Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/04/19

Area Forecast Discussion

National Weather Service Amarillo TX

 702 PM CDT Mon Jun 3 2019

.AVIATION...

00z TAF Cycle:

Watching scattered thunderstorms entering the western Oklahoma
Panhandle with one or two isolated storms in the western Texas
Panhandle. Added a tempo group for KGUY for this TS activity as
confidence is on the high side that storms will impact that
terminal. TS mention was left out at KDHT and KAMA, as confidence
is too low to include at this time, but amendments may be needed.
Any storms could produce gusty downburst winds, heavy rain and
some hail resulting in brief periods of MVFR vsbys. Storm activity
is expected to shift east of the terminals by 09z. VFR conditions
should prevail for most of the period. Another round of storms
could move into the area towards the end of this TAF period, so
included POP30 groups to account for this potential.

Ward

&&

.PREV DISCUSSION... /Issued 309 PM CDT Mon Jun 3 2019/

SHORT TERM...This Afternoon through Tonight...

Upper level analysis reveals broad cyclonic flow across the Desert
Southwest with slow moving upper low over souther CA. The main 500mb
jet streak remains over western NM with very minor perturbations
ejecting into central and eastern NM. These perturbations are almost
impossible to detect via water vapor imagery. Raw models do indicate
a few vorticity maxima advancing east, but this may just be
convective feedback. For storms to survive as they move into the
Panhandles, some kind of lift associated with a shortwave will be
needed.

Storms are forming near Ruidoso and Angel Fire, where terrain
induced moisture convergence is being enhanced. As these storms move
east, they will move closer to the ridge axis situated across the
southern Plains. This setup has not changed much from the last two
days, however there are some indications of slight height rises, and
without better lift associated with a better shortwave, storms may
struggle a bit more as they move into the Panhandles. This is
especially true given the recent model trends suggesting a drier
PBL, and more pronounced EML with MLCIN values of 50 to 100 J/kg
which certainly won`t help storms as they move into the Panhandles.
That being said, CAMs and and the latest model runs still try to
bring convection across the area from NM, and the latest HRRR now is
developing storms around 06z in the western zones. Confidence in
anything more than isolated to perhaps scattered activity is not
high. Slightly better surface dew points do exist across the central
and eastern Oklahoma Panhandle and northeastern Texas Panhandle, so
the cap issues may not be as bad there. Instability is higher based
today, with an axis of MLCAPE around 2000 J/kg extending from
northeast NM across our northwest zones. Shear is not as strong
today given weaker winds aloft and overall less turning in the cloud
bearing layer. Effective shear may approach 30 knots this evening as
the low level jet ramps up along with some backing of the surface
winds. DCAPE is quite large today given more inverted-V type
soundings, with 1400-1500 J/kg showing up on the current SPC
mesoanalysis page. Moreover, some multicell storms will be possible
(there is enough anvil layer winds to get some tilt to the updraft).
Large hail and dry microburst winds will be the main concern with
the stronger storms into the evening, but this threat should be
isolate.

Perhaps a higher concern is the localized flooding potential. Even
through the precipitable water values aren`t as high as yesterday,
and are now well below the 90th percentile, storms do not have a lot
of steering flow resulting in slower storm motions. Soil conditions
are quite saturated over a good portion of the Panhandles, so storms
will have the potential to produce some flash flooding in a
relatively short period of time.

Ward

LONG TERM...Tuesday through Monday...
No major changes have been made to the forecast.  Models and
ensembles still in good agreement regarding evolution of closed
mid-level low taking aim at the Texas and Oklahoma Panhandles.
Some slightly slower movement has been noted, but the story
remains the same.

Low-level moisture will continue to be sustained for the next
several days.  Moderately high values of CAPE are expected
through Thursday, but shear is not expected to be high.  Thus,
widespread severe thunderstorms are not anticipated.
Thunderstorms are forecast, with Wednesday through Thursday
offering the best time frame for widespread precipitation.

Closed low expected to cross Panhandles Wednesday night and
Thursday.  Heavy rains are likely to occur, which could lead to
flooding issues, mainly Wednesday through Thursday.  Rain and
thunderstorms may linger Thursday night across eastern sections
as low departs.  Dry weather expected Friday through Saturday as
brief ridging develops in the wake of the departing low.

Poor agreement between models regarding surface features in later
periods, but low-level moisture and instability expected to
increase Saturday night, with eventual passage of a cold front by
Sunday night, followed by moist upslope flow on Monday.  Blended
pops for thunderstorm chances have been utilized for Saturday
night through Monday.

Cockrell

&&

.AMA Watches/Warnings/Advisories...
TX...None.
OK...None.

&&

$$

7/2




Area Forecast Discussion

National Weather Service Des Moines IA

 640 PM CDT Mon Jun 3 2019

.DISCUSSION.../Tonight through Monday/
Issued at 332 PM CDT Mon Jun 3 2019

Tonight into Tuesday...weak area of theta-e advection continues to
provide enough lift for showers and a few isolated thunderstorms
to dribble eastward this afternoon. The slow movement east and
with the large surface high pressure over the Great Lakes
providing plenty of dry air to contend with should limit the
extent in the east-southeast of the shower activity this
afternoon/early evening. Another batch of weak mid-level theta-e
advection pushes across the state late tonight into early Tuesday
morning and looks to provide enough forcing to spawn showers and a
few thunderstorms over the north. The NAM and ARW/NMM suggest
redevelopment b/t 03z-06z Tuesday along the Highway 30 to Highway
20 corridors. Even the latest ESRL HRRR shows hints of rain in
this location tonight. Have a brief dry period this evening before
the rain starts up again by the aforementioned period. This
shower/storm activity will be over by 12z with some lingering
showers across the northeast.

Tuesday afternoon and evening remain troublesome as instability
increases dramatically. Surface based CAPE ranges from 3000-4000
J/kg by 00z Wednesday but the deep layer shear ranges from 25 to
maybe 40 knots across the forecast area Tuesday afternoon. Low
level shear is even weaker and it is difficult to pinpoint any
sort of forcing mechanism to initiate storms tomorrow
afternoon/evening. Still, with the amount instability present and
any outflow boundary hanging around to potentially cause storms
to develop, kept with chance pops past 21z Tuesday across the
forecast area. Severe weather potential looks to be elevated hail
threat as well as damaging winds threat due to the DCAPE of
500-1000 J/kg.

Wednesday through Monday...Large upper level ridge covers much of
the central CONUS mid to late week with a cutoff low trickling
out of the southern Rockies Wednesday and then meandering over the
central to southern Plains into the weekend. The cutoff low
finally moves into the mid-Mississippi River Valley by Saturday.
Thus, from Wednesday night through Saturday, southern Iowa has the
potential see rain and a few storms as the upper low brings
several waves of weak theta-e advection and vorticity into this
location. With the large surface high pressure remaining planted
across the Great Lakes, it will be difficult to get any rain north
of Interstate 80 until the early part of the weekend when the
surface high begins to breakdown. Thus, trended drier across the
central to northern sections of the forecast area during the
extended forecast period.

&&

.AVIATION.../For the 00Z TAFS through 00Z Tuesday evening/
Issued at 640 PM CDT Mon Jun 3 2019

Showers passing through central Iowa from highway20 to the MO border
will bring brief MVFR conditions mainly with respect to ceilings.
Cannot rule out a brief rumble of thunder either but any thunder
will be insignificant.  Several disturbances will pass across Iowa
overnight and Tuesday, each will bring with it a chance for
shra/tsra but timing location confidence is low so I only have vcsh
in the forecast.  The reason for the low confidence is that
instability is strong but shear is fairly weak so convection is
conditional.  MVFR cigs will be more prevalent in the morning (12Z -
16Z)but overall VFR conditions expected.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

DISCUSSION...Podrazik
AVIATION...FAB



Area Forecast Discussion

National Weather Service Green Bay WI

 1034 PM CDT Mon Jun 3 2019

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Tuesday
Issued at 238 PM CDT Mon Jun 3 2019

The latest RAP analysis and satellite/radar imagery show surface
high pressure stretching from northern Ontario, across the western
Great Lakes, to the Ohio Valley early this afternoon. A band of
mid-level clouds above 8 kft continues to hold back temps after a
chilly start to the day. Readings remain in the upper 50s over
north-central WI to the mid 60s over the Fox Valley. The cloud
cover will continue to slowly move to the east, which may allow a
couple hours of rapidly warming temps over north-central and
central WI later this afternoon. Looking upstream, a warm front
remains positioned across the Plains with a cluster of
showers/storms near the Nebraska-Iowa state line. As this warm
front moves towards the area on Tuesday, forecast concerns mainly
revolve around thunderstorm potential and any threat of severe
weather.

Tonight...The clouds will continue to lift off to the northeast,
and exit northeast late in the evening. After a period of mostly
clear conditions, clouds will return from the southwest ahead of
the northeast advancing warm front. Although instability never
reaches this far north, there is a small chance of a shower
reaching central WI after 09z. High pressure will continue to move
away from the region, and the tightening pressure gradient should
keep a steady south or southwest wind. Temps should therefore be
significantly warmer than last night and range from the upper 40s
over far NE WI to the mid 50s over central WI.

Tuesday...Southwest winds will continue to lead to warmer and more
humid air invading the region. With increasing elevated moisture
transport and some indications of a weak shortwave impulse, the
greatest threat of showers will likely occur over central and
east-central WI in the morning. Instability does not increase
until afternoon from the west, but the warm front is only forecast
to reach the Mississippi Valley by 7 pm, which is still
relatively far west of the area. In a weak warm advection regime
ahead of the boundary though, perhaps this will be enough to kick
off an isolated storm. Most likely, however, the afternoon will be
dry for most places, while thunderstorm chances increase in the
evening. Mostly cloudy skies will hold back temps some, but
thinking mid to upper 70s for highs.

.LONG TERM...Tuesday Night Through Monday
Issued at 238 PM CDT Mon Jun 3 2019

Low amplitude WNW mid level flow is expected to prevail across
the region through much of this week before a closed circulation
in the southern Plains moves toward the Great Lakes late in the
week.

There is a chance for showers and tstorms Tuesday night
associated with mid level short-wave trof and surface low/cold
front. Timing of the cold front across forecast area (late Tue
night) should preclude widespread tstorm activity in this part of
the state. SPC Day 2 looks reasonable, with best chance for strong
storms over western part of Wisconsin.

Typical early June temps expected much of the week. Cooler temps
expected as upper low and associated clouds/rain moves into the
region later in the weekend. Forecast temps a blend of best
performing bias-corrected models.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1030 PM CDT Mon Jun 3 2019

VFR conditions will continue overnight into Tuesday morning. A
few sprinkles are possible along the Michigan border overnight.
On Tuesday, models indicating low level moisture, combined with
daytime heating will CIGS to drop into the MVFR category. Some
discrepancy in the bufkit soundings and the latest MET/MAV
guidance if the low clouds will be in the MVFR or VFR category.
Leaned toward the lower cloud heights based on the bufkit
soundings. The chances of showers and thunderstorms will be
on the increase late Tuesday afternoon and especially Tuesday
evening. CIGS are likely to drop into the IFR category
Tuesday evening across portions of central and north-central
Wisconsin.

&&

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

$$

SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......Eckberg