Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/07/18
Area Forecast Discussion
National Weather Service Cheyenne WY
556 PM MST Sat Jan 6 2018
.SHORT TERM...(This evening through Monday night)
Issued at 215 PM MST Sat Jan 6 2018
Current observations across the region show relatively mild
temperatures for early January with readings in the upper 30`s to
upper 40`s, with a few locations around 50 degrees this afternoon.
Skies are primarily overcast across the area with widespread mid
to high cloudiness. This is in advance of a fast moving upper
level trough which will move across the area tonight and early
Sunday morning bringing some snow and cooler temperatures.
Main forecast concern over the next 48 hours will be the potential
for snow, mainly across southeast Wyoming. Winter Weather Advisory
continues for the Sierra Madre Range tonight with snow just
starting to fall across southern Carbon county this afternoon
based on current webcams. The Snowy Range may need an advisory as
well, but that area does not do as well with llvl west to
southwest winds, so kept accumulations between 2 to 5 inches for
now. The main question will be the valleys, where some locally
moderate to heavy snow bands may develop. Models have consistently
shown a band of heavy snow beginning across southern Carbon/Albany
county late this evening with a gradual shift eastward into the
I-25 corridor just before/around midnight. This area of
moderate/heavy snow is co-located with some llvl frontogenesis,
weak instability, and impressive but brief upper level jet
dynamics. The HRRR and NAM have shown this solution for several
runs now, so there is the potential for a heavy snow band to set
up between Wheatland and Cheyenne and the Nebraska border. Not a
lot of cold air with this front, so locations below 6000 feet may
struggle to switch to all snow initially. Therefore, will not
issue a statement on this activity just yet and will let tonights
shift decide if anything is warranted. Did increased POP up to 60
percent along and just east of I-25. There may be a quick 1 to 2
inches of snow with this activity before it dissipates by sunrise
Sunday. Otherwise, expect less than an inch of snow west of
Interstate 25 where slick and icy roads may be more of an issue.
The upper level trough will rapidly move southeast of the area for
Sunday. It will be cooler, but still around seasonal norms with
highs in the 40`s. Models then show an upper level ridge axis
pushing into the area for Monday, with temperatures increasing
into the upper 40`s to mid 50`s for most locations.
.LONG TERM...(Tuesday through Friday)
Issued at 245 AM MST Sat Jan 6 2018
Broad upper-level ridging will quickly flatten early in the period
with a vigorous disturbance tracking across CA between 00z and 12z
Tuesday. We should see one more warm, generally dry day on Tuesday
across southeast WY and the western NE Panhandle in advance of the
aforementioned system. There are a few notable differences between
the GFS/ECMWF concerning the track/intensity of this wave, but are
in agreement with a fast moving system ejecting across the central
and southern high plains on Wed. Meanwhile, an intense arctic cold
front will blast southward across the CWA. The models show intense
H25 jet energy diving across the Pacific Northwest midweek, so our
confidence is high in a fairly widespread precipitation episode on
Wednesday/Thursday. Accumulating snow is likely, along w/ a period
of strong winds. Impacts from winter conditions look to be a solid
bet during this time. A chinook appears to set up along & E of the
Laramie Range on Thu night/Fri, yielding a quick warming trend for
much of the area late in the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 530 PM MST Sat Jan 6 2018
Main aviation concern tonight will be the timing, areal extent,
and potential impact of snow to area terminals over the first 12
hours. Thus far, snow has yet to develop across much of southeast
Wyoming, with the only observing sites reporting in the hier
terrain south/southeast of RWL. Do expect a period of -SN to
impact especially RWL, CYS, and possibly as far east as BFF.
Confidence overall is fairly low on timing/strength specifics, but
have geared the current TAF package targeting the 02-06z period at
RWL, 5-10Z period at CYS, and 06-12z period at BFF. These will no
doubt need to be tweaked. Mountains will be obscured as well for
routes crossing southeast Wyoming. Conditions will gradually
improve 12-18z Sunday, with VFR gradually returning.
&&
.FIRE WEATHER...
Issued at 1255 PM MST Sat Jan 6 2018
No Fire Weather concerns through this next week with cool
temperatures, high humidities, and chances for snowfall tonight
and again on Wednesday.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until 9 AM MST Sunday for WYZ112.
NE...None.
&&
$$
SHORT TERM...TJT
LONG TERM...CLH
AVIATION...CAH
FIRE WEATHER...TJT
Area Forecast Discussion
National Weather Service Wichita KS
557 PM CST Sat Jan 6 2018
.SYNOPSIS...
Issued at 324 PM CST Sat Jan 6 2018
A trough is still over the Northeast with the next trough over the
Rockies. The latter trough will be the highlight for the short
term portion of this forecast. High clouds can be found over
the Sunflower State with temperatures ranging from the lower 30s
in the northeast corner to around 50 in the southwest corner.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 324 PM CST Sat Jan 6 2018
Forecast highlights/challenges: Precipitation chances have
returned to the forecast for tonight into Sunday. The speed
at which the chances will be brought into the area was questionable.
Additionally temperatures given the non-diurnal trend complicated
the potential type.
The trough along the Rockies is on its eastward track and will move
across the Plains on Sunday. Ahead of this system, the southerly
winds are aiding in bringing the moisture to the north. While the
greatest moisture transport still appears to be over eastern
Kansas into Oklahoma and the Ozarks, areas further west may not be
able to contain even the slightest excitement for finally getting
a chance of precipitation.
Tonight into Sunday was certainly the most challenging part of the
forecast. Model soundings still suggest that the onset will be
drizzle given the dry air from near 850-650mb. Southeast Kansas
will have rain beginning in the morning as the system continues to
move east. Another challenge was trying to determine the low
temperatures for tonight which will obviously influence the
surface/roadway temperatures. The latest model trends do suggest a
cooler solution which was preferred. Thus the minimums were
dropped for tonight by a couple of degrees. Current frost depths
are still several inches, and the expected roadway temperatures
at the potential onset could be below freezing. Given the updated
temperature values in the forecast, freezing drizzle may occur
for areas along I-70. This is going to be something that will need
to be monitored this evening and tonight. As mentioned above, the
non-diurnal temperature trend given the warm air advection made
it difficult to determine what the hourly values will be at the
surface including on the roadways with the arrival of the
precipitation. Increasing cloud cover is going to be another
player in this game which would make temperatures not fall as
quickly. An advisory could be warranted for a couple of counties,
but there is little confidence given the current uncertainties.
Unfortunately for many people, the highest chances of measurable
precipitation are across far eastern Kansas into the Ozarks. Elsewhere
there will be a tease with the predominant type being drizzle.
Total accumulations will range from 0.05 in south central Kansas
to 0.5 of an inch in the southeast corner.
A ridge will follow this system as another system is brewing along
the Pacific coast. The warming trend continues for the first part
of the week as this system does not have cooler air associated
with it. Temperatures on the gradual rise will be welcomed with
open arms as highs return into the 50s. This is a definite
contrast to the past week as values are going above the seasonal
normals of the lower 40s.
.LONG TERM...(Wednesday through Saturday)
Issued at 324 PM CST Sat Jan 6 2018
The system mentioned above will track east to the Desert Southwest
into the Panhandles on Wednesday. There are varying degrees of
depth with this system in its northeastward progression to end
the week. Precipitation may return once more with this more
dynamic system on Wednesday into Thursday. The type of
precipitation could be rain or snow. A sharp temperature gradient
can be found with this system which will drop those highs down to
the upper 20s to upper 30s. Winds are going to pick up ahead of
and behind the frontal passage.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 554 PM CST Sat Jan 6 2018
IFR conditions are expected to develop later tonight at all sites
and persist for most of the day at most sites. Low level moisture
will stream north overnight ahead of the front with MVFR then IFR
ceilings developing. Some potential for drizzle on leading edge,
then scattered areas of light rain closer to the front.
Temperatures will increase overnight, and current HRRR and RAP
soundings suggest temperatures will be above freezing by the time
drizzle starts everywhere except possibly KRSL/KGBD. Given
uncertainty vs impact, left fzdz out of TAFs for now, but will
revisit this after perusing the 0000 UTC model runs. -Howerton
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 31 45 27 52 / 50 70 10 0
Hutchinson 29 44 26 54 / 50 70 0 0
Newton 30 42 26 51 / 50 70 10 0
ElDorado 30 43 27 50 / 40 80 10 0
Winfield-KWLD 33 45 27 51 / 50 80 10 0
Russell 25 46 23 55 / 20 30 0 0
Great Bend 28 46 24 56 / 30 30 0 0
Salina 28 44 26 53 / 50 60 10 0
McPherson 29 44 25 53 / 50 70 10 0
Coffeyville 32 44 29 48 / 20 90 50 0
Chanute 30 41 28 48 / 20 90 40 0
Iola 29 40 28 48 / 30 90 40 0
Parsons-KPPF 31 42 29 48 / 20 90 50 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...VJP
SHORT TERM...VJP
LONG TERM...VJP
AVIATION...PJH
Area Forecast Discussion
National Weather Service Miami FL
752 PM EST Sat Jan 6 2018
.UPDATE...
The 00Z MFL sounding depicts dry air residing in the lower levels
with an increase in moisture near 850 mb. The flow remains from
the northeast, which has helped to moderate temperatures and bring
a couple of showers across southern portions of the east coast
metro region. However, current NWS radar shows a lull in the
precipitation. Tonight, short range models prog spotty activity to
continue through the night, mainly over the Atlantic waters. In
the update, raised PoPs over the Atlantic reflect these isolated
showers. Otherwise, all other variables appeared on track.
&&
.PREV DISCUSSION... /issued 656 PM EST Sat Jan 6 2018/
AVIATION...
VFR conditions through the TAF period for all sites. The forecast
calls for the land breeze to develop along the east coast, once
again turning the wind to the northwest. Then the models indicate
the wind will pick up again out of the northeast in the morning.
There is a chance for SHRA tomorrow afternoon for the Atlantic TAF
sites.
PREV DISCUSSION... /issued 440 PM EST Sat Jan 6 2018/
DISCUSSION...
This afternoon, surface high pressure continues to drift eastward
into the central CONUS, veering flow to northerly or north
northeasterly across the Florida peninsula. This flow pattern has
allowed for a slight increase in moisture from the Atlantic. PWAT
values rebounded to 0.63", much higher than the last few days.
Latest visible satellite imagery shows a line of thick strato- cu
streaming over Miami- Dade county from the the northeast. This
line of showers has been persistent for the majority of the day,
stretching from Miami Beach to Homestead, but dry elsewhere in the
CWA. Short term models, including the HRRR and WRF prog much of
this activity to dwindle after sundown. Tonight, northeast flow
will continue to moderate the airmass, leading to minimums higher
than the last several nights. Expect temperatures to bottom out
in the mid 50s along the east coast metro region, down to near 40
degrees west of Lake Okeechobee. These values are still around 5
degrees below seasonal norms.
Sunday through early next week: As the aforementioned surface
high pressure drifts further east on Sunday, flow will veer
further to the northeast. Thus, moisture from the Atlantic should
continue to advect towards the east coast metro. Similar to
today, expect isolated showers to develop, mainly affecting the
eastern third of the peninsula. Instability parameters appear
rather weak, so not anticipating any thunder with this activity.
Maximum temperatures could actually break 70 degrees in most
areas, creeping back to within a few degrees of seasonal norms. By
early next week, the surface high will drift over the mid
Atlantic, eventually veering our winds out of the east. This
pattern will lead to slightly warmer weather and more persistent
showers moving onshore from the Atlantic.
Mid next week: The GFS and ECMWF both a agree in dropping a
closed low into the Gulf of Mexico, then slowly drift it eastward
towards the Florida peninsula. The ECMWF produces a stronger low,
advecting in deeper tropical moisture and greater instability.
Meanwhile, the GFS generates a weaker low with less moisture and
instability. In either solution, rain chances increase by Tuesday
or Wednesday next week as this feature approaches.
MARINE...
High pressure building to the north this weekend will
lead to breezy east-northeast winds over the local waters around
15-25 KT. Waves will mainly range from 4 to 6 feet through this
weekend. A few showers are possible over the local Atlantic the
next few days, with increasing rain chances early next week.
BEACH FORECAST...
Breezy north northeast winds will veer northeasterly tonight and
Sunday, maintaining a high risk for rip currents along the
Atlantic beaches.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 52 68 63 74 / 10 30 40 30
Fort Lauderdale 55 69 63 74 / 10 40 40 30
Miami 55 70 64 77 / 10 30 40 30
Naples 45 70 53 77 / 0 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Sunday evening for FLZ168-172-173.
AM...Small Craft Advisory from 7 AM Sunday to 4 PM EST Monday for
AMZ650-651-670-671.
GM...None.
&&
UPDATE...27/JT
DISCUSSION...27/JT
MARINE...27/JT
AVIATION...13
BEACH FORECAST...27/JT
Area Forecast Discussion
National Weather Service Norman OK
936 PM CST Sat Jan 6 2018
.UPDATE...
Raised forecast min temperatures and reoriented POPs for
overnight.
&&
.DISCUSSION...
Temperatures have stayed relatively warm as clouds increase and
south/southeasterly winds increase. There will be a limit to how
low the temperatures can go given the increasing dewpoints in the
area. But even in the drier air of northwest Oklahoma,
temperatures have been rising - likely initially with increased
mixing as winds pick increase. Have updated temperatures closer to
the RAP which has shown a better trend.
As far as POPs, it still looks like drizzle will be the best bet
overnight. Both the HRRR and RAP forecast higher reflectivity
developing roughly from Mangum/Elk City to Cherokee in the 10Z to
12Z time frame. Will not get too cute with timing, but will
reorient the POPs more southwest given the HRRR/RAP signal.
&&
.PREV DISCUSSION... /issued 551 PM CST Sat Jan 6 2018/
AVIATION...
07/00Z TAFs. VFR conditions expected to become MVFR and IFR after
06Z through much of the rest of the forecast period, lingering the
longest across central and north-central parts of Oklahoma. There
will be areas of MVFR/IFR conditions across far western Oklahoma
after 06Z through at least 14Z before winds veer quicker to
southwest/westerly ahead of cold front. Widespread drizzle/fog
with stratus overnight all but far northwest Oklahoma. Best rain
chances will be after 18Z across eastern half of Oklahoma.
Clearing is expected within a couple hours of fropa tomorrow
afternoon.
PREV DISCUSSION... /issued 301 PM CST Sat Jan 6 2018/
DISCUSSION...
A developing upper-level wave and its associated surface low will
cause our winds to become more southerly tonight/Sunday, bringing
warmer and more moist air into our region. This will, in turn,
cause our chances for rain to increase quite a lot by Sunday
afternoon. Some drizzle is expected overnight in a shallow
moisture layer near the surface. Instability will be lacking for
thunderstorms over most of our forecast area, but some weak
instability may be enough for a few flickers of lightning over our
south-central and southeast counties Sunday afternoon and early
evening.
After a brief "cooling" on Sunday (temperatures will still be
mostly above average for this time of year), temperatures will
begin to rise again on Monday. By Wednesday, moderate south to
southwest winds will bring the warmest weather we`ve had in a
couple of weeks. They will also raise the fire risk.
A strong cold front will push temperatures back below average for
Thursday through the end of the week. There may be some light
rain with this system, but chances appear to be very low at this
point, as relatively dry air should be in place at that time.
Medium-range models show another cold front arriving around
Saturday, which would prevent the warmup that was previously
expected...and this forecast includes a downward revision in
temperatures for next weekend.
CmS
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 47 51 34 52 / 20 80 30 0
Hobart OK 47 53 31 57 / 20 40 10 0
Wichita Falls TX 50 59 34 55 / 10 40 20 0
Gage OK 40 50 28 60 / 20 20 0 0
Ponca City OK 39 48 30 52 / 30 80 20 0
Durant OK 46 54 38 52 / 10 80 70 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$