Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/17/19

Area Forecast Discussion

National Weather Service Bismarck ND

 935 PM CDT Tue Apr 16 2019

.UPDATE...

Issued at 931 PM CDT Tue Apr 16 2019

No big changes with this update. Forcing will increase across
central North Dakota late this evening into early Wed morning as a
mid level wave moves towards the ND/MT border, and as a sfc
trough now over eastern Montana pushes east. Forcing will also be
enhanced farther east as upper level jet dynamics (right entrance
region) moves east from my southwest into the central.


UPDATE
Issued at 631 PM CDT Tue Apr 16 2019

Area of light to moderate rain showers continues over the
southwest and far south central, slowly developing to the east and
slightly north. Rain encountering a dry low level atmosphere
across portions of the south central so there is a delay in the
rainfall some locations, including here at Bismarck. T/Td spread
decreasing the past couple of hours so should see rain picking up
for these locations over the next few hours as we saturate
better.

Overall the forecast for this evening/overnight remains in good
shape, with the only edits delaying the onset of showers a tad.
Thunderstorms over far northeast Wyoming/far southeast Montana
transitioning to showers as they move north and encounter more
stable air so will keep thunder out of the forecast.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 355 PM CDT Tue Apr 16 2019

Through the rest of today and into tonight, we will transition
from near zonal to southwest flow aloft as a low amplitude
shortwave trough approaches from the west. Ahead of this wave,
temperatures have warmed quickly through the early part of the day
as some sites in the southwest and south central observed 3-hour
surface temperature changes of 15 to 25 degrees late this morning.
At the surface, an inverted surface trough is extending north
into eastern Montana from a developing low over eastern Wyoming.
This trough will be the focus of showers and a few isolated
thunderstorms through Wednesday.

20 UTC RAP mesoanalysis shows that very steep low-level lapse
rates have developed along and north of the precipitation/cloud
shield currently spreading across the southwest. In these areas
mid-level lapse rates are fairly meager but will steepen at least
modestly as the wave continues to approach, bringing with it
colder temperatures aloft. The latest HRRR and RAP iterations show
these favorable lapse rate areas may begin to slightly overlap
late this afternoon and through the overnight, suggesting an arc
of potential MUCAPE in the range of 100 to 200 J/kg along the
leading edge of the precipitation. While rain showers appear to be
the primary convective activity as precip chances spread north
and east, a few rumbles of thunder can`t be ruled out with some
elevated instability floating around, but confidence is not high
enough to include mention in the forecast yet.

The leading wave passes quickly to our east by early Wednesday
afternoon and another wave rides down an amplifying ridge to our
west, providing the focus for widely scattered showers and
isolated thunderstorms during the afternoon and evening.
Instability will once again be meager (~250 to 500 J/kg MUCAPE)
but appears to be a bit more favorable for thunder. With the
setting sun and loss of daytime heating, showers and thunderstorms
will likely diminish rather quickly Wednesday night.

.LONG TERM...(Thursday through Tuesday)
Issued at 355 PM CDT Tue Apr 16 2019

As the upper-level ridge continues to move into the state behind
the departing trough, there is a chance for showers and
thunderstorms Thursday during the day associated with a low-level
convergence zone. 300-400 J/kg of CAPE is possible, and combined
with daytime heating could be enough for some brief thunderstorms
in central ND. As this clears out, an upper-level ridge will
develop and bring a surge of warm temperatures. Current highs on
Friday are in the low 70s, but these are on the low end of the ECM
MOS guidance. Left them where they are for now, but we`ve been
chasing high temperatures the past few days so these could be
bumped up a few degrees if the multi-model blends do not raise
them in the next few runs.

A cold front is forecast to move through on Saturday, with the
main forecast struggle being timing. The 12Z GFS has it moving
through central ND around 15Z, while 12Z Euro is closer to 18z. As
these details are ironed out, a better picture of the sensible
weather fields should come into focus. Behind the front, cooler
and drier conditions are expected for the remainder of the
forecast period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)

Issued at 631 PM CDT Tue Apr 16 2019

Rain will continue for KDIK and develop into KBIS this evening,
then eventually other terminals tonight. Decreasing ceilings as
well, to MVFR/IFR and MVFR visibility tonight. Improving
conditions after 18Z Wednesday for all but KJMS. Isolated
thunderstorms will then be possible late Wed aft/Wed evening over
western North Dakota (KISN-KDIK).


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...NH
SHORT TERM...ZH
LONG TERM...MJ
AVIATION...NH



Area Forecast Discussion

National Weather Service Cheyenne WY

 526 PM MDT Tue Apr 16 2019

.SHORT TERM...(This evening through Thursday)
Issued at 330 PM MDT Tue Apr 16 2019

Scattered thunderstorms are beginning to develop across southeast
Wyoming and will continue to do so this afternoon. These storms
will move into the Nebraska Panhandle early this evening and will
last until about 06Z Wednesday. High resolution guidance shows
thunderstorms initiating east of the Laramie Range where RAP
analysis CAPE of around 500 J/kg exists near a weak frontal
boundary and 0-6 km bulk shear around 40 kts. These storms will
bring slightly heavier rainfall amounts than the storms the past
few days, however they should still remain sub-severe. Isolated
showers have developed west of the Laramie Range and will continue
through Wednesday morning while light snow showers are possible
above 8000 feet in the Snowy and Sierra Madres.

Strong winds are in-store Wednesday behind the cold front as
Tuesday`s disturbance pushes east. Sustained winds out of the
northwest will reach 25 MPH, especially in the Nebraska Panhandle.
Besides light snow showers in the mountains, most of the area
should see sky`s clearing Wednesday as an upper level ridge builds
in bringing drier and warmer conditions through week`s end.

.LONG TERM...(Friday through Tuesday) Issued at 258 PM MDT Tue
Apr 16 2019

Friday...Rather impressive ridging aloft moves over Wyoming,
producing a dry and quite mild end to the workweek with 700 mb
temperatures near 6 Celsius yielding maximum temperatures from the
60s to middle 70s.

Saturday...Another mild day expected as the flow aloft turns west
southwest with the ridge flattening. With adequate low and mid level
moisture, we may see some showers over and near the Snowy, Sierra
Madre and Northern Laramie Ranges in the afternoon.

Sunday...The next potent shortwave trough aloft approaches from Utah
and with a cold frontal passage and adequate moisture, we expect
cooler and cloudy conditions with scattered showers.

Monday...The cooler and unsettled weather pattern continues with a
trough aloft over our counties and adequate low and mid level
moisture along with low level upslope east and southeast winds
producing a chance of showers.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 524 PM MDT Tue Apr 16 2019

VFR to MVFR conditions are expected at all terminals this period.
A cold front sliding down from the Northwest will trigger
scattered showers and storms this afternoon and evening. SCT to
BKN mid decks will develop overnight and this morning with MVFR
CIGS. Visibility should remain high but patchy fog cannot be ruled
out. MVFR to VFR conditions are expected for more terminals
tomorrow.

&&

.FIRE WEATHER...
Issued at 330 AM MDT Tue Apr 16 2019

Unsettled weather to continue through the early part of this week
as low pressure remains over the area. Will see chances for
wetting rains and mountain snow tonight into Wednesday morning as
low pressure tracks across the area. Drier weather for Thursday
through Saturday with afternoon humidity falling to the low 20
percent range. Another cold front Saturday afternoon/evening will
bring increasing chances for wetting rains and mountain snow.
Overall...fire weather issues are minimal.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&

$$

SHORT TERM...MB
LONG TERM...RUBIN
AVIATION...AL
FIRE WEATHER...GCC



AREA FORECAST DISCUSSION

National Weather Service Sioux Falls SD

 655 PM CDT Tue Apr 16 2019

.SHORT TERM...(This Evening through Wednesday)
Issued at 410 PM CDT Tue Apr 16 2019

Primary concern the next 24 h is the thunderstorm chances.

All models agree on the overall set up later tonight. Strong warm
air and moisture advection around 1 km AGL will result in an
increasingly unstable atmosphere - especially along and east of
I-29. An weak upper wave will move north later tonight in an area
where 1 km moisture convergence will be greatest. HRRR, RAP, NAM
and GFS model soundings all show that initially there is a fairly
strong cap around 700 mb but this cap is gradually eroded after
06Z as the unstable layer and area of convergence move northward.
The model differences and largest uncertainty is where and when
convection will develop later tonight as well as how widespread
convection will be. One consistent message is that around 06Z
near KSUX there is ~1000 J/kg MUCAPE but CIN of 50-100. At KFSD
around 11Z there is similar MUCAPE but < 10 J/kg CIN. While we
cannot rule out convection at KSUX the most likely area for
development is in the vicinity of I-90 from far eastern SD into
southern Minnesota. Bulk shear is only 20-25 kts so expect
elevated multicellular convection. However, the initial updrafts
may be strong enough to support up to dime size hail late
tonight. As more updrafts develop north of I-90, the instability
will decrease and storms should produce primarily rain Wednesday
morning as they move north toward Highway 14.

Expect additional development of showers on the southern side of
the precipitation shield. This will keep rain over much of
southwestern Minnesota and portions of east central South Dakota
much of the morning and this is where we have categorical PoPs.
The region from Sioux Falls to Spencer Iowa seems to be where new
showers will be developing at least through midmorning before
shifting north. Farther south toward YKN and SUX, while showers
cannot be ruled out with continued instability, a capping
inversion is likely to result in little precipitation in the
morning.

On Wednesday afternoon, the surface low will move eastward from
the Missouri River into north central Iowa. It will remain
unstable ahead of the cold front. The southern jet streak will
move northward in the afternoon with enhanced divergence aloft in
the exit region. This is expected to result in convection
developing by early afternoon along the boundary. The GFS, ECMWF,
RAP and HRRR have pushed this front east more rapidly with the
initial cells developing near Highway 71 or even farther east. Did
extend likely PoPs along Hwy 71 during the early afternoon for
this convection with only chance PoPs around KSUX and KFSD.
Convection will be east of the area by late afternoon and the
persistent rain is expected to be north and east of the area by
evening.

West of I-29, the chances of precipitation are less. There is
less instability and weaker advection. The northern stream jet
streak is expected to move northeast into North Dakota. This
leaves little forcing for ascent in south central South Dakota and
there is likely to be little or no rain. North of I-90, around
KHON and KMDS, there will be better forcing for ascent but
instability is still very limited. So while rain is more likely -
especially in the morning - it will be fairly light.

The highest QPF, up to 0.75", is expected in southwestern
Minnesota where there is expected to be a few thunderstorms and
more persistent rainfall. Rainfall decreases going going farther
west and south into South Dakota and Iowa.

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 410 PM CDT Tue Apr 16 2019

The primary concern in the long term is the low chance for rain
Thursday and then warm up for Saturday.

Any precipitation is expected to end by late evening on Wednesday.
Another jet streak and associated wave will move south out of
Canada Thursday. With cool air aloft, a few afternoon and evening
showers are possible west of I-29. These showers should quickly
dissipate after sunset.

Then a ridge will build across the area for Thursday and Friday.
Friday looks to be a near or just above normal - in the 60s to
around 70. Saturday looks to be the warmest day of the year so
far. A thermal ridge will develop just ahead of a cold front
which will move through during the afternoon and evening. With 925
mb temperature around +20C, this would mix well into the 70s. In
fact with brown vegetation and enhanced mixing near the front,
fairly deep mixing is possible with a few places approaching or
even exceeding 80 degrees.

After the cold front goes through normal April weather will
return with highs in the 50s and 60s. There will also be a small
chance for rain on Sunday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 643 PM CDT Tue Apr 16 2019

Difficult aviation forecast warm air advection and weak wave later
tonight leading to scattered convection. Best chances for
thunderstorms mainly looks to be between 06-18Z Wednesday. Could
see some lower ceilings develop as convection/boundary move
through the area. MVFR to IFR ceilings will linger through the
daylight hours on Wednesday, with gusty winds possible.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...Schumacher
LONG TERM...Schumacher
AVIATION...BT



Area Forecast Discussion

National Weather Service Goodland KS

 606 PM MDT Tue Apr 16 2019

.UPDATE...
Issued at 530 PM MDT Tue Apr 16 2019

Increased rainfall chances for the northwest and northern part of
the forecast area for tonight as an upper level short wave trough
moves through. All near term models are showing a group or two of
thunderstorms initiating over East Central Colorado and moving
northeast this evening. RAP has been trending the area of elevated
CAPE/lift to the southern group of storms.  Current radar is
beginning to show storms already.

As these thunderstorms move northeast into the forecast area ahead
of the upper level short wave trough, the low level jet also
moves up from the south bringing moisture advection with it and
higher shear/helicity. DCAPE is quite low north of the stalled
weak frontal boundary along the southeast border of the forecast
area, so severe wind gusts are not much of a concern. However, the
enhanced helicity/low level shear, presence of a weak boundary
near the western border of Kit Carson/Yuma counties, and potential
absence of an inversion raise the concern for tornadic potential.

Model soundings show the inversion being erased by mid evening.
This could be in response to the storm activity moving through.
A tornado has occurred due to the wet-bulb effect removing the
inversion after midnight, but this was behind a line of training
thunderstorms. Not sure if this will be one of those events since
the storm activity will not be as long lasting as the event
referenced, and this evening will likely be a cluster of storms,
not distinct supercells following each other.

Main threats will be large hail up to ping pong balls. Confidence
of this occurring is on the low side, however the environmental
support of this is not out of the question given the large hail
parameter values and the amount of effective shear to work with.



&&

.SHORT TERM...(This evening through Wednesday)
Issued at 217 PM MDT Tue Apr 16 2019

As of 300 PM CDT, 2 PM MDT, skies across the Tri-State Region are
partly cloudy to mostly clear, depending on your location and the
position of the cirrus. Temperatures have climbed into the upper 60s
to low 70s for many locations where clouds have cleared. Winds are
southeast at 5 to 15 mph with some gusts up to 20 mph observed
earlier. At the surface, a low pressure continues to deepen in far
southeast Colorado. Aloft, a short wave trough is moving across
northern New Mexico into southern Colorado.

For the rest of today into this evening, am anticipating some
thunderstorms to develop over Colorado, spreading into the forecast
area. Overall, the environment isn`t terribly favorable for storms.
For example, there is a decent cap over portions of the area, mainly
south of the interstate.  However, there is also a stalled frontal
boundary in the same area which provides a localized boost in
moisture and therefore instability. Further north, the forcing is
stronger but the atmosphere isn`t as moist, thus limiting
instability. Based on the latest forecast guidance, there should be
a couple areas of thunderstorms. The first area will form on the
Palmer divide, spreading northeast across NE Colorado and extreme
southwest Nebraska. The second area looks to form in east central
Colorado. This area will struggle with initial development due to a
poor environment. However, as these storms approach the stalled
front and better instability, we should see an uptick in coverage
and intensity, most likely around Logan and Gove Counties in NW
Kansas. As the storms spread northeast, they may be come strong with
gusty winds and small hail as the primary threats. This is not an
event that is one to worry about too much but it does pose the risk
of a strong storm or two.

For tonight, the low pressure moves northeast, exiting the region
after midnight. North winds return behind the low and precipitation
will diminish. Depending on where the stalled is, there may be some
low stratus.

During the early morning hours Wednesday, a cold front will move
through. Behind the front, expect cooler weather and gusty northwest
winds. Winds should gradually climb through the day with peak winds
observed by mid-afternoon. No precipitation should be expected as all
the instability will be south of the area. In addition, subsidence
will spread in behind the departing low pressure. Am unsure on dust
potential as wind speeds aren`t terribly high but it is always
something to keep in mind, especially with it being somewhat drier
lately.

.LONG TERM...(Thursday through Tuesday)
Issued at 151 PM MDT Tue Apr 16 2019

An upper trough pushes east of the region on Thursday, placing the
region under northwest flow aloft as a ridge builds across the
western half of the country. Dry conditions are anticipated along
with gusty north to northwest winds on the backside of the low
associated with this passing system. Gusts of 40 to 50 mph will be
possible in the afternoon before declining in the evening.

Following this disturbance, ridging progresses east, leading to
warm and dry weather Friday and Saturday. A trough and cold front
move into the High Plains Saturday night, breaking down the ridge
and generating chances for light rain showers Saturday night
through Sunday. Some spotty chances linger into Monday and Tuesday
as a series of shortwaves pass through the westerly flow.

Temperatures fluctuate throughout the long term period, starting
with a warming trend Thursday (low 60s), Friday (70s), and Saturday
(near 80 degrees). A cold front drops highs into the upper 50s/low
60s on Sunday, followed by another warming trend with highs back
near 70 degrees on Tuesday. Low temperatures range mainly in the 30s
and 40s.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 530 PM MDT Tue Apr 16 2019

VFR conditions forecast for the TAFs. Main issue with these TAFs
will be when/if the thunderstorms move near the sites.  Am
expecting thunderstorms to develop in the next hour or so over
Eastern Colorado and move northeast. Two groups of storms may end
up forming, one moving over Yuma County and nearby counties, the
other southern group moving through KOEL and KHLC.

At this time KGLD should be between these two groups, so
confidence of thunderstorms moving in the vicinity of KGLD is not
quite to moderate yet, so have left a mention out of the TAF.
Timeframe for thunderstorms would be 3-5z for KGLD.

As the two groups of thunderstorms move northeast, they may merge
together or the northern group may expand east. Either way,
confidence of thunderstorms in the vicinity of KMCK is moderate so
added a mention to the TAF. In addition, there may be MVFR
ceilings for the site behind the storms before the cold front move
through (cold front passage around 12z).

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...JTL
SHORT TERM...RRH
LONG TERM...JBH
AVIATION...JTL



Area Forecast Discussion

National Weather Service Northern Indiana

 639 PM EDT Tue Apr 16 2019

.SYNOPSIS...
Issued at 632 PM EDT Tue Apr 16 2019

A warm front will provide a focus for shower chances overnight
into Wednesday morning along and north of Route 30. Dry and mild
otherwise with lows tonight ranging between the upper 40s and mid
50s. Highs on Wednesday will range between the mid 60s and mid
70s. Better chances for showers and thunderstorms arrives late
Wednesday night into Thursday evening. Heavy rain and strong
thunderstorms will be possible on Thursday. Chances for showers
will linger into Saturday before drier air moves in and sunshine
returns for Easter Sunday with mild temperatures.

&&

.SHORT TERM...(This Evening through Wednesday)
Issued at 351 PM EDT Tue Apr 16 2019

Warm front has pushed well north into MI allowing for mostly
sunny skies and temps well into the 60s and eventually even 70 in
a few spots. Challenges in the short term remains how far south
this boundary will return tonight and shower/thunderstorms chances
that may accompany it. NAM and to lesser extent HRRR both show a
weak sfc reflection across central Lake Michigan, which is
confirmed on surface observations, leading to some model
preference shift to these 2. That being said all models force the
front back south to at least the I 80/90 corridor with HRRR and
NAM to between the US 30 and 24 corridors. Isentropic lift does
increase tonight along the boundary with 30 kt or so low level jet
settling in. Plenty of elevated instability takes shape along the
front with Showalters 0 to -3 C. Low levels will still be quite
dry which will likely limit coverage as well. Pulling it all
together, looks like slight chance to chance pops still warranted
with a rumble of thunder possible with anything that can manage to
develop. Previous grids had the general idea already but did
confine any pops till after 3Z and possibly well after 6Z.

Warm front will attempt to work back north again on Wednesday but
how far NE it makes it will be a challenge again with large
difference in temps possible SW to NE with highs well into the 70s
SW and maybe struggling to reach 60 far NE. Rain chances will end
during the morning.

&&

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 351 PM EDT Tue Apr 16 2019

No significant changes to long term as copious amounts of moisture
(by mid April) standards will advect in on Thursday in advance of
deep upper level trough now onshore in the western US. As noted in
previous discussion not only will moisture from the Gulf of
Mexico arrive but also Pacific moisture that has been caught up in
the trough. PWATs will increase towards 1.5 inches to bring
pockets of moderate to heavy rain mainly Thursday. QPF amounts are
still on the lower side but think models will catch up with most
locations seeing 1 to maybe 2 inches of rain. ESF already in
place to handle these concerns. As for severe threat, something
still to be monitored depending on amount of clearing and
instability as well as timing/location of low and upper level jet
maxes.

With trough likely to slow down, precip will linger into Friday
although thunder chances will end by overnight Thursday. Friday
will be a raw day with highs only in the 40s to maybe lower 50s.
Quick rebound though with highs back into the 50s and 60s into the
weekend and next week as the next system takes aim for the start
of the work week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 632 PM EDT Tue Apr 16 2019

VFR/dry conditions through this evening. A frontal boundary will
dip south through KSBN at or shortly after issuance, and stall
near KFWA later tonight into tomorrow morning. A few showers may
develop near this feature later tonight into Wednesday morning,
though chances/coverage remain too low for a shower mention at
this time. Post-frontal saturation/cooling may support a trend
toward high MVFR cigs at KSBN by later tonight and Wednesday
morning.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...Steinwedel
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Steinwedel


Visit us at www.weather.gov/iwx

Follow us on Facebook...Twitter...and YouTube at:
www.facebook.com/NWSNorthernIndiana
www.twitter.com/nwsiwx
www.youtube.com/NWSNorthernIndiana



Area Forecast Discussion

National Weather Service North Platte NE

 626 PM CDT Tue Apr 16 2019

.SHORT TERM...(This evening through Wednesday night)
Issued at 328 PM CDT Tue Apr 16 2019

Two discrete areas of rainfall are in place tonight and Wednesday.
The models are showing a disturbance moving off the cntl Rockies
late this afternoon which should lift through swrn and ncntl
Nebraska tonight and Wednesday. A second candidate area of rain
forms off the low level jet tonight and lifts northeast through
scntl Nebraska tonight and Wednesday morning. The two areas of rain
will compete for moisture and it is possible the srn rain area will
dominate. The rain forecast uses a model blend of the RAP, HRRR,
GFS, NAM and HRRR plus the model blend and the previous forecast.

Thunderstorm chances appear speculative as the SREF maintains less
than a 15 percent chance and the RAP and NAM models show very little
elevated instability. The low level jet is aimed at southeast
Nebraska and this shunts the significant instability mostly south
and east of swrn Nebraska.

The temperature forecast uses a model blend tonight and Wednesday.
The guidance blend is in place for Wednesday night. Bias correction
was added to all temperature forecasts. The guidance blend is in
place for winds. H850mb winds of 30 to 40 kts should support winds
of 20 to 25 mph Wednesday with gusts to around 35 mph.

.LONG TERM...(Thursday through Tuesday)
Issued at 328 PM CDT Tue Apr 16 2019

A high amplitude ridge will build across the western US on Thursday
as a upper level trough moves through the central US. This trough
will enhance the chance for some light rain across the central
Nebraska region on Thursday evening. For now, not anticipating any
severe weather, but that can certainly change over the next day or
two. Stay tuned to later forecasts for more detailed information.

Beyond Thursday night, surface high pressure will build into the
area with dry conditions returning. Temperatures will also continue
to slowly climb through Saturday as warm air advection surges into
the high plains. Highs on Saturday will be in the 70s across the
entire forecast area with locations south of I-80 possibly rising
into the low 80s.

Rain returns on Sunday as a stronger mid-level wave develops off the
Rockies and pushes eastward. Rain only lasts into Sunday night as
high pressure quickly builds back by Monday morning. Temperatures
return to near normal (low 60s) for the beginning of next week as
colder air rushes in behind the departing disturbance.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 625 PM CDT Tue Apr 16 2019

VFR is generally expected throughout wrn and ncntl Nebraska
tonight. Scattered showers and isolated thunderstorms across
northeast Colorado will move northeast and mainly affect southwest
into eastern portions of north central Nebraska from 02z-12z
tonight. By morning, easterly winds across ncntl Nebraska are
expected to produce widespread MVFR cigs as low as 1000 ft agl near
and east of Valentine through Broken Bow which will hang around
during the morning. There is still a chance of showers Wednesday
morning across eastern portions of north central Nebraska.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...CDC
LONG TERM...Kulik
AVIATION...Roberg



Area Forecast Discussion

National Weather Service Marquette MI

 758 PM EDT Tue Apr 16 2019

.SHORT TERM...(This evening through Wednesday)
Issued at 412 PM EDT TUE APR 16 2019

WV imagery and RAP analysis indicated a mid/upper level trough over
the western CONUS with ridging from the southeast into the Northern
Plains resulting in wnw flow through the Great Lakes. At the
surface, weak ridging extended through the northern Great Lakes into
MN bringing light winds and mostly sunny conditions.

Tonight, favorable radational cooling conditions under mostly clear
skies will allow teps to drop into the lower 40s inland. However, an
increase in southerly downslope flow over the west near Lake
Superior should keep temps into the upper 30s.

Wednesday, a shortwave trough lifting from the Central Plains to nw
WI and a deepening sfc low to se MN will bring increased WAA and
moisture advection toward Upper Michigan. 293k-305 isentrpoic ascent
from the mid afternoon into the evening should be strong enough
overcome dry se flow at the lower levels. However, model trends have
been toward a later arrival of the pcpn.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 425 PM EDT TUE APR 16 2019

Active storm track, featuring significant pcpn producing systems,
that developed across the CONUS last week under a progression of
shortwaves dropping se off the ne Pacific will continue this week.
The third shortwave trof in the series is currently over the far
western CONUS. It will reach the Mississippi Valley Thu/Fri and then
slowly shift across the eastern CONUS thru the weekend. While
widespread rainfall will occur across the fcst area with this
system, the last 24hrs of model runs have fortunately trended
downward with pcpn amounts. This downward trend is due to the trof
closing off a mid-level low well se of here over the southern
Appalachians early this weekend as opposed to farther n over the
Ohio Valley over even southern Great Lakes as suggested by previous
days model runs. Result is a shorter duration rainfall for Upper MI.
Still, with widespread rainfall falling somewhere in the range of
0.5 to 1.25 inches Wed-Thu along with plenty of snow on the ground
yet to melt, there will be increased concerns for minor river and
stream flooding, beginning Thu and continuing thru next week under
continued snow melt. See the lastest Hydrologic Outlook issued this
aftn for more info on the potential of flooding. The next trof will
reach the western CONUS late this week. It now appears that the flow
across the CONUS next week will be more progressive and more split
than it appeared yesterday. With the Upper Lakes falling under a
more progressive/lower amplitude northern stream, the potential of
any additional widespread significant pcpn next week has diminished
significantly. The trof arriving over the western CONUS late week
will shift across the area early next week, providing a chc of some
light pcpn. Drier weather should following into the midweek period.
As for temps, brisk northerly winds/diminishing rain on Thu will
lead to cool conditions/blo normal temps. Temps will rebound
Fri/Sat, rising above normal under dry weather. Many locations away
from lake moderation will see high temps on Sat into the 60s, maybe
well into the 60s. The more progressive regime next week may end up
bringing the next front across the area on Sun. Temps on Sun will
depend on the timing of this front. If slow, Sun will be another day
well into the 60s. If the front is faster which is the trend, Sun
will be cooler than Sat, especially so near Lake Superior. Temps
will be back close to normal early next week.

The main period of pcpn associated with the trof shifting e to the
Mississippi Valley Thu into Fri will occur Wed aftn into Wed
evening. This pcpn will be driven by fairly strong isentropic ascent
in advance of lead shortwave energy lifting up across the Upper
Lakes in the sw flow ahead of the trof as it moves out over the
western Plains. Bulk of the rainfall will occur Wed aftn through Wed
night, though pcpn will be diminishing sw to ne overnight Wed night.
With general rainfall amounts of 0.5 to 1.25 inches, expect rises on
streams and faster responding rivers Wed night/Thu. Some ponding of
water in low-lying areas and poor drainage areas may occur as as
well. With a little instability aloft, up to a couple hundred j/kg
spreading across the s central and eastern fcst area, not out of the
question that there could be a few rumbles of thunder s central/e.
There is still a small potential that the rain could switch over to
sloppy snow over the high terrain of the nw fcst area. NAM is most
supportive of cooling the column just enough for a switch over to
snow. Will be something to monitor. For now, will carry a rain fcst.

Most of the rainfall will be done by Thu morning with departure of
the isentropic ascent and arrival of some mid-level drying. However,
with the mid-level trof axis still to the w to provide some forcing,
expect some lingering -ra/-dz, especially where northerly wind
leads to upsloping across the w and n. With a brisk wind off Lake
Superior, it will be chilly across the w and n with temps only in
the 30s to around 40F.

Lingering -ra/-dz will gradually end from w to e Thu night, followed
by clearing skies into Fri. Deep, dry air mass on Fri will support
sunny skies or clearing to sunny skies where any clouds still linger
to start the day. Temps will respond by rebounding into the 50s,
except near Lake Superior. Stronger gradient flow across Lake
Superior into the eastern fcst area will keep temps no higher than
around 40F near the lake over the e.

Although there will be some increase in mid/high clouds w, abundant
sunshine will be the rule e on Sat. Warming will continue with highs
into the 60s w. Will be cooler e, especially near the Great
Lakes with a wind component off the water.

12z models have continued to trend faster with the flow progression
early next week. As a result, it appears the next shortwave will
push a cold front across the area on Sun. There won`t be much
moisture avbl, so pcpn chc will be limited as the front crosses the
area. As mentioned above, high temps on Sun will be highly dependent
on timing of the front.

Cooler (temps close to normal) and dry weather should follow Mon/Tue
as high pres builds se into the northern Great Lakes.
&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 754 PM EDT TUE APR 16 2019

With ridging and dry air persisting, expect VFR conditions through
this evening along with light winds. Overnight, radiational cooling
along with light southeast winds could bring some fog into KSAW with
MVFR and possibly IFR vsby. Confidence in the lower end of vsby is
lower. Expect thickening mid clouds on Wednesday with rain
developing by early evening at IWD and SAW as a low pressure system
moves to southeast Minnesota and an associated warm front lifts
across Wisconsin and lower Michigan. Plan on conditions
deteriorating to IFR or lower in periods of rain and fog at all
sites Wednesday evening into Wednesday night as the low pressure
system lifts tracks toward northern lower Michigan.
&&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 412 PM EDT TUE APR 16 2019

Light winds of less than 15 knots are expected through Wednesday
morning. As low pressure approaches the region, NE winds will
increase from 15 to 25 knots late Wednesday to 25 to 30 knots
Wednesday night then become N and subside to around 20 knots
Thursday morning. These winds persist through Friday morning then
calm back below 15 knots for the weekend.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&

$$

SHORT TERM...JLB
LONG TERM...Rolfson
AVIATION...JLA
MARINE...JLB




...Update to aviation forecast discussion...



 .SHORT TERM...(This evening through Wednesday)
Issued at 340 PM CDT Tue Apr 16 2019

A severe weather threat remains on the docket for Wednesday
afternoon, with large hail, damaging winds, and heavy rainfall the
main threats.

Several forecast challenges lead up to the severe weather event
for Wednesday afternoon. The first couple of hurdles that need to
be jumped are with respect to cloud cover, precipitation chances,
and temperatures. Lower-tropospheric moisture gradually streams
northward on a broad southerly fetch through Wednesday afternoon.
Increasing 300K isentropic lift and theta-e advection under a
strong EML may lead to the development of a thin
stratus/stratocumulus deck tonight. The early signs of this cloud
deck have been noted in satellite/surface observations in
Oklahoma and the GFS/RAP support these clouds advecting into the
forecast area overnight. There is some discrepancy in the
thickness of the cloud shield, with the RAP depicting a very thin
deck as opposed to the habitually over-saturated NAM solution. For
the going forecast, have trended closer to the RAP in the timing,
height, and behavior of the clouds.

The first hurdle overcome, we now turn to precipitation chances
for tonight. The aforementioned EML and shallow nature of the
stratus will substantially limit the threat for precipitation and
have trended drier in the going forecast. There are some signals
in the RAP bufr soundings of a weakening in the inhibition closer
to the lifting surface boundary/warm front along the Nebraska
border and have maintained the mention of a stray shower or
thunderstorm in this area. Earlier CAM runs were quite bullish in
the areal extend of their PoP and QPF fields, but a closer
inspection of these fields, in combination with forecast
soundings, points towards more convective feedback noise driving
these values than realistic meteorological solutions. The synoptic
models trended back on PoPs 12 hours ago and only now are the
HRRR/RAP likewise backing off on these chances. Did keep some
mention of sprinkles in the forecast along and north of I-70 to
account for any stray, shallow showers that manage to generate
along the best forcing axis attendant with a passing H500 wave,
but these should have minimal impacts on the sensible weather.

Highs for Wednesday will depend on how quickly the low clouds mix
out, but given the thin nature of the clouds, am expecting that
clearing should take place by mid to late morning with a rapid
warming trend into the afternoon. Increased highs into the low 80s
in agreement with the GFS/EC/CMC guidance given the strong warm
nose in place and ample mixing ahead of the approaching front.

We finally turn our attention to Wednesday afternoon`s severe
weather threat. The overall timing, coverage, and mode forecast
has varied little from previous updates. With the northern and
southern stream waves remaining slightly out of phase until
Wednesday night, the threat for the best severe weather appears
tied to the subtropical low over TX and OK. Across the forecast
area, southwesterly synoptic flow will feature a large line-
normal component relative to the orientation of the cold front and
rapid upscale growth into line segments and clusters is expected
shortly after convective initiation in the mid to late afternoon
hours along and east of a line from Abilene to Marysville.
Forecast hodographs also feature multiple inflection points and
loops that would not favor discrete cells. These storms will move
in a northeasterly fashion with the entire system shifting
eastward into the evening. MLCAPE values of 1500-2000 J/kg and
deep shear of 30 to 40 kts would support any robust updrafts that
manage to become sustained. Large hail--possibly up to 2 inches in
diameter--and strong winds would be the main threat. Any line
segments that roll up the surface boundary could become oriented
into a favorable QLCS tornado alignment, but with 0-3 km shear
values of only 15 kts, it will take a large mesoscale augmentation
of the pattern to realize this potential. The heavy rain threat
would likely manifest itself after 00Z and is covered in the long-
term discussion below.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 340 PM CDT Tue Apr 16 2019

Storms persist Wednesday night across east-central Kansas, with
temperatures briefly cooling down before rebounding by the
weekend.

Convective coverage along the surface to H850 boundary should be
widespread throughout Wednesday night owing to strong forcing for
ascent and unidirectional, boundary-parallel storm-relative flow.
The near-surface front advances slowly, but steadily,
southeastward during the night and should clear the forecast area
around sunrise Thursday. There is some concern that a flash flood
threat may develop, mainly along and southeast of the Kansas
Turnpike, during the overnight hours as multiple waves of
convection ride up and along the lower tropospheric baroclinic
zone. Model progs depict strong low-level moisture convergence and
H925-700 mixing ratios of nearly 10 g/kg. PWATS of 1.25"+ are
well above the 90th percentile of values observed on the TOP/SGF
RAOB for this time of year, possibly even approaching the daily
max value of around 1.4". Thankfully, the pattern has been dry
going into this event and flooding potential may hinge more on
rainfall rates than amounts (at least initially). Multiple
convective resolving and parameterizing solutions print 1 to 2+
inches of storm-total QPF over the southeastern forecast area and
given the meteorological setup, these solutions are within the
realm of possibilities.

Thursday looks to be blustery and cooler with highs topping out
in the low 60s and northwesterly winds of 10 to 15 kts--with steep
low-level lapse rates mixing down gusts of 25 to 30 kts. The
surface cyclone and attendant deformation zone should reach the
Great Lakes region Thursday afternoon, therefore the chance for
any showers Thursday afternoon will be dependent on the degree of
solar insolation and differential CAA during the peak heating
hours. With this latest update, have removed most of the
precipitation chances across all but the far northwestern forecast
area during the afternoon where deeper convective processes could
be realized.

Large scale subsidence should lead to quiet weather for Friday
and Saturday with the surface ridge axis passing through Friday
afternoon. As WAA ensues, highs rebound back into the upper 60s
on Friday and mid-70s for Saturday under mostly clear to clear
skies. The next chance for precipitation comes late in the weekend
as a series of subtle upper-tropospheric shortwaves propagate
around the periphery of a western North America longwave trough.
These waves will interact with a surface baroclinic zone
meandering southward through the region, but it is too soon to pin
down the exact timing of this precipitation. Early next week does
look to feature cooler temperatures behind this surface trough,
but given the subtleties in this pattern and inconsistent inter-
and intra-model continuity, confidence is low in this forecast.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 627 PM CDT Tue Apr 16 2019

VFR conditions continue until late overnight. Toward early
morning, MVFR CIGS should move into the area. Expect any overnight
showers to remain well north of the terminals. Winds should stay
brisk from the south with even a few gusts into the late night.
Therefore, have removed LLWS mention as the trend with model
guidance was also supportive of stronger surface flow and overall
winds aloft a little weaker than previous forecasts. Therefore,
currently thinking that LLWS would be see a very small window of
time and be marginal if it does pan out.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Skow
LONG TERM...Skow
AVIATION...Drake