Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/25/19
temperature are still on track. Remainder of forecast discussion
below.
A surface trough currently over southern Ontario will drop
south through the region overnight. Limited moisture and weak
lift will result in only isolated snow showers. The only area
which may see brief scattered coverage would be northern Oneida
county and parts of the Finger Lakes region. Snow accumulations
here could result in a dusting. Overnight lows will range in the
lower to mid 20s across central New York and upper 20s to mid
30s across northeast Pennsylvania.
Monday/Monday night...High pressure will build into the central
Great Lakes as a low pressure system passes to our south into
the mid Atlantic region. Skies will clear out quickly Monday
morning behind the surface trough with clear skies for Monday
night. In the far southeast high clouds may persist due to the
system in the mid Atlantic region. A fairly cold airmass will be
over the area with highs on Monday in the mid/upper 30s in
central New York and upper 30s to lower 40s in northeast
Pennsylvania. Lows Monday night will range from the teens to
lower 20s.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Very quiet weather in the short term with a large area of high
pressure at the surface building across the region keeping the area
dry with gradually warming temperatures.
Upper level cyclonic flow will be replaced by weak ridging aloft
Tuesday and Wednesday...and when combined with much drier air and
the presence of a strong surface high, the chances for precipitation
will remain near zero.
The surface high will shift off the New England coast Wednesday
night as the next system prepares to move in across the upper
Midwest and the Great Lakes. Cloud cover will begin to increase late
Wed night, along with an up-tick in sw winds due to a strengthening
sfc pressure gradient.
Temperatures Tuesday will start off on the cool side...only into the
mid and upper 30s during the day...and then drop into the teens and
lower 20s under mostly clear skies Tue night. Conditions rebound on
Wed into the upper 40s and lower 50s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A weak front will push in from the west Thursday with a minimal amt
of rain expected during the day as the dry air will first need to be
overcome. The front will lay out west-east across the region Thur
night through Friday with scattered rain showers
possible...especially across central NY. Winds will increase on
Thursday out of the s/sw with sustained winds around 10 to 15 mph
and gusts around 20 mph possible.
The next system will move in from the sw...tracking from the Ohio
Valley into the Northeast. There is still a good deal of uncertainty
with respect to the track of the sfc low...which will be significant
in determining precip amts and timing. For now just keep with a
chance of rain showers into the weekend.
Temperatures Thursday through Saturday will remain on the mild side
with afternoon highs in the 50s and lower 60s, and overnight lows in
the upper 30s and 40s.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
730 pm update...
Primarily VFR conditions expected for the next 24 hours at most
taf sites. A cold front drops south through the region from 05z
at SYR/RME to 09z at AVP. With and just behind the front will be
enough low level moisture for MVFR clouds at ITH/BGM/ELM for a
few hours between 7 and 12z. High confidence ITH/BGM and medium
at ELM. ITH/BGM might fall to fuel alternate MVFR.
Rapid clearing is expected from north to south from 09z to 15z.
Southwest to west winds at 5 knots shifting to the northwest
with the front. Monday northwest winds at 8 to 10 knots.
Outlook...
Monday night through Thursday night...VFR.
Friday...Restrictions possible in rain showers.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MWG/RRM
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...TAC
Area Forecast Discussion
National Weather Service State College PA
1150 PM EDT Sun Mar 24 2019
.SYNOPSIS...
An upper low over the Miss Valley will weaken as it pushes east
and merges with a shortwave diving southeast across
Pennsylvania Monday. Canadian high pressure and associated dry
air mass will settle south across the area during midweek. A
cold front is then likely to push southeast across the region
next weekend.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
Radar shows some scattered disorganized light echoes, so far
no rain reaching the ground all the way back into Central OH.
The HRRR keeps the precip disorganized and suggests the best
chance for some small measure of rain will be over the SW and
along the Mason Dixon line overnight. In general I trimmed back
the already low POPs and QPF.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
A shortwave over the Midwest will get absorbed into the very
fast WNW flow aloft, causing the surface wave to get squeezed
mainly south of the forecast area. The HREF shows mainly light
rain moving across the southern stripe of counties tomorrow
afternoon into the early evening.
Surface ridging and much drier air mass over upstate NY will
build back in for Monday night.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
The axis and SWWD extend of an upper trough over southeastern
Canada and deepening cold air will extend across PA Monday
night. At the same time, the northern extent of light precip
(from a weak sfc low and southern stream trough) will brush our
southern zones and will transition into a light rain/snow mix
for a short period prior to ending by 04Z Tuesday. No snow accum
is expected as sfc temps will be in the mid to upper 30s.
NW flow aloft and dry conditions with below normal temps will
follow for Tuesday, with strongly anticyclonic flow/subsidence
at llvls.
The NW flow aloft will abate for midweek as a large area of sfc
high pressure builds across the Commonwealth. Mainly clear
skies are expected for later Monday night right through
Wednesday.
A slow-moving frontal boundary, draped to our northwest across
the Grt Lks, may sink SE into the region Thu night or Friday
before stalling out as a weak northern stream trough slides
from the Upr Glakes to the Canadian Maritimes.
A deepening upper trough and 1000 mb sfc low over the Central
Plains and Mid Miss Valley respectively late Fri Night/Sat will
lead to a quickly expanding rain/snow field from the Central
Plains to Upper Glakes, with a building ridge along the East
Coast keep us very mild and mainly dry under south-southwest
flow at the sfc and aloft.
Near to slightly above normal temps are forecast for Wed under
the central of the high. Afterward, temps will rebound to 7-10F
above normal Thursday, and peak at 15-18F above normal Friday
and Saturday.
Will maintain a chance of showers across northwest Pa late in
the week through Saturday to account for model differences with
regard to the exact location of the quasi-stationary/warm front
that`s expected to stretch from Lake Erie NE across the St.
Lawrence Valley.
The greatest prob for rain showers comes for later Sat and
Saturday night, when east coast ridge breaks down and a cold
front pushes across the state. Above normal temperatures should
hang on Sat before dropping back to near normal for Sunday with
scattered rain/snow showers possible across the Mtns and
isolated-sctd rain showers in the Valleys.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
VFR conditions continue to prevail across the region tonight. A
cold front over central New York will slip southward through
Pennsylvania during the overnight hours. A shift to northerly
winds will accompany the frontal passage. While actual
precipitation will be spotty overnight, increasing low level
moisture and the upslope flow into the mountains will likely
generate some MVFR ceilings.
On Monday, a weak wave will ride eastward along the front, which
should be south of Pennsylvania. Models generate limited
moisture with this feature as is is sheared, but threat exists
for some light precipitation and ceiling restrictions across the
southern tier during the day.
High pressure will then prevail through Thursday, with a frontal
system approaching for Friday.
.Outlook...
Mon...AM rain/snow. Restrictions possible, mainly northern and
western mountains.
Tue-Thu...No sig wx expected.
Fri.....VFR, but with some scattered showers possible northwest.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Fitzgerald/La Corte
NEAR TERM...La Corte/Ceru
SHORT TERM...Fitzgerald/Ceru
LONG TERM...Fitzgerald/Lambert
AVIATION...Jung
Area Forecast Discussion
National Weather Service Dodge City KS
1030 PM CDT Sun Mar 24 2019
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
Issued at 1023 PM CDT Sun Mar 24 2019
WV imagery indicates a zonal flow aloft prevailing across the
Western High Plains. Near the surface, broad high pressure extends
from the Northern Plains into the Upper Midwest.
&&
.SHORT TERM...(This afternoon through Monday night)
Issued at 1130 AM CDT Sun Mar 24 2019
Slow-moving upper low centered in SW IA at midday is still
influencing SW KS weather, with stratus and stratocumulus still
rotating into the northern zones. Updated sky grids to match this
trend, but expecting some improvements this afternoon. Despite
last night`s weak cold front and today`s modest northerly flow,
temperatures should still manage to reach the lower 60s for many
zones this afternoon. Northern zones where stratus is more
persistent will remain in the 50s.
A weak shortwave approaching in the NW flow aloft is expected to
generate scattered high-based/weak convection across the Colorado
Rockies and near the Raton Mesa this afternoon. 12z NAM and the
latest HRRR iterations continue to show some of this convection
reaching the western/SW zones this evening. Increased pop grids to
the solid 50% chance category in the Elkhart vicinity, with some
showers possibly surviving as far east as Liberal by midnight
tonight. Moisture is scarce, as such much of the rainfall will be
lost as virga. With dry subcloud layers, some gusty outflow winds
may accompany some of this activity. Most of SW KS will remain dry
tonight, with increasing mid layer clouds early, followed by
increasing stratus through Monday morning. Lows Monday morning
will be held above normal by the cloud cover, in the upper 30s and
lower 40s.
Monday will feature plenty of clouds, especially early, as the
weak shortwave shears its way through. High pressure surface ridge
over SW KS at sunrise Monday will hold firm much of the day, which
will keep winds light NE or light and variable. Conversely, the
cloud cover and this lack of mixing, coupled with minor cooling at
850 mb, will hold temperatures back Monday, with many locations
holding in the 50s. 12z NAM MOS appears too cold with a high of
50 at Dodge City Monday, but if the expected morning stratus is
stubborn, then the going forecast of mid to upper 50s would be
several degrees too warm.
.LONG TERM...(Tuesday through Sunday)
Issued at 230 PM CDT Sun Mar 24 2019
Tuesday...Much windier and much warmer. Broad ridging builds over
the plains aloft, with little cloud cover. Strong return flow is
expected by afternoon, with strong south winds behind the large
eastward retreating surface high. South winds of 20-30 mph will be
common, with gusts near 40 mph. Afternoon max temps warm to the
lower 60s east, to the lower 70s west.
Wednesday...Still windy, and warmer still. Near zonal flow
continues on top of broad ridging over the southern plains, for
little cloud cover other than passing cirrus. Placed the
strongest wind guidance available in the grids, with S/SW winds
averaging 25-35 mph, with gusts near 45 mph. Models show a decided
downslope component, which will propel temperatures to the mid 70s
east, to near 80 west.
Thursday...The warmest temperatures from this warming trend are
expected across the southern counties. Thursday morning low
temperatures will be abnormally warm, in the 50s, with mixing,
increasing moisture and the LLJ. 12z MEX/GFS guidance is still
quite warm Thursday afternoon, with lower 80s common, although 12z
models introduce a weak prefrontal trough/boundary and associated
wind shift that may relegate these warmest temperatures to near
the Oklahoma border. At any rate, Thursday will be pleasant with
well above normal temperatures, and much less wind as low pressure
organizes nearby. Continued dry through daylight Thursday.
Although models are waffling a bit on timing, a strong cold front
will race through SW KS sometime during the Thursday night/Friday
time frame. The models are in agreement tracking the synoptic
trough far enough north, such as to keep the majority of
precipitation north of SW KS during the Friday timeframe. Retained
the pops offered by the model blend for Friday for mainly
scattered rain showers, out of respect for dynamic lift and
frontal convergence.
Much colder air will arrive Friday and Saturday, with afternoon
temperatures struggling to reach 50, with morning low temperatures
Saturday returning to near freezing.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 536 PM CDT Sun Mar 24 2019
Under weak flow in the low levels and under an induced upper level
ridge, fair weather cumulus will continue the rest of the evening
with scattered to broken clouds around the 3-4kft level. Winds are
mostly out of the north 10-12kts under a weak gradient expecting
to diminish to light and variable after 09Z through the rest of
the period as high pressure is the main influence during this
time. With decent enough instability, weak air mass thunderstorms
will push out of eastern Colorado this evening but should not make
it as far east as GCK and LBL but something to keep an eye on for
amendments. Other than that, low level stratus will invade the
CWA affecting all sites by 09Z and possible MVFR ceilings after
12Z through mid morning. Stratus will lift and scatter out at this
point due to daytime heating and weak mixing of the boundary
layer winds to the surface.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 58 38 66 / 10 10 0 0
GCK 37 58 39 67 / 20 20 0 0
EHA 39 61 40 70 / 40 10 0 0
LBL 39 61 40 70 / 20 10 0 0
HYS 39 55 37 65 / 10 10 0 0
P28 41 58 39 64 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Lowe
Area Forecast Discussion...UPDATED
National Weather Service Glasgow MT
742 PM MDT Sun Mar 24 2019
.DISCUSSION...
Sent an update this evening to fine tune the location and timing
of the wintry mix. Expect most of the change over from rain to
snow thus far has been west of Highway 24. As the night wears on,
will probably see more of a widespread change over to snow, but as
it does, the storm system will become more disorganized. Freezing
temperatures overnight will likely lead to slippery surfaces from
the cold wetting rains from earlier today. Given the lingering
threat as these scattered showers moves back eastward overnight,
felt it was best to leave the Winter Weather Advisory in place for
the combination threat of snow and freezing rain overnight
tonight. BMickelson
Previous discussion: Forecast challenge this package is on the
ongoing precipitation.
Tonight/tomorrow...
So far today, we`ve had reports of mixed precipitation in
Plentywood, and freezing rain in Roosevelt County (a CoCoRaHS
report forwarded to us), and in Glasgow, with other areas of rain
changing to snow. Decided to keep the winter weather advisory up
for a few reasons: 1) precipitation is still ongoing; 2) icing
events are a fairly rare event in the CWA, and we`ve already had
icing and will continue to get it; 3) the wintry precipitation
will stress newborn livestock in the area. So, it boils down to
being an impact-based advisory because we are already being impact
and will continue to be.
All that being said, precipitation type will bounce around
tonight across the area. The main area of precipitation shifted
westward from before, so increased POPs generally west of Highway
24 and lowered them east of 24. Leaned a little more on the HRRR
and RAP with making the adjustments tonight, which were more in
line with reality initially, but still further east than the
global models. The regional and high resolution models want to end
the precip altogether tonight, while the global models keep
things going through the night.
Fog is also a possibility in the area tonight, and will need to be
monitored especially for the southern zones.
Precipitation should end from west to east tomorrow, with
temperatures warming back up into the 40s.
Tomorrow night and beyond...
The upper level ridge begins to flatten out a bit Tuesday into
Wednesday. Tuesday should be the warmest day of the week ahead,
with areas south of the Missouri River easily going into the 60s.
The next chance of precipitation begins to move into our southern
zones Wednesday night as an upper level trough moves into the
Pacific Northwest and the ridge pulls away. Precipitation chances
will spread area-wide by Thursday, tapering off Friday.
Temperatures fall back off late week as well as a result of the
change in pattern.
Avery
&&
.AVIATION...
FLIGHT CAT: A range of IFR to near LIFR expected tonight,
improving to at least MVFR by tomorrow afternoon.
DISCUSSION: A wintry mix of precipitation and associated low
ceilings and reduced visibilities will affect area terminals
across the region tonight through early tomorrow morning.
Ceilings may remain low tomorrow afternoon due to the moisture
from snowmelt and new precipitation. KGDV and KSDY will need to be
monitored for fog potential tonight, and may require TAF
amendments.
WINDS: East at 10 to 20 kts, diminishing to around 10 kts early
Monday morning. Winds shift to the southeast 10 to 15 kts by
Monday afternoon.
Avery/BMickelson
&&
.HYDROLOGY...
Creeks and streams across NE Montana are flowing high, with near
bankful to out of bank conditions, adding to larger rivers
downstream with levels rising for many locations along the Milk
River, Yellowstone River, and the Missouri River East of Fort
Peck.
Decent snowpack yet remains to melt across Valley, Phillips,
Daniels, and western Roosevelt counties. Flooding is already
occuring over parts of this area and will continue into next week.
Occasional ice jams have been reported along portions of the Milk
and Yellowstone Rivers leading to areas of flooding. Sections of
ice, both flowing and jamming continue to cause sudden rises and
falls for many locations.
Updated forecasts for areas near Tampico and Glasgow along the
Milk River in Valley County show flood stages reaching and
remaining near Major Flood Stage levels throughout this week.
Today`s and tonight`s precipitation may briefly add to these
rises.
The current storm system will dissipate and move east of the
region later on Monday.
To monitor river stage readings, go to our Advanced Hydrologic
Prediction Service (AHPS) page at www.weather.gov/glasgow then
click on "Rivers and Lakes" then "River Observations". Data for
this page are provided by the USGS.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM MDT Monday for Central and
Southeast Phillips...Central and Southern Valley...Northern
Phillips...Northern Valley.
Winter Weather Advisory until noon MDT Monday for Daniels...
Eastern Roosevelt...Sheridan...Western Roosevelt.
&&
$$
weather.gov/glasgow
Area Forecast Discussion
National Weather Service San Francisco Bay Area
902 PM PDT Sun Mar 24 2019
.SYNOPSIS...A Pacific storm system will spread moderate rain
across the North Bay late tonight and Monday morning, with light
rain then expected to develop south across much of the rest of the
area on Monday afternoon and evening. Periods of rain are then
likely to continue from Monday night through Thursday, with the
most widespread rainfall expected late Tuesday night into
Wednesday. Dry weather is forecast to return late in the week and
into next weekend.
&&
.DISCUSSION...As of 9:00 PM PDT Sunday...Evening IR satellite
imagery shows a large upper low centered about 800 miles off the
coast of the Pacific Northwest. To the south and east of this low
center is the initial frontal boundary that is currently
approaching the northern California coast. Models forecast light
warm advection rainfall to develop out ahead of the frontal
boundary and into the North Bay by around midnight tonight, and
the KMUX radar is already showing weak returns near northwest
Sonoma County. Latest HRRR and the 00Z NAM indicate that rain
rates will increase in the North Bay late tonight as the frontal
boundary approaches our coast. Moderate to locally heavy rainfall
can be expected in the North Bay from late tonight through the
Monday morning commute. The latest HRRR also forecasts moderate
rainfall rates developing as far south and east as the San
Francisco Peninsula and western Alameda County by midday tomorrow.
The frontal boundary is then forecast to weaken significantly as
it pushes south into the south Bay and Monterey Bay Area on Monday
afternoon and evening. Rainfall totals in the North Bay through
Monday evening are forecast to range from 0.5-1.5 inches with as
much as 2 inches possible in northwest Sonoma County. Rain totals
through late Monday for the remainder of our area are expected to
be a quarter inch or less except up to a half inch along the SF
Peninsula, and locally in the Santa Cruz Mountains and East Bay
Hills.
The weakened frontal boundary is forecast to stall along a line
from about San Jose to Monterey late Monday night and persist
there through Tuesday. During this time frame, scattered showers
will be most likely near the stalled frontal boundary, but could
occur most anywhere in our area. In any case, rainfall amounts
from late Monday night through Tuesday evening are expected to be
light.
The upper low will finally begin to approach the far northern
California coast late Tuesday night. A vigorous shortwave trough
rotating around the low is expected to bring another round of
widespread rainfall to our area from late Tuesday night through
Wednesday morning. Scattered showers will continue into Wednesday
afternoon and evening. In addition, the airmass will become
increasing unstable late Tuesday night and Wednesday morning as
the upper low approaches and we could see isolated thunderstorms
on Wednesday. The upper low will be very slow to move to the
northeast and out of our area, so scattered showers may continue
through Wednesday night and into Thursday, primarily across the
northern portion of our area. Additional rainfall from Tuesday
through Thursday is forecast to range from 0.50-1.50" in most
areas, with as little as 0.25" in our far southern valleys and as
much as 2 inches in northwest Sonoma County. Forecast rainfall
from late tonight through Thursday will mostly be beneficial,
although some minor nuisance flooding is possible in the North
Bay, particularly on Monday morning.
Gusty winds can be expected at times through midweek. South winds
may gust as high as 35 mph along the coast of the SF Bay Area
from late tonight through early Monday afternoon. More widespread
gusty winds are then likely from late Tuesday through Wednesday
when southwest winds may gust up to 40 mph at the coast and in
the hills.
Southerly flow ahead of this system will result in mild
temperatures through early Wednesday, with cooling then expected
late Wednesday into Thursday. A forecast update earlier this
evening included increasing temperatures, particularly at night,
from Monday night through Tuesday night.
Longer range models indicate dry conditions will return by Friday
and continue into the weekend, although rain may develop in the
North Bay by Sunday afternoon.
&&
.AVIATION...As of 5:40 PM PDT Sunday...VFR extending through the
evening with southerly wind flow, drying lower levels; the WRF
model`s boundary layer and surface humidities initialized well
except RHs are over-forecast along the Monterey county coast.
High pressure moving to the Central Coast is setting up a SMX-SFO
pressure gradient, currently 1.1 mb, and the SFO-ACV gradient is
1.6 mb. An eastern Pacific trough will bring lowering ceilings,
mainly to the Bay Area, on Monday. Forecast is MVFR ceilings in
light to moderate rain preceding an incoming cold front, post
frontal wind shifts over to SW-W direction Monday. IFR ceilings
and visibilities in rain over the North Bay mainly Monday morning.
Light rain with a slow moving cold front eventually arrives along
the north Central Coast Monday evening.
Vicinity of KSFO...VFR, wind briefly onshore and mainly light
becoming SE early to mid evening. Tempo light rain 11z-15z Monday
with gradually lowering ceilings becoming MVFR in light rain by
15z. SE wind Monday shifting to westerly by late afternoon with
cold frontal passage, wind gusty to 20-25 knots near late afternoon
frontal passage and wind gusts lingering into the early evening.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR, wind onshore until mid evening then
becoming E-SE with SE wind increasing in the Salinas Valley Monday
morning and afternoon prior to cold frontal passage. Light rain
developing 21z-22z and lasting into the evening.
&&
.MARINE...As of 8:44 PM PDT Sunday...Winds southerly and rain
developing through Monday morning ahead of approaching low
pressure system and cold front. Gusty winds can be expected ahead
of the front. Showers linger Monday night and Tuesday. Rain
develops again during the mid-week then dry weather returns late
week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...Pt Reyes to Pigeon Pt 0-10 nm from 3 AM
SCA...Pigeon Pt to Pt Pinos 0-10 nm from 3 AM
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pt Arena to Pt Reyes 0-10 nm from 9 PM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 9 PM
&&
$$
PUBLIC FORECAST: Dykema
AVIATION: Canepa
MARINE: Canepa
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Area Forecast Discussion
National Weather Service Blacksburg VA
1158 PM EDT Sun Mar 24 2019
.SYNOPSIS...
High pressure slides off the North Carolina coast tonight. A front
crosses the area Monday. High pressure builds back in for Tuesday
and Wednesday.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 1155 PM EDT Sunday...
Temperatures still running a bit warmer in most areas that
originally advertised. Thus, made some minor adjustments to the
T and Td readings. No other changes needed at this time.
As of 755 PM EDT Sunday...
Just some minor changes to update the temperature and dewpoint grids.
Temperatures a running a bit warmer than anticipated at this
hour and dewpoints are running a bit lower. Warm dry air mass
continues into the evening. So, slowed the cooling and
moistening a bit based on latest HRRR and GLAMP25. Pops coming
in tomorrow morning look good with isolated thunder in the
afternoon south and Piedmont.
As of 239 PM EDT Sunday...
High pressure will slide east tonight and push into the Atlantic
ocean. Meanwhile, low pressure in Missouri with a warm front
extending east and a cold front trailing south will travel eastward
tonight into Monday.
For tonight, the warm frontal precipitation will lift north across
the Ohio Valley with some spillover of rain showers toward central
West Virginia. Clouds will increase tonight as the cold front
approaches from the west. Isolated to scattered showers may reach
into the western mountains by dawn. Played pops close to NAM for
tonight. Low temperatures tonight will be milder with readings from
around 40 degrees in the mountains to the upper 40s in the piedmont.
A shortwave trough will spread southeastward over the Tennessee
Valley toward the Carolinas on Monday. The cold front will move east
across our region Monday. Scattered showers and a few thunderstorms
will develop ahead and along the frontal boundary. Southwest flow
ahead of the front will advect warm moisture air into our region.
There is some weak convective instability from 18z-00z across
southern portions of our forecast area. The Day Two Convective
outlook places southern half of CWA in general thunderstorms.
However, there is a chance for some graupel or small hail in
stronger cells based on low wet-bulb zero heights. High temperatures
Monday will range from around 50 degrees in the northwest mountains
in western Greenbrier to around 70 degrees in the piedmont.
Forecast confidence is high.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 215 PM EDT Sunday...
Surface low along with its associated cold front will shift slowly
off to the southeast Monday night bringing the majority of the
significant precip to an end. However as the upper trough
consolidates over the area and the boundary layer flow turns more
northeast, may see low level moisture get trapped beneath the
subsidence inversion aloft later Monday night into early Tuesday
espcly west. This as strong wedging starts to develop ahead of cold
high pressure heading east out of the Great Lakes through midweek.
Depth of the moisture and subsequent precip potential remains iffy
since the Nam likely overdone and the GFS too dry per the surface
high building in faster. Does appear better focus will be across the
west/southwest while more north/northeast flow likely to limit to
more of a cloud/drizzle/flurry scenario. Thus trimmed back going
chance pops to mainly the west Monday night with a faster exodus of
moisture Tuesday from north to south.
High pressure and better drying to take shape Tuesday afternoon into
Wednesday night as the high shifts offshore while still maintaining
some wedging. This supports mainly sunny/clear skies for midweek but
still cool given the low level wedge and 850 mb cold pool in place
under northeast flow. Highs mostly 40s and 50s with lows 20s/30s
each night.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 130 PM EDT Sunday...
Wedge of cool air across the region will gradually break down as the
parent surface high slides offshore on Thursday allowing deepening
warm advection to take shape ahead of another cold front arriving
over the weekend. This in conjunction with sunshine under strong
ridging/warming aloft per 850 mb temps climbing to +10 deg/C or
higher should bring a quick moderation to above normal temperatures
espcly from Friday onward. Timing of arrival of moisture with the
weak upstream cold front remains uncertain given the strong ridge
aloft over the southeast and best support with the front passing
well north. Guidance suggests that pieces of shortwave energy may
scoot east ahead of the boundary perhaps resulting in showers mainly
mountains Saturday into Saturday night and elsewhere on Sunday.
However solutions remain at odds with the GFS hanging the front up
to the west through Day7, while the ECMWF/CMC keep things mostly dry
with a more pronounced frontal passage Sunday including more
showers. Since the GFS appears overdone with added energy off to the
west will lean closer to the Euro and subsequent WPC solutions in
having a cleaner fropa into Sunday. Highs mostly 50s/low 60s
Thursday, warming to 60s and a few 70s east from Friday through
Sunday including lows mainly in the 40s.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
As of 755 PM EDT Sunday...
VFR conditions expected to continue across the forecast area
until Monday afternoon as upper-level disturbance and cold front
advance into the region from the west. BKN-OVC ceilings expected
overnight, but all high-mid clouds mostly at or above 10kft to
15kft. Ceilings will lower into the MVFR and eventually IFR
range late Monday afternoon into the evening as rain showers
overspread the region and saturate the lower atmosphere from its
very dry current condition. Visibilities will also remain VFR
and mostly P6SM until the rain showers arrive mid to late
afternoon Monday, then trend toward periods of MVFR in -SHRA BR.
Winds will decrease a bit this evening to SW 4-8kts overnight
with isolated low end gusts at times. Winds will become more WSW
through the day Wednesday at 5-8kts then shift to the WNW and
increase to 7-10kts during the late afternoon/evening coincident
with the showers/frontal passage. An isolated thunderstorm is
possible in the Danville area during the afternoon, so included
VCTS there. Otherwise, did not mention TSRA at the TAF sites at
this time, with little threat of any thunder west of the Blue
Ridge.
/Confidence in Forecast Parameters/
Ceilings - Moderate to High,
Visibilities - Moderate to High,
Winds - Moderate to High,
Thunderstorm Threat Monday Afternoon - Low.
EXTENDED AVIATION DISCUSSION...
Sub-VFR conditions will continue into early Tuesday behind the
front, mainly across the western mountains. W-NW winds may be a
bit strong and gusty Tuesday, but do not appear to rival recent
wind events. Dry weather on tap for Wednesday into Friday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...KK/WP
NEAR TERM...KK/RAB
SHORT TERM...JH
LONG TERM...JH
AVIATION...KK/RAB
Area Forecast Discussion
National Weather Service Springfield MO
607 PM CDT Sun Mar 24 2019
.MESOSCALE DISCUSSION...
Issued at 558 PM CDT Sun Mar 24 2019
Strong to severe convection continues ahead of the surface front
in south central MO, as of 6 pm from near Shell Knob to Rolla.
Areas to the south of the convection still in favorable area for
future convection as air mass has not been modified yet. Large
hail would be the primary severe weather concern. Convection
should start to diminish after sunset with loss of daytime heating
and diminishing instability. Hail up to 2 inches in size will be
possible with the stronger storms.
&&
.SHORT TERM...(This evening through Monday)
Issued at 205 PM CDT Sun Mar 24 2019
Update: 18z KSGF sounding indicated a weak cap, but radar and
satellite imagery increasing shows evidence of weakening
inhibition with a small uptick in convective towers and isolated
radar returns. This is in line with recent HRRR guidance. In
general HRRR trends have been indicating a slightly later onset
time of more widespread convection versus runs from this morning,
however, the eastern cwfa should see scattered convection.
Shear/instability profiles (nearly 1000 j/kg mlcape and 50kts
0-6km bulk shear) are supportive of supercells with large hail the
main concern. A localized wind risk is also possible. A veered
low level wind profile should limit the overall tornado threat
The front is expected to shift east of the area this evening, so
expecting a a brief window for severe storms in our area.
After some brief clearing, low clouds should moves south on the
backside of the system with some drizzle expected late tonight and
Monday morning, especially in the northeast quarter of the cwfa.
Cloud will likely hold on into Monday night as well
.LONG TERM...(Tuesday through Sunday)
Issued at 205 PM CDT Sun Mar 24 2019
Tuesday: A ridge of high pressure will nose south form the Midwest
with finally some clearing expected Tuesday with seasonable
temperatures.
Wednesday: South winds will become gusty with warm weather as the
sfc high moves off and a large upper ridge builds over the central
CONUS.
Thursday-Friday-Saturday: The upper ridge flattens out and shifts
east as the southern branch of an upper level split flow pattern
becomes the main player in our weather. Moisture will spread north
in the persistent strong south low level flow on Thursday. By late
in the weak the surface pattern becomes more active with a wave of
low pressure likely to move through supported by a shortwave
moving through the central Rockies into the Plains. Decent
agreement with ECMWF and GFS in moving a sfc low through eastern
KS and MO with a trailing cold front Fri night.
Sunday: Guidance differs by this time on how far south the front
will get. The GFS is more active with another sfc wave moving
through the southern CONUS while the ECMWF is dry. Forecast
reflects a blend of guidance.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 558 PM CDT Sun Mar 24 2019
Convection was located southeast of SGF/JLN, but will still be
possible at BBG for the first couple/few hours of the 00z TAFS.
Clearing should take place behind the convection, but will see
stratus deck move in after midnight with MVFR and IFR ceilings
possible through much of the remainder of the period.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Lindenberg
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Lindenberg
Area Forecast Discussion
National Weather Service Shreveport LA
1025 PM CDT Sun Mar 24 2019
.SHORT TERM.../Tonight/
The sct convection that did affect portions of McCurtain County OK
earlier this evening have diminished/remained just N of this area
and the adjacent counties in SW AR, as the convection has outran
the greater axis of instability along the cold front, which
extends from near FSM, to just S of MLC, AQR, SW to the Nrn and
Wrn sections of the DFW Metroplex, to near SEP. However,
additional sct convection has recently redeveloped near and just
ahead of the front over portions of N TX, in the area of better
instability where MLCapes near or slightly better than 1000 J/kg
exist ahead of a shortwave trough noted over Srn OK and N TX. The
short term progs have done a poor job with the handling of the
ongoing convection, with the latest 00Z NAM much drier/less
bullish with convection development through the remainder of the
evening (especially near and N of DFW), but does suggest
convection building ESE into more of E TX/extreme Nrn LA after
06Z. The latest run of the HRRR has initialized too far E with the
ongoing convection and also does not take into account the
convection N of DFW, but does suggest clusters of convection which
should track SE across E TX into N LA overnight. Although some
instability will persist overnight with additional low level
moistening, the short term progs suggest that overall CAPE will
continue to slowly diminish overnight, but with 500-800+ J/kg
remaining over portions of E TX before the shortwave shifts E into
slightly more stable air farther E into Scntrl AR/Ncntrl LA.
Although an isolated severe threat may persist beyond the 05Z SVR
Watch #33 expiration, did remove SVR mention after midnight, and
did lower pops to likely across much of E TX/SW AR/N LA. But in
the meantime, did add Smith and Gregg Counties in E TX to the
existing SVR Watch #33 to account for extrapolation of the
isolated severe warned supercell now entering Western Wood County.
Also made very minor adjustments to the min temp forecast, with
this convection diminishing from NW to SE late as H850-700 winds
veer more WNW late.
Zone update already out...grids will be available shortly.
15
&&
.PREV DISCUSSION... /issued 750 PM CDT Sun Mar 24 2019/
AVIATION...
For the ArkLaTex terminals. No major changes to going TAFs with as
KTXK only tempo group this cycle. All other sites will see this
line of TS move from N to S from 06-12Z. Large hail and some wind
will be wide spread until dawn. Fropa 12-18Z with SKC looming
terminals becoming NW 10-20KT all day Monday./24/
PREV DISCUSSION... /issued 536 PM CDT Sun Mar 24 2019/
UPDATE...
Zone update just sent for the issuance of SVR Watch #33 until 05Z
for much of NE TX/SW AR/SE OK. Already seeing isolated supercell
storms developing attm across portions of N TX/Ern OK, along a
cold front that continues to slowly progress SE across these
areas. SBCapes have risen to 1500-2000 J/KG along a narrow
instability axis along/ahead of the front, with MLCapes expected
to gradually increase this evening across the expanding warm
sector over E TX/N LA/SW AR as a shortwave trough, analyzed over
the Lower TX Panhandle and Wrn OK, continues to progress along and
N of the Red River Valley through the evening and into Cntrl/Srn
AR/N LA overnight. While isolated supercells with large hail are
expected initially given the bulk shear of 50kts, some clustering
of the convection is expected later this evening which will lead
to more of a svr wind/hail threat, as they eventually shift SE
into NE TX/SW AR late this evening, to near the I-20 corridor of E
TX/N LA between 07-10Z.
Did not make any additional adjustments attm to the going forecast.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 61 77 49 67 / 60 60 0 0
MLU 61 77 49 66 / 60 60 0 0
DEQ 52 68 44 67 / 70 10 0 0
TXK 57 71 46 65 / 60 10 0 0
ELD 58 74 46 66 / 60 30 0 0
TYR 60 74 47 69 / 60 60 0 0
GGG 60 75 48 68 / 60 60 0 0
LFK 64 80 49 71 / 30 40 10 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
15
Area Forecast Discussion
National Weather Service Tulsa OK
735 PM CDT Sun Mar 24 2019
.DISCUSSION...
Severe event is ongoing, and has played out much like the HRRR has
been suggesting. A pair of supercells developed to the southwest
of FSM and are moving east southeast with the Bunkers right
moving supercell vector. Have had baseball size hail reported with
one of the supercells. With the straight line hodograph wind
profile, there have been several left movers, some of which could
also extend the severe threat some over far SE OK longer into the
evening. Portions of the watch have been cleared behind the
convection, and more of it will be cleared in the next hour or so.
Current PoPs trends are in great shape, and no changes are planned
attm.
Lacy
&&
.PREV DISCUSSION... /Issued 410 PM CDT Sun Mar 24 2019/
DISCUSSION...
At mid afternoon...the upper low was positioned across Northern
Missouri/Southern Iowa with the cold front extending southwestward
through Southwest Missouri into Northeast Oklahoma along a line
from near Grove to Okemah and finally into South Central Oklahoma
and Western Texas. Latest meso analysis indicated the cap
continuing to weaken with a surface instability axis centered
along and just east of the cold front. In response...radar echoes
have begun to develop along the front across East Central
Oklahoma...moving eastward toward Northwest Arkansas.
Into the evening hours...the cold front is expected to continue to
slide east southeast through Southeast Oklahoma and Western
Arkansas as the upper low begins to trek more southeast toward the
Ohio River Valley. The surface instability axis is forecast to be
maximized across Southeast Oklahoma...where surface dewpoints in
the low 60s currently resided. Thus...as the cap continues to
erode into the early evening hours...thunderstorms are forecast to
continue to develop along the frontal boundary mainly across
Southeast Oklahoma into Northwest Arkansas with the potential to
become strong to severe. 40-50KT of deep layer shear combined
with steep mid level lapse rates will allow for the potential for
large hail and also damaging winds to be the main threats with
this activity. 0-1km shear values continue to look fairly weak
which should limit over all tornado potentials...though the threat
is not zero. The greater severe potential looks to be generally
along and east of a line from near Antlers to near Fort Smith
where the surface instability max was located.
Current indications are that by mid evening...03z...the cap
should begin strengthening over the region as the cold front is
forecast to be nearly exiting the CWA to the south and east. The
result is the greater thunderstorm potential should shift south
and east of the CWA with any remaining thunderstorms exiting the
CWA by 06z. Between the 03-06z range...a decreasing strong/severe
potential will remain possible though much more limited than
earlier in the evening.
Behind the cold front...drier air and northerly winds will spread
southward over the region tonight as well as cloud cover
associated with the backside of the upper low. These conditions
will help to keep temperatures from bottoming out with lows in the
40s forecast for most locations over the CWA. During the day
Monday...this cloud cover looks to remain over mainly Northeast
Oklahoma and Northwest Arkansas until another quick moving
shortwave within upper level northwesterly flow pushes through the
region Monday night/Tuesday. Behind this shortwave...a ridge of
high pressure is progged to push through the Plains with a return
of southerly winds and a warming trend Wednesday and Thursday.
Southerly winds increase Wednesday and become gusty Thursday
ahead of the next forecast low pressure looking to move into the
region. Gusts 25-35 mph and temps back in the upper 60s/lower 70s
will help to increase fire weather dangers for the CWA before
moisture returns with the approaching low pressure system Friday.
Latest extended model solutions differ on the timing of this next
system and its associated cold front. Thus...for this
forecast...have continued with a blended approach with shower and
thunderstorm chances becoming possible Thursday and increasing
Friday into Saturday as the system moves through.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 45 60 40 65 / 0 10 0 0
FSM 48 64 42 65 / 50 10 0 0
MLC 47 65 39 66 / 20 10 0 0
BVO 44 59 36 63 / 0 10 0 0
FYV 44 56 36 59 / 20 10 0 0
BYV 46 55 37 57 / 20 10 0 0
MKO 46 61 40 64 / 10 10 0 0
MIO 45 56 37 60 / 0 10 0 0
F10 46 61 40 65 / 0 10 0 0
HHW 50 68 44 67 / 80 0 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
LONG TERM....30