Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/24/18

Area Forecast Discussion

National Weather Service Binghamton NY

 1046 PM EDT Mon Apr 23 2018

.SYNOPSIS...
High pressure will reside over the region overnight only
gradually increasing clouds. Clouds will continue to increase
through the day on Tuesday with a low pressure system that will
bring periods of rain late Tuesday through the middle of the
week. Expect generally dry and seasonable weather Thursday night
and Friday.

&&

.NEAR TERM /THROUGH TUESDAY/...
1030 pm update...updated to tighten up the onset times for the
rain Tuesday into Tuesday evening. Used the NAMnest 3 km
simulated reflectivity as well as the HRRR reflectivity.
Generated hourly POPs from these fields and start times are more
defined from previous shift which is typical as we get closer
to the onset time.

The basic dynamical set-up is another southern branch upper
level low over the southern U.S which will track slowly east-
northeast tonight and Tuesday. This feature has a well developed
low-level cyclone which tracks northeast reaching the southern
Appalachians and NC/VA by 00Z Wednesday. A southeasterly low-
level jet will increase and tighten up across VA/WV and western
and southern PA Tuesday with strong low-level moisture
advection. This jet will also support strong isentropic lift on
the 290-300K surface Tuesday in NY and PA. Aloft this upper
level low will merge into a northern branch upper level wave
Tuesday night with strong upper level divergence. Hence it will
support a swath of rain spreading across NY and PA into Tuesday
night.

Models indicate that most of northeast Pa and central NY will be
rain free Tuesday. Some light showers could affect areas from
the Finger Lake southeast to the Poconos mid to late afternoon
Tuesday. The bulk of the rain looks like it comes Tuesday night.

We are not expecting enough rain to cause any flood issues.
Rainfall totals should range from around one half inch in the
Finger Lakes to near an inch in the Poconos/Catskills.

730 pm Update...
A little cirrus was heading north but the night will feature
mainly clear skies and chilly temperatures but milder than last
few mornings due to southerly winds. Some protected valleys east
of Binghamton will likely de-couple and see temperatures back
down to the upper 20s and lower 30s Tuesday am. Rest of
forecast area will see minimums in the mid 30s to lower 40s.
Didn`t make any significant changes to previous forecast.

330 PM Update...

Clear skies and warm temperatures will be the
rule for the rest of this afternoon and early evening as high
pressure remains firmly in control of our weather. Few to
scattered cirrus clouds move in from the south late this evening
and into the overnight period. With clear skies and light south
winds expect temperatures to fall off rather quickly after
sunset this evening..but likely not as cold as yesterday
evening. Temperatures should begin to level off, holding fairly
steady late tonight as clouds and moisture increase. Overnight
lows will be in the mid-30s to lower 40s areawide.

Tuesday starts off mostly cloudy in NE PA and partly cloudy
across Central NY. Clouds continue to increase from south to
north through the morning hours...so that by midday or early
afternoon the entire CWA should be mostly cloudy. Conditions
will stay dry through the morning hours. Then, a slight chance
to chance of showers will slowly move into our forecast area
from the southwest. With a dry ridge of high pressure still
hanging on over the far eastern portion of the forecast area
expect the northeastward progress of the rain showers to be
very slow...reaching the I-81 corridor by around 5-8 PM.
Rainfall amounts during the day on Tuesday are looking very
light, with just a few hundredths of an inch from I-81
west...especially in Steuben, Bradford and Luzerne counties.
Temperatures remain mild, but slightly cooler then today. Highs
will be in the upper 50s to mid-60s.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
330 PM Update...

Very little change to the short term forecast period, as it
still looks unsettled and wet.

Rain will continue to overspread the region Tuesday night and
Wednesday as a short wave passing through the Great Lakes phases
with a cut-off upper low moving from the srn Appalachian Mtns
newd to near NJ. A weak surface low associated with this system
will track out ahead of the upper low from the Carolinas to the
New England coast. A push of warm moist air northward ahead of
the low will prime the air mass for widespread rain showers into
Wednesday. The most favorable period for moderate rain will be
during the day Wednesday with the sfc low near the Delmarva
peninsula resulting in tight thermal packing within a moderate
baroclinic zone lifting north hrough tonightthrough ern PA and
east-central NY. The development of a weak-mdt layer of mid lvl
f-gen should be enough to enhance precipitation efficiency
during the late morning and afternoon hours on Wednesday.
Guidance is hinting at some marginal instability over the far
southeastern portion of our CWA, but not enough confidence to
add any thunder into the forecast at this time. Rainfall amts
from Tue night through Wednesday should range from 0.5 to 1
inch...with locally higher amts in the elevated regions of the
Poconos and Catskills.

Temperatures will remain fairly mild Tuesday night and Wednesday with
highs in the 50s to near 60 and lows in the 40s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
300 pm update...

Start of the period cold rain on back side of surface low and
upper level trough in eastern NY. The rain and low lift
northeast Wednesday night and Thursday. Rain may continue into
Thursday night in the far northeast. Temperatures at low levels
stay above freezing so precipitation should remain as rain.
Cooler highs Thursday in the 50s under the trough and with
neutral advection. Lows Thursday night in the mid and upper 30s.

Weak ridging aloft and weak surface high on Friday before the
next system approaches Friday night. The weekend system a cold
front and narrow but deep upper level trough moving in from the
west. Ahead of this is a coastal that stays well east of the
area. Rainfall amounts look light centered on the daytime
Saturday. Highs in the 50s Saturday. Sunday a large surface
high and upper level ridging moves in with dry mild air. The
high moves to the coast Monday but the region stays dry. Highs
in the 50s Sunday rise to the upper 50s and lower 60s Monday.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
VFR conditions will prevail through the terminal period with
high confidence. Cirrus clouds from approaching system from
southwest of NY and Pa will overspread terminals later tonight
and Tuesday morning. In our southern / western terminals VFR
mid clouds will arrive between 22z and 00z Wednesday. We do
expect a little rain at KELM before 00Z Wednesday from a lower VFR
overcast layer. We also expect a lower VFR layer to arrive at
KAVP at 23z.

Winds will be light southerly overnight and between 5 and 12
knots with gusts 15 to 22 knots Tuesday late morning/afternoon.

Outlook...

Tuesday evening...Rain developing with some restrictions
possible toward sunset. Moderate confidence.

Tuesday night through Thursday... Some restrictions likely with
rain showers. High confidence.

Thursday night and Friday...Generally VFR. Moderate confidence.

Friday night and Saturday...Some restrictions possible with rain
showers. Lower confidence.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

$$
SYNOPSIS...MJM
NEAR TERM...DJN/MJM
SHORT TERM...MJM
LONG TERM...TAC
AVIATION...DJN




Area Forecast Discussion

National Weather Service Brownsville TX

 600 PM CDT Mon Apr 23 2018

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...VFR ceilings expected to continue through Tuesday
afternoon with high pressure in place and some thinning of mid-
level clouds expected overnight. Chance of fog remains too low to
include into the TAFs at this time and will be monitored for
mainly BRO and HRL early Tuesday morning.

&&

.PREV DISCUSSION... /issued 239 PM CDT Mon Apr 23 2018/

SHORT TERM (Now through Tuesday Night): Quiet weather will
prevail with surface high pressure in place over the NW Gulf of
Mexico and flat ridging/zonal flow aloft. Mid-level cloud is
progged to continue thinning into the evening with some high
cirrus continuing to stream by overnight. GFS and HRRR hinting
that a shortwave trough aloft may speed by in the moderately fast
zonal flow and initiate some convection over the Mexican plateau
this evening. Guidance keeps any QPF south of the Rio Grande so
will just insert some silent 10% PoP`s.

The combination of near-surface moisture and light winds may
allow some patchy, shallow fog to develop across mainly eastern
portions of the Rio Grande Valley and northern Ranchlands during
the wee hours of Tuesday morning. Signals in the model guidance
are mixed on this, though. Will retain the inherited areas and
expand northward to match up with WFO/CRP. Not really expecting
visibilities to fall below about 3SM anywhere, though. Overnight
lows will range from the mid-upper 60s along the Rio Grande to
around 60 near Falfurrias and Sarita.

Moderate southeast surface flow returns by mid-day Tuesday as
surface high center moves offshore. Moisture in the atmospheric
column thins out somewhat, so skies should be sunnier than today.
This should in turn allow afternoon temps to nudge up from today`s
readings, with mid-upper 80s along the Hwy. 77/I-69E corridor and
low-mid 90s far west. Partly cloudy and mild on Tuesday night, as
dewpoints creep up into the mid-upper 60s on continued SE flow.
No precipitation is expected, though.

LONG TERM (Wednesday through Monday): Quiet weather will continue
Wednesday, with a short wave trough digging south over the
central high Plains and an underlying cold front moving south over
central and south Texas. A mid level ridge will be positioned
over the Southwest United States with surface high pressure over
the northwest Gulf. The weak cold front will push across the area
late Wednesday night to Thursday morning, with just enough
moisture, instability, and lift to potentially generate a few non-
severe thunderstorms late Wednesday night through Thursday
morning. The ECMWF appears a little more aggressive with rainfall
for the upper valley Wednesday night as the front pushes toward
the coast around dawn Thursday morning.

Once the front clears the area Thursday, high pressure will build
in, with light onshore flow into Friday. As high pressure shifts
east, winds will return to southeast. The rich low level return
moisture combined with westerly mid level flow with embedded
minor perturbations over northern Mexico may keep the threat of
isolated convection in the picture through the weekend. Daytime
high temps will be near normal Thursday through the weekend as
increased cloud cover and onshore flow temper the heat.

MARINE:
Now through Tuesday Night: Favorable boating conditions are
expected through the short-term. Buoy 42020 reported northeast
winds of 10-12 knots with seas of 2-3 feet and a period of 5
seconds as 1:50 PM CDT. Surface high pressure will prevail across
the western Gulf of Mexico through Tuesday night. A weak pressure
gradient will support light east to southeast winds, becoming more
moderate Tuesday night, and low seas around 2 feet through the
period.

Wednesday through Saturday night: Light to moderate east to
southeast winds and low to moderate seas will prevail Wednesday
through Wednesday night. Winds will turn to light northeast or
east late Wednesday night or Thursday morning as a weak cold
front passes across the area, bringing the possibility of a few
showers to the marine areas. Winds will then remain light to
moderate northeast to east with low to moderate seas through
Saturday night as high pressure spreads over the northwest Gulf.
Advisory condition chances will be low during this period.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

56




Area Forecast Discussion

National Weather Service Cheyenne WY

 216 PM MDT Mon Apr 23 2018

.SHORT TERM...(This evening through Wednesday night)
Issued at 330 PM MDT Mon Apr 23 2018

Tonight...Looks and feels like spring outside. Surface low pressure
continues to develop across our western counties with decent
pressure rises over northern Wyoming and decent pressure falls over
southeast Wyoming and western Nebraska. As a vigorous shortwave
trough aloft and its associated strong cold front pass our counties
the rest of today, expect increasing coverage of showers and
isolated thunderstorms, some of which may produce small hail and
wind gusts up to 50 mph based on shear and instability expectations.
Showers and thunderstorms will be most numerous over western
Nebraska this evening near the cold front with scattered showers
after midnight, mainly over western Nebraska.

Tuesday...Blustery and cold day as the shortwave trough aloft moves
slowly across western Nebraska with cold air advection at low levels
across our counties. Low and mid level gradients suggest a windy day
at most locations.

Tuesday night...Drying out period as the shortwave trough aloft
moves to northwest Kansas with decreasing cloud cover. Hard freeze
expected with cold airmass, clearing skies and light winds.

Wednesday...Much warmer with a transitory shortwave ridge aloft over
our counties and plenty of sunshine. With 700 mb temperatures rising
near 4 Celsius, expect maximum temperatures in the 60s at lower
elevations.

Wednesday night...Another cold frontal passage, mostly dry, as a
shortwave trough swings southeastward across the Dakotas. Orographic
type showers expected after midnight over the northern Laramie Range
and nearby portions of Converse County, otherwise dry. Not quite as
cold as the airmass recovers and mixing limits cooling.

.LONG TERM...(Thursday through Monday)
Issued at 330 PM MDT Mon Apr 23 2018

Weak cold front Thursday moves through the area during the day for
some light rainshowers. After this front moves through looking at
rising 500mb heights and warmer temperatures. By Saturday, 700mb
temperatures up to +8C. MEX guidance for Saturday showing 78 for a
high at Cheyenne and 80 for Sidney. Did go above guidance on
forecast temperatures.

Another shortwave possible for Sunday into Monday next week. GFS
further north over the ECMWF. That far out, confidence is low on
PoPs and the forecast track is sure to change between now and
then.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1012 AM MDT Mon Apr 23 2018

Introduced thunderstorms into the 18Z TAFs this afternoon. Latest
HRRR guidance showing earlier than expected development this
afternoon, so moved up timing as well. Possibility of seeing KCYS
going IFR as winds turn northeasterly shortly after 00Z. WIll
continue to monitor unfolding events.

&&

.FIRE WEATHER...
Issued at 230 PM MDT Mon Apr 23 2018

Cold front moving through southeast Wyoming this afternoon will
bring widespread wetting rains and mountain snow to the area.
Colder temperatures Tuesday before high pressure builds
in. Warmer temperatures should end out the week. With recent
rainfall and upcoming warm temperatures, would expect a rapid
acceleration of greenup across both southeast WYoming and
Nebraska Panhandle fire weather zones. Fire weather will not be a
concern this week.

&&

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

$$

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



Area Forecast Discussion

National Weather Service Green Bay WI

 1035 PM CDT Mon Apr 23 2018

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Tuesday
Issued at 206 PM CDT Mon Apr 23 2018

The latest RAP analysis and satellite/radar imagery show a ridge
of high pressure extending east from New England and into the
northern Mississippi Valley early this afternoon. A cold front
remains largely inactive across eastern North Dakota, while a
larger low pressure system is spinning over the central
Mississippi Valley. The far northern edge of the cirrus associated
with this southern system continues to reach northeast WI.
However, any deeper moisture remains north and south of the
region. With a dry airmass in place, forecast concerns revolve
around clouds and temps tonight, and small precip chances on
Tuesday afternoon as the front from the north moves into the
region.

Tonight...Low pressure will continue to spin over the southern
Ohio Valley, while the surface ridge axis will weaken over
northern WI. As minor height falls occur aloft, will see mid and
high clouds push in from the south and across northeast WI. Low
levels will remain dry though, so no threat of precip. Temps will
continue their slow warming trend and will go with a range from
the low 30s over the north to the upper 30s over the southern Fox
Valley.

Tuesday...Will continue to see some high clouds along the Lake
Michigan shoreline during the morning, but those clouds should
depart by midday. Then attention turns to the west where a digging
shortwave trough will push a weak cold front across the northern
and central parts of the state during the afternoon. The shortwave
itself appears relatively robust and will bring a moderate amount
of upper support. However, moisture as well as low level
convergence are lacking, so coverage of showers appears isolated
to scattered at best. Will keep a small chance of showers from the
Fox Valley to north-central WI for the afternoon. Otherwise,
clouds will be on the increase during the afternoon with highs
ranging from the low to mid 60s in the east to the low to mid 50s
over Vilas county.

.LONG TERM...Tuesday Night Through Monday
Issued at 206 PM CDT Mon Apr 23 2018

The effects of the cold front, arriving late Tuesday afternoon,
will linger into the start of the long term for Tuesday night.
Kept slight chance pops for Tuesday night due to possible post-
frontal rain. This shortwave trough/cold front will exit the
region by early Wednesday morning. In addition, cooler air will
funnel in behind this front, causing Wednesday high temperatures
to rise slightly below normal with even cooler temperatures along
the lakeshore.

The next shortwave trough/cold front will move into the region
Thursday afternoon. Model guidance is in better agreement with
timing and the evolution of this system compared to yesterday.
However, the GFS and Canadian present more mid-level
frontogenetic forcing allowing for more lift and precipitation to
occur. The forecast timeframe for precipitation would be Thursday
evening and Thursday night. The precipitation would start as rain
then transition to a mix or all snow before ending Friday
morning.

Then quiet weather returns for next weekend. Temps return above
normal by Sunday.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1034 PM CDT Mon Apr 23 2018

Ridge of high pressure extending over the Great Lakes region
through Tuesday morning. A weak cold front will then approach the
area on Tuesday afternoon. A slight chance of showers will be
possible along it during Tuesday afternoon and evening. However
chances are too low to include in the TAFs with this issuance.
Will handle the front with increasing clouds and lower cigs on
Tuesday, with clearing skies behind the front Tuesday evening.
&&

.HYDROLOGY...
Issued at 206 PM CDT Mon Apr 23 2018

River levels continue to rise from the snow melt runoff. A few
rivers have already reached minor flood stage as of this afternoon,
with many others forecast to reach or exceed bankfull this week.
There are a few chances of rain this week, Tuesday afternoon and
then again toward Thursday afternoon and Thursday night. Both
systems are not expected to generated much rainfall, so runoff
will occur from the warmer temperatures chipping away at the
snowpack. The upcoming weekend looks dry as well.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......Hykin
AVIATION.......Kurimski
HYDROLOGY......Hykin



Area Forecast Discussion

National Weather Service North Platte NE

 645 PM CDT Mon Apr 23 2018

.SHORT TERM...(This evening through Tuesday)
Issued at 351 PM CDT Mon Apr 23 2018

The primary focus through Tuesday morning deals with a strong
cold front passage. The cold front is in association with the
upper ridge giving way to a trough and the beginning of a closed
low. Ahead of the front, a light southeast breeze and sunshine
pushed temps into the upper 60s for much of the area today.

This evening... Slowed the progression of the PoP somewhat through
06z per RAP and HRRR trends. As of 20z, convective initiation is
underway off the Cheyenne Divide and is nearing the WY/NE border.
Brought schc into the eastern panhandle at 00z, then gradually
increase PoP and coverage eastward through the evening. Included
TSRA through 02z in the west given decent shear and mid-level lapse
rates. One issue through the late evening may be dry air in the
lower levels and how quick the column saturates. Despite
southeasterly flow, dew point depressions approach 30F this
afternoon across the Sandhills and into the western Panhandle.

Overnight... The combination of better forcing/lift with the fropa,
broad isentropic lift (best seen around 300K, roughly correlating to
H7-8), and steady dew points supports more widespread precip after
06z. The greatest CAA begins generally after 06z with H85 temps
falling about 5C through 12z. However, with the coldest air lagging
well behind, Looking at all rain. A mix is possible in the panhandle
toward 12z where temps drop into the mid 30s. Made little change to
forecast lows overall with mid/upper 30s west and lower 40s east.



.LONG TERM...(Tuesday night through Monday)
Issued at 351 PM CDT Mon Apr 23 2018

An upper trough and closed will dig across South Dakota and
Wyoming into Nebraska. The upper low center is forecast to track
over central Cherry County by late Tuesday afternoon. During the
morning, likely rain chances east of Gordon through Hayes Center.
In the afternoon, rain chances not expected in far southwest
zones, as better lift will reside along and ahead of advancing
cold front moving into the eastern zones. Rain chance will also
remain or increase to likely over most of north central Nebraska
as the upper low drops south. Northerly winds will also range from
20 to 30 mph behind the front through the day. Due to overcast
skies, weak cold air advection, and rain expected, highs were
trended down a few more degrees to the low 40s northwest
Sandhills to near 50 far eastern zones.

Models in better agreement in the forecast track of this system
Tuesday night into Wednesday, moving the low central through
central Nebraska 06z Wednesday and near the Nebr/Ks border by 12z
Wednesday. Wrap around precipitation is expected to the east and
north of this system Tuesday night, and even lingering into
Wednesday morning across the far southeast zones. Tuesday night,
likely POPs eastern parts of nctrl into central Nebraska lowering
to a slight chance far southwest zones. This followed by a
lingering, mainly slight chance across southeast zones Wednesday
morning. Models are mostly warm enough Tuesday night into
Wednesday morning, to keep precipitation type as mainly rain,
except a rain/snow mix or snow on the northwest side of the upper
low center. Any snow accumulations limited to grassy surfaces and
only a tenth or two of snow expected at most. Sun return by
Wednesday afternoon all areas with lower 60s northwest and upper
50s southeast.

Thursday through Friday, northwest flow aloft will prevail. A
cold front is forecast to move in Wednesday night, cooling highs
Thursday to the upper 50s with northwest winds 20-30 mph. There
is a slight chance for rain Thursday morning, however this is
mainly supported by the ECMWF. Warming to the upper 60s Friday as
upper ridge to the west nudges eastward. An upper trough will digs
across the Great Basin Saturday through Monday. The GFS continues
to support a slight chance for showers and thunderstorms across
the west Saturday evening as a lead disturbance may eject onto the
Central High Plains. Otherwise, mainly dry and mild with highs in
the low to mid 70s each day.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 645 PM CDT Mon Apr 23 2018

A strong cold front and upper level low will track across western
and north central Nebraska over the next 24 to 36 hours, leading
to overcast conditions and occasional rain. MVFR ceilings are
likely after 12z Tuesday at the KLBF terminal, and after 09z
Tuesday at the KVTN terminal. Winds will shift to the northwest
overnight and increase to 10 to 20 KTS with gusts approaching 30
KTS by mid morning Tuesday. Light rain will be possible after 09z
Tuesday at the KLBF terminal and after 06z Tuesday at the KVTN
terminal.

&&

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

$$

SHORT TERM...Snively
LONG TERM...Roberg
AVIATION...Buttler