Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/30/19
Area Forecast Discussion
National Weather Service Bismarck ND
951 PM CDT Mon Apr 29 2019
.UPDATE...
Issued at 935 PM CDT Mon Apr 29 2019
High pressure continues to build over western and central North
Dakota this evening. Skies have cleared quite a bit across the
northwest and north central while clouds hold on in the south. We
ended up lowering temperatures over the northwest and north
central where we expect the best chance for an extended period of
clear skies and light winds tonight. Kept temperatures close to
the previous forecast elsewhere. A couple of the CAMS are
indicating an area of fog from around Minot to Stanley, and this
could certainly occur given the amount of moisture in the lower
levels. Latest RAP forecast sounding at KMOT does show the
potential for radiational fog via the crossover method which seems
reasonable given current dewpoints and forecast low temperatures.
Moisture is very shallow, so will just add a mention of patchy fog
for now. Of coursre this could also hinder current forecast lows
tonight, but overall think a lowering of temperatures north seems
reasonable.
UPDATE Issued at 627 PM CDT Mon Apr 29 2019
High pressure currently situated over far northeast Montana will
drop south and east across the forecast area tonight. Made some
minor adjustments to sky cover, with some clearing occurring in
the north. Also updated the latest sensible weather elements and
blended to early evening values. Will keep an eye on
temperatures, especially across the north tonight with clearing
skies and diminishing winds. Could see temperatures drop lower
than forecast.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 219 PM CDT Mon Apr 29 2019
Latest visible satellite imagery shows cloudy to mostly cloudy
sky conditions this afternoon. Following the NBM and visible
imagery, northwest North Dakota will see a lot more sunshine as
the afternoon progresses with much less elsewhere. Broad mid
level ridging tonight will keep it dry, however, low clouds will
begin to fill across our southern forecast zones as southwest
flow aloft begins to push a few mid/upper level shortwaves towards
western and central ND. Lows tonight will generally be in the
20s, to lower 30s far southern James River Valley.
On Tuesday, large scale ascent will overspread the area during
the day resulting in a chance of snow/rain in the morning,
expanding and transitioning to rain central and south. The far
north will see the lowest PoPs with this event. The shortwave
exits Tuesday evening, however, another stronger shortwave via
southwest flow is slated for Tuesday night and Wednesday. More
details on this in the long term discussion. Another cool day
Tuesday with highs in the upper 30s to mid 40s.
.LONG TERM...(Tuesday night through Monday)
Issued at 219 PM CDT Mon Apr 29 2019
From the short term, southwest flow aloft dominates Tuesday night
through Wednesday night. A stronger mid level shortwave/700mb
closed low approaches the southern border Tuesday night, then
transitions towards the southern James River Valley by Wednesday
night. Rain will change back to snow southwest Tuesday night
through Wednesday morning. Gridded snowfall accumulations range
from a tenth of an inch central to around 1 inch far southwest.
Expect a good chance of rainshowers during the day Wednesday for
most of the forecast area, however the northwest will see the
lowest chances. Rainshowers will mix with and change to snow
showers Wednesday night as they shift into the James River Valley,
closer to the track of the 700mb low. Highs Wednesday will remain
on the cool side with clouds and showers around. Expect highs in
the 40s.
The upper air pattern transitions from a southwest to westerly
flow Thursday. A transitory mid-level ridge slides across and
and results in a mostly sunny to partly cloudy day with highs in
the 50s.
Thursday night and Friday, another shortwave trough embedded within
a west to northwest flow will produce a chance of showers and
thunderstorms. MUCAPE looks meager at this point, however sufficient
deep layer shear and mid level lapse rates might warrant a thunderstorm
mention and will maintain this in the gridded data. Highs Friday
will reach the mid 50s to lower 60s.
For the weekend and into early next week, much cooler air can be
expected with highs in the upper 40s to lower 50s. A progressive
west to northwest flow with additional shortwaves will result in a
chance of showers and perhaps some thunderstorms Friday night
through Saturday. Sunday looks drier, then maybe another system
Monday for a chance of showers per GFS/ECMWF. With a progressive
flow in place, timing of successive waves this far out results in
greater uncertainty.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 935 PM CDT Mon Apr 29 2019
VFR conditions at KISN and KMOT, with MVFR conditions at KDIK,
KBIS and KJMS to begin the 00Z TAF period. Expect VFR to remain
across the north tonight. MVFR will be dominant across southern
TAF sites but could see a period of VFR ceilings late evening into
the early morning hours. An advancing system from the southwest
will bring MVFR conditions to the southern TAF sites around 12
UTC, if the already aren`t MVFR, and to near KISN and KMOT by
18-21 UTC Tuesday. Rain showers move into the southern TAF sites
Tuesday afternoon.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...KS
AVIATION...TWH
Area Forecast Discussion
National Weather Service Charleston SC
906 PM EDT Mon Apr 29 2019
.SYNOPSIS...
High pressure will prevail through Thursday. A trough of low
pressure may develop off the coast Friday and linger into
Saturday, then a cold front could move through Saturday night
or Sunday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
The forecast is generally on track and only required minor
adjustments for the late evening update.
Atlantic high pressure will hold through the night. A robust
pure sea breeze circulation will clear the far interior within
the hour with modest southeast winds in place. The boundary
layer looks to decouple overnight, first across the far
interior, then working east closer to the coast after midnight.
Low-level moisture is forecast to pool a bit under a strong
nocturnal inversion, but RAP soundings suggest the moisture
layer will remain paper thin with high 1000 hPA condensation
pressure deficits. This scenario points to a shallow ground fog
situation with some pockets of shallow, but locally dense fog
developing near low-lying areas such as rivers, swamps, marshes
and coastal waterways. Widespread dense fog does not look likely
at this time, although some observation sites may very well
report vsbys <1/4 mile, especially inland. Lows will range from
the upper 50s/near 60 well inland to the upper 60s/near 70 at
the beaches and Downtown Charleston.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
A deep layer ridge will continue anchored over the region through
Wednesday, then begin to shift eastward into the Atlantic later
Wednesday and Thursday. Have maintained above normal temperatures
with no rainfall chances. Model soundings and SREF guidance
indicating the potential for at least shallow, patchy fog each
night. Have added patchy fog into the grids for Tuesday night, but
held off for Wednesday night for now due to uncertainty and the fact
that the models are showing tad more low level flow Wednesday
night.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A relatively progressive pattern will develop late week into
the weekend. A series of shortwaves will ripple through, though
the best vorticity energy will stay to our north. A coastal
trough may develop Friday and lift north Saturday, bringing
enough low-level moisture for isolated showers/tstms. A cold
front is progged to move through Saturday night or Sunday though
rain chances do not look terribly impressive with this feature.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
VFR. Synoptic setup supports shallow ground fog early Tuesday
morning. Vsbys should generally remain 6SM or greater, but a
brief period of lower vsbys could occur just before daybreak at
both KCHS and KSAV. At KSAV, would not be surprised to see
vsbys jump around 08-11z as shallow fog banks develop near the
sensor and site remains unaugmented by an observer prior to 11z.
Extend Aviation Outlook: Patchy fog and some low clouds will be
possible each night, with flight restrictions possible.
Otherwise, VFR conditions rest of the period. Isolated afternoon
showers possible both sites Friday and Saturday with the
potential for brief flight restrictions possible.
&&
.MARINE...
Tonight: Atlantic high pressure will maintain a light onshore flow
below 15 kt. Seas 1 to 2 ft.
Tuesday through Saturday: Atlantic high pressure is expected to
dominate through mid week, then high pressure will push further
east into the Atlantic. South winds of 15 knots or less and
seas 2 to 4 feet. Deeper moisture starts to return Friday and
Saturday, which will bring the chance for some showers or
isolated thunderstorms.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Cleveland OH
1020 PM EDT Mon Apr 29 2019
.SYNOPSIS...
Low pressure will track east across northern Ohio this evening,
reaching New England by Tuesday morning. A cold front will sag
just south of the area tonight and remain stationary through Tuesday
before lifting north as a warm front Tuesday night as low
pressure moves into the western Great Lakes. The front will
settle back into the area Wednesday and remain until another low
moves through the area Thursday.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
The surface low has reached northeast Ohio in the vicinity of
Akron, Canton, and Youngstown. This low will continue east and
rain will remain east of the low. Have axed PoPs considerably
across the area and removed all mention of thunder as this
system exits the forecast area.
Previous Discussion...
As of the 3 PM hour this afternoon, compact convectively-
enhanced remnant MCV/synoptic low was between KFWA/KMIE,
quickly moving east towards the area. Scattered rain showers
were moving northeast across northeast Ohio on the nose of a
850-700mb wind max, but are expected to slowly diminish as the
jet becomes refocused near the synoptic low across western Ohio
over the next couple hours. An area of stratiform rain with some
embedded heavier showers on the northeast flank of the low will
move eastward over the northern part of the area over the next
few hours.
Attention turns to potential convective development with the
MCV/low across the western part of the area towards 22Z-00Z.
Narrow corridor of instability is trying to race northeastward
ahead of the system through southern Indiana into west central
Ohio, with the surface warm front lifting into the southwest
part of the CWA in another hour or two. Hi-res models have been
struggling to handle this system, with the HRRR capturing a
decent depiction of the current evolution, although lagging a
few hours behind with the surface pressure center and ongoing
stratiform precip. Although there is still a conditional
marginal severe weather risk as highlighted by SPC, latest
trends point towards the low/mid level forcing racing east and
outrunning appropriate moisture/instability return for any
significant or widespread convective development. There still
could be an isolated cell or two that pops up near 00Z across
the southern part of the area, but the window for severe weather
will only persist for a couple of hours or less. Will continue
to monitor these trends and latest observational data for hints
of convective development, as even a minimal amount of
instability will allow for potential severe storm development.
Any severe weather threat should end across the local area by
03-04Z.
The lagging cold front will sink south through tonight and
should settle south of the area by early tomorrow morning. Dry
conditions are anticipated through the early morning hours for
much of the area until a mid level vort/speed max rides the
front northeast across central Ohio tomorrow morning/early
afternoon. The surface front will lift back north tomorrow
evening as surface low pressure deepens over the southern Plains
and tracks northeast into the western Great Lakes by Wednesday
morning. Precip will be hit or miss through this period, with
anticipated dry periods tomorrow and tomorrow night, with better
rain chances moving just northwest of the area with the ramping
low level jet. Will still carry some low chance/slight chance
pops for southern areas Tuesday/western areas Tuesday night.
Have lowered highs a touch on Tuesday with the boundary a bit
farther south in recent model runs. Highs range from the low 50s
north to the low 60s south. Temperatures will rise fairly
rapidly after midnight Tuesday night with the warm front lifting
north, but early lows in the upper 40s/mid 50s will rise to the
mid/upper 50s by the morning.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
An upper level trough will dive into the Plains states
Wednesday and slowly become negatively tilted by Wednesday
night. The trough will cause cyclogenesis to take place over the
middle Mississippi Valley region by Thursday. The surface low
is expected to be relatively weak as the negatively tilted
trough begins to become absorbed into another reinforcing upper
level trough that will dig southeast. The weak surface low
pressure system will move northeast into the Great Lakes by
Friday morning. The low will cause some warm air advection to
take place in earnest Wednesday and Thursday as a warm front
lifts north of the area. A cold front trailing from the low will
move east across the area Friday. As warm air advection takes
place Wednesday, instability will increase across the forecast
area. CAPE values increase across the area supporting the threat
for thunderstorms. Instability also supports the threat for
severe thunderstorms Wednesday and we are well into a marginal
risk by then. The surface low pressure system and associated
moisture will also support the threat for additional rainfall.
Ground is somewhat saturated in some places allowing for good
runoff. So, the threat exists for potential additional flooding
of rivers and streams across the area through the end of the
week. As far as temperatures go, due to the strong warm air
advection expected Wednesday, we have a run at hitting 80
degrees in many areas Wednesday and well into the 70s for
Thursday. Highs will cool off Friday as cold air advection
develops across the area after the cold frontal passage.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Upper level flow will become transient over the extended periods. A
blend of broad troughiness and ridging will move quickly east across
the area during this period. A vigorous shortwave will move east
across the central Great Lakes Saturday followed by a broad weak
upper level ridge Saturday into Sunday. Otherwise, west to east
flow develops with no ridging or troughing expected by Monday.
Surface high pressure is expected to move east across the area
Saturday into Saturday night. This will allow for another surge of
warm air advection across the area Sunday into Sunday night ahead of
a cold front. A cold front will sweep east across the forecast area
Monday allowing for some cold air advection to take place. The
weekend is looking relatively dry across the area due to the surface
high pressure. A threat for showers will return Sunday night into
Monday with the cold front.
&&
.AVIATION /00Z Tuesday THROUGH Saturday/...
Low pressure was located over mid-Ohio this evening and will
bring variable conditions to the terminals for this evening into
the overnight. Ahead of the low, a stratiform rain shield over
the area has brought MVFR to occasional IFR visibilities to
much of the area, but ceilings have not budged far from 4 kft.
This area of rain has only a couple more hours to move through
NE OH and NW PA and have timed as appropriate. Behind the low,
ceilings are dropping to MVFR and eventually to IFR as a cold
front moves through the area. Flow will shift around to the
northeast tomorrow as the front continues south of the area and
ceilings may improve to MVFR across the area.
OUTLOOK...Non-VFR in periods of showers/thunderstorms through
Thursday night.
&&
.MARINE...
Waves this afternoon into tonight will approach small craft advisory
criteria but should be just below along the nearshore waters. Winds
gradually diminish through Tuesday and become light northeast. An
increasing easterly flow will develop in advance of the next system
Tuesday night and then become southeast. Downsloping flow will
occur along the shores of Erie County, Pennsylvania Wednesday
morning and there is the possibility a small craft advisory may be
needed in this location. Flow becomes southwest on the lake during
the day Wednesday and could very well increase threat for small
craft advisories over the rest of the lakeshore through evening.
Otherwise, light and variable winds develop Thursday through
Friday.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Greenawalt
NEAR TERM...Greenawalt/Sefcovic
SHORT TERM...Lombardy
LONG TERM...Lombardy
AVIATION...Sefcovic
MARINE...Lombardy
Area Forecast Discussion
National Weather Service State College PA
1128 PM EDT Mon Apr 29 2019
.SYNOPSIS...
A weak frontal system will move through the state overnight.
The front will remain nearly stalled very near the forecast area
keeping the region unsettled for much of the upcoming week.
&&
.NEAR TERM /THROUGH TUESDAY/...
Bands of showers continue to work across the northern half of
the area.
The HRRR favors the northern 2/3 of my CWA with best chance of
some light rain this evening into the wee hours, before activity
moves east after about 3-5 AM. The HREF is more generous with
both aerial coverage as well as QPF, but the timing of the
showers fading after midnight is very close to the same.
Min temps tonight will range from the low-mid 40s across the
Northern Mtns to between 50-55F across much of Southern PA.
The HREF suggests just small chances for showers Tuesday in the
wake of the weak front, so I trimmed POPs somewhat trying to be
a bit more optimistic.
Temps will peak into the 55-60 deg range across the north, and
upper 60s to mid 70s in the south.
&&
.SHORT TERM /TUESDAY NIGHT/...
Another small area of showers and scattered thunderstorms will
likely form in OH and wrn PA, and could slide into the western
half of the CWA Tuesday evening.
Min temps early Wed should be a few Deg F warmer than Monday
night as layered clouds overspread the fcst area from the south
and west as the pesky frontal boundary drifts back to the north
and into PA.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Overall, an unsettled period still looks to be in store next
week, with a frontal boundary in the vicinity of the
Commonwealth much of the time. Also, zonal flow aloft will keep
short-waves frequently zipping across the northern CONUS.
Consequently, at least hit and miss showers will be in the
forecast throughout the week.
One area of uncertainty is how much cool air damming will
prevail east of the higher ridges in central PA, particularly in
the mid-week period. At this time, the national blend of models
shows a pretty tight thermal gradient across central PA by mid-
week, with highs in the 70s progged from the Lower Susquehanna
Valley up across our western zones (the Allegheny ridges), with
cooler low-mid 60s over most of the northern tier.
The prospect for embedded thunderstorms should increase as we
head towards Thursday, and a better push of warmer air occurs
ahead of an approaching cold front. Behind the front, next
weekend appears drier and cooler from this early vantage point.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Low pressure lifting through upstate NY will spread showers
across the region late this evening, affecting primarily
northern Pa. However, the larger aviation concern will be an
increasingly moist southeasterly flow ahead of this system,
which will lead to lowering cigs across northern and eastern Pa,
with IFR cigs likely late tonight over this area. The region
least likely to experience significant reductions will be the
south central part of the state from KUNV south through KAOO.
A period of LLWS is possible across western Pa overnight, as
strong winds aloft overspread the region. An examination of
model soundings suggests the inversion height and shear will
remain above 2000ft across the eastern half of the state.
The low pressure system and associated showers/LLWS should have
exited the region by dawn Tuesday. However, upsloping flow will
likely yield lingering low cigs across the northern mountains
(KBFD) and Laurel Highlands (KJST) into late morning.
A drier northerly flow should result in continued improvement by
afternoon, with even the N Mtns/Laurels becoming VFR.
.Outlook...
Wed...Low cigs possible, especially central mountains.
Thu...AM low cigs/fog possible eastern Pa. Isolated PM tsra
impacts Laurel Highlands/SC Mtns.
Fri...AM low cigs/fog possible. Scattered PM tsra impacts
possible.
Sat...Showers/cig reductions possible, mainly southern Pa.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...Lambert
LONG TERM...Jurewicz
AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service Cheyenne WY
951 PM MDT Mon Apr 29 2019
.UPDATE...
Issued at 938 PM MDT Mon Apr 29 2019
A couple areas of concern heading into the overnight period. There
is potential for a band of heavy snow to develop across some parts
of Carbon, Albany and Converse counties over the next few hours as
low-level convergence & isentropic upglide become focused along an
inverted surface trough expected to strengthen over these areas in
the next several hours. High-resolution guidance suggests moderate
to heavy precipitation banding, but still differ considerably with
the precise location. It also remains to be seen just how long the
heavier snow rates will be maintained, as this will play a role in
the overall impacts on Tuesday morning. One other possible area of
concern is the Platte River Valley around Scottsbluff w/ very good
upvalley flow continuing through the night and the HRRR seeming to
focus precipitation over this region. At this time however, do not
believe that precipitation rates will be sufficient to warrant the
issuance of a Winter Storm Warning. Nonetheless, the midnight crew
will need to closely monitor trends in the next few hours.
Looking a bit further ahead, some guidance remains very aggressive
toward the Tuesday Night & early Wednesday system. We felt it best
to address this system first, and then adjust headlines later with
any new guidance over the next few shifts.
UPDATE Issued at 514 PM MDT Mon Apr 29 2019
We have issued an update to add the city of Cheyenne to the Winter
Storm Warning. A band of very heavy snow developed this afternoon,
with rates of 2 to 3 inches per hour observed over the last couple
of hours at peak intensity. Radar trends indicate the heaviest has
moved eastward. However, some upstream enhancement is already seen
across western Laramie County due to southeasterly low-lvl upslope
flow. This should maintain a persistent light to moderate snowfall
well into the evening and overnight. The heavy snowfall rates have
caused roads to quickly become slick and snow covered, and thus we
no longer anticipate melting to be a problem. Updated hazards have
been sent. Forecast products will be updated shortly. Expect about
5-10 inches of snowfall in the Cheyenne area through Tue AM.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 330 PM MDT Mon Apr 29 2019
Challenging forecast over the next 48 hours as two separate
disturbances move through the area. Winter headlines and snow
amounts are the primary challenges.
Surface low pressure currently analyzed over east/central Utah
this afternoon. Fairly widespread moisture moving up through
western Colorado into Carbon County this afternoon. Has been
snowing fairly steadily over Laramie County this afternoon.
Webcams showing snow covered roads up on the Summit. Water vapor
imagery showing upper low still over southern California at 2PM
this afternoon.
Models in great agreement showing heavy precip developing
somewhere west of the Laramie Range tonight. GFS/NAM/ECMWF/SREF
showing 6 hour QPF values of 0.5 to 0.6 inches after 06Z...running
through roughly 15Z Tuesday. This sets up somewhere from Douglas
to Laramie and points west. Strong isentropic lift across this
area. With up to an inch of liquid precip overnight...decided to
upgrade the advisories to warnings for a few zones out there
tonight. Evening shift will need to monitor trends on where
exactly that band sets up for possible further upgrades.
Could be some strong winds near Laramie tonight. GFS soundings
showing winds right off the surface of 40-45kts that could create
blowing snow and poor visibility as well.
A brief break Tuesday afternoon before the second upper shortwave
moves through Tuesday evening. This system impacts Converse and
Niobrara Counties more...so we will need to monitor for upgrades
up there tomorrow night.
.LONG TERM...(Wednesday night through Monday)
Issued at 330 PM MDT Mon Apr 29 2019
Wednesday night/Thursday...Drying out for Wednesday night in the
wake of the shortwave trough aloft. Brisk zonal flow aloft will
prevail with limited low and mid level moisture producing dry
conditions for Thursday. Definitely a warming trend with more
sunshine and 700 mb temperatures near -1 Celsius.
Friday...May see a few showers early in the day as another
progressive shortwave trough aloft moves across our counties. Will
be even more mild with 700 mb temperatures near 1 Celsius.
Saturday...A slow warming trend continues as 700 mb temperatures
rise to near 6 Celsius, yielding maximum temperatures in the 60s to
lower 70s at lower elevations. Cyclonic flow aloft will continue
some cloud cover, though precipitation looks unlikely with lack of
lift.
Sunday...Another cold front moves south across our counties,
producing cooler temperatures, perhaps even cooler than we currently
have in our forecast. At least a chance for some showers in the
cool, moist upslope overridden by southwest flow aloft.
Monday...With abundant cloud cover and moist southwest flow aloft,
we expect to see at least scattered showers in the afternoon.
Temperatures will be quite tricky with cloud cover, though will
stick with highs in the 60s for now to blend well with our
neighboring offices.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 403 PM MDT Mon Apr 29 2019
Wyoming TAFS...IFR at Cheyenne and Laramie until 15Z, then MVFR
until 18Z, then VFR. MVFR at Rawlins until 06Z, then IFR until
13Z, then MVFR until 16Z, then VFR.
Nebraska TAFS...MVFR at Chadron and Alliance until 18Z, then VFR.
MVFR at Scottsbluff until 06Z, then IFR until 15Z, then MVFR until
18Z, then VFR. MVFR at Sidney until 02Z, then IFR until 15Z, then
MVFR.
&&
.FIRE WEATHER...
Issued at 330 PM MDT Mon Apr 29 2019
Minimal fire weather concerns as accumulating snow spreads across
southeast WYoming and Nebraska Panhandle. Cold temperatures will
keep afternoon humidity on the high side and well above critical
levels. No fire weather concerns expected the next several days.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until noon MDT Wednesday for WYZ101-102-
104-107>109-111-113-119.
Winter Storm Warning until noon MDT Wednesday for WYZ103-105-106-
110-112-114>118.
NE...Winter Weather Advisory until noon MDT Wednesday for NEZ002-003-
019>021-054-055-095-096.
&&
$$
UPDATE...CLH
SHORT TERM...GCC
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Dodge City KS
620 PM CDT Mon Apr 29 2019
...Updated Aviation Discussion...
.SHORT TERM...(This afternoon through Tuesday night)
Issued at 1200 PM CDT Mon Apr 29 2019
The latest cold front continues to plow southward through West
Texas at midday, with another round of strong north winds in
progress. North winds will diminish rapidly this afternoon as the
pressure gradient weakens. Afternoon temperatures will fall about
10 degrees short of late April normals, in the lower 60s.
Tonight, increasing/lowering clouds and rain developing. Closed
low near San Diego at midday will weaken into a progressive
shortwave, arriving near the Four Corners at sunrise Tuesday. As
this system approaches, all models saturate the lower atmosphere
amid moist upslope and light NE winds. Stratus will prevail
Tuesday morning, with widespread mist/drizzle and areas of fog.
NAM is showing its typical drizzle QPF signature early Tuesday.
Dynamic lift ahead of the approaching shortwave will arrive early
Tuesday, with numerous rain showers expected to spread into SW
Kansas. Latest HRRR iterations show this evolution nicely. Most
models suggest QPF of about 0.25" will be a reasonable
expectation at most locations, with heavier amounts of 1/2-2/3
inch favoring the southern zones. For many in SW Kansas, including
Dodge City, this is the last chance to avoid April 2019 being one
of the driest Aprils in history. It will not be the rain we need
to make up for the dry month, but certainly a widespread one
quarter inch would be beneficial to the spring`s young vegetation.
Kept a small mention of thunder in the grids, with NAM depicting
elevated CAPE up to 1000 J/kg above the stable boundary layer.
Likely pop coverage is still justified in the grids.
Tuesday afternoon, showers and thunderstorms may increase in vigor
across the eastern zones ahead of strong shortwave ejecting
through western Kansas. Instability will remain limited in SW KS,
with any appreciable severe weather threat well east of our CWA.
This said, several CAMs/NAM are suggesting we may have enough time
to recover from morning rain/clouds to allow for isolated strong
convective development in the afternoon. It`s a messy pattern with
high uncertainty, but something we will be monitoring. Clouds,
rain, and upslope easterly wind components will again hold
temperatures well below normal for the last day of April, ranging
from the 50s north to the 60s south.
.LONG TERM...(Wednesday through Monday)
Issued at 248 PM CDT Mon Apr 29 2019
Temperatures will have an opportunity to warm a few degrees
Wednesday, ahead of lee side cyclogenesis near SE Colorado and the
next approaching cold front. Will need to monitor for warm sector
and instability placement again Wednesday afternoon, with SPC
marginal/slight risks clipping the SE zones. The best probability
of strong/severe convection will likely be across the SE zones
Wednesday night, as the next cold front intercepts the moisture
and instability axis. Otherwise, scattered showers and
thunderstorms will accompany the cold front passage Wednesday
night with more strong north winds.
Cool stable high pressure will be in control Thursday, with
sunshine, light E/NE winds, and temperatures several degrees below
early May normals. A pleasant spring afternoon.
Another passing disturbance may generate another round of
scattered showers and thunderstorms during the Friday time frame
as shown by 12z ECMWF, and model blended pops were accepted.
Next weekend is expected to be mostly quiet and dry, with warmer
afternoon temperatures well into the 70s. Synoptic pattern offered
by 12z ECMWF is very quiet with regards to thunderstorm potential,
with the stubborn Hudson Bay low persisting, and broad ridging
building over the western U.S., forcing dry NW flow over the
central plains. Model blend pops for the weekend were retained,
but are likely overdone. Could see some weak convection arrive in
the western counties from Colorado each evening, but not the
caliber of convection we are accustomed to seeing in May.
Early next week, medium range models depict a closed low sinking
south across California on Monday. Eventually, this cyclone is
expected to dig through the SW U.S. Tuesday, and eject onto the
plains as a strong shortwave Wednesday, May 8th. This will most
likely be our next episode of significant severe weather in/near
SW KS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 618 PM CDT Mon Apr 29 2019
IFR ceilings will develop after midnight as low level moisture
increases across southwest and north central Kansas. Based on the
latest BUFR soundings the VFR ceilings early this evening will
lower into the MVFR category after 03z Tuesday and then lower to
less than 1000 ft AGL after 06z Tuesday. The depth of this low
level moisture will also be on the increase overnight with the
chance for some drizzle or very light rain becoming possible
towards daybreak. This low level moisture will be slow to erode
but after 18z Tuesday ceilings will improve into the MVFR
category. Winds overnight and Tuesday will be northeast at 10 to
15 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 44 64 44 69 / 70 60 20 20
GCK 43 59 42 67 / 70 50 20 20
EHA 43 73 44 74 / 80 20 10 10
LBL 44 71 45 74 / 80 30 20 10
HYS 43 54 40 59 / 50 60 20 20
P28 50 69 49 71 / 80 80 30 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Goodland KS
825 PM MDT Mon Apr 29 2019
.UPDATE...
Issued at 825 PM MDT Mon Apr 29 2019
Latest 00z NAM model as well as past several runs of the HRRR
showing less precipitation potential compared to afternoon
forecast requiring a lowering of pops overnight.
Best 850-500mb moisture and forcing is generally north of the
interstate overnight with perhaps an increase in coverage south of
the interstate shortly after sunrise Tuesday as a pretty good area
of moisture moves in from the southwest. HRRR model runs pretty
bullish with 1km agl radar reflectivities but placement varies
from run to run so confidence low right now in highest pop
placement. Will maintain some light snow across the far western
portion of the forecast area with under an inch accumulation still
expected.
Otherwise widespread low clouds will increase across the area
overnight. Low temperatures range from the low to mid 30s in far
eastern Colorado to the low 40s from Hill City to Leoti. Winds
generally from the northeast to east-southeast at 10 to 15 mph.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 122 PM MDT Mon Apr 29 2019
As of 2 PM CDT, 1 PM MDT, skies across the Tri-State Region are
partly to mostly cloudy as some mid-level clouds spread in from
Colorado. Temperatures have been held in check for areas with more
persistent cloud cover so there is a decent range...from the upper
30s in NE Colorado to the mid 50s in north central Kansas. North
winds have weakened throughout the day, now in the 10-15 mph range.
At the surface, a lee trough is deepening along the Rockies with
surface high pressure moving out of the region to the east. Aloft,
an upper level low is spinning along the California coast, heading
east. A shortwave trough is moving out ahead of this low...and this
is the disturbance that will bring us precipitation tonight.
For tonight, the main concern will be the potential for some wintry
precipitation. Overall, this is not a terribly impressive system so
not expecting anything significant to occur. As the disturbance
lifts through the High Plains, expect precipitation to develop along
the Rockies, then spread northeast across northeast Colorado.
Sounding profiles indicate a slight warm layer aloft but still well
below 3C where full melting would occur. Soundings appear saturated
so there should be ice in the column, so as long as temperatures
drop enough (and they should although stratus may be a problem),
then we should observe some snow. Wet bulb temperatures also go
below 0C so that is another factor leaning towards a change to snow.
With lower temperatures, there could be some frost in the area but
thinking that won`t be the problem, the snow will. Across the rest
of the area, expecting light showers to pass through. Latest trends
in precipitation have lower amounts across the entire forecast area.
Highest precipitation amounts will be along to generally south of
HWY 40. In fact, some of the rain may actually be heavy drizzle
which could lower visibility to the 3-5 mile range in a few spots.
For tomorrow, precipitation spreads to the northeast east. However,
low cloud cover should linger throughout most of the day behind the
weak/stalled cold front. This will impact temperatures so decided to
lower highs a few degrees from guidance due to the anticipated
persistent cloud cover. Southeast winds will help bring some
additional moisture into the area, setting the stage for
precipitation development overnight.
During the Tuesday night hours, anticipating a saturated low level
in the atmosphere. Broad weak lift should be in place over the
region. Without a discernible shortwave, not anticipating much in
the way of shower activity. Any instability for thunderstorm
activity will remain well to the south...over southwest Kansas.
Sounding profiles show a saturated low layer with dry air
aloft...from about 800 mb up. Therefore, with the broad lift, low
level saturation, and upper level dry air, anticipating the
development of drizzle across most of the area as the warm front
retreats to the north. There may also be some fog so that is yet
another thing to watch. With warm/moist air advection, am
anticipating low temperatures to fall only into the upper 30s to low
40s. This would prevent any frost formation that may damage crops.
.LONG TERM...(Wednesday through Monday)
Issued at 117 PM MDT Mon Apr 29 2019
Expect an active pattern through Saturday as the models are showing
an upper-level longwave trough over the western U.S. and a longwave
ridge over the Eastern U.S. As the ridge builds the trough will
move eastward and become elongated over the High Plains. This will
produce mostly southwesterly-westerly winds aloft. Within this flow
multiple shortwaves are expected to move across the forecast area.
Currently, the forecast calls for a chance of rainshowers and slight
chance of thunderstorms on Wednesday. Followed by frost wednesday
night over the northwestern part of forecast area. The next round of
shower and thunderstorms will be Thursday afternoon/evening through
Friday morning followed by another round on Saturday. With this
shortwaves expected to be fast moving, it is difficult to have
confidence in the precipitation amounts.
Beyond this coming up weekend, confidence is low. The models are
showing an closed upper-level low, located over the Eastern Pacific,
moving onshore; however, once onshore they are not in agreement with
placement and intensity. So will wait and see how this system is
handled in the next few model runs. Until then, will keep what
Superblend gives.
Afternoon temperatures will start out in the upper 50s on Wednesday
and gradually reach the lower 70s by weekend. Meanwhile, the
overnight lows will drop into the lower 30s on Wednesday night then
hold steady in the lower to upper 40s for the rest of the
extended.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 440 PM MDT Mon Apr 29 2019
For KGLD and KMCK, vfr conditions expected through about 08z at
KGLD and 11z at KMCK before sub vfr cigs (stratus) move in from
the south and continue through the remaining taf period. Winds
generally from the northeast and east around 10kts taf issuance
becoming more easterly at 12-15kts through much of the day before
subsiding a bit from late afternoon through the end of the period.
Any precipitation looks to hold off until around sunrise with
multiple weather disturbances moving through providing a few
chances for moisture. Its possible that the precipitation could
improve conditions to vfr at times.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...RRH
LONG TERM...BW
AVIATION...99
Area Forecast Discussion
National Weather Service Grand Rapids MI
926 PM EDT Mon Apr 29 2019
LATEST UPDATE...
Update
.SYNOPSIS...
Issued at 326 PM EDT Mon Apr 29 2019
-Soaking rain expected Tuesday night into Wednesday
-Ponding of water on roads and fields is possible
-Additional showers and storms possible Thursday
&&
.UPDATE...
Issued at 926 PM EDT Mon Apr 29 2019
Given the light winds and low ceilings already in place and all
the rain that fell near and south of I-96 today, plus the fact
that it was drizzling when I went outside a few minutes ago, it
seems more than reasonable to add patchy drizzle and fog to the
forecast overnight.So I did just that. Due to the low clouds, I
do not expect dense fog, more of a 1 to 3 mile vis sort of fog.
&&
.DISCUSSION...(This evening through next Monday)
Issued at 326 PM EDT Mon Apr 29 2019
A classic late April / early May pattern is shaping up for this week
across the Great Lakes region with several opportunities for showers
and even some thunderstorms. The first round of rain is exiting the
region and has laid out a swath of 0.50"-1.25" south of a Muskegon
to St. Johns line. The heaviest amounts occurred from Kalamazoo to
South Haven. There will be at least two more rounds of showers and
some thunderstorms to contend with before week`s end that will
impact the region.
After a break in the rain through at least the first half of
Tuesday, low level moisture advection begins in earnest Tuesday
evening with PWAT values transitioning from around 0.60" to 1.25"
with a robust LLJ of 50-60 kts. The upper level pattern reflects a
familiar setup for several waves of rain to track through the
region. Southwest flow aloft, a surge of Gulf moisture, and a
surface warm front nearby combine to support an increased risk for
soaking rainfall.
There look to be several subtle 500 mb shortwaves moving through the
region and the surface warm front will gradually lift north into
southern Lower Michigan by Wednesday. A solid LLJ intersecting this
boundary will ensure a blossoming of precipitation from Tuesday
evening through Wednesday. MUCAPE inches up Tuesday night with some
thunderstorms possible though we are not expecting widespread
coverage of storms. A steady rain may be the most likely outcome.
With bulk shear of 60 kts Tuesday night and unidirectional flow
from 850 mb to 250 mb, there will likely be training showers and
storms with little eastward propagation from where they set up.
This points to some locally heavy rain and both the medium range
guidance and hi-res models concur that a swath of 1"-2" is a
likely outcome by Wednesday morning or early afternoon. The I-96
corridor and a county or two either side of it appears to be the
favored location for the highest amounts. Given how quickly some
locations achieved 1" of rain this morning in a less moist
airmass, I would not be surprised at all if some locations get over
2" Tuesday night into Wednesday.
By Wednesday afternoon and evening, any risk for strong to severe
storms depends on whether or not the morning convection modulates
the location of the warm front. Current projections are the
combination of SBCAPE of a few hundred J/kg and bulk shear of 30-40
kts may support one or more sustained thunderstorms with marginally
severe wind gusts south of I-96 Wednesday. With instability
potentially a limiting factor, this risk does not look great but
still something to watch should morning convection stay far enough
north of our southeast forecast area near Marshall and Jackson, for
example.
A final round of showers and perhaps some thunderstorms may come
through on Thursday, with lighter amounts expected in comparison to
Tuesday/Wednesday. A good number of the EPS members have some precip
moving through the day, though there are differences in timing that
may be tough to resolve until we get closer to the event.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 7392 PM EDT Mon Apr 29 2019
Being north of a warm front that will not move north of our TAF
sites in the next 36 hours, I believe IFR/MVFR cigs/vsbys are more
likely than not into Wednesday morning. Winds will be light to
calm at the surface tonight so with all the rain that fell early
today, I could see a fog developing overnight. The low clouds
however may keep that from happening. The NAM12 and HRRR and RAP
model suggest dense fog near the Lake Michigan shore overnight
tonight and given the light winds, I could see that happening so I
do have thicker fog there.
Tuesday the front moves back northward and will push showers and
maybe some thunderstorms into the TAF sites overnight into
Wednesday morning. I started the showers late in the afternoon for
now.
&&
.MARINE...
Issued at 326 PM EDT Mon Apr 29 2019
Waves will be highest across western Lake Michigan given
predominantly easterly flow. Onshore flow does return on Wednesday
which may bump wave action into the 2-4 ft range. Currently we are
not anticipating any SCAs to be needed. Also being closer to the
front, the I-94 taf sites are more likely to go solid IFR tonight
in fog and low clouds.
&&
.HYDROLOGY...
Issued at 326 PM EDT Mon Apr 29 2019
The Kalamazoo River basin received generally 0.50"-1.00" from
this morning with roughly 0.40"-0.75" for the Grand River basin
and around 0.25" for the southern stretch of the Muskegon River
basin. All of these basins will be receiving 1"-2" of additional
rain over the coming days. Rises on main stem rivers are expected
though most stretches should likely hold below flood stage unless
higher amounts occur. Smaller rivers and streams will experience
rises as well and will be monitored.
Nuisance ponding of water on roads and fields will be a likely
outcome at times this week. Significant flooding is currently not
anticipated.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&
$$
UPDATE...WDM
SYNOPSIS...Hoving
DISCUSSION...Hoving
AVIATION...WDM
HYDROLOGY...Hoving
MARINE...Hoving
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
954 PM CDT Mon Apr 29 2019
.UPDATE...
Issued at 938 PM CDT Mon Apr 29 2019
Thin band of showers and isolated thunderstorms is currently
slowly moving northward across the central part of the CWA. This
is occurring in a thin band of low level moisture convergence
north of surface front which currently stretches across far
southern Missouri and Illinois. This low level forcing will shift
northward and increase overnight in response to increasing low
level jet. This will cause an increase in showers and
thunderstorms across central and northeast Missouri as well as
west central Illinois which is already reflected well in going
forecast. Flash flood watch starting over the northern third of
the CWA still looks good as 00Z upper air analysis showed strong
moisture transport into the area with KSGF PWATs around 1.5". Any
thunderstorms over the northern part of the CWA overnight will
have the potential for training.
Britt
&&
.SHORT TERM... (Through Late Tuesday Night)
Issued at 409 PM CDT Mon Apr 29 2019
A cold front stretching from near Springfield Missouri northeast
along the I-44 corridor and into south central Illinois near
Effingham Illinois will continue to drift south for a few more hours
this evening before moving back to the north up to near the
Missouri/Iowa border by Tuesday afternoon. The northward movement
is due in part to a 25-30kt low level jet tonight which will be
blowing perpendicular to the baroclinic zone at 850 mb. All models
are printing out QPF over a good portion of the area tonight to a
greater or lesser extent due to the moisture convergence along the
baroclinic zone. The NAM is particularly bullish late tonight strong
moisture convergence across northeast Missouri into west central
Illinois. Since some of those same areas received in excess of 1
inch (2+ in a few spots according to radar estimates) have issued a
flash flood watch for those areas beginning at 06Z tonight.
Attention turns to Tuesday and the severe weather threat as well as
additional flooding. A shortwave aloft will be moving off the
Rockies forcing cyclogenesis over the central Plains. The negatively
tilted wave will move quickly to the northeast into the Missouri and
Upper Mississippi Valley on Tuesday night. This will push the
surface low northeast from northern Texas to southeast Iowa by 12Z
Wednesday morning. 2200+ CAPE in the warm sector ahead of the low
level cyclone in eastern Kansas and Missouri combined with 35-50kts
of 0-6km shear will be more than enough to support severe
thunderstorms on Tuesday afternoon and the CAMs are advertising a
QLCS organizing in eastern Kansas or western Missouri and racing
east during the late afternoon and evening. The latest HRRR looks
especially strong with a prominent bow echo moving through central
Missouri around 00Z. The exact timing and strength of the
convection is of course difficult to determine and will depend
greatly on how unstable the atmosphere can get at peak heating
Tuesday afternoon.
While a bow echo moving through central Missouri is certainly not
good news, the silver lining may be that there will be less rain
than expected earlier in northeast Missouri and west central
Illinois on Tuesday night. However...it looks like the outflow
boundary from the QLCS may slow and take on an east-west orientation
across southern Missouri including our eastern Ozark counties. Since
the shortwave which is kicking this system off is lifting out rather
than digging, the 850mb front is not expected to move south with the
convection. Therefore, warm and moist advection will continue
across the outflow boundary Tuesday night. The GFS and especially
the NAM produce very strong moisture convergence across the Ozarks
and the NAM prints out areas of 2 inch or greater QPF. While this
may be too high, it`s not out of the realm of possibles
considering precipitable water values in excess of 1.5 inches and
warm cloud depths in excess of 10,000 feet. Given the potential for
flash flooding not only overnight across the eastern Ozarks but also
with heavy rain and lingering stratiform precip behind the QLCS,
have expanded the flash flood watch further south to encompass all
Missouri counties and parts of southwest Illinois as well beginning
Tuesday afternoon. Both segments of the flash flood watch continue
through Wednesday morning and the southern segment which includes
central and eastern Missouri and parts of southwest Illinois
continues until 12Z Thursday.
Carney
.LONG TERM... (Wednesday through Next Monday)
Issued at 409 PM CDT Mon Apr 29 2019
An unsettled period will persist Wednesday into Thursday with
potential for several rounds of showers and storms and heavy rain. A
broad longwave trof will remain centered over the western U.S.
during this time frame resulting in active southwest flow aloft with
multiple disturbances in the flow aloft traversing the area and
contributing to the development of convective storms. That said,
while the broad scale pattern will largely be favorable for showers
and storms, the convective scale and mesoscale details will
ultimately impact the severe weather threat and most favorable
location for heavy rain.
A decaying/weakening MCS from Tuesday night should have passed
through the area by daybreak Wednesday with a position expected from
far southern IL/southeast MO extending southwestward into northern
AR and eastern OK. There will also likely be a remnant large scale
outflow boundary in this same area. It would seem only scattered
showers will be impacting the immediate region during the first part
of the morning, namely in the eastern CWA. So the big question will
be the recovery potential for the remainder of the day on Wednesday
and into the afternoon as the synoptic scale cold front begins to
enter the northwest CWA. Both the GFS and NAM show relatively
undiluted steep mid level lapse rates and with diurnal heating the
air mass becomes quite unstable by afternoon, whereas the ECMWF is
not quite as aggressive with instability. These model differences
persist from Wednesday afternoon into Wednesday night. The GFS
and NAM suggest a new round of convection developing late
Wednesday afternoon/evening in central MO in association with a
moderately strong and veering southwesterly LLJ, the
aforementioned unstable air mass, and potentially in the region of
the old retreating outflow and ahead of the slow eastward moving
cold front. The mesoscale pattern and model QPF distribution would
suggest upscale growth and the potential for either an elongated
MCS or series of MCSs evolving along or south of I-70 on Wednesday
night. Training potential and high moisture content would support
a heavy rain threat within this region should the scenario evolve
as envisioned. The instability and sufficiently strong deep layer
shear would also support the potential for organized multicell
storms from late afternoon into the evening. The caveat to all of
the above heavy rain threat is the ECMWF generally has this
scenario but focused much further south and removed from the CWA.
Nonetheless we have the flash flood watch covering this time frame
and location given the heavy rain and flood potential.
The flow aloft will veer a bit more westerly on Thursday with the
passage of the initial disturbance, allowing the cold front to
finally move east and through the CWA by early Thursday evening.
Depending on how the whole Wednesday night scenario evolves,
showers and thunderstorms should be ongoing across eastern MO and
western IL during the morning, shifting east and southeast with
time as the cold front advances. I think the heaviest rain will
have ended by this time frame.
The flow aloft will be in transition Friday through the weekend into
early next week with the eventual evolution to a split flow
regime. The GFS and ECWMF do suggest that Friday/Friday night may
not be dry as previously expected with both showing a low
amplitude trof traversing the area and low level lift along and
north of the boundary draped southern MO and southern IL. The GFS
and ECWMF then diverge heading into the weekend and early next
week with the large scale pattern and westerly or southwest flow
aloft vs. northwest flow aloft. There does appear at this time to
be another cold front passage centered sometime around Sunday,
however uncertainty with accompanying precipitation with this
front and into Monday is high and confidence low.
Lastly...Present indications and RFC forecasts suggest a number of
river forecast points on the Mississippi River above Alton will
return to moderate and major flooding resulting from observed
rainfall over the last 24 hours and additional rainfall forecast for
the next 24 hours. All people with interests should closely monitor
the forecasts and updates in the coming days due to the impacts from
prolonged rainfall potential into the end of the week.
Glass
&&
.AVIATION... (For the 00z TAFs through 00z Tuesday Evening)
Issued at 648 PM CDT Mon Apr 29 2019
Scattered showers and isolated thunderstorms over southern
Missouri will move northward and affect the terminals later this
evening and overnight, particularly KUIN and KCOU. The chance for
showers and thunderstorms will continue through most of the period
thereafter, though the chances at any once place is too low to
have any more than VCSH or VCTS at the terminals. Better chance
will come late tomorrow afternoon into tomorrow evening when a
line of thunderstorms is expected to move into the area from the
west. This line will have the potential to bring hail and gusty
winds in excess of 35kts. MVFR ceilings are starting initially at
KUIN, but are expected to spread during the night at all of the
terminals, with some IFR ceilings.
SPECIFICS FOR KSTL:
Scattered showers and isolated thunderstorms over southern
Missouri will move northward and affect the terminal later this
evening and overnight, though the chance isn`t high enough to have
more than VCTS. Low chances for showers and thunderstorms will
continue through the rest of the night into Tuesday, though best
chance will remain north of the terminal. Better chance will come
late tomorrow afternoon into tomorrow evening when a line of
thunderstorms is expected to move into the area from the west.
This line will have the potential to bring hail and gusty winds in
excess of 35kts. VFR ceilings are starting out at the terminal,
but MVFR and IFR ceilings are expected at times throughout the
rest of the period starting at 04Z.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flash Flood Watch from Tuesday afternoon through Thursday
morning for Audrain MO-Boone MO-Callaway MO-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Lincoln MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
Reynolds MO-Saint Charles MO-Saint Francois MO-Saint Louis
City MO-Saint Louis MO-Sainte Genevieve MO-Warren MO-
Washington MO.
Flash Flood Watch from 1 AM CDT Tuesday through Wednesday
afternoon for Knox MO-Lewis MO-Marion MO-Monroe MO-Pike MO-
Ralls MO-Shelby MO.
IL...Flash Flood Watch from Tuesday afternoon through Thursday
morning for Calhoun IL-Jersey IL-Madison IL-Monroe IL-
Randolph IL-Saint Clair IL.
Flash Flood Watch from 1 AM CDT Tuesday through Wednesday
afternoon for Adams IL-Brown IL-Greene IL-Pike IL.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Midland/Odessa TX
638 PM CDT Mon Apr 29 2019
.DISCUSSION...
See 00z aviation discussion below.
&&
.AVIATION...
Isolated TS will develop along a stationary front over the next
few hours. TS has only been mentioned in the INK TAF at this time,
and any storms could become severe with strong winds and large
hail the main threats. Later tonight MVFR CIGs will affect sites
east of the Pecos River with gusty west winds Tuesday pushing the
clouds east and returning VFR conditions.
Hennig
&&
.PREV DISCUSSION... /issued 221 PM CDT Mon Apr 29 2019/
DISCUSSION...
WV imagery shows the upper trough has made landfall in SoCal,
leaving West texas and Southeast New Mexico under SW flow aloft.
Closer to home, a sfc analysis at 17Z shows the cold front extending
from as far SW as KCNM NE to KCDS and into OK. A dryline extended
along the Texas portion of the Pecos Rvr to KFST before curving back
SW into the Big Bend Area. This puts the triple point near Red
Bluff Reservoir. In the warm sector, forecast soundings at KMAF at
00Z show mucapes in excess of 2000 J/kg, w/little in the way of CIN
to surmount. Both the NAM and GFS depict mid-lvl lapse rates of 7-8
C/km, and wet-bulb zeros of 9-10 kft AGL, laying the ground work for
more large hail along the front. Models differ a little on damaging
wind potential, however. The NAM retains more moisture in the PBL,
yielding dcapes of ~600 J/kg, whereas the GFS gives the classic
inverted-V and dcapes ~1500 J/kg. Both models develop enough 0-1km
helicities along the cold front that a tornado can`t be ruled out,
although the threat looks confined to our top two tiers of counties
in West Texas.
All that`s needed at the moment is to overcome the cap, which is
still holding at 19Z. Hires models like the HRRR initiate
convection 22-23Z, but otherwise look unimpressive, whereas the
NAM/GFS are a bit more widespread. Convection overnight should
remain along/east of the Pecos.
Overnight, the trough is forecast to open and move to the Four
Corners by 12Z Tue. Leeside troughing will induce SW sfc flow, and
mix the dryline east, confining further chances of convection along
the ern zones. Marginal high winds will be possible in the
Guadalupes, and we`ll issue a watch for this.
For the rest of the week, zonal flow aloft is anticipated, w/the
dryline developing over the ern half of the CWA each day, and a
chance of convection along and east of this feature each day. A
weak cold front tries to muscle in on Thursday, but looks dry and
will bring temps down to near-normal Fri/Sat. Thursday
night/Friday, the dryline will surge up against the wrn mtns,
increasing convective chances a little further west into the CWA.
Chances then generally drop off over the weekend, w/above-normal
temps returning.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 62 87 61 88 / 40 20 10 20
Carlsbad 59 84 54 88 / 10 0 0 0
Dryden 65 92 65 90 / 0 0 30 20
Fort Stockton 63 91 59 88 / 0 0 20 10
Guadalupe Pass 58 77 56 80 / 0 0 0 0
Hobbs 57 83 53 86 / 30 0 0 0
Marfa 51 83 48 82 / 0 0 0 0
Midland Intl Airport 63 88 60 89 / 20 10 10 10
Odessa 63 88 60 89 / 20 10 10 10
Wink 62 89 56 90 / 10 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...High Wind Watch from Tuesday morning through Tuesday afternoon
for Guadalupe Mountains of Eddy County.
TX...High Wind Watch from Tuesday morning through Tuesday afternoon
for Guadalupe Mountains Above 7000 Feet-Guadalupe and
Delaware Mountains.
&&
$$
99/99/10
Area Forecast Discussion
National Weather Service Paducah KY
718 PM CDT Mon Apr 29 2019
.UPDATE...
Issued at 718 PM CDT Mon Apr 29 2019
Early evening update for the remainder of tonight to reflect
elevated convective trends overnight. May need to make a second
adjustment later this evening to refine temperature trends,
especially for the northern sections of the WFO PAH forecast area.
KSGF sounding a little more representative (versus KLZK sounding) of
the upstream moisture and instability advecting into parts of the
WFO PAH forecast area overnight. KSGF sounding suggesting the
best saturation in the 700-500 mb (roughly 8-18kft agl layer) with
7.5C/km lapse rate in this layer. Some elevated CAPE above 12kft
(near the freezing level on KSGF sounding).
Local VAD (Velocity Azimuth Displays) from the local radars KPAH
(Paducah), KHPX (Fort Campbell), and KVWX (Evansville/Fort Branch)
show some noticeable veering of 25-35 knots between 925-500 mb,
hinting at warm advection aloft.
The ESRL HRRR, HRRR, and RAP CAM`s appear to be initializing well
with the current convection and expected location of frontal zone
the last few hours and were used as a template for overnight
convective activity. Considering the elevated instability in the
aforementioned layer, will keep a small mention of showers and
thunderstorms over southeast Missouri into southern Illinois this
evening, with pockets of light rain or isolated elevated
thunderstorms overnight further east.
UPDATE Issued at 558 PM CDT Mon Apr 29 2019
Updated aviation discussion for the 00 UTC TAF issuance.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 219 PM CDT MON APR 29 2019
High confidence in the short term.
A warm front had lifted north of the area today providing clouds and
sprinkles this morning. The clouds will move out this afternoon with
gusty south winds in its wake. Tonight we will lose the gusts and
clouds will begin to return to the region. This front will stall
along our northwest periphery tonight as a surface low lifts
northeast along the front. This could allow a chance of rain showers
and possibly a thunderstorm along our northwest. Mainly along a line
from the Ozarks to the Wabash River Valley. Temperatures will be
little warmer in the warm fronts wake and overnight lows will range
from 60 to 65 across the area.
.LONG TERM...(Tuesday THROUGH Monday)
ISSUED AT 219 PM CDT MON APR 29 2019
Models are in general agreement through Friday and after that only
slightly diverge. Overall pattern at 500H has a trough over the
west coast with some ridging over the eastern US. Very little
change through Friday however minor ripples in the flow will
determine the precipitation chances. Essentially an unsettled
pattern.
The northwest sections may see a shower or thunderstorm tomorrow
and this will gradually spread east Tuesday Night and Wednesday as
one of the weak waves moves in from the southwest. Better chances
arrive Wednesday Night and Thursday as a stronger wave rotates up
from the southwest trough. A slight increase in the ridge along
the east coast during that time will help to sharpen the wave and
increase the dynamics over the region.
We are in a marginal risk for severe weather Wednesday and
Wednesday night in part due to the increased dynamics creating
better shear. Cloud cover and precipitation will help determine
the amount of instability for the shear to work with.
This is the time of year when instability becomes increasing tied
to diurnal cycle and the question becomes more about shear. The
best combination after mid week looks to be Saturday over the I-64
area. Things will likely change before we get to that time.
Might be a dry period Saturday Night into early Sunday before more
storms move in.
&&
.AVIATION...
Issued at 558 PM CDT Mon Apr 29 2019
MVRF to VFR conditions expected through the TAF issuance period.
Winds will relax tonight, generally remaining southwesterly around
5 to 10 kts. Winds will increase after 18z at most sites, with
sustained winds of 11 to 15 kts and gusts of 19 to 22 kts
possible. At KMVN, the warm front may sag south around 9z,
shifting winds back to easterly, with a few showers possible.
Small possibility the front could reach KEVV/KOWB as well, but
confidence in this solution is low, so for now will monitor for
possible adjustments for the next TAF issuance.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...Smith
SHORT TERM...KH
LONG TERM...PS
AVIATION...DWS
Area Forecast Discussion
National Weather Service Shreveport LA
1017 PM CDT Mon Apr 29 2019
.SHORT TERM.../Tonight/
Quiet conditions remain this evening despite the deepening low
level moisture advection regime in place, as evidenced in the 00Z
KSHV raob which depicts a moist lyr up to 7kft. While much of the
cu field has diminished since the setting sun, the RGB satellite
imagery indicates a stratocu field beginning to advect N into Deep
E TX and SW LA this evening, with a developing 30-35kt Srly LLJ
advecting these low clouds quickly N across much of the region
overnight. Both the 18Z GFS and 00Z NAM depict the H850 moisture
lyr deepening overnight especially over E TX/SE OK, as a weak mid
level shortwave ejects NE into E TX late tonight. This could
result in isolated -SHRA development over E TX/SE OK late tonight
beneath the capping inversion near 790 mb, which has already
developed just NE of DFW and farther W towards SPS and Srn OK, and
thus have maintained slight chance pops for these areas overnight.
This is also supported by the latest HRRR run, which does begin to
ramp up sct convection by/after 12Z Tuesday across portions of
NE TX/SE OK through midmorning before quickly shifting N. Did trim
pops back a tad over NW LA/SW AR Tuesday morning, before sct
convection increases during the afternoon as a stronger shortwave
trough ejects NE across the middle Red River Valley of N TX/Srn OK,
with strong to svr convection increasing over these areas.
Also made a few minor tweaks to the min temps tonight, mainly to
lower temps a tad over Scntrl AR/Ern sections of Ncntrl LA, where
the short term progs are in agreement with some drier air
advecting NNW into the Lower MS Valley late tonight around the SE
CONUS ridging in place. Otherwise, the remainder of the forecast
is on track.
Zone update already out...grids will be available shortly.
15
&&
.PREV DISCUSSION... /issued 700 PM CDT Mon Apr 29 2019/
AVIATION...
VFR conditions should continue through much of the evening with a
mix of sct cu and cirrus, although MVFR cigs are expected to
develop by mid evening over SE TX/SW LA, and quickly spread N into
Lower E TX S of I-20 as well as Wrn LA by late evening. These cigs
should primarily affect LFK initially, followed by the TYR/GGG/SHV/MLU
terminals by/shortly after 06Z, and the SW AR terminals by/after
08Z. Some isolated -SHRA may develop late tonight across portions
of E TX/SE OK, but have not included mention into the E TX
terminals attm given the low confidence. While these cigs should
linger through much of the morning Tuesday, some drier air
rounding the Wrn periphery of the large scale ridging in place
over the SE CONUS is expected to advect NNW into the Lower MS
Valley by/prior to daybreak Tuesday, resulting in the lower cigs
scattering out as MLU initially, and eventually ELD around mid-
morning. Elsewhere, the MVFR cigs should lift/become VFR by
midday/early afternoon, as this drier air is mixed farther NNW,
allowing for the tight pressure gradient to mix stronger winds
down to the sfc by mid to late morning areawide. Thus, SSE winds
5-10kts tonight will become S and increase to 12-18kts by 15Z,
with gusts to 25-30kts possible across much of E TX/SW AR/Wrn LA,
and slightly weaker gusts to 20kts over Scntrl AR/Ncntrl LA.
Isolated convection will remain possible Tuesday afternoon over
portions of NE TX/SE OK/adjacent sections of SW AR, but should
remain NNW of the TYR/TXK terminals. /15/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 69 84 69 83 / 10 10 30 40
MLU 66 84 68 85 / 5 10 10 20
DEQ 67 81 67 78 / 10 50 70 70
TXK 68 82 69 80 / 10 30 40 60
ELD 66 85 68 82 / 5 10 20 40
TYR 71 83 71 81 / 20 30 40 60
GGG 70 84 70 82 / 20 20 40 60
LFK 70 84 71 84 / 20 10 20 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
15
Area Forecast Discussion
National Weather Service Sacramento CA
310 PM PDT Mon Apr 29 2019
.SYNOPSIS...
Cooling trend early this week with temperatures near or a little
below average by Tuesday. Dry conditions except for a chance of
showers or isolated thunderstorms over the foothills and mountains
through Tuesday. Temperatures trend warmer throughout the week
with a chance for showers returning to the higher terrain this
weekend.
&&
.DISCUSSION...
Northern California remains in a split flow regime as one closed
low moves toward western Arizona while a longwave trough to the
north will cross the region on Tuesday. Currently, terrain induced
cumulus fields are evident in GOES-17 visible imagery with the
better instability over the northern Sierra. Based on a lack of
echoes showing up on local radars, capping is likely an impedance
from shower development. Recent high-resolutions models show mixed
signals in forming such showers. Most notably, the last several
HRRR runs keep the Sierra dry through the peak diurnal heating
cycle.
By Tuesday morning, a positively-tilted trough will swing through
the Central Great Basin allowing for increased cloud cover across
the region. The stronger ascent is likely to remain east of I-5
keeping shower chances highest from the foothills eastward.
Limited moisture will keep precipitation amounts on the lower
side, generally maximizing up to a third of an inch over Sierra
and Plumas Counties. Widespread cloud cover should preclude any
discernible thunderstorm threats. Over elevations 7,000 feet and
above, some light snowfall accumulations perhaps up to an inch
will be possible.
Tuesday will be the coolest day of the week given cold advection
occurring in the wake of the trough passage. Highs between 70 and
75 will be commonplace over the Valley while the foothills remain
in the mid 50s to lower 60s. Temperatures will gradually rise
throughout the week in response to a building ridge over the
southwestern U.S. Highs back into the low 80s should return to
the Valley by Thursday. ~BRO
&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)
Dry weather continues Friday as slight upper ridging resides over
northern California ahead of closed low moving towards the area
this weekend. Ensembles bring the best chances for
mountain/foothill precipitation late Saturday night through
Sunday. Rain chances do look to continue through the beginning of
next week as models tend to differ on how this closed low will
track. As for temperatures, Valley highs in the low to mid 80s on
Friday will gradually drop into the upper 70s by Sunday and
Monday.
&&
.AVIATION...
VFR conditions expected over interior NorCal except for areas of
showers and thunderstorms across the higher terrain. These would
be primarily south of Highway 50 through 03Z this evening. Surface
winds remain below 12 knots except local southwesterly gusts up to
27 knots are possible across the Delta through the late evening.
&&
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Tulsa OK
934 PM CDT Mon Apr 29 2019
...UPDATE...
.DISCUSSION...
This evening the surface frontal boundary was positioned from far
West Texas to South Central Oklahoma into Northeast
Oklahoma...just south of the Interstate 44 corridor...and extended
northeast into Southern Missouri. Scattered areas of light
rain/drizzle have been observed over parts of Eastern Oklahoma and
Northwest Arkansas within an area of warm advection. Further
south into Western Texas...showers and thunderstorms were
developing along/near the surface boundary where the surface
instability was maximized and an upper level vort max currently
resided.
Overnight tonight...the surface boundary is expected to stall near
its current position and then slowly retreat northward slightly
late tonight/early Tuesday morning just north of the Interstate 44
corridor. Also overnight...the upper level vort max is forecast to
lift northeast into Eastern Oklahoma late tonight while at the
same time an increasing low level jet looks to lift into the CWA.
The combination of these two features along with a weakening cap
forecast over elevated instability will allow for an increase in
thunderstorm potential mainly across Northeast Oklahoma where the
surface boundary sets up. Have leaned toward the latest HRRR with
increasing pops/thunder after 08-09z. In response...a limited
severe weather potential will be possible with large hail and
locally damaging winds the main threats...with the greater
potential in Northeast Oklahoma near the boundary.
With the northward push of the front...surface temps/dewpoints
look to rise slightly late tonight especially just behind the
frontal passage. Low temps look to range from around 60 degrees
near the Kansas border to the upper 60s in Southeast Oklahoma. By
12z Tuesday...the upper 60s look to reach back into parts of
Northeast Oklahoma. Thus for the evening update...have adjusted
hourly pops and temps based the mentioned above...while added
minor tweaks to winds/dewpoints based on latest trends and
observations. With the forecasted rainfall..will leave current
flash flood watch as is for now.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 64 76 63 81 / 70 90 80 30
FSM 67 81 66 80 / 20 70 90 50
MLC 68 78 66 78 / 30 80 70 40
BVO 61 75 61 80 / 90 90 80 40
FYV 63 75 65 76 / 20 80 90 40
BYV 64 77 64 78 / 20 60 80 40
MKO 65 76 65 78 / 40 80 80 30
MIO 63 75 62 78 / 50 90 90 40
F10 67 77 65 79 / 60 80 80 40
HHW 68 78 67 77 / 30 70 70 60
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Flash Flood Watch from 1 AM CDT Tuesday through Wednesday
morning for OKZ054>064-067>069.
AR...Flash Flood Watch from 1 AM CDT Tuesday through Wednesday
morning for ARZ001-002-010-011.
&&
$$
SHORT TERM...20