Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/05/20
Area Forecast Discussion
National Weather Service Green Bay WI
528 PM CST Tue Feb 4 2020
Updated aviation portion for 00Z TAF issuance
.SHORT TERM...Tonight and Wednesday
Issued at 244 PM CST Tue Feb 4 2020
The latest RAP analysis and satellite/radar imagery show arctic
high pressure centered over the northern Plains and a stalled
front over the Ohio Valley. A period of clearing has moved over
northern WI as lake effect clouds retreated closer to Lake
Superior and mid/high clouds moved east of Wisconsin. Meanwhile,
more mid and high clouds are moving northeast over the central
Plains. With a cold and dry airmass that is more typical of
winter in place across the region, forecast concerns continue to
revolve around clouds and temps.
Tonight...The arctic high pressure will become centered across the
region. Normally this would be conducive for tanking temps, but
guidance insists on periods of mid and high clouds overhead. The
clouds will likely be more widespread and thicker over southern
parts of the region, while clouds should be thinner over the
north. As a result, temps should be substantially colder across
the north (where deeper snow pack exists). Used a blend of the
statistical guidance and the previous forecast as a starting
point, then made a few minor adjustments to tweak temps up where
more clouds should be present. This put lows ranging from near 10
below over the northwoods to the middle teens near Lake Michigan.
Wednesday...High pressure will remain centered across the region.
Mid and high clouds should exit for a time during the morning
before they return in the afternoon ahead of the developing
cyclone over the southern Plains. Perhaps tweaked temps up a tad
from the previous forecast, but still mainly in the middle 20s.
.LONG TERM...Wednesday Night Through Tuesday
Issued at 244 PM CST Tue Feb 4 2020
The main highlights for the extended forecast are the various
chances for light snow and temperatures remaining near or above
normal.
Wednesday night through Thursday...An upper-level trough
positioned over the central U.S. will help a surface low pressure
system move northeast over the central Appalachia region Thursday
morning. Although models have been somewhat consistent with the
northwest portion of this system bringing light snow to portions
of southeastern Wisconsin, they are not all in agreement with how
far north to bring the snow. Continued the light snow
accumulations up to 2 inches in east-central Wisconsin by Thursday
evening, with locally higher amounts in Manitowoc County. As the
main upper-level trough moves over Wisconsin Thursday evening and
the low pressure system pushes further east, it is possible for
some lake enhanced snow to develop over Manitowoc and Kewaunee
County Thursday night.
Friday through Saturday...The upper-level pattern will transition
to a northwest flow over the Upper Mississippi Valley by Friday
morning. An weak embedded shortwave riding the northwest flow
looks to move over the region sometime between Friday morning and
Saturday. Any snow associated with this shortwave would be
light, with the best chances across northern Wisconsin.
Rest of the extended...By early Sunday morning, the upper-level
pattern will transition to a zonal flow stretching across the
entire CONUS, with a 125+ knot jet and a mid-level shortwave
moving into the Upper Mississippi Valley. Model guidance appears
to be in decent agreement with this system bringing accumulating
snow to the region. Although some uncertainty remains with the
timing and exact location of highest precipitation, confidence is
high enough to increase PoPs to likely for Sunday afternoon. An
area of high pressure will then move in behind this system for
Monday, which may allow for some peeks of sunshine.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 528 PM CST Tue Feb 4 2020
High pressure is forecast to build into Wisconsin tonight and
slide to our east on Wednesday. Still expect to see mid and high
clouds spread across the area over the next 24 hours as a system
organizes over the southern Plains and taps gulf moisture. Light
and variable winds expected for tonight, then become southwest at
5 to 10 knots on Wednesday.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Hykin
AVIATION.......AK
Area Forecast Discussion
National Weather Service Wichita KS
939 PM CST Tue Feb 4 2020
.UPDATE...
Issued at 933 PM CST Tue Feb 4 2020
Thinking essentially remains unchanged regarding accumulating
snow late tonight through Wednesday. Latest model data, including
the HREF, continues to indicate 1-4" (locally 5") mainly east of
the KS Turnpike. Highest amounts should be extreme southeast KS
(e.g. Labette, Cherokee, Crawford), where amounts closer to 4-6"
are possible. Thinking locations generally west/northwest of KS
Turnpike will see one-half inch at best, including Wichita metro.
Central KS should see little if any snow.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 400 PM CST Tue Feb 4 2020
Late this afternoon and early evening, most light snow/freezing
drizzle has ended up in central Kansas, though a brief flurry or
light patchy drizzle cannot be ruled out over the next few hours.
However, any lingering precipitation would be very light, and few
impacts are to be expected from this activity. The winter weather
advisory has thus been adjusted accordingly.
After a break in precipitation this evening, things should start
to ramp back up for mainly southeast Kansas but portions of south
central Kansas as well by late tonight and tomorrow morning.
During the day tomorrow in far southeast Kansas, an impressive
axis of mid-level frontogenesis and lift will coincide with a
southern stream shortwave that will move across central and
eastern Oklahoma and into the Missouri/Arkansas region during the
day. An analysis of RAP model forecast soundings from the
Labette/Neosho County area shows a very deep, saturated profile
extending well into the ice producing layer aloft and a lack of a
warm nose that exceeds the freezing mark. As a result,
precipitation should be all snow. Given potential mesoscale
processes and a narrow band of impressive lift, it is not out of
the question for an axis of much higher snowfall amounts somewhere
in the vicinity of where the the
Kansas/Oklahoma/Missouri/Arkansas borders meet. Though there is
still some uncertainty on where the heaviest accumulations will
exactly land, felt, in collaboration with surrounding WFOs, that a
Winter Storm Warning was justified to account for this potential,
especially in the Montgomery, Neosho, and Labette area.
Another question that remains is how much snowfall will be
received in areas further to the west in south central Kansas. In
general, snowfall amounts should taper off the further west you
go, with a trace to two inches likely along the Kansas Turnpike
corridor into the Wichita metro and then slightly higher 1-3
inches roughly between the Eureka and Chanute corridors. A few
models (including HREF data) show a second lighter axis of
snowfall just west of the main one in far southeast Kansas, so
felt keeping the Winter Weather Advisory in tact as far west as
Harper County was justified at this time, though it is possible
that later shifts will need to make slight adjustments based on
trends.
After this system moves off Wednesday night, drier air and a slow
but steady warm-up will ensue in the next few days. The main
mid/upper trough will translate east of the forecast area by late
Thursday, and do think that at least some cloud cover and
northerly flow will limit temperatures to the 30s and 40s for
Thursday (with the coldest areas being in southeast Kansas
corresponding to fresh snowfall). Temperatures should be slightly
warmer on Friday, though once again cloud cover may be the
limiting factor to prevent them from reaching higher than the mid
40s or so.
.LONG TERM...(Saturday through Tuesday)
Issued at 400 PM CST Tue Feb 4 2020
Few changes were made to the long term forecast. A surface ridge
will slide across the forecast area this weekend keeping the
weather dry as temperatures gradually increase into the upper 40s
or low 50s. Early indications are that some light rain or a wintry
mix may be possible in southeast Kansas early next workweek.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 550 PM CST Tue Feb 4 2020
MVFR ceilings will persist overnight across the region. Cannot
rule out patchy areas of light snow or flurries overnight, but
accumulations will be little if any. Better chances for
accumulating snow and associated IFR conditions arrive from the
southwest late tonight through Wednesday, especially along and
southeast of the KS Turnpike corridor. Wichita should be on the
far western edge of this snow.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 24 32 18 39 / 40 40 10 0
Hutchinson 21 31 17 40 / 20 20 0 0
Newton 22 30 17 38 / 30 40 10 0
ElDorado 24 31 17 37 / 60 70 20 0
Winfield-KWLD 25 32 17 38 / 70 70 30 0
Russell 19 32 14 41 / 20 10 0 0
Great Bend 18 33 14 43 / 20 10 0 0
Salina 22 31 16 40 / 20 10 0 0
McPherson 21 30 16 38 / 20 20 0 0
Coffeyville 28 32 16 35 / 70 90 50 0
Chanute 27 31 16 33 / 70 90 40 0
Iola 26 30 16 33 / 60 90 40 10
Parsons-KPPF 28 32 16 34 / 70 90 40 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight CST Wednesday night for
KSZ052-053-068>072-083-091>095-098.
Winter Weather Advisory until 6 AM CST Wednesday for KSZ096-099-
100.
Winter Storm Warning from 6 AM Wednesday to midnight CST
Wednesday night for KSZ096-099-100.
&&
$$
UPDATE...ADK
SHORT TERM...TAV
LONG TERM...TAV
AVIATION...ADK
Area Forecast Discussion
National Weather Service Jackson MS
543 PM CST Tue Feb 4 2020
.UPDATE...
Updated for 00Z aviation discussion
&&
.AVIATION...
00Z TAF discussion:
Some light rain showers will move through parts of the region this
evening. SHRA/TSRA may occurr at GLH/GWO after 02-06Z. Overall,
flight categories will drop to IFR/LIFR ceilings tonight with
potential for a slight improvement before additional storms
tomorrow afternoon through the evening hours. Flying conditions
not expected to be good for the next 18-24 hours.
&&
.DISCUSSION...
Tonight & Wednesday:
Overall an active weather maker is on tap for the next 24 hours as a
strong cold front moves into the region. Severe weather & flash
flooding potential will be on the increase ahead of this strong cold
front through Wednesday.
Tonight: As a strong trough digs over the lee side of the Rockies &
into the southern Plains & Texas Panhandle tonight, expect a lead
shortwave jet to lift out to the east-northeast into the
Appalachians. In addition, the stronger spoke of energy will be
diving far to the south, while another area of forcing will be
swinging to the east across southern Canada. Lastly, the strong mid-
level ridge will be centered over the southwestern Atlantic &
Caribbean Islands, leading to continued southwesterly return flow of
moisture into the region. This -PNA blocking pattern will lead to a
gradual slowing of the eastward progression of the trough &
attendant cold front. In addition, the juxtaposition of severe
weather parameters (i.e. bulk shear & limited lapse
rates/instability) & southwest-northeast parallel orientation of the
cold front, looks to limit severe weather potential. This will lead
to a slowdown of any storms ArkLaMiss Delta. Due to very limited
forcing & severe potential, decided to remove the "Marginal" severe
threat for the overnight hours. Can`t rule out an isolated strong-
severe storm or so across the Delta, but coverage looks limited
enough to not mention in the HWO/graphics.
Wednesday: As the mid-level ridge breaks down over the southwestern
Atlantic & Caribbean Islands, the synoptic pattern will quickly
amplify & eject to the east-northeast. This will lead to strong
surface cyclogenesis along the baroclinic zone from the western Gulf
of Mexico up through ArkLaTex, ArkLaMiss Delta & Mid-South. This
will continue to provide feedback into the synoptic mid-upper level
jet & will intensify to nearly 90-130kts @ 500mb & 300mb,
respectively. With strong surface cyclone rapidly deepening from
around 1005mb to nearly 1000mb across the ArkLaMiss Delta by mid-
afternoon, strong reflection low-level wind fields response will
occur. In addition, juxtaposition of increasing mid-level lapse
rates & strong mid-deep layer shear (i.e. 6.5 deg C/km lapse rates @
700-500mb & 40-65kts effective bulk shear @ 0-3km & 0-6km,
respectively) will lead to very favorable severe weather
environment.
Some global consensus shows some potential for some coastal
convection, but there remains a good feed of low-level Theta E
across central to southwest Mississippi & northeast Louisiana to
serve as an impetus for severe weather development along the
Mississippi River around noon & to spread east-northeast through
the afternoon to evening. Some hi-res guidance indicates even more
concerning juxtaposition of parameters, with some experimental
HRRR runs showing significant tornado parameter (STP) approaching
6+, bullseye over southwest Mississippi & northeast Louisiana &
central portions of ArkLaMiss on the northern gradient & strong
updraft helicity swaths. This environment will be very anomalously
destabilized (i.e. 1000-1500+ MLCAPE) & sheared. Strong clockwise
curving hodographs will lead to supercell & tornado potential,
with some increasing potential for even more significant severe
weather & upgrade in future outlooks possible. For now, in
conjunction with SPC, expanded the "Slight" risk area for severe
weather further northwest across the Delta, with "Marginal" risk
area across the far northwest Delta. All modes of severe weather
are possible, including damaging winds of 60-70mph, large hail of
quarter to golf ball size & tornadoes. Keep a close eye on future
outlooks for any increase in severe weather potential & upgrades
in the HWO/graphics.
In addition, there will be flash flooding potential as well as some
areas in synoptic jet structure will be diffluent over the
baroclinic zone. This will lead to some heavy rain potential near
the developing surface low. Further to the southeast, there will
remain convective potential in conjunction with anomalous deep layer
moisture & very wet antecedent conditions that haven`t completely
dried out. Due to that, rainfall of 1-3 inches, with locally higher
amounts, is possible across the region. Local hi-res CAM guidance &
HREF suite supports this idea. Due to more mesoscale than synoptic
driven details, will hold off on any Flash Flood Watch for now. In
coordination with the Weather Prediction Center (WPC), expanded the
"Limited" risk area for flash flooding for the entire region
Wednesday & into Wednesday night.
Lastly, due to a strong developing pressure gradient some gusts
upward of 25-30mph can`t be ruled out. Expect these winds to really
ramp up into the afternoon as the surface low rapidly deepens &
moves through the Delta. For now, winds shouldn`t be high enough for
a Wind Advisory but will keep an eye on this. /DC/
Wednesday night through next Tuesday: Overall, a wet and
potentially stormy pattern can be expected on average during the
long range portion of the forecast as a -PNA pattern featuring a
western CONUS trough and eastern CONUS ridge re-establishes
itself.
Initially, the threat for severe storms and heavier rain will
shift east of the area later Wednesday night as the cold front
pushes through the forecast area. With the shortwave trough
lagging well behind the surface front, expect chances for
additional light rainfall to continue through Thursday into
Thursday evening as cold advection continues. Thereafter, a brief
period of dry weather and seasonable temperatures can be expected
as we go through Friday into Friday night. But a quick-moving
shortwave trough will move in with a chance for showers returning
Saturday. Another brief period of dry weather will take place
Sunday before unsettled weather returns to start next week. A more
significant trough could approach for the middle of next week and
this will need to be monitored for more impactful weather. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 64 73 47 50 / 53 97 90 64
Meridian 63 74 53 55 / 45 95 97 77
Vicksburg 64 72 46 48 / 60 98 73 49
Hattiesburg 63 74 54 56 / 39 98 95 78
Natchez 65 72 45 48 / 50 98 70 51
Greenville 56 62 43 44 / 80 96 66 48
Greenwood 61 68 45 47 / 82 98 85 62
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
28
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Wednesday)
Issued at 311 PM CST Tue Feb 4 2020
An upper level trough extended from the central high Plains southwest
across AZ. Minor mid-level perturbations embedded within the
southwesterly mid level flow east of the trough axis has provided
enough ascent for slight snow, snow grains and sleet to develop
across the southwest and southern counties of the CWA. There was
also weak isentropic upglide at the 285 K level. At 115 PM an area
of light snow has been expanding across Dickinson, Geary and Morris
counties. This area of light snow will continue to push east-northeast
and may accumulate up to a half inch across the south central
counties and along the I-70 corridor late this afternoon into the
early evening hours. The light snow and snow grins will be on and
off through most of the night but only expect very light
accumulations. As the main H5 trough shifts east across the
central and southern plains, A more intense PV anomaly will shift
northeast cross central OK into southeast KS. Mid level
frontogenesis will increase ahead of the PV anomaly across east
central KS through the day. The colder temperatures will cause a
higher liquid to snow ratio of around 16:1. At this time the
heavier snowfall will remain south and southeast of the CWA, with
4 to 6 inches possible across northeast OK, southeast KS into
southwest MO. Light snow will expand north-northeast across east
central KS after 12Z WED and continue through the afternoon hours
of Wednesday before shifting east of the area Wednesday evening.
Total snowfall amounts will be up to 1 inch along the KS turnpike,
with 2 to 3 inches of snowfall possible southeast of I-35 across
Coffey and Anderson Counties by Wednesday evening. I`m leaning
more towards the HREF and WRF solutions for this forecast. There
will be a tight gradient on the northwest edge of the light snow
band. Northeast and north central KS will remain dry, if the PV
anomaly tracks a bit farther to the east, then the northern and
western portions of east central KS may remain dry and the HRRR
model solution is hinting at this potential.
Since there is snow already falling across
central KS and moving into east central KS later this afternoon, I
will keep the winter weather advisory going through the evening
hours. After midnight the winter weather advisory will be continued
from Morris to Jefferson counties and points southeast for the next
round of light snow on Wednesday. Highs on Wednesday will only reach
the upper 20s to around 30 degrees.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 311 PM CST Tue Feb 4 2020
Wednesday night, the light snow will be ending during the evening
hours from west to east across east central KS as the upper trough
shifts east into MO and the PV anomaly moves northeast into western
IL. Lows will drop into the mid to upper teens.
Thursday through Saturday, the plains will be under northwest flow
at mid-levels. A few weak perturbations embedded in the northwest
flow may provide some snow flurries Friday into Friday night. Highs
Thursday will only reach the mid to upper 30s with slightly warmer
temperatures on Friday and Saturday with highs in the upper 30s to
lower 40s.
Saturday night through Sunday, an upper level trough will move
onshore across the Pacific northwest and dig southward into southern
CA. Highs Sunday will reach the mid to upper 40s.
Sunday night through Tuesday, a norther stream H5 trough will move
east across the northern plains and stronger low-level CAA will
cause a cold front to move southward across the CWA. As the upper
trough across southern CA shifts east across the southwestern US
into the Plains on Tuesday. A wintry mix of precip will develop
late Sunday night as isentropic lift develops ahead of the H5
trough as the H5 trough tracks into the plains. The stronger
ascent will cause more widespread precipitation to develop Monday
night into Tuesday. There is the potential for heavier snowfall
across western and northern KS with a freezing rain and snow mix,
changing to rain across east central KS Monday night into Tuesday.
HIghs Monday and Tuesday will be in the mid 30s to lower 40s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 531 PM CST Tue Feb 4 2020
Gusty northeast winds continue into the overnight period before
gusts subside. CIGS should drop a category into MVFR after 06Z at
Topeka terminals and a few hours later around KMHK. A batch of
light snow is then expected to overspread terminals around 12Z
Wed, so lower visibilities are also expected at that time.
Current thinking is that snow will taper off a few hours later but
stratus will stick around for most of this TAF period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight CST Wednesday night for
KSZ026-037>040-054>056-058-059.
Winter Weather Advisory until midnight CST tonight for
KSZ022>024-035-036.
&&
$$
SHORT TERM...Gargan
LONG TERM...Gargan
AVIATION...Teefey
Area Forecast Discussion
National Weather Service Tulsa OK
550 PM CST Tue Feb 4 2020
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
IFR to MVFR ceilings will continue through the period across the
CWA. Winter weather chances increase overnight for Eastern
Oklahoma with rain chances for Northwest Arkansas. During the
morning hours...snow and sleet becoming all snow are expected for
Northeast Oklahoma with a rain/wintry mix elsewhere. Toward the
end of the TAF period...snow should be common for most locations
with light rain remaining for the KFSM area. Within the
snow/sleet...periods of LIFR/IFR conditions with heavier bands of
precip will be possible.
&&
.PREV DISCUSSION... /Issued 503 PM CST Tue Feb 4 2020/
UPDATE...
A quick update was made to the grids for this evening, inserting
the potential for a light wintry mix across northeast Oklahoma.
See discussion below.
DISCUSSION...
A lead impulse is ejecting northeast across the Panhandles and
will lift up into Kansas this evening, ahead of the main positive
tilt upper trough to the west. Lift with this feature is producing
some light precip across western OK. There have been reports of
light snow in NW OK with this activity north of the freezing line.
The latest HRRR guidance suggests that some of this light precip
will spread across northeast OK this evening. If this does occur,
precip amounts will be pretty light and shouldn`t cause issues.
The main show will arrive after midnight and more toward Wednesday
morning.
Lacy
PREV DISCUSSION... /Issued 322 PM CST Tue Feb 4 2020/
DISCUSSION...
Main forecast concerns continue to revolve around the impending
winter storm set to impact the region late tonight and into
tomorrow. The Winter Storm Warning that was issued earlier this
morning will be left unchanged, with the previous Winter Storm
Watch now converted to a Winter Weather Advisory.
Rain showers continue across the far eastern fringes of the
forecast area this afternoon, resulting from an upper level
disturbance moving through western Arkansas at present. Once this
moves out, there will be a break in the accumulating
precipitation, although there should continue to be a few areas of
drizzle or freezing drizzle this evening.
The main show should begin to move into eastern Oklahoma from the
southwest after midnight and likely after 3 am. For areas roughly
along the I-44 corridor, the low and mid level temperature
structure should support a wintry mix, with portions of northeast
Oklahoma to the north and northwest of the Tulsa metro the only
areas being cold enough to support all snow at the onset. This
will change through the day as the cold air deepens, with all snow
likely by midday for most of northeast and a portion of east
central Oklahoma. The highest snow/sleet totals still look to
occur along the I-44 corridor, where embedded convective elements
and resultant enhanced upward motion may lead to locally higher
snow/sleet rates. These higher rates currently appear most likely
beginning during the latter part of the morning commute in the
Tulsa metro area. Some concern exists that the period of sleet
will last longer than currently forecast, leading to lower overall
snow/sleet totals so this will have to be watched closely. Another
area of concern includes portions of southeast Oklahoma into far
northwest Arkansas. Depending on surface temperatures, ice
accumulation could become a bigger problem than currently
forecast, especially in the higher terrain areas of northwest
Arkansas. Current accumulations are a tenth of an inch or less in
much of this part of the forecast area, with isolated from one to
two tenths, but if surface temperatures are just a couple of
degrees colder than forecast, accumulations could be higher for
areas from McAlester northeastward into northwest Arkansas.
A lull in the activity is expected during the afternoon before
another band of lighter snow associated with the main upper level
trough affects mainly northeast Oklahoma. Additional accumulations
of an inch or maybe two could occur through tomorrow evening
before the entire system makes a quick exit.
Warmer and drier weather will be on the way for the latter part
of the week, although the expectation of snow/sleet cover across a
large part of northeast Oklahoma should keep temperatures low,
especially at night, for the next couple of days. Another storm
system for the beginning of next week could bring thunderstorms to
portions of the area, with colder air to follow toward mid week.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 29 32 17 38 / 60 100 50 0
FSM 39 40 26 38 / 30 100 40 0
MLC 32 34 20 40 / 60 100 20 0
BVO 27 32 16 37 / 60 100 50 0
FYV 35 37 24 35 / 30 100 60 0
BYV 34 35 24 34 / 20 100 70 0
MKO 31 33 20 36 / 60 100 40 0
MIO 30 32 16 34 / 50 100 80 0
F10 29 31 17 38 / 70 100 30 0
HHW 36 39 26 40 / 50 100 20 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Winter Weather Advisory from 3 AM Wednesday to midnight CST
Wednesday night for OKZ049-068>075.
Winter Storm Warning from 3 AM Wednesday to midnight CST
Wednesday night for OKZ054>067.
AR...Winter Weather Advisory from 3 AM Wednesday to midnight CST
Wednesday night for ARZ001-002-010-011.
&&
$$
AVIATION.....20