Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/10/22

Area Forecast Discussion

National Weather Service Grand Rapids MI

 1055 PM EDT Mon May 9 2022

LATEST UPDATE...
Update/Marine

.UPDATE...
Issued at 1054 PM EDT Mon May 9 2022

A line of showers and thunderstorms is located across portions of
Central Wisconsin southwest into Iowa at 1045 pm. This line will
likely dissipate upstream of Western Lower Michigan tonight given
the loss of daytime heating and therefore overall instability. A
few isolated showers will be possible late tonight and into
Tuesday morning up near Big and Little Sable Points. Both 850mb
moisture transport and the low level jet itself diminish
considerably as the convection moves our way. So, have 20 percent
chance pops for an isolated shower or storm around daybreak.
Otherwise and increase in clouds will be noted as convective
cirrus debris clouds move our way. In addition, models continue to
want to bring some lower clouds into the area tonight and this can
be seen occurring in Eastern Wisconsin and Western Lake Michigan
at this time.

&&

.DISCUSSION...(This evening through next Monday)
Issued at 227 PM EDT Mon May 9 2022

- Increased potential for some thunderstorms Tue Night to Wed

Models were showing a weak cold front approaching from the
northwest later Tuesday night into Wednesday. The atmosphere is
forecast to become rather unstable along and ahead of this front
with projected CAPE values topping 1500 J/kg here in the CWA. The
low level jet is not in a favorable position for us to see
numerous showers and storms. The CWA is mostly in the entrance
region of the low level jet. Still...if some storms could get
going upstream in eastern WI later Tuesday...the may have enough
momentum to roll into west MI later Tuesday night into Wednesday
before diminishing. We will increase the coverage of the
thunderstorm potential as several models like the 12z HRRR have
trended toward more convection.

- Well above normal temperatures expected into the weekend

While any diminishing convection and associated debris clouds
could lead to an increased uncertainty of max temperatures(mainly
Wednesday)...the period overall looks very warm. Part of the
reason for this will be the moderating overnight
temperatures.  As surface dewpoints eventually climb into the
60s...the overnight lows will remain relatively warm...thereby
give each day a higher start to the diurnal rise. We are already
about 10 degrees warmer than normal today. The warm air advection
persists for most of the week.

The warmest 850 mb temperatures are progged to occur on Friday
with values around 20 deg C. This bump in warmer air occurs ahead
of an approaching cold front. With a decent amount of sunshine
expected we should be able to mix to that level which would
support high temperatures in the upper 80s to near 90 away from
the lakeshore.

- Highest chance for storms is Saturday night

Models are in relatively decent agreement in tracking stronger mid
level wave and associated cold front through the area Saturday
night. The organized lift combined with an axis of instability
should lead to at least scattered thunderstorms. The timing is not
favorable for severe weather especially with the diminishing
instability...but that will need to be monitored.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 819 PM EDT Mon May 9 2022

At this point we have VFR TAFs through the entire period from 00Z
this evening through 00z Tuesday evening. High confidence that VFR
weather will continue this evening and into the overnight hours.
Latest analysis of ceilings and visibilities across the area
reveals clear skies in Southwest Lower Michigan with VFR
conditions upstream into Wisconsin and Illinois.

The question mark is related to the ongoing showers and storms out
on the MN/WI border. Models show this activity making a run at
Western Lower Michigan in a diminishing mode as it moves our
direction late tonight and Tuesday morning. The main time frame
of concern is from roughly 08Z through 18Z. At this point think
the low level moisture shown in the models is a bit overdone and
have therefore held ceilings about 3,000ft. We will continue to
monitor trends on the upstream precipitation and RH values in the
models in the 2,000-3,000ft layer especially. Some models are
indicating MVFR ceilings at most TAF sites at 15Z.

We may see some decaying showers at MKG towards daybreak, but have
held this out of the TAFs for now. Feel the best chance for
showers will be late tonight and tomorrow morning towards LDM, so
north of the TAF sites. Also, there will be a period of
LLWS, especially towards MKG this evening from roughly the current
time through 06Z.

&&

.MARINE...
Issued at 1054 PM EDT Mon May 9 2022

We extended the Small Craft Advisory through 800 AM. A strong core
of winds aloft is mixing down in the nearshore waters with
numerous sites reporting wind gusts between 20 and 30 knots. The
Ludington Buoy has now seen waves increase to around 4 feet. We
may need to extend the advisory into the midday hours of Tuesday
to allow for the waves to dampen out. 40-50 knot winds are in the
core aloft at this time around 2,000ft. By midday on Tuesday
winds in the lowest 5,000ft should be 20 knots or less.

&&

.FIRE WEATHER...
Issued at 227 PM EDT Mon May 9 2022

Surface temperatures have risen into the mid 70s for many
locations in the Red Flag Warning area. Southeast winds were
gusting mostly in the 25 to 30 knot range. The humidity values
were generally between 25 to 35 percent...which is a little shy of
the criteria. We still have a few more hours to go and the
humidity will likely lower another 5 percent or so. We will keep
the headline going given the forecast conditions.

Looking ahead...the surface dewpoints and associated humidity
levels will be higher for Tuesday. This occurs as a cold front
approaches in from the northwest. As a result...no fire weather
headlines are planned for Tuesday.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 8 AM EDT Tuesday for LMZ844>849.

&&

$$

UPDATE...Duke
DISCUSSION...MJS
AVIATION...Duke
FIRE WEATHER...MJS
MARINE...Duke



Area Forecast Discussion

National Weather Service North Platte NE

 659 PM CDT Mon May 9 2022

.SHORT TERM...(This evening through Tuesday night)
Issued at 408 PM CDT Mon May 9 2022

A Frost Advisory is in place across Sheridan county for a few hours
early Tuesday. The guidance blend plus bias correction was the basis
for lows around freezing. Temperatures this afternoon rise into the
lower 60s. The light winds and weak sfc high pressure predicted
tonight support a period of modest radiational cooling and lows near
freezing.

The High Wind Warning will continue across the same region until the
approach of sunset. The potential for high winds however, would
appear to be farther west across the northwest Panhandle, according
to the RAP and HRRR wind gusts. BUFkit would suggest deep mixing to
600mb will produce gusts to 60 mph near Merriman.

The SREF backed by the NAM suggests rapid moisture-return late
Tuesday night into Wednesday morning will produce stratus. The HREF
probabilities are much less aggressive with the formation of stratus.
The forecast remains uncertain for one reason: the NAM and SREF
could be too quick or too aggressive with the moisture advection.

Otherwise, the forecast tonight through Tuesday is uneventful. Sfc
high pressure will build through nrn Nebraska and SD and this will
place a stationary front across KS by Tuesday evening. The cloud and
moisture forecast Tuesday night hinges on how far south into KS this
front will located. The further south, the longer it will take to
return north; presumably.

.LONG TERM...(Wednesday through Monday)
Issued at 408 PM CDT Mon May 9 2022

All eyes are on Wednesday and Thursday...prime time for storm development
across wrn and ncntl Nebraska both days would appear to be 4 to 7
pm, perhaps along and east of highway 83 where a dryline will be
lurking Wednesday. A strong cold front will move through the
region Thursday and this will be the focus for storm development.

The timing forecast is based on the NAM, down-scaled NAM and ECM
solutions. If the GFS verifies, no storms will develop across the
region either day. The blended forecast suggests isolated to
scattered storm coverage both days. The storm mode Thursday is
beyond the reach of the NAM which runs out through just Thursday.
BufKit/NAM suggests splitting supercells Wednesday.

Wednesday, the NAM and ECM suggest mostly isolated storm coverage
generally along and east of highway 83. A surge of dry air should
move into swrn Nebraska, according to the NAM. If this is correct,
the dry air would intersect a warm front lifting through the
Sandhills. Location of storm development will remain uncertain for
this forecast but areas where the shear is strongest and the CAPE is
properly balanced relative to the winds aloft would be the favored
environment for storm development. The NAM and ECM suggest this
favored environment will be along and east of highway 83.

The models are in very good agreement amplifying heights across the
wrn U.S. Friday through Sunday and this will place wrn and ncntl
Nebraska in a northwest flow aloft. The forecast is dry during this
time period but we have to watch for moisture return beneath the
northwest flow. The GFS and ECM suggests this may occur as early as
Saturday across KS. If the return moisture were to reach the high
plains of ern Colo and WY, then rain chances could return to wrn and
ncntl Nebraska.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 643 PM CDT Mon May 9 2022

VFR conditions will prevail tonight and through the day Tuesday.
Winds will become light tonight and switch to the east at 10 kts
during the day Tuesday.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 7 PM MDT this evening for NEZ004.

Frost Advisory from 3 AM to 8 AM MDT Tuesday for NEZ004.

&&

$$

SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Taylor



Area Forecast Discussion

National Weather Service Memphis TN

 812 PM CDT Mon May 9 2022

.UPDATE...

8PM Update

No changes were made. Previous forecast is on track.

SMW

&&

.PREV DISCUSSION... /issued 214 PM CDT Mon May 9 2022/

DISCUSSION...

The Mid-South will remain under the influence of an anomalous
ridge over the next few days, resulting in generally hot and dry
conditions. Both the NAEFS and EPS mean 500 mb geopotential
heights are forecast to exceed the maximum of climatology Tuesday
through early Thursday, with a gradual decrease late week as an
upper-level cyclone retrogrades across the Southeast. This will
spell above normal temperatures and generally dry weather in the
short- term.

Low clouds persisted much of this morning, slightly depressing
temperatures. HREF probabilities suggest a strong likelihood that
we`ll see similar conditions tomorrow with AM cloud cover and PM
clearing. This may keep temperatures below 90F in most areas
tomorrow, despite 850 mb temperatures above the 90th percentile.
That said, even the NBM 25th percentile temperatures are reaching
the 90F mark in some areas. Temperatures are expected to tick
upward a bit on Wednesday, climbing into the 90s pretty much area
wide. NBM sky cover is a bit on the low side, so will bump that up
the next few days with the anticipation of a diurnal Cu field.

The cut-off low currently off the Carolina coast is forecast to
retrograde back to the west mid/late week. The ridge will build
poleward as this occurs, spilling over the top of the upper-level
low and settling over the Atlantic by the week`s end. Guidance is
indicating a weak, back-door cold front moving into the Mid-
South Wednesday afternoon and evening. This could provide
sufficient lift for a few showers and thunderstorms as mid-level
cooling erodes the subsidence inversion around 700 mb. However,
confidence is very low at this time so will leave the forecast dry
for now.

Current guidance brings the upper low as far west as east TN
before it gets picked up by a northern branch trough and quickly
lifts into the Northeast. This trough axis swings through the OH
Valley late this weekend, pushing another cold front through the
Mid-South. Rain chances will trend upward this weekend with
temperatures retreating back to near climatology.

MJ

AVIATION...
00Z TAFs

Quite a spread in short range guidance regarding a repeat of
morning MVFR CIGs around sunrise Tuesday. HRRR, NAM Bufr
soundings, RAP and NBM guidance depict either scattered layer near
FL025, or clear skies Tuesday morning. SREF Cig Prob consensus
splits the difference between the aforementioned guidance and the
nearly certain MVFR CIG scenario depicted by the HREF consensus.

The synoptic pattern consists of a weaker low level jet under
more robust upper level ridging, relative to this morning. With
this and forecast continuity in mind, 00Z TAFs scales back the
morning MVFR a bit, splitting the range of guidance solutions.

PWB

&&

.AVIATION...


&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&

$$