Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/23/17

Area Forecast Discussion

National Weather Service La Crosse WI

 1029 PM CDT Wed Mar 22 2017

.SHORT TERM...(This evening through Thursday)
Issued at 345 PM CDT Wed Mar 22 2017

At 3 PM, a 1037 mb surface high was centered over central Lake
Michigan. East and southeast winds on the back side of this high
continues to bring very dry air into the Upper Mississippi River
Valley. Dew points ranged from 5 to 15F. Temperatures ranged from
30 to 35F north of Interstate 94 and 35 to 41F across the
remainder of the area. Meanwhile further west, weak to moderate
800 to 600 mb frontogenesis was producing some a light wintry mix
of precipitation from southwest Minnesota southeast into central
Iowa.

The 22.12z models continue to show that an elevated warm front
will move east across southeast Minnesota and northeast Iowa
late tonight and Thursday morning and across western Wisconsin on
Thursday afternoon. The HRRR continues to show that maybe some
elevated showers may develop across western Wisconsin overnight
ahead of this warm front. However with the low levels (sub-cloud
layer) remaining very dry, this precipitation may not make it to
the ground. As a result, kept the forecast dry for the overnight.

During the day Thursday, BUFKIT soundings show that the air mass
will gradually saturate as moisture surges ahead of an approaching
front from the northwest. This will result in the development of
rain across the region. The highest chances will be during the
afternoon. With very dry air still advecting into the area during
the morning, there may be the potential for a light wintry mix at
the onset. However this looks to be brief and should not cause any
impacts.

.LONG TERM...(Thursday night through Wednesday)
Issued at 345 PM CDT Wed Mar 22 2017

From Thursday night into Sunday, a slow moving upper level low
will move from the Southern Plains into the Ohio River Valley. A
deformation band of rain on the north side of this low will slowly
move south across the forecast area. This deformation band will be
mainly along and north of Interstate 90 from Thursday night into
Friday night, and along and south of Interstate 90 from Friday
night into Sunday. It continues to look like the much of the
instability will remain south of the forecast area. As a result,
kept the mention of thunder out of the forecasts. Rainfall amounts
from this system will likely range from 1 to 1.5 inches. With this
rain spread out of over a long-period of time, only anticipating
in bank rises on area rivers.

With the potential that the southern part of the forecast area
could enter the warm sector of this system on Friday, the
temperatures forecast is rather tricky. The ECMWF ensemble is
showing standard deviations of 4 to 6. For the time being, just
staying close to the ensemble mean. However with that said there
could be potential for a large bust in the temperature forecast
for areas along and south of Interstate 90.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 1029 PM CDT Wed Mar 22 2017

Mid clouds continue to thicken and gradually lower through
sunrise, with VFR conditions transitioning to MVFR through the
afternoon and early evening hours, north of a warm front lifting
into Iowa. Ahead of that front, a smattering of showers and
perhaps even a few thunderstorms is expected, though with plenty
of questions regarding coverage, a "vicinity" mention remains
warranted. Winds will remain from the southeast the next 24 hours,
becoming gusty at both LSE and RST with some gusts to around 25
knots at times from late morning onward. Even with those gusts,
low level wind shear is expected to develop at RST after 00Z.

&&

.HYDROLOGY...(Thursday night through Wednesday)
Issued at 345 PM CDT Wed Mar 22 2017

It continue to look like the area will be in a prolong wet period
from Thursday night into Sunday as a thin ribbon of Gulf of Mexico
moisture is brought northward into the region. Precipitable water
values continue to be 2 to 3 standard deviations above normal.
Rainfall totals will likely be in the 1 to 1.5 inch range. However
with this rain spread out of over a long-period of time, only
anticipating in bank rises on area rivers.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&

$$

SHORT TERM...Boyne
LONG TERM...Boyne
AVIATION...Lawrence
HYDROLOGY...Boyne




Area Forecast Discussion

National Weather Service Bismarck ND

 926 PM CDT Wed Mar 22 2017

.UPDATE...
Issued at 921 PM CDT Wed Mar 22 2017

As the warm front has moved east this evening the lower clouds
have pretty much cleared out of the James River Valley. Scattered
high thin clouds remain over the west and central. Warm advection
should limit temperatures from falling much tonight east. Current
forecast looks good with increasing clouds far west and a slight
chance of rain by morning southwest.

UPDATE Issued at 636 PM CDT Wed Mar 22 2017

This Wednesday evening a warm frontal boundary had progressed
through central North Dakota resulting in decreasing clouds
across the northwest. Temperatures had warmed into the middle 50s
late this afternoon over much of west central and southwest North
Dakota. Meanwhile stratus cloud cover and cool temperatures in
the lower 30s remained in place across the James River valley.
Mainly scattered to broken high clouds covered the central and
west. Gusty southerly winds should extend into the evening hours
across the James River valley otherwise the winds will diminish
west and central. Updated the sky cover to account for less cloud
cover northwest otherwise forecast trending ok.

&&

.SHORT TERM...(This evening through Thursday)
Issued at 309 PM CDT Wed Mar 22 2017

Precipitation chances late tonight through Thursday highlight the
short term forecast.

The 12 UTC global suites and the 19 UTC RAP are in agreement on a
shortwave ejecting out of the southwest CONUS deep trough to
propagate into the Northern Plains late tonight through Thursday.
Overall forcing is aided by jet coupling between a jet streak
across northeast Montana into southern Canada, and the jet across
Colorado and New Mexico in to the southern portions of the
Northern Plains. Did significantly reduce the mention of freezing
rain for Thursday morning from the previous forecast as the 12 UTC
NAM/GFS bufr soundings depict rather dry air in the 800-700mb
layer Thursday morning that will limit significantly how much
liquid precipitation may be able to reach the ground in a narrow
temporal window with favorable surface temperatures for freezing
rain.

.LONG TERM...(Thursday night through Wednesday)
Issued at 309 PM CDT Wed Mar 22 2017

Above normal temperatures highlight the extended forecast.

The 12 UTC global models are in agreement on split flow across the
Northern Plains Friday and Saturday transitioning to quasi-zonal
Sunday into Monday before an upper level ridge potentially builds
across the region by Tuesday. This overall favors above normal
temperatures with highs in the 40s and 50s and sporadic, weak
precipitation events.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 636 PM CDT Wed Mar 22 2017

At 6 PM CDT a warm front extended across central North Dakota.
Mainly scattered to broken high clouds were found from KISN-KDIK-
KBIS-KMOT with ceilings around 5 thousand agl at KJMS. For tonight
VFR is expected. On Thursday low pressure will spread increasing
rain chances across southern North Dakota. A brief period of
freezing rain is possible after sunrise along and north of KBIS-
KJMS route. At this time not enough confidence to add FZRA to the
KBIS-KJMS TAFS. MVFR possible at KJMS after 20z.


&&

.HYDROLOGY...
Issued at 309 PM CDT Wed Mar 22 2017

In response to increased releases from Alameda Reservoir, Lake
Darling will increase its releases to 1000 CFS by Thursday, with
the potential for further increases next week. This will cause the
Souris River downstream of Lake Darling near Foxholm to rise but
remain just below flood stage. As this pulse of water travels
further downstream where greater ice cover remains on the Souris
River, ice break up will have to be closely monitored.
Furthermore, snowmelt will be on the increase with a sustained
period of above normal temperatures late this week and through
next week. While soil moisture was high across the Souris Basin
going into the winter, early snow insulated the ground, preventing
much frost from forming. Thus, some uncertainty remains as to how
much melt from the snowpack will infiltrate into the ground
versus runoff and reach the river, streams and coulees.

&&

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

$$

UPDATE...WAA
AVIATION...WAA



Area Forecast Discussion

National Weather Service Las Vegas NV

 308 PM PDT Wed Mar 22 2017

.SYNOPSIS...A Pacific system will bring a chance of showers and
thunderstorms to portions of the area through this evening with
showers persisting overnight into Thursday morning over Lincoln,
Clark and Mohave counties. Otherwise, expect breezy winds and
seasonal temperatures through Thursday. A second system will move
into the area late Friday into Saturday bringing another round of
showers to portions of the area.
&&

.SHORT TERM...through Saturday night.

A low pressure system will move across the southern Great Basin and
Mojave Desert tonight and then into Utah and Arizona Thursday. This
will bring plenty of cloud cover and an increasing chance of showers
tonight which will linger across portions of the area on Thursday.
The latest HRRR has been nudging a line of showers it had forecast
earlier over the Spring Mountains further east and now has the line
mostly east of Las Vegas...focused primarily on the Lake Mead NRA,
southeastern Lincoln and northern Mohave counties. There is also a
second area of shower activity forecast along the front as it moves
south and east through the southern Great Basin tonight into early
Thursday. Counties potentially impacted include portions of Inyo,
Esmeralda, Nye, Lincoln, Clark and Mohave. The HRRR forecast lines
up fairly nicely with the 18z NAM12 in where showers are expected to
develop and move. Thunderstorms will be possible through this
evening but should tail off behind the front. Eastern Lincoln and
Mohave counties will be the focus areas for showers and
thunderstorms Thursday afternoon as moisture wraps around the back
side of the low. Gusty winds...southwest to west ahead of the front
and northwest behind...will affect the area through Thursday as
well.

Shortwave ridging and area wide dry conditions are expected Thursday
night and Friday as a ridge axis shifts across the region. A second
trough will bring another round of showers beginning in the Sierra
Friday evening and spreading south and east through Saturday. In
addition, local breezy conditions will be possible. Showers end
overnight Saturday as the system moves east of the area.

Expect seasonal temperatures through Saturday.

.LONG TERM...Sunday through Tuesday. Model agreement is pretty good
through Sunday, but quickly deteriorates thereafter, so confidence
beyond Sunday is low. Solid model to model and run to run
consistency on ridging for Friday points to a dry day with
temperatures rising back to a few degrees above normal. Next storm
passing through Saturday looks like a quick hitter, with precip
chances mainly from Las Vegas north and breezy to windy conditions
over the deserts. The next storm should be approaching the West
Coast Sunday afternoon, but as was the case yesterday, the models
disagree on whether this storm will be another quick moving weak
trough or will deepen and slow down as it moves inland. By Monday
night, model solutions range from shortwave ridging over our area to
a cold closed low overhead. Chose to make no changes for Monday and
Tuesday due to a lack of confidence in any one pattern evolution.
&&

.AVIATION...For McCarran...Gusty southwest winds this evening
turning more westerly later tonight as a front approaches from the
north. The winds are expected to turn to the northwest with the best
timing between 14Z and 16Z Thursday morning. Winds should then stay
primarily out of the northwest through the day Thursday. There
remains a small chance of rain showers later this afternoon near the
airport with an initial round of showers forecast to pass just east
of the airport between 5 and 7 pm. Probably a better chance of
showers actually impacting the airport complex will be after 5 am
Thursday morning and continuing through the late morning. Dry
conditions are expected in the afternoon.

For the rest of southern Nevada, northwest Arizona and southeast
California...Showers and thunderstorms are possible through this
evening becoming mainly showers overnight into Thursday morning. A
few storms may redevelop Thursday afternoon over eastern Lincoln and
Mohave counties. Southwest winds gusting 25-35 knots will persist
ahead of front moving south and east through the area tonight. Winds
will turn to the northwest behind the front and be locally breezy.
&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&

$$

Short Term/Aviation...Salmen

Long Term...Morgan

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