Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/20/19
Area Forecast Discussion
National Weather Service Columbia SC
815 PM EDT Sun May 19 2019
.SYNOPSIS...
High pressure will extend from the Atlantic westward along the
northern Gulf Coast through this week. A diffuse front will sink
southward and be close to the forecast area Monday and Tuesday. The
ridging will keep moisture limited and bring above normal temperatures.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Dry and warm mid-levels will prevent showers through the near
term. A 25 kt low level jet and a few convective debris clouds
from upstream should keep overnight temperatures slightly
warmer than would otherwise be. Expect lows generally in the mid
60s. Fog is unlikely due to the low level jet but a few low
clouds may form overnight, lingering into the early morning.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Surface High pressure will ridge from the Atlantic westward
along the northern Gulf Coast. There will be lee-side troughing
in the forecast area. The cold front sinking southward and
toward the forecast area is forecast to become diffuse under the
upper ridging. Convergence into the surface trough and seabreeze
front plus a little upper support with a mid-level shortwave
trough brushing the northern periphery of the upper ridge will
be the main support for thunderstorms mainly late Monday
afternoon and evening. Still, with general upper ridging and
little moisture we believe thunderstorm coverage will be low.
The ARW along with the NAM, GFS, and ECMWF MOS indicate very
little coverage. We maintained the forecast of just slight
chance pops. Instability associated with intense heating and dry
air in the middle levels aiding downdrafts indicates a
potential for strong wind with any thunderstorms. The
temperature guidance was close with continued hot conditions.
Expect highs in the lower and middle 90s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The main concern is hot conditions during the medium-range
period.
The models indicate general high pressure at the surface with
some troughing, mainly thermal. The models have been consistent
with strong upper ridging. The pattern indicates hot conditions
with thunderstorms mainly suppressed. The GFS and ECMWF MOS
have highs mainly in the upper 90s to around 100 with pops less
than 20 percent.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
An upper level ridge axis will continue to slowly shift east of
the area overnight while at the surface high pressure centered
off the Atlantic coast will continue to circulate boundary layer
moisture into the region. Models are forecasting another low
level jet (20-25 knots) although not quite as strong as last
night which should help inhibit fog formation. Some lingering
diurnal cumulus clouds will persist early but should diminish
with only some passing high cirrus expected overnight through
around 08z.
Bufkit time heights and HRRR show abundant low level moisture
and forecast stratus developing after 08z with support from the
SREF, although the MOS guidance is not indicating any
restrictions. Will introduce prevailing MVFR cigs at
CAE/CUB/OGB at 08z with tempo IFR cigs 09z-13z. Slightly lower
confidence in restrictions at AGS/DNL so will keep the tempo
group for MVFR cigs there 09z-13z.
An approaching weak front, along with some increase in
atmospheric moisture, may provide some convective coverage
Monday afternoon and evening, mainly across northern areas with
the front, and near southern areas along a sea breeze boundary
after 18Z. However, coverage is expected to be isolated and
will not be included in this forecast.
EXTENDED AVIATION OUTLOOK...Some late night/early morning
fog/stratus potential, along with isolated diurnal thunderstorms
possible, through the period.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Fort Worth TX
534 PM CDT Sun May 19 2019
.UPDATE...
I have went ahead and removed late afternoon-early evening slight
chances of storms across Central Texas. GOES visible satellite has
shown cumulus field struggling to get going along and south of our
stalled surface front.
A couple of factors are likely playing into this:
1. Subsidence behind yesterdays storms and disturbance.
2. LAPS and RAP soundings showing an EML(likely from the aforementioned
residual subsidence) strengthening between 700mb-800mb. Also,
southwest flow aloft is amplifying in advance of a the next upper
system dropping south across CA/NV.
and finally...
3. Dry-air entrainment -- (moisture is minuscule thin both above
and below the EML).
Otherwise, the front should lift back northward toward the Red
River Valley after midnight and through daybreak Monday in
response to increasing 925mb-850mb to between 20-30 knots,
especially west of I-35. As such, patchy fog/drizzle remains
possible across Central Texas overnight with the increasing low
level warm advection.
05/
&&
.SHORT TERM... /Issued 337 PM CDT Sun May 19 2019/
/Tonight/
There will be a low risk for showers and an isolated thunderstorm
this afternoon mainly across the Brazos Valley. While the CU field
looks a little less than impressive. This may be in response to to
lingering subsidence. However...the instability---thanks to 90
degree temperatures and dewpoints in the low to mid 70s---remains
quite robust at this hour. There will still remain a risk for
convective initiation through the late afternoon to early evening
hours southeast of a Temple to Mexia to Palestine line. A strong
or severe storm capable of strong to possibly damaging winds will
remain possible if a storm can mature.
The aformentioned front should lift northward tonight in response
to a deepening surface low to the northwest. Moisture will slosh
northward with the aid of southerly winds. The subsequent
WAA/isentropic upglide could result in some sprinkles or light
rain showers, but widespread measurable rain appears unlikely.
There will be a risk for some patchy drizzle or perhaps light
fog...especially south of I-20. At this time, winds aloft (around
925mb) may be too strong to preclude a more appreciable fog
episode across the region. Should these winds aloft underachieve,
then increasing low level moisture coupled with recent rainfall
could set the stage for a hybrid advection/radiation fog scenario
across the area.
Bain
&&
.LONG TERM... /Issued 337 PM CDT Sun May 19 2019/
/Monday through Sunday/
A low pressure system will gather strength across the western U.S.
on Monday, resulting in a warm, humid and breezy day. Increasing
southerly surface winds will lift the cold front north of the Red
River quickly Monday morning while southwesterly flow aloft draws
warm air off of the Mexican Plateau, reinforcing the cap.
Therefore, storms are not expected for most areas during the day
Monday, but a few brief storms may develop on the retreating
front across the northwest zones in the morning along with a few
warm air advection sprinkles farther south. Isolated to scattered
storms are possible across the northwest zones during the
afternoon/early evening on outflows from West Texas/Southwestern
Oklahoma storms, but the cap may hold until stronger forcing
arrives.
Additional storms are expected to develop across the Low Rolling
Plains and Permian Basin Monday evening as the powerful upper low
pivots northeast towards the Central High Plains. The storms
should organize into a linear complex as large scale lift, mid
level instability and deep layer shear increase. The line of
storms will enter into western North Texas late in the evening and
spread eastward through the night/Tuesday morning. Damaging winds
will be the primary hazard, but some storms may contain hail. An
overall decrease in storm strength is anticipated as the line
moves east of the I-35 corridor from mid morning through early
afternoon Tuesday. However, storm intensification is likely during
the heat of the afternoon, but this should occur east of the
forecast area. We will have to watch the speed of the line closely
since a slower progression would result in a better chance for
strong to severe storms across the eastern zones Tuesday
afternoon.
We were considering a Flash Flood Watch for portion of the area
for Monday night/Tuesday since most areas received appreciable
rainfall yesterday. However, moisture should remain confined below
850 mb with this system and the progressive nature of the
anticipated line should keep rainfall totals generally less than
an inch. If future guidance suggests slightly deeper moisture or
slower speed of the storms, later shifts may need to issue a Flash
Flood Watch.
Rain/storm chances will end Tuesday night once the lead upper low
moves toward the Northern Plains and an amplified ridge begins to
nudge in from the east. Although the upper ridge axis should
remain east of the region, its presence should keep North and
Central Texas warm and generally rain free the second half of the
week through the weekend. It will remain humid, however, with low
pressure in the west keeping a constant influx of Gulf moisture.
It does look like storms will remain a possibility across West
Texas and western Oklahoma the second half of the week as a series
of weak disturbances move through southwest flow aloft. These
storms may send some outflows toward the northwest zones during
the afternoon and evening. Therefore, we will maintain some low
PoPs in that area generally Thursday through Saturday.
Temperatures next week will be near or above seasonal normals
with highs generally in the middle and upper 80s and lows ranging
from the middle 60s to the middle 70s.
79
&&
.AVIATION... /Issued 116 PM CDT Sun May 19 2019/
/18 UTC TAF Cycle/
Concerns---Gradual wind shift and ceiling trends.
VFR currently prevails at all TAFs this afternoon in the wake of
a cold front. A few showers and perhaps a thunderstorm or two may
develop to the south and east of ACT where activity should remain
late this afternoon and into the evening. The cold front will
stall and lift northward---as a warm front---through the
overnight hours. East winds will accompany the warm frontal
passage along with the potential for MVFR and occasional IFR cigs
starting just after midnight and continuing through the Monday
morning push. There is a chance for BR or even FG...but breezy
winds should preclude this threat. Trends will need to be
monitored, however, as weaker low level winds could result in IFR
or LIFR vsby. Confidence in MVFR cigs occurring at at all
terminals is high...with medium confidence in IFR cigs. There does
appear to be weak ascent associated with the front, so I cannot
rule out a period or two of showers...but this potential looks
greatest to the west of I-35. Otherwise, increasing southerly flow
is anticipated from mid-morning Monday through Monday evening as
surface winds crank to near 20 knots.
Bain
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 70 86 70 81 67 / 5 10 40 70 10
Waco 72 88 72 83 68 / 10 10 30 60 10
Paris 66 84 70 78 64 / 0 10 30 60 10
Denton 68 86 67 79 64 / 5 20 40 70 10
McKinney 67 85 69 79 64 / 5 20 30 70 10
Dallas 72 87 71 81 68 / 5 10 30 70 10
Terrell 70 87 71 79 66 / 5 10 30 60 10
Corsicana 73 88 71 80 69 / 10 10 30 60 10
Temple 73 88 72 82 68 / 10 10 30 60 10
Mineral Wells 67 86 65 81 62 / 10 20 60 50 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
05/08
Area Forecast Discussion
National Weather Service Indianapolis IN
1201 AM EDT Mon May 20 2019
.UPDATE...
The AVIATION Section has been updated below.
&&
.SYNOPSIS...
Issued at 310 PM EDT Sun May 19 2019
A cold front will move through central Indiana tonight.
Thunderstorms are possible along and ahead of the front. Much cooler
weather moves in for the start of the work week. A front will
meander across the area mid to late week, bringing chances for rain
at times mid-week into next weekend. Temperatures will rebound to
above normal mid-week and then remain there.
&&
.NEAR TERM...(Rest of This Afternoon and Tonight)
Issued at 310 PM EDT Sun May 19 2019
Early this afternoon a dry slot was moving into central Indiana,
ending the widespread rainfall. However, a line of storms had
developed in central Illinois ahead of a cold front.
The line of storms will move across central Indiana during the rest
of the afternoon and into the early evening hours before 00Z. Will
handle with a pre-first period in the text products to cover this.
Severe storms remain possible with building instability and some
decent shear, but at the moment am not expecting widespread severe
weather.
HRRR and some other models indicate still some shower or
thunderstorm potential with the front itself as it moves across the
area after 00Z. Will have some low PoPs this evening.
Colder air will move in overnight, and some stratocumulus will
accompany it. Will keep skies partly cloudy.
The model blend looks reasonable for temperatures.
&&
.SHORT TERM...(Monday through Wednesday)
Issued at 310 PM EDT Sun May 19 2019
Models are close enough that the model blend initialization
was accepted for most items.
The colder air and stratocumulus will stick around on Monday,
keeping skies partly cloudy and high temperatures only in the 60s
most areas.
Dry and cool conditions will continue into Tuesday with some upper
ridging briefly working into the area.
A large upper system across the western part of the country will
send some energy just to the northwest of the area Tuesday night
into Wednesday. This will also bring a warm front through the area.
Forcing isn`t that impressive with the strongest forcing remaining
out of central Indiana. Will go with mainly chance category PoPs.
The warm front will allow temperatures to return into the 80s for
highs on Wednesday.
&&
.LONG TERM /Wednesday night through Thursday/...
Issued at 312 PM EDT Sun May 19 2019
Accepted the initialization. An upper level high will sit over
the deep south for much of long term range. Models are showing a
couple of short waves that may affect the area during that time so
there are a couple chances for rain. The best chance looks to be
Memorial Day weekend as models are in agreement that there will be
precipitation but exact timing and location are still to be seen.
Temperatures will be above normal as highs are anticipated to be
in the 80s.
&&
.AVIATION /Discussion for the 20/06Z TAF Issuance/...
Issued at 1151 PM EDT Sun May 19 2019
VFR will be the predominant flight category for the TAF period,
but will not rule out some MVFR stratocu from Mon 14-16Z. Current
southwest winds will continue to veer to the northwest today and
will generally be in the 5 to 11 kt range with some occasional gusts
to 22 kts at times in the wake of cold front.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....KH
AVIATION...TDUD
Area Forecast Discussion
National Weather Service Northern Indiana
858 PM EDT Sun May 19 2019
.SYNOPSIS...
Issued at 856 PM EDT Sun May 19 2019
A cold front will continue to work across the area tonight,
bringing rain chances to an end and also sending overnight lows
into the mid 40s to near 50 degrees. It will be notably cooler on
Monday with highs shy of 60 degrees. Looking ahead, the next
opportunity for rain is Tuesday night.
&&
.UPDATE...
Issued at 856 PM EDT Sun May 19 2019
Convective event quickly winding down with most of the watch
cancelled except far southern Michigan which will either be
cancelled or allowed to expire on time at 10 pm EDT. Grids have
been cleaned up to remove pops as cold front continues to sweep
across the area.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 309 PM EDT Sun May 19 2019
First round of convection has moved over the area and is starting
to move off to the east with time. While there has been a few
embedded enhanced echos the main impacts have been periods of
heavy rain and a few wind gusts into the 40mph range. Weak updraft
strength with this first round have been easily sheared apart.
Clearing line of clouds is quickly encroaching into the far
western counties. This should result in a quick jump in temps of
3-5 degrees. Looking across eastern IL, dewpoints have remained
in the mid-60s as temperatures have risen into the mid-70s.
Further south and west into southern IL, lower dewpoints in the
upper 50s have been able to mix to the surface. Ongoing convection
across southeastern IL developed on the intersection of these
dewpoints. This development also correlate with the left exit
region of a jet rounding the base of the upper trough. Trajectory
of this jet region would bring it across our western/central zones
over the next few hours. This, coupled with any destabilization
from the clearing line, will help to support renewed/reinvigorate
convection. Radar VAD profiles across IL show mostly unidirectional
flow within this area of developing/ongoing convection. Will have
to watch influence of the clearing line as the KIWX VAD profile
does show some veering in the lowest 1000m. If this veering
persists despite mixing, then a non-zero chance for a tornado
would exist. Greater confidence is with a quick jump in
temperatures, low level mixing, and VAD winds quickly becoming
unidirectional. Primary hazard with storms remains damaging wind.
As mentioned above, strongly sheared storms are unlikely to result
in much of a large hail risk.
Front starts to push into the area late this afternoon/early
evening. There is a window where the lifting jet exit region and
the front overlap to strengthen convection. The best area for this
overlapping would be along and north of I-80. This is well
reflected in the HRRR with a progressive line of convection. This
line moves across the northern zones before exiting around 03Z.
&&
.LONG TERM...(Monday Night through Sunday)
Issued at 309 PM EDT Sun May 19 2019
Focus of the forecast is on the near term, but the general theme for
the remainder of the forecast remains unchanged. Dry and cool
conditions Monday into Tuesday, next chance for precipitation
Tuesday night/Wednesday, warmer Thurs and Friday. Location of the
building sub-tropical high over the southeastern US will dictate
if Thurs/Fri have chances for precip.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 711 PM EDT Sun May 19 2019
Main line of storms just passing through FWA at the onset of the
TAF period with clearing skies to the west behind it. Shortwave
moving across Lake Michigan, hence leaving a tempo tsra at SBN.
VFR overnight before dropping down to MVFR by morning as front
passes through the region. Improving conditions by the afternoon
tomorrow.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...Small Craft Advisory until noon EDT Monday for LMZ043-046.
&&
$$
UPDATE...Fisher
SYNOPSIS...Brown/Fisher
SHORT TERM...CM
LONG TERM...CM
AVIATION...Heidelberger
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Area Forecast Discussion
National Weather Service Louisville KY
944 PM EDT Sun May 19 2019
.Forecast Update...
Issued at 935 PM EDT Sun May 19 2019
Surface cold front currently lies from SW IN to SE MO and will move
to SE across our forecast area overnight. To this point, showers and
storms have been most prevalent and strongest over parts of central
IN, with limited activity to our west. Latest radar now shows
showers and isolated thunder have developed farther to the SW along
the convective axis into SW IN, along and just ahead of the front.
The latest couple runs of the hi-res HRRR model suggest this narrow
axis of showers will continue to progress into and across our area
into the overnight hours, with even some new development possible
farther south along the line in central KY. Mesoscale analysis shows
instability just starting to diminish a tad as slow boundary layer
cooling will reduce low-level lapse rates. Would expect mainly
showers overnight (with brief downpours possible) and only isolated
thunder. Expect some clearing behind this line and the surface cold
front with lows Monday morning in the mid-upper 50s in south-central
IN to the lower 60s in our eastern counties of central KY.
&&
.Short Term...(This evening through Monday)
Issued at 335 PM EDT Sun May 19 2019
...Strong Storms Still Possible Into This Evening...
Upper-level impulse ejecting into the Great Lakes ahead of a complex
cyclone over the Upper Midwest, with a sfc cold front now bisecting
Illinois just west of the Interstate 57 corridor. Main challenge
will be the timing and impact of any convection, and that is made
even more difficult by the showers that have affected west-central
Kentucky and southern Indiana today, at least temporarily limiting
instability.
Even the hi-res models are struggling to initialize ongoing
convection, so confidence in the details of this forecast is low. We
are fairly confident that there will be multiple opportunities for
scattered thunderstorms especially during the early evening hours as
the front progresses eastward. If the clearing that has taken place
over far southern Illinois and western Kentucky can expand eastward
in time, that could generate at least some marginal instability, and
open the door for a damaging wind threat. Believe the best
opportunity for strong/severe storms will be in west-central Indiana
and could clip a few of our Indiana counties. The main thunderstorm
hazard will be damaging winds.
As the front pushes eastward, the window of opportunity for strong
or severe storms will close fairly quickly around or just after
sunset with the loss of heating. Any storms that are ongoing should
weaken and eventually dissipate, so POPs will be lower south and
east of a line from Bowling Green to Lexington.
A cooler and drier air mass will come in behind the front, with
pleasant late spring weather in store late tonight through Monday.
Expect plenty of sunshine and temps near normal for mid/late May.
.Long Term...(Monday night through Sunday)
Issued at 327 PM EDT Sun May 19 2019
Monday night - Sunday
High pressure has parked over the southeastern United States and is
securely in place over the CWA with an upper ridge axis sitting west
of the CWA through western Kentucky. Skies remain mostly clear with
temperatures ranging from the low 70s in Indiana to the low 80s
closer to Tennessee.
On Tuesday into Tuesday night, the ridge inches east as a cold front
follows behind the ridge towards the CWA. The cold front quickly
bows from Texas through the Hoosier state with the front setting up
along the Ohio River on Wednesday, but at this time the moisture
feed to the front dries and precipitation along the front fades.
Southern Indiana could see some isolated precipitation that could
extend into central Kentucky, but believe this will trend drier in
future model runs/forecasts. However, the front will likely bring
clouds overhead to most except possibly the Lake Cumberland area.
This won`t limit temperatures as strong warm advection from a
stiff south wind will drive temperatures to the upper 80s.
The parked high over the Southeast continues to shield moisture from
getting across the Ohio River into the CWA. Minor disturbances will
continue to ride the flow around the north side of the high.
Thursday could bring our most northern areas in southern Indiana
some minor precipitation. A better chance of rain exists on Saturday
according to GFS, but the Euro keeps us much drier. Believing the
models have been more saturated than reality lately. Believe drier
conditions are more likely through the weekend.
Temperatures in the upper 80s to around 90 are expected from
Wednesday through Sunday.
&&
.Aviation...(00Z TAF Issuance)
Updated at 730 PM EDT Sun May 19 2019
The chance for showers/storms near the TAF sites will continue
through late evening. HNB/BWG have the best chance at VCTS. Think
that convection should weaken as it approaches SDF so went with
VCSH. LEX is already experiencing -SHRA and may see another late
evening round of showers ahead of the cold front. Reduced flight
conditions will be possible in any t-storm or heavier showers. After
5Z, all convection should diminish with VFR conditions expected.
Wind gusts should diminish this evening with south winds turning SWW
behind the fropa late this evening. Winds will be predominantly W
tomorrow between 8-12 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Update.......TWF
Short Term...RAS
Long Term....KDW
Aviation.....AMS
Area Forecast Discussion
National Weather Service Nashville TN
914 PM CDT Sun May 19 2019
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Radar imagery this evening shows scattered showers continue across
eastern zones, but the rest of the area is currently dry albeit
quite humid with dewpoints in the mid to upper 60s. Latest HRRR
shows some isolated to widely scattered showers and maybe an
isolated thunderstorm or two developing along the cold front as
it moves across the area tonight, mainly along and north of I-40.
However, coverage looks to be much less than previously thought,
so have lowered pops for tonight especially across the south.
Rest of forecast looks good and only made minor tweaks.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR conditions are expected at airports this TAF period except for
a few hours of MVFR visibility at CSV Monday morning. -SHRA will
impact CSV this evening, but just VCSH anticipated at the other
airports until a fropa arrives between 09-13Z Monday. South to
southwest winds this evening will veer to west and northwest after
fropa.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......Shamburger
AVIATION........Shamburger
Area Forecast Discussion
National Weather Service Pendleton OR
459 PM PDT Sun May 19 2019
.AVIATION...
00Z TAFS...Conditions ranged from VFR to MVFR across the TAF
sites and this is expected to continue through the evening, with
RDM and BDN most likely to be the MVFR locations. Latest radar
imagery showed some showers and thunderstorms moving into
southeastern Washington and KALW just reported thunder, so have
introduced TSRA for a few hours there. Otherwise, most locations
will remain VFR. Gradual improvement is expected later tonight and
on Monday ahead of the next low.
&&
.PREV DISCUSSION... /issued 205 PM PDT Sun May 19 2019/
SHORT TERM...Tonight through Wednesday...A stationary front is
currently in a line from Goldendale to John Day down to the Lower
Treasure Valley. Rainfall amounts over the past 6 hours in the
forecast area have been 0.25-0.5 inch throughout the John Day Basin
and surrounding mountains with lesser amounts over north central and
northeast Oregon and south central Washington. The front will be
oriented more west-east over northern Oregon this evening. Although
the Blue Mountains north of Ukiah and Wallowa County north of the
Eagle Caps have seen little rain today, precipitation will increase
in these areas this evening. Flood Watches are in effect for a
large portion of northeast Oregon down to the John Day-Ochoco
Highlands. Based on latest radar trends and rainfall amounts, the
area of most concern at this point is in Grant County, including
along HWY 395, where rock and mudslides are a possibility. A small
thunderstorm developed near North Powder this afternoon, and there
is a potential for isolated thunderstorms over northeast Oregon and
southeast Washington this evening. Visible satellite shows clearing
or breaks in the overcast in this area, and the HRRR indicates a few
cells this evening. The front will stretch apart as the upper flow
splits, and precipitation will taper off after midnight. The Flood
Watch may be cancelled earlier depending on rainfall amounts this
evening.
Another closed upper low will quickly follow and dive southeast
along the eastern Pacific tonight and Monday then over the corner of
southwest Oregon on Monday night. Therefore, more precipitation is
on the way. The east slopes of the WA/OR Cascades and central
Oregon will have scattered to numerous showers Monday afternoon then
the remainder of the area on Tuesday. The Blues and Wallowas will
likely receive most precipitation with 0.3-0.6 in the forecast.
There will also be light snow accumulations above 5000 feet and at
least several inches along the peaks of the Eagle Caps, Elkhorns,
and Strawberries. The low will move into Nevada late Tuesday,
leaving scattered showers in a cyclonic flow aloft Tuesday night and
Wednesday. An interesting pattern will set up by Wednesday with the
Nevada low pinwheeling around another low over the northern Great
Plains. This leaves a very large elongated trough across the U.S.
west of the Mississippi, including the Pacific NW. Northerly winds
at the surface and aloft will increase Wednesday and will be breezy
in many areas. Wister
LONG TERM...Wednesday night through Sunday...Models in good
agreement in showing Great Basin upper low finally moving off to the
northeast resulting in northerly flow across the area Wednesday
night and Thursday. This will result in a very short-lived break in
the precipitation. The next upper level low drops down from BC on
Friday. The GFS is a little stronger with this system than the
ECMWF. Despite this fact, showers should develop over the CWA
Friday afternoon, especially the mountains. The activity will
decrease Friday night as the system heads into northern California.
Models begin to diverge on their solution to this system on Saturday
as it hangs out over California. The GFS keeps the aforementioned
low over northern California while the ECMWF moves it into central
California. Given the differences, will keep scattered showers over
our southern forecast area, primarily mountains. By Sunday, the low
has moved far enough to the south that most of the CWA should remain
dry. However, an isolated shower may be seen over Deschutes county.
Daytime highs will begin near normal but warm to above normal by the
weekend. Earle
AVIATION...Previous discussion...18z TAFs...A storm system over
northern California will bring areas of rain through the period, but
mainly over Oregon. VFR conditions will prevail, except MVFR/IFR
CIGS and VSBY are likely, especially during periods of rain, at KRDM
and KBDN. Winds will be 10-15 kts with higher afternoon gusts, but
are expected to decrease overnight. Earle
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 46 68 47 61 / 60 10 70 60
ALW 47 70 48 64 / 60 10 70 60
PSC 51 76 52 70 / 10 0 60 40
YKM 50 69 48 69 / 10 20 60 40
HRI 48 72 49 67 / 30 0 60 40
ELN 47 64 47 64 / 10 20 70 40
RDM 39 61 39 60 / 90 40 70 40
LGD 44 62 42 54 / 90 10 80 80
GCD 43 59 41 54 / 100 30 80 60
DLS 49 65 47 67 / 50 30 50 40
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Flood Watch through Monday morning for ORZ049-050-502-503-505-
506-508.
WA...None.
&&
$$
85/81/77
AREA FORECAST DISCUSSION
National Weather Service Charleston WV
908 PM EDT Sun May 19 2019
.SYNOPSIS...
Cold front Monday. Then, high pressure builds to provide plenty
of sunshine and a gradually warming through Friday along with
chances for showers and thunderstorms.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
As of 905 PM Sunday...
Will increase pops in the western counties and attempt to better
time that band of showers.
As of 745 PM Sunday...
Updated pops to better handle convection in the mountains this
evening.
As of 150 PM Sunday...
Isolated to scattered convection has indeed developed along the
mountain ridges as of 18Z. The lift for these storms is
primarily due to orographics from strengthening southerly flow,
though not an ideal direction. Latest run of RAP indicates ML
CAPE values are in the 1200 to 1400 J/kg range. The approach of
a mid level trof and associated increase in mid level flow
should allow coverage to increase a bit across these locations
in the thru 21Z. Outside of the high terrain, convection chances
diminish rapidly for the remainder of the afternoon with no
real forcing to lift parcels. Some of the mountain convection
may spill over into the adjacent lowland counties, however
steering flow should motion storms to NNE. Confidence is not
high on this occurring ATTM. Having said that, the best
adjacent lowland locations to see any convection later this
afternoon would be say from Sutton to Clarksburg.
SPC continues to highlight the northern mountains with a slight
risk this afternoon. Shear values are marginal for overall
organization, however surface to mid level delta theta e values
and DCAPE do support a damaging wind potential...primarily with
the stronger collapsing cores.
Mountain/adjacent convective activity will diminish in intensity
and coverage with sunset. The upper trof and associated cold
front will move thru the area tonight. However, with little in
the way instability, I have only low chances for a prefrontal
band of showers moving thru.
A secondary front looks to cross on Monday, however with
moisture confined to the low levels, thinking any precip would
be in the afternoon across the mountains and void of thunder.
CAA and lower dewpoints will arrive across SE OH late in the
afternoon on a refreshing breeze, taking until the evening to
arrive east of the OH River.
&&
.SHORT TERM /MIDNIGHT TONIGHT THROUGH TUESDAY NIGHT/...
As of 244 PM Sunday...
A surface high pressure system builds from the northwest to
provide dry and about normal temperatures under light northerly
flow Monday night into Tuesday night. Lows will range from the
lower 50s lowlands to the low 40s highest elevations. Highs
Tuesday will stay a around 70 degrees lowlands ranging into the
upper 50s northeast mountains.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 300 PM Sunday...
On Wednesday morning, a warm front develops south of the area
and should gradually lift north under increasing southwest
flow into early Thursday. Then, the area will remain in the warm
sector of an approaching low pressure system. Model`s consensus
indicate warm air and moisture advection will gradually
increase through the end of the week. Temperatures will increase
from the mid 80s Wednesday, to around 90 degrees Thursday and
Friday.
Showers and storms will be possible, mainly during the afternoon
and evening hours.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
As of 655 PM Sunday...
Some scattered convection this evening should gradually tapper
off. A cold front will then push across the region late tonight
and early Monday. Some MVFR clouds are possible along the cold
front, along with a chance of some showers producing some
restrictions.
A cumulus deck can be expected on Monday, with some afternoon
showers possible in the lingering moisture.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: High.
ALTERNATE SCENARIOS: Some showers along the cold front could
cause restrictions.
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 MON 05/20/19
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 H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H L
AFTER 00Z TUESDAY...
Widespread IFR conditions are not expected.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...RPY/30
SHORT TERM...RH
LONG TERM...ARJ
AVIATION...RPY