUA corridor.
&&
.MARINE...SE flow averaging about 15KT will continue overnight. Seas
3-4FT near shore and 5FT well offshore. Expect coverage of showers
(and an isolated storm or two) to increase later tonight especially
over the Gulf Stream.
&&
UPDATE/AVIATION...Cristaldi
IMPACT WX...Weitlich
&&
.PREV DISCUSSION... /issued 328 PM EDT Mon May 21 2018/
...Heavy Rain Possible Again Tuesday, Especially Near the Coast...
Tuesday...Axis of Atlantic surface ridge will extend into north
Florida. This will maintain a moist, breezy southeast flow in the
lower levels. The upper level trough in the eastern Gulf of Mexico
will weaken, but broadly diffluent flow aloft is still shown across
the area. Little change in the extensive cloud cover is expected
with these conditions remaining in place, so high temps are forecast
in the upper 70s to lower 80s.
MOS guidance continues to have high rain chances (60-80%), along
the Space/Treasure Coasts tonight, then areawide on Tue. This
very moist pattern is not likely to come to a halt as fast as the
NAM based guidance suggests, so have bumped up PoPs to likely.
Locally heavy rainfall will continue to occur especially along the
coast where the flood threat has been increasing.
Wednesday...The axis of the Atlantic surface ridge is forecast to
settle a little closer to the local area. Low level flow looks a
little more southerly and slightly weaker. Therefore, early morning
Atlantic showers should not be pinned at the coast as much as recent
mornings, and with precipitable water forecast to start off a
little lower, convection may become more due to daytime heating.
MOS guidance supports this, showing high temps in the mid 80s at
the coast to around 90 inland. Expect showers/storms to be more
scattered as influence of the upper level trough wanes, so will
have 40-50% rain chances for now.
Previous Discussion...
Thu-Sun...The ridge axis does gradually sink south and east while
weakening slightly during the period. Unfortunately the deep plume
of moisture continues across the area into the weekend. Medium range
models show weak surface low development over the southern Gulf by
Thu with both GFS/ECMWF lifting this feature toward the Louisiana
coast by Sat. The ECMWF remains a bit deeper with this low pressure.
Aloft, troughing will deepen and take up residency across the Deep
South to include much of the GOMEX. This will strengthen the S/SWRLY
steering flow into the holiday weekend as well as send occasional
shortwave impulses over the region. This will signal increasing rain
chances with a threat for heavy rainfall and localized flooding over
already saturated ground. It will remain humid with max temps in the
L-M80s with min temps continuing in the U60s to L70s.
&&
.AVIATION...Moderate to heavy showers will continue to occur this
afternoon in Volusia County and along the Treasure Coast. These
heavy downpours are resulting in IFR visibilities of 1-2 SM at
KDAB, and MVFR CIGs of BKN-020-030 at KDAB and KMLB-KSUA. Included
TEMPO groups in the TAFs to account for ongoing rain through
21/21Z at all coastal terminals. It is possible that this heavy
rainfall extends beyond the current TEMPO groups, so amendments
may be needed later this afternoon if the rain persists. The
inland terminals have dodged most of the heavy rainfall so far
today with some light rain and occasional MVFR CIGs, but otherwise
VFR conditions. As showers move inland this afternoon some
terminals may see periodic MVFR/IFR conditions with any moderate
to heavy shower activity. High resolution models, HRRR and local
WRF, indicate most of the showers will end after 21/24Z with VFR
conditions prevailing through the overnight. If the last couple of
days are any indication there may be shower development early in
the morning after 22/06Z, as a result I have continued VCSH at all
coastal terminals through the overnight. However, there is too
much uncertainty to include SHRA in the TAFs at this time. Due to
the abundance of moisture and high chances of rain for Tuesday,
have included VCSH prevailing at all terminals after 22/14Z.
&&
.MARINE...
Tonight-Tuesday...The pressure gradient still looks tightened enough
to maintain 15 knot southeast flow, and possibly up to 20 knots
offshore at times. This will continue to produce poor boating
conditions with seas 3-5 feet and up to 6 feet offshore. The
weather conditions also look poor as scattered to numerous showers
and isolated storms are indicated late tonight in the southern
waters, then spreading northward through Tue.
Wednesday-Thursday...The Atlantic ridge is still forecast to settle
close to the waters Wed while weakening. This will diminish
south/southeast winds and allow seas to subside to 3-4 feet.
Moisture will remain high enough for at least scattered showers and
isolated storms.
Friday-Saturday...The forecast for the start of the Memorial Day
weekend is still uncertain as the models don`t agree on the
evolution of low pressure forecast to develop over the
central/eastern Gulf of Mexico. The Atlantic ridge looks like it
is going to become well established again with an axis to our
north. This will provide a moist southeast wind flow, and while
the speed forecast is uncertain, at least some increase towards
15-20 knots would be expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 71 80 70 84 / 40 60 40 40
MCO 70 82 70 88 / 30 70 30 50
MLB 73 80 73 84 / 50 70 40 50
VRB 73 81 72 85 / 60 70 40 50
LEE 71 83 70 88 / 30 70 30 50
SFB 70 81 70 87 / 40 70 40 50
ORL 70 81 70 87 / 30 70 30 50
FPR 72 81 72 84 / 60 70 40 50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Area Forecast Discussion
National Weather Service Nashville TN
845 PM CDT Mon May 21 2018
.DISCUSSION...
Although some showers and thunderstorms were observed on KOHX
radar this afternoon and evening, this round of convection was,
thankfully, much more subdued than yesterday`s. At 830 pm, Mid-
State precipitation was mainly confined to a patch of showers and
isolated thunderstorms over parts of Dickson, Humphreys and
Houston counties. This activity should continue to diminish,
although, just as in previous nights, we will keep at least a
small chance for showers and thunderstorms running during the
overnight hours.
The HRRR shows some scattered showers and isolated thunderstorms,
located over eastern Alabama this evening, possibly working their
way northward into parts of our area later tonight, mainly after
06z. This activity lies along the eastern edge of a weak area of
low pressure over the central Gulf coast states.
Our current overnight PoPs and temperatures look reasonable, and
don`t see the need for any changes at the moment.
&&
.AVIATION...
00Z TAF DISCUSSION.
BNA/MQY/CKV/CSV...Radar showing much less coverage tonight than
last evening, with only scattered showers occurring mainly west of
BNA. Will handle the low evening rain chances with VCSH remarks.
Not looking for radiation fog overnight, given last night`s VFR
conditions. Once again expecting afternoon convection Tuesday, and
have handled this with PROB30 remarks.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 68 85 68 87 65 / 30 50 20 10 0
Clarksville 66 83 66 85 63 / 50 40 10 0 0
Crossville 63 78 63 81 61 / 20 60 30 20 0
Columbia 66 84 65 86 64 / 30 50 20 10 0
Lawrenceburg 66 83 64 86 64 / 30 50 20 20 0
Waverly 66 84 67 86 65 / 50 30 10 10 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......19
AVIATION........08
Area Forecast Discussion
National Weather Service Pueblo CO
324 PM MDT Mon May 21 2018
.SHORT TERM...(This evening through Tuesday)
Issued at 324 PM MDT Mon May 21 2018
Shortwave embedded in southwest flow is currently ejecting across
southern CO, firing off thunderstorms much earlier in the day vs the
past couple days. There have been a couple of embedded stronger
cells capable of producing some hail up to the size of dimes along
with brief heavy rain and gusty winds, but overall, storms have had
a difficult time maintaining strength due to weak deep layer shear.
Latest HRRR runs continue to expand precipitation eastward across
the southern plains through the afternoon and evening. Still some
residual low level moisture out that way, with MLCAPES in SPC
mesoanalysis suggesting up to 1500 j/kg will be present. This will
be sufficient for a strong storm or two through the evening with
hail up to dime size and wind gusts to around 45 mph the main
threats. Will have to monitor burn scars for the potential for heavy
rainfall through this evening as well. Activity will shift eastward
and diminish overnight. The best chance for rain still looks to be
south of highway 50.
The upper low over the western U.S. will start to lift northeastward
towards the Great Basin on Tuesday with the next shortwave expected
to eject across CO ahead of the system. Another round of isolated
to scattered afternoon thunderstorms can be expected with greatest
coverage over the mountains. Another convergent boundary will
likely set up across the southeast plains within the surface trof
axis during the late afternoon and evening serving as another
potential focus for thunderstorm development. Dew points look a
little lower across southeast CO by afternoon. CAPE values of up to
around 1000 j/kg and shears around 20-30 kts will lead to some
localized strong storms with small hail and gusty erratic winds the
main concerns. Doesn`t appear to be sufficient shear for much of a
severe thunderstorm risk at this time. Temperatures will continue
the upward march with highs topping out in the 80s, with 60s and 70s
for the mountain/valley communities. -KT
.LONG TERM...(Tuesday night through Monday)
Issued at 324 PM MDT Mon May 21 2018
Tuesday night-Wednesday...Increasing southwest flow aloft continue
to be progged across the region as a broad upper trough across Great
Basin lifts north and west across the Northern Rockies. Models
continue to suggest drier air within the southwest flow mixing
across the area. This along with the breezy west to southwest winds
will lead to increasing fire danger Wednesday afternoon, especially
across the San Luis Valley where could see critical fire weather
conditions. Otherwise, isolated to scattered showers and storms
across the area Tuesday afternoon to diminish Tuesday evening, with
best chances of storms on Wednesday across the far southeast
Colorado Plains, where models are indicating a dry line developing
through the afternoon. Latest SPC Day2 outlook has this area in
marginal risk of severe storms, with large hail and strong outflow
winds the main threats. Temperatures look to warm back to above
seasonal levels, with highs Wednesday in the 80s to lower 90s
expected across the lower elevations, 60s and 70s across the higher
terrain and 40 and 50s at the peaks.
Thursday-Friday...Moderating westerly flow aloft expected across the
region as short wave ridging builds across the Rockies. Pattern
continues to support warm and mainly dry weather, with temperatures
expected to remain above late spring norms, with highs remaining in
the 80s and 90s across the lower elevations, and mainly 60s and 70s
across the higher terrain. As for precipitation, can`t totally rule
out some high based convection in the afternoon and early evening
hours, though soundings support mainly virga and gusty winds.
Saturday-Monday...Latest models indicating increasing southwest flow
aloft once again, as more Eastern Pacific energy digs into the Great
Basin, though differ on timing and location of this energy lifting
out across the Rockies. Again, pattern would suggest mainly dry and
warm conditions early in the weekend, with the potential for
critical fire weather conditions across portions of the South
Central and Southeast Colorado, along with the potential for strong
to severe storms across the far Southeast Plains later in the
weekend, with a possible dryline.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 324 PM MDT Mon May 21 2018
VFR conditions expected at the terminals through this evening though
there will continue to be a window for thunderstorms to impact KALS
through 00z. KPUB could also see a VCTS late this afternoon and
evening. Overall, thunderstorm coverage looks less widespread north
of highway 50 so will have to monitor KCOS for possible inclusion
of VCTS in the TAF but for now, chances look on the lower side.
Erratic gusty winds up to 35 kts, brief VFR to localized MVFR
cigs/vis and some small hail may accompany the stronger storms.
Activity should diminish after 03z with residual showers and
isolated thunderstorms possible through 06z across southern portions
of the area. Tuesday will be a similar pattern with thunderstorm
coverage more in the isolated category for the terminals. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT
Area Forecast Discussion
National Weather Service Charleston WV
945 PM EDT Mon May 21 2018
.SYNOPSIS...
Weak warm front moves northward today. Cold front crosses
Tuesday night. High pressure to end the work week but more
unsettled weather arrives in time for the weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 945 PM Monday...Moderate to heavy rain continues across
parts of the NE Mountain Counties and a flash flood warning
remains in effect in those areas. Have updated PoP based on
latest Radar and Meso Model trends. Complex currently across NWS
ILN`s area in Ohio will likely clip our SE Ohio Counties
tonight. May have to watch for possible water issues in areas
hit by storms earlier today, where parts of Athens and
Washington County received over 2 inches in some isolated spots.
As of 510 PM Monday...Increased PoP across most of the area with
thunderstorms being more widespread than previously forecast.
Radar is indicating numerous outflow boundaries that have been
the focus for new convection to initiate. Some storms have been
able to reach severe limits and this threat will continue into
this evening until about sunset. Flash flooding is also a
concern at this time.
As of 145 PM Monday...
Front which was stalled near I-64 is starting to drift back
north early this afternoon... a trend which should continue
through the remaining of the afternoon. Starting to get showers
popping up near and south of the front which will also
gradually expand in the instability of the warm sector this
afternoon and drift northward into this evening. Also currently have
a cluster of showers and storms approaching the far NW forecast
area which. Models had been struggling a bit with activity
north of the front, but HRRR seems to have latched on to this
and carries it across the NW corner of the CWA over the next
couple hours. Shear is not all that great today -- 0-6km bulk
shear maxes out around 25kts across the west and north, but with
plenty of instability some storms may become strong to severe
with gusty outflow and hail the main threat. With slower storm
motion and precipitable water around 1.5 inches, any repetitive
cells could lead to isolated water concerns.
In a rather juicy atmosphere think at least some isolated to
scattered showers and storms will linger through the night so
kept POPs going.
A cold front will approach from the west late Tuesday. Ahead of
this front we should see areas of showers and thunderstorms
across the forecast area. Did go with an area of likely POPs
crossing from west to east through the day associated with an
upper level shortwave trough running out ahead of the surface
cold front. With lots of clouds around all day, instability is
pretty sparse, but with the upper level support and some
surface convergence an isolated stronger storm or two is
possible.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 344 PM Tuesday...
The cold front will pass through Tuesday night into Wednesday
morning with a good chance showers and a few thunderstorms. A
drier airmass moves in behind this front by Wednesday afternoon
and persists through Thursday night. Dewpoints drop into the 50s
behind the front so a dry and rather comfortable period is
expected Wednesday night through Thursday night.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 344 PM Tuesday...
High pressure moves east of the area on Friday, and return flow
begins to transport increasing amounts of moisture northward
from the Gulf of Mexico and western Atlantic into our area.
Dewpoints will increase into the 60s on Friday and there will be
a small chance for a shower and/or storm to develop over our
southern counties. This threat for showers/storms will then
expand northward Saturday through Monday. Generally kept with
the blended model guidance for the weekend forecast to wash out
any model differences regarding how fast the moisture returns
and the track of the responsible storm system which develops
over the Gulf. This results in chance PoPs throughout the
weekend with highs in the 80s Friday and Saturday, dropping to
the 70s to near 80 on Monday.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
As of 810 PM Monday...
Showers and thunderstorms will be coming to an end over the next
couple hours with only EKN and CKB still likely to be impacted.
Brief restrictions to IFR are possible in these storms. Should
be some cloud cover remaining tonight, but uncertain at this
time that even with the cloud cover if we will see fog develop.
With the rainfall and moist ground, fog will be likely if any
sites are to clear out overnight. The frontal system that kicked
off the showers and storms across the area today will remain in
our vicinity tomorrow, and afternoon showers/storms will likely
bring another round of restrictions.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Possible fog overnight and some sites could
see brief restrictions from showers and storms.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 05/22/18
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H H H H H H H L
HTS CONSISTENCY H H H H H H H H H H H L
BKW CONSISTENCY H H H H H H M M M M M L
EKN CONSISTENCY H H M M M M M H H M M L
PKB CONSISTENCY H H H H H H H H H L L L
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 00Z WEDNESDAY...
Brief periods of IFR possible in showers and storms into Tuesday
night.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.
&&
$$
SYNOPSIS...MZ/30
NEAR TERM...MZ/MPK
SHORT TERM...ABE
LONG TERM...ABE/30
AVIATION...MPK
Area Forecast Discussion
National Weather Service Blacksburg VA
814 PM EDT Mon May 21 2018
.SYNOPSIS...
A southerly flow will continue to push warm and humid air into
our region early this week. The nearly stationary front to our
north will finally push south across our area Wednesday. High
pressure will follow the front Wednesday night and keep the area
mostly dry through Friday.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 200 PM EDT Monday...
A blocking ridge centered over Bermuda stretches westward to cover
portions of the southeast and Mid Atlantic states tonight. This
ridge is expected to sink south Tuesday, losing its influence on the
region and allowing an upper level trough and a cold front to
approach the area from the northwest. Over the Gulf states north
into the Tennessee Valley, a weak upper level trough will continue
to draw Gulf and Atlantic moisture northward into the area tonight
and tomorrow.
From this afternoon into this evening, storms will track from the
southeast to the northwest. Tomorrow the steering flow shifts with
storms moving from the southwest to the northeast. All storms will
be slow moving and with the addition of tropical moisture, heavy
downpours are likely this afternoon and evening and again tomorrow
afternoon and night. Since the ground remains wet and creeks,
streams and rivers are elevated, there is a chance for renewed
flooding this evening and tomorrow.
As far as severe threat, model soundings suggest very moist layer
with SBCAPEs around 1000 J/KG this afternoon. Cannot rule out some
isolated wet microbursts but main threat is localized flash flooding.
Temperatures will remain muggy overnight with readings in the 60s.
Temperatures Tuesday will range in the 70s across the mountains to
low to mid 80s east.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM EST Monday...
Scattered to widespread showers and thunderstorms are expected
Tuesday evening into early Wednesday as an upper level
disturbance pushes across the central Appalachians toward the
coast ahead of an approaching cold front. Right now, instability
appears to be modest with this disturbance such that it wouldn`t
be a surprise to see a few cells become strong to severe before
midnight Wednesday, mainly across the Piedmont, but the threat
of widespread severe storms overall appears limited.
The cold front will sink southward, advancing to the Interstate
81 corridor around dawn before loosing speed somewhat as it
continues a southward drift. Believe we will see a
redevelopment of showers across the mountains in the northwest
flow upslope regions, however instability will be limited.
Greater instability will be found in the vicinity of the front
across extreme southern Virginia and northern North Carolina,
where scattered strong storms may redevelop with afternoon
heating where CAPEs may exceed 2000 J/Kg. Outflows from any of
these storms will help to push the front further southward by
evening, clearing the boundary through our area after sunset
Wednesday.
High pressure will shift toward New England Wednesday night,
causing winds across the Mid Atlantic to swing more easterly by
Thursday morning. Though instability will be very modest within
the weak high pressure wedging across the region, may see a few
showers/isolated storms develop along the Blue Ridge with
afternoon heating as marine air off the Atlantic is forced into
the mountains.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 300 PM EST Tuesday...
Winds will shift more southerly on Friday as high pressure
slides off shore. Though moisture and instability will remain
limited, expect slightly greater coverage of spotty, daytime
heating-driven showers and thunderstorms. Coverage of showers
and thunderstorms will increase during the weekend as a warm
front lifts northward through the mid Atlantic, bringing a
return of deeper moisture from the Gulf coast region. Afternoon
temperatures will range from the mid 70s to the mid 80s each
day, while overnight lows will generally be in the 60s areawide.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 800 PM EDT Monday...
Numerous thunderstorms will continue east of a KDAN to KLYH line
this evening where the air mass is still unstable. KLYH will be
starting the TAF forecast period with MVFR conditions and
erratic winds due to a strong thunderstorms. Hi-Res guidance and
HRRR indicated areal coverage of showers and thunderstorms will
diminish after 06Z/2AM.
High confidence of MVFR fog overnight in areas where there has
been rain this afternoon across much of southwest Virginia,
northern North Carolina and southeast West Virginia. Medium
confidence that KLWB will lower to LIFR in dense fog after
08Z/4AM. Ceilings across much of the region will lower to IFR
late tonight.
The fog and stratus that forms overnight will be gone by
12-14Z/8-10AM Tuesday. More thunderstorms are expected Tuesday
afternoon and evening. Confidence low as to the location where
the storms will first develop. MVFR conditions are likely with
any of the storms, otherwise high confidence of a scattered to
broken VFR stratocumulus layer.
.Extended Aviation Discussion...
MVFR showers and thunderstorms are likely again Wednesday.
Conditions are will be drier and are expected to be VFR Thursday
and Friday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...NF
LONG TERM...NF
AVIATION...AMS/RCS