Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/20/17
Area Forecast Discussion
National Weather Service Bismarck ND
939 PM CST Sun Feb 19 2017
.UPDATE...
Issued at 935 PM CST Sun Feb 19 2017
Dense fog continues over northwest North Dakota per latest webcams
and observations. Latest HRRR tries to spread the dense fog east
but so far it has been a bit reluctant to do so and visibilities
further east have been holding above a couple miles so far. Will
continue to monitor and if need be expand the advisory if
visibilities start to diminish. As for rain chances, have brought
a slight chance of precip in a bit earlier over the far west with
development over eastern Montana. Otherwise, remaining changes
were minimal.
UPDATE Issued at 630 PM CST Sun Feb 19 2017
Dense fog has developed over portions of northwest North Dakota,
with visibility in the Tioga and Stanley area dropping under a
quarter mile. Latest HRRR spreads this out over the northwest
this evening so have issued a Dense Fog Advisory for the northwest
5 counties in North Dakota. Will keep it until early Monday
morning when models suggest things starting to clear out. Will
monitor surrounding areas to see if they need to be added as the
evening wears on, but for now they look to be good with a few
areas dipping down a bit.
&&
.SHORT TERM...(This evening through Monday)
Issued at 314 PM CST Sun Feb 19 2017
Tonight, a shortwave trough will begin to sweep across the
Northern Plains. A cold front associated with it will shift
through western and central North Dakota, with increasing chances
for precipitation after midnight. The bulk of the precipitation
should be rain, however, light freezing rain is a possibility
across north central North Dakota tonight into Monday morning.
Temperatures should only marginally support freezing rain for a
few hours during the early morning hours. Therefore, impacts
should be limited, but even a brief period of freezing rain can
cause hazardous travel.
.LONG TERM...(Monday night through Sunday)
Issued at 314 PM CST Sun Feb 19 2017
Monday looks breezy as the surface cold front and upper shortwave
trough sweep through. The system looks a little faster than
previously forecast, so the bulk of the low level cape and
shear should be further east by the time afternoon heating kicks
in. This will limit chances for thunderstorms to far southeast
North Dakota.
Another system slides through beginning Tuesday afternoon through
Wednesday afternoon, mainly affecting northern North Dakota.
Colder air will filter in behind this system late Wednesday into
Thursday. Rain is forecast to change over to snow across the
north Tuesday night. There is the potential for up to one inch in
the far north. Across the south, expect mild temperatures Tuesday
with highs in the 50s, and possible lower 60s southwest. Cooler
Wednesday with highs in the lower 30s north to mid 40s south.
Another system slated for Thursday through Friday continues to
trend snow chances south of Interstate 94. Because of this more
southerly track, colder air via a northerly flow will encompass
all of western and central North Dakota. Expect highs only in the
20s Friday and Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 630 PM CST Sun Feb 19 2017
Widespread LIFR condition in fog will continue to develop over
northwest North Dakota tonight and remain into Monday morning
before gradually improving. Areas of IFR visibility will be
possible over north central into portions of south central North
Dakota tonight into tomorrow morning with some fog and light rain.
Conditions will gradually improve throughout the area mid-day
Monday into the afternoon.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 8 AM CST /7 AM MST/ Monday for NDZ001-
002-009-010-017.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JJS
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
712 PM CST Sun Feb 19 2017
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...Currently the KBRO radar is showing an area of
convection firing up west of Zapata County moving up to the NNE.
The 00z BRO sounding continues to show a CAPE of 2800 j/kg.
However a fairly strong cap remains in place over the RGV. The
latest HRRR model run looks to be initializing on the ongoing conv
pretty well with this model showing the conv primarily impacting
the northern and western counties through around 09z mainly
staying clear of the lower RGV airports. The HRRR then brings a
more ragged line of conv through the lower RGV during the morning
hours tomorrow. The conv will then end after midmorning tomorrow
as drier and more stable air moves into the region as the 500 trough
axis moves east. So will bring down the ceilings to MVFR/IFR
levels late tonight into early Monday generally in line with the
trends indicated by the HRRR with VFR conditions returning late in
the current TAF period.
&&
.DISCUSSION...Updated for latest marine discussion below.
&&
.MARINE...Surface obs from across the marine locations indicate
that the winds across the bay have dropped down below SCA levels
while Buoy020 is showing stronger SE winds at 20g25kt with swells
near 6 feet this evening. Expect the PGF ahead of the surface low
pressure system to our west to remain stronge enough for the Gulf
waters to maintain hazardous winds and seas through around
midnight tonight. So will post up an SCA for the Gulf waters.
&&
.PREV DISCUSSION... /issued 318 PM CST Sun Feb 19 2017/
..Potential still exists for marginal severe weather threat
across portions of deep south Texas this evening through early
Monday morning...
SHORT TERM (Tonight through Monday Night): Satellite and radar
images indicate showers and isolated thunderstorms continue to
develop across portions of northern Mexico northward across portions
of southwest Texas and the Big Bend region ahead of the 500mb trough
moving eastward across the southwest United States and northwest
Mexico this afternoon. The cap across the area continues to inhibit
convection across the CWA this afternoon but models indicate the cap
will erode across northern and western portions of the CWA late this
afternoon into early this evening. This will allow showers and
thunderstorms...some possibly severe...to develop rapidly across
western portions of the ranchlands and extreme western portions of
the Rio Grande valley this evening through tonight before evolving
into a quasi-linear convective system (QLCS) and moving eastward
across the CWA late tonight into early Mon morning. There still is
some uncertainty if the cap along the coastal sections will erode
and what impacts that would have on the potential squall line
reaching the eastern portions of the CWA. Will continue to mention
high pops for tonight into Monday with heavy rainfall/severe wording
for tonight. Per the latest SPC outlook...the main severe threat
appears to be damaging winds but large hail and isolated tornadoes
cannot be ruled out especially is isolated thunderstorms develop
ahead of the main line. The bulk of the rainfall should be north and
east of deep south TX tonight into Monday but heavy rainfall can be
expected with thunderstorms associated with the QLCS.
Drier air will filter into the western portions of the CWA Monday
into Monday night as the flow aloft veers from the south to
southwest and eventually west as a cut-off low develops across
southwest TX and moves across deep south TX Tues night. Rain chances
will diminish from west to east Mon afternoon through Mon evening as
a result.
LONG TERM (Tuesday through Sunday): The forecast begins with a
closed 500mb low over the middle Texas coast Tuesday morning. The
mid level low will eventually move eastward over the western Gulf
of Mexico Tuesday night into Wednesday. Some wrap around moisture
on the backside of the 500mb low will support some isolated
convection along the Lower Texas coast Tuesday. Differences
continue between the GFS/ECMWF with the placement of the mid level
low and the amount of available moisture. Subsidence will prevail
across the region Tuesday night and Wednesday courtesy of
northerly flow aloft and at the surface. Winds become southeast on
Thursday as surface low pressure develops across the Plain
states. A dry cold front is expected to move across Deep South
Texas Friday night. Breezy northeast winds Saturday morning
quickly veer to the southeast Saturday night as surface high
pressure moves east.
MARINE:
Tonight through Monday night: Seas were near 5 feet with south to
southeast winds near 18 knots at buoy020 early this afternoon.
Moderate to strong south to southeast winds will prevail offshore
the lower Texas coast tonight with light to moderate south to
southwest winds across the Laguna Madre before a convective
frontal boundary/weak cold front moves across the coastal waters
late tonight into early Mon morning. Winds and seas will be
considerably stronger and higher as a line of showers and
thunderstorms...likely a squall...moves through the coastal waters
late tonight into early Monday. In the wake of the cold
front...winds will be shifting to the north and northeast in the
wake of low pressure developing along the frontal boundary
offshore the lower TX coast Monday. Light northeast winds will
prevail across the coastal waters Mon night as the weak frontal
system offshore moves farther east into the western Gulf of
Mexico.
Tuesday through Friday: Light to moderate northwest to north winds
will prevail across the Lower Texas Coastal waters through Wednesday
as high pressure spreads over the area. Winds will gradually turn to
the southeast Wednesday night then south on Thursday as high
pressure moves east. Low to Moderate seas expected through the
period.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory until midnight CST tonight for GMZ150-155-
170-175.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
Short Term...60
Long Term...64
Graphicast/Upper Air...62
Area Forecast Discussion
National Weather Service Cleveland OH
640 PM EST Sun Feb 19 2017
.SYNOPSIS...
Temperatures will continue to run well above normal this
week. A cold front Tuesday will not even be able to break the
streak. A stronger system Friday will bring colder air back to
the region for the weekend.
&&
.NEAR TERM /THROUGH MONDAY/...
Slight increase in cloud cover overnight as cirrus streaming
around the upper level ridge arrives with periods of partly
cloudy skies. There is also a considerable gradient noted in
dewpoints across central Ohio at 23Z with 35 degrees observed
FDY/MNN and 45 degrees at DAY/CMH. HRRR model data shows
extensive fog expected to develop across much of Indiana and
southern Ohio in the moisture rich area. Did introduce a mention
of patchy fog overnight in the southwestern counties as a light
east to southeast wind will put these locations on the fringe of
the expected fog/stratus deck.
Previous discussion...In general high pressure will be in
control across the area tonight. Skies will be clear through the
evening and with light winds...temperatures will fall quickly
toward and after dark. The remnants of a back door cold front
will press across NY...and this may bring cloud cover into
northwest PA overnight. The bulk of the cold air stays northeast
of our area...but will likely see temperatures dip below
freezing for far eastern OH and nw PA. Others will be in the
30s. A decent amount of drying has taken place today and not
expecting fog to be all that bad. Confidence is low...but would
be most likely across the southern locations where dewpoints
remain a bit higher.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
The surface high will be shifting east of the area on Monday and
winds will come around from the east-northeast to the
southeast...and eventually south by Monday night. We will warm
nicely again tomorrow...with the exception of the immediate
lake shore where winds will remain northeast. Another spread of
upper 40s near the lake...upper 50s for most...and a few spots
hitting 60. Southerly flow Monday night will keep areas warmer
than the night before.
There is a cold front Tuesday. It has remained on target for the
daytime hours. Most of the guidance brings showers into Toledo
in the morning...midday Cleveland Mansfield and takes showers
across the eastern part of the area in the afternoon. Coverage
still does not warrant higher than 60 or maybe 70 percent. Bulk
of the upper support will be north of the area. Will still go
above guidance temperatures. There will be time for the
central/eastern areas to warm well. Guidance has been running
cool too...as would be expected in a unseasonably warm regime.
There is room though for those temperatures to not pan out...but
it will not be too far off.
Again no real cold air behind the front and with high pressure
returning to the Ohio Valley...a southwest flow will mean
another really warm day. Made no change to the mid/upper 60s we
had going.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Ridging is progged to continue across the area and our spring
pattern will continue into late week. One of the west coast storms
will dig across the southern Rockies mid week and lift out late in
the week.
In the meantime, the models are coming more into agreement of a weak
front, or at least frontogenesis, across the lower Great Lakes on
Thursday. Not sure how much rain might occur but will include at
least a chance or slight chance of showers in most areas. Warm
frontogenesis will occur Thursday night into Friday. The warm front
should move north of the area on Friday in the increasing south
flow. Again, not very confident on the amount of showers that will
occur. We will likely break into the warm sector for a while and I
suspect Friday will become very warm, perhaps nearing 70 again in
many areas.
The models have been suggesting the passage of the strong cold front
will come between late Friday afternoon and about midnight or so
Friday night. Will have higher pops for the frontal passage and will
include thunder and wind.
Colder and blustery on Saturday. Temperatures will likely drop back
to near normal. It will be colder aloft and could see a few
snow/rain showers, especially downwind of Lake Erie in the wrap
around moisture with the trough aloft. High pressure should build in
on Sunday.
&&
.AVIATION /00Z Monday THROUGH Friday/...
The weak cold front should settle over the central part of the area
tonight. Not expecting any cloudiness with the front but the weak
convergence associated with the front may aid in helping some
surface moisture pooling over our southern airports tonight.
Dewpoints have dropped late today as the airmass has mixed with the
daytime heating and not sure if the weak frontal boundary will be
enough to pool moisture to the point of having a lot of fog form
like last night. Will take a middle of the road approach and go for
some fog late tonight in the south with only a few hours of possible
ifr for fdy and mfd where wind direction should loose the northerly
component by the end of the night. Also, the cirrus moving in from
the west should help limit fog development.
Generally expect partly cloudy skies on Monday once we evaporate the
fog in the south with patches of high clouds and a light east to ne
wind.
OUTLOOK...Non-VFR may develop Tuesday and continue into Tuesday
night. Non-VFR will develop again Thursday or Thursday night and
continue at times Friday.
&&
.MARINE...
Have had some brisk west winds over the central basin this afternoon
in the vicinity of a weak cold front dropping across the south shore
of Lake Erie. Those winds will diminish quickly and veer north and
then east tonight and Monday as high pressure slides east across the
Great Lakes.
The next cold front is due later Tuesday. South to southwest winds
will pick up nicely ahead of the front and become southwest to west
behind the front. Not expecting enough wind for a small craft
advisory.
A light to moderate southwest flow will persist until the next front
drops across the lake on Thursday. Then winds will veer northwest
Thursday but come quickly around from the southeast on Friday as low
pressure tracks across the plains.
The low will be a significant storm system as it tracks across the
northern Great Lakes Friday into Friday night pushing a strong cold
front across Lake Erie Friday night.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Oudeman
NEAR TERM...KEC/Oudeman
SHORT TERM...Oudeman
LONG TERM...Kosarik
AVIATION...Adams
MARINE...Kosarik
Area Forecast Discussion
National Weather Service Dodge City KS
605 PM CST Sun Feb 19 2017
...Updated for aviation discussion...
.SHORT TERM...(This evening through Monday)
Issued at 224 PM CST Sun Feb 19 2017
Boundary layer moisture continues to increase this afternoon, as
observed with dew points across our south central Kansas counties
making it to the 50 degree threshold. Fog and expanding stratus
could redevelop just as the loss of isolation begins across that
region. Additionally, the NAM family of models has been in general
agreement with spreading showers and embedded thunderstorms north
across the area from western OK around 00 UTC and though central
Kansas though midnight, with precipitation generally ending after
that. As the precipitation moves off to the east towards early
Monday morning, the HRRR at this time developing another round of
advection fog through the highway 183 corridor, which may cause
travel problems in those areas as was the case last night and this
morning. With a wave moving through the region, the fog won`t linger
anywhere near as long as it did this morning, as westerly downslope
surface winds develop by around 12 UTC Monday.
On Monday, an 850 mb ridge shifts across western Kansas with breezy
northwest surface winds preceding light winds heading into the
evening and overnight. Temperatures may be similar to what we`ve seen
on Sunday. The initial 850 mb cold pool will quickly be replaced
with adiabatically warmed air with NAM taking surface temperatures
into the 60s by mid afternoon.
.LONG TERM...(Monday night through Sunday)
Issued at 224 PM CST Sun Feb 19 2017
Moderation right back into the climatological abnormally warm regime
through mid week is expected starting Tuesday. Looking like 80
degrees can`t be ruled out any of the days Tuesday through Thursday
near the OK line. The next wave continues to be advertised by the
models by late Thursday and Friday timeframe, with a chance for snow
and rainshowers precluding a colder and windier Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 600 PM CST Sun Feb 19 2017
The wind will gradually shift from the south to southwest toward
12z ahead of a cold front. The front will pass around 15-16z
with a wind shift to the northwest at 15 kts. VFR conditions
are expected to persist at DDC/GCK but MVFR CIGS will return
for a few hours at HYS along with a few showers between 04z
and 08z.
&&
.FIRE WEATHER...
Issued at 224 PM CST Sun Feb 19 2017
Hamilton and Kearney counties were added to the Fire Weather Watch
primarily covering northwest KS and northeastern CO for Monday
afternoon. Any combination of slightly warmer temperatures or
drier dew points than the models are showing could easily send
the area (or more) into the red flag criteria for around 3 hours
or so late Monday afternoon. Notably the ECMWF has much drier dew
points than our current mesoscale model runs. Other than that, dry
fuels and breezy winds it the afternoon would discourage outdoor
burning across the entire area west of highway 283.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 71 37 75 / 30 0 0 0
GCK 40 69 32 76 / 10 0 0 0
EHA 39 68 35 76 / 10 0 0 0
LBL 40 71 33 77 / 20 0 0 0
HYS 48 69 36 75 / 30 0 0 0
P28 52 74 39 74 / 60 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch Monday afternoon for KSZ061-062.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Finch
FIRE WEATHER...Russell
Area Forecast Discussion
National Weather Service Duluth MN
558 PM CST Sun Feb 19 2017
.UPDATE...
Issued at 421 PM CST Sun Feb 19 2017
We added a light shower to the forecast through early evening over
portions of northeast Minnesota. A few observations have reported
light rain under those echoes seen on area radars over northern
Minnesota.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 342 PM CST Sun Feb 19 2017
The focus remains on the rain likely for Monday. There was little
change to the forecast. It still looks like the Northland will see
a period of wet weather, and there could be isolated thunder.
Tonight...The Northland will continue to see very unusually warm
southerly flow, with 850 hpa temperatures about 8 to 10 degrees
Celsius. There will be increasing upper-level cloud cover
overnight as low pressure works its way east from the High Plains
into the Northern Plains. There will be increasing dew point
temperatures later tonight in advance of the approaching cool
front in the Dakotas. The cloud cover and increasing dew point
temperatures will help to bolster the overnight temperatures to
very unusually warm levels more reminiscent of high temperatures
for this time of the year. Lows will only be in the 30s to lower
40s, so there will continue to be a bit of melting of the snowpack
overnight.
Monday...The Northland will see a surge of moisture amidst the
very unusually warm southerly flow ahead of an approaching cool
front and potent upper-level trough from the west. The
precipitable water values will increase to around 1 inches, quite
high for overall atmospheric moisture for this time of the year. A
period of deep saturation and rain will develop as falling
heights and a 100 to 120 knot jet streak develop substantial
atmospheric lift across the Northland. Strong south-southwesterly
flow aloft, combined with embedded shortwaves in the southerly
flow, could develop isolated, elevated thunder across parts of the
forecast area, primarily the southern half of the forecast area.
Several models have up to a couple hundred J/kg of MUCAPE,
including the GFS, SREF, NAM, and regional Canadian. The storms
would likely be relatively weak, mainly just providing some
rumbles of the thunder. There will likely be widespread rainfall
of 0.25" to 0.5" and isolated areas could get quite a bit more,
all depending on the track of and/or training of any heavier
showers or storms. The melting snow, combined with the rain and
difficulty any rain will have penetrating the relatively frozen
ground, will likely contribute to ponding on low-lying roadways.
Monday Night...There could be lingering showers across the
Arrowhead and northwest Wisconsin in the early evening, but cooler
and drier air will filter into the Northland amidst the westerly
flow in the wake of the cool front. Lows will likely be in the low
to middle 30s.
.LONG TERM...(Tuesday through Sunday)
Issued at 342 PM CST Sun Feb 19 2017
A rain/snow mix is possible for much of the Northland Tuesday
evening and Wednesday and then a significant storm system takes
aim on the region Thursday night through early Saturday morning.
Quasi-zonal flow expected to return behind the departing occluded
system Tuesday morning. A weak shortwave trough is forecast to
scoot across far northern Minnesota during the day increasing
cloud cover across the Northland. The lack of moisture behind
Monday night`s cold front will keep the risk of precipitation low.
Cloud cover will increase Tuesday night as a clipper system moves
out of the northern Rockies into the Dakotas and southern
Canadian Prairies. A compact shortwave trough and a slug of
Pacific moisture will raise the potential for a rain/snow mix
across much of the Northland. The best chance of precipitation
continues to be focused over the northern half of our CWA. Raised
QPF amounts with this forecast. Precipitation will begin as light
snow and change to rain Wednesday morning. Even with the higher
QPF, we are only carrying one-half up to an inch of snow
accumulation in our northern tier of zones. Temperatures will
trend cooler on Wednesday, and especially Thursday, behind the
clipper. Even with the surge of cooler air however, temperatures
will be closer to, but still above, normal.
Focus then shifts to the Thursday night through early Saturday
morning time period. A significant trough will dig into the
western CONUS Wednesday night and emerge over the Central Plains
Thursday morning. The quasi-zonal pattern over the Upper Midwest
will quickly shift to a southwest flow regime ahead of the
approaching trough. Baja Pacific and Gulf moisture will stream
northward into the Mississippi River Valley ahead of the
approaching low, setting the stage for a potent storm system to
affect the region late this week. The surface low is forecast to
track from southwest Colorado Thursday morning to somewhere in the
Great Lakes and eastern Canada by Saturday morning. Deterministic
solutions diverge considerably in handling this system with the
ECMWF moving the surface low to near James Bay by Saturday
morning, while the GFS low is centered over southern Ontario, and
the GEM farther west over Upper Michigan. Ensemble members feature
a wide envelope of solutions, too. Continued to lean on the
consensus for now, which brings accumulating snow to an area from
Lake Mille Lacs to the Twin Ports and all of northwest Wisconsin.
Snow will move northeastward into central Minnesota and east-
central Wisconsin late Thursday night or early Friday morning and
spread across all but far northwestern portions of our CWA by noon
Friday. The highest confidence continues to focus east of the
I-35 corridor and across all of northwest Wisconsin. Snow will
slowly diminish late Friday night and early Saturday. There is a
potential for a period of lake effect snow over snowbelt areas of
northwest Wisconsin through Saturday night.
With considerable uncertainty regarding the track and intensity
of this system, confidence in snow amounts is low, other than the
expectation that measurable to plowable snow seems likely for
portions of Minnesota and Wisconsin. Anyone with travel plans late
this week is encouraged to keep up with the latest forecast as
details become clearer.
High pressure will build into the Northland Saturday afternoon
and winds will veer northwesterly behind the departing storm. The
fresh snow pack and northerly breezes will bring near to below
normal temperatures back to the area Saturday and Saturday night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 558 PM CST Sun Feb 19 2017
VFR conditions were occurring across the Northland with mid and
upper level clouds covering most areas. There are some light
showers over parts of northern Minnesota that will continue into
the evening before moving north of the International Border.
Confidence in stratus development later tonight into Monday is
higher than the past few days. The RAP was doing a decent job
depicting the MVFR/IFR ceilings over OK and forecasts those to
lift north and east tonight on a strong low level jet. We have at
least a chance for these ceilings into most TAF sites late tonight
with them becoming prevailing through the day Monday. Some light
rain or drizzle will be possible late tonight with the
coverage/intensity increasing through the morning into the
afternoon. A few thunderstorms will also be possible as CAPE
increases late tonight into Monday.
The low level jet will also create non-convective low level wind
shear for most areas into at least Monday morning.
&&
.CLIMATE...
Issued at 937 AM CST Sun Feb 19 2017
For record highs and record warmest low temperatures for Duluth
and International Falls, please see the Public Information
Statement (PNSDLH) issued by our office this morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 37 49 33 50 / 10 90 60 0
INL 37 48 32 46 / 20 90 50 0
BRD 44 54 33 54 / 10 80 0 10
HYR 41 53 35 54 / 0 90 70 0
ASX 37 53 37 54 / 10 80 60 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
UPDATE...Melde
SHORT TERM...Grochocinski
LONG TERM...Huyck
AVIATION...Melde
Area Forecast Discussion
National Weather Service Grand Junction CO
605 PM MST Sun Feb 19 2017
.UPDATE...
Issued at 602 PM MST Sun Feb 19 2017
The Winter Weather Advisory for the San Juan Mountains has been
allowed to expire. Please keep in mind that lingering snow showers
are anticipated through this evening with locally up to 2 inches
of additional snow fall possible for the San Juans. The Winter
Weather Advisory for the Central Colorado Mountains remains in
effect through 7 AM MST Monday morning.
&&
.SHORT TERM...(Tonight through Monday night)
Issued at 349 PM MST Sun Feb 19 2017
The closed low bringing the clouds, rain and snow continues to
open this afternoon and will become an open wave/trough by later
this evening. There is hardly any change to forecast thinking as
plenty of moisture remains in the atmosphere and continues to be
worked on by the trough as it moves through. Widespread
precipitation is being reported across the CWA with snow at higher
elevations and rain at lower elevations. Snow levels vary across
the area but 9,000 feet still looks good for the going advisories
which continue at this time. The NAM continues to show the trough
syncing up with another wave well to our north later tonight. When
this occurs, winds will become northwesterly and precipitation
will pick up especially over favored northwest facing slopes
ending by daybreak. Do have some concern that advisories for San
Juans may end too soon (6PM) this evening and may need to be
extended as latest guidance does keep some precip going through
tonight. However, HRRR and RAP not too enthusiastic about this
precip. Either way, next shift will need to keep an eye on precip
and where focus sets up. Also, a few lightning strikes were
reported in Cortez which makes sense as instability from the low
pressure aloft caused some low top thunderstorms. Included the
chance of storms for southern valleys through the rest of the
afternoon for the off-chance a few more pop-up.
The rest of the forecast area will see showery precipitation
through this evening and overnight with plenty of clouds hanging
around. These clouds will moderate temps somewhat keeping lows a
little bit warmer than yesterday. Expect some areas of patchy fog
to form overnight in those normally fog-prone areas, too, thanks
to increased moisture from today`s precipitation.
On Monday, clearing conditions will kick in as the trough shifts
well to our east. Partly cloudy skies are expected with partly to
mostly cloudy skies for the mountains. The jet stream then becomes
oriented from the southwest to northeast over the Intermountain
West. Little ripples of energy will work through the jet stream
bringing plenty of rain and snow to central and northern
California up through Nevada and into Idaho while we stay just to
the southeast of this precipitation. A few showers are not out of
the question, especially for the Uintahs and our far northern
zones, but with most support to our northwest, little
precipitation is expected. No big swings in temperature either so
similar highs and lows remain in the forecast.
.LONG TERM...(Tuesday through Saturday night)
Issued at 349 PM MST Sun Feb 19 2017
The jet stream starts dropping southward Monday night into Tuesday
as a trough starts digging down from the Gulf of Alaska. As the
jet starts dropping, some showers are possible over the highest
terrain though no appreciable accumulation is expected. These
showers will start forming Tuesday and persist through Wednesday.
Again, these look to be more nuisance showers than anything of
much consequence. As the base of the trough drops down to central
California, an area of deformation looks to set up over central
Nevada through Utah and into our northern valleys. This
deformation looks to persist Wednesday afternoon through Thursday
morning when the trough finally moves through during the day. Once
it moves through, light precipitation will persist into Friday. As
this is occurring, a deep area of low pressure will be dropping
down the West Coast. As it does so, the low will eject a short
wave that will bring a reinforcing shot of rain and snow for the
central and northern mountains late Friday night into Saturday
morning. Like the last disturbance, once the short wave moves on
showery precip looks to continue through Saturday.
So Monday through Wednesday look to be the nicest days this week
with more widespread precipitation moving in Thursday and beyond.
Temperatures will run warm through the same timeframe and then
dropping to at or below normal to end out the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 523 PM MST Sun Feb 19 2017
A storm system continues to pass over the forecast area this
evening, supporting MVFR conditions and lingering shower activity.
This storm system should exit the area around midnight bringing an
end to shower activity. Once the system exits the area mid and
high clouds will scatter out but low clouds and fog will become a
possibility through roughly 1500Z at most terminals. VFR is
anticipated at all terminals on Monday.
Forecast confidence is moderate tonight and high tomorrow.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Winter Weather Advisory until 7 AM MST Monday for COZ009-010-012-
013.
UT...None.
&&
$$
UPDATE...Larry
SHORT TERM...TGR
LONG TERM...TGR
AVIATION...Larry
Area Forecast Discussion
National Weather Service Houston/Galveston TX
543 PM CST Sun Feb 19 2017
.AVIATION...
Not too many changes to the TAFs for the 00z package. Primary
short term issue will be lowering cigs, and possibly some sea fog
at the coast. Later tonight we`ll be keeping a close eye on
evolution of storms expected to organize into a line west of the
region and then move into SE Tx after 8z. Latest HRRR runs are a
bit faster with timing of the line & closer to what the Tx Tech
WRF has been depicting. (maybe leading edge CLL 8-10z, UTS/CXO
10-12z, IAH/SGR 11-13z, HOU/LBX 12-14z, & GLS >14z). We`ll watch
trends and update for timing best we can, but there is uncertainty
with a lot of variables in play. Will likely see the heaviest
rain along the leading band, but possibility for steady moderate
rains for several hours in its wake are expected as well. Should
see slowly improving conditions later in the afternoon. 47
&&
.PREV DISCUSSION... /ISSUED 250 PM CST Sun Feb 19 2017/
Cloud cover starting to break up this afternoon with some mixing.
Where we are seeing the sun, temps have already made it to the
upper 70s, so SE areas will likely see some 80 degree temps this
aft. It is breezy and very humid as well for Feb with sfc dw pts
in the mid/upper 60s areawide.
Model guidance is in fairly good agreement that widespread showers
and storms will develop early this eve well west of SE TX across
central/north TX ahead of a slow eastward moving longwave
mid/upper level trough. Meso models show that an area of showers
and storms will develop out ahead of this main precip. band across
western portions of Se Texas just after midnight and this lead
band will be a slow mover across our W/NW areas during the early
morning hours. With PW values peaking around 1.8 inches Mon
morning, and upper level divergence increasing Mon morning as well
as a split jet structure develops, key parameters are in place
for heavy rainfall. The fairly unidirectional s/sw flow in the
low-mid layers of the atmosphere points to the possibility of
cell training in this very moist airmass. Think this all equates
to widespread 1 to 3 inches late tonight and tomorrow as well as
the threat for localized 4 to 6 amounts. Given that the ground is
fairly moist from previous rainfall, have issued a flash flood
watch for most of SE TX beginning during the early morning hours
on Mon and continuing through most of the aft.
The heavy rainfall threat should end by the eve hours. A trailing
mid/upper low that hangs around on Tue and this feature will
extend the chc of showers into Tues, but no heavy rainfall is
expected with this feature. Dry conditions with above normal
temperatures are expected on Wednesday and Thursday. A cold front
will move through on Friday aft/eve and bring a brief cooler
airmass to the region early next weekend. 33
MARINE...
Southeasterly flow very slow to come up this afternoon. Throughout
the evening hours expect winds to increase and will continue with
the SCEC for winds increasing to 15-20 knots...lighter in the bays.
Moisture still rich but with shorter residency over the warming
shelf waters and more mixing expect fog to be lighter throughout the
night with areas from around Freeport to Galveston probably dropping
to 1 to 3 miles. Will hold off on a Marine Dense Fog Advisory as it
isn`t as clear cut as last night. Seas building to 5 to 6 feet
toward morning. Storms will move in from the west and will be
capable of gusty conditions and significant reduction in visibility
in heavy downpours. Shear is a little higher over the southwest
waters between midnight and 8 am and will have to keep an eye out
for fast moving spinners/waterspouts over the far waters. Pacific
cold front eventually pushes through Monday night with a gusty
northwesterly winds probably below SCEC. Another Pacific cold front
late Friday may boost offshore winds to SCEC for Saturday morning.
Long southeasterly fetch develops Sunday and may see a period of
elevated seas/tides/sea fog late Sunday through Tuesday.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 64 72 57 76 55 / 90 70 10 20 10
Houston (IAH) 69 72 61 76 59 / 80 100 30 30 10
Galveston (GLS) 68 70 63 72 62 / 60 90 50 30 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Flash Flood Watch from 3 AM CST Monday through Monday afternoon
for the following zones: Austin...Brazoria...Brazos...
Burleson...Chambers...Colorado...Fort Bend...Galveston...
Grimes...Harris...Jackson...Liberty...Madison...Matagorda...
Montgomery...San Jacinto...Walker...Waller...Washington...
Wharton.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION through late tonight for the
following zones: Coastal waters from Freeport to the
Matagorda Ship Channel out 20 NM...Coastal waters from High
Island to Freeport out 20 NM...Waters from Freeport to the
Matagorda Ship Channel from 20 to 60 NM...Waters from High
Island to Freeport from 20 to 60 NM.
&&
$$
Area Forecast Discussion
National Weather Service Lincoln IL
842 PM CST Sun Feb 19 2017
.UPDATE...
Issued at 835 PM CST Sun Feb 19 2017
Latest surface map indicating the weak area of high pressure that
pushed across central Illinois today has shifted off to our east
this evening. This has allowed a southeasterly flow to develop over
the forecast area which should help keep overnight lows from dropping
too far tonight. That coupled with a large area of cirrus tracking
across the Midwest this evening should also keep the temperatures
up most of the night. The main forecast concern will be another night
with fog overspreading the area from the south. Already seeing
visibilities dropping off to a quarter mile in a few locations over
southeast Illinois and expect that trend to continue to shift north
and northwest late this evening into the early morning hours.
Hard to beat how well the RAP and HRRR did with the stratus and
fog last night and both of these models through much of today have
been advertising a large band of low clouds and fog tracking north
and northwest tonight again. Two negative factors for widespread
fog that has us a bit concerned about going too far west and north
with any advisory are the extensive high clouds and then a
southeasterly wind that is expected to hold between 5 and 10 mph
overnight. Forecast soundings continue to show quite a low level
inversion in place through the night with the boundary layer wind
fields more east to southeast bringing the stratus and fog more
northwest into our forecast area, similar to what the high
resolution models have been advertising for quite some time. As a
result, we will be needing a Dense Fog Advisory soon for far
southeast and east central Illinois and then wait to see how far
west and north to take it later tonight.
Have already sent an updated ZFP out to address the widespread
fog starting to develop in the southeast early this evening. Once
we have determined the areal extent of any advsiory, we will have
an additional ZFP update later this evening.
&&
.SHORT TERM...(This evening through Monday)
ISSUED AT 312 PM CST Sun Feb 19 2017
Dry weather will continue tonight as a weak weather system
develops to the west and moves toward the area for tomorrow. Fog
will be an issue again tonight as there has not been any change in
airmass since this morning and the HiRes models continue to
forecast fog across the area. Will have patchy fog in the west
with areas of fog in the west. Fog will also linger into the
morning hours. Fog could become dense again, but hoping enough
mixing has taken place today to keep visibilities from going as
low as they did this morning. So advisory is not being issued at
this time. Models in good agreement on timing of precip with all
models suggesting that all precip will remain west of the I-55
through afternoon. However, some showers could be possible east of
I-55 during the late afternoon as the system moves into the state.
Temps during the day Monday will remain well above normal, with
records again possible.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 312 PM CST Sun Feb 19 2017
Models are in very good agreement with the bulk of the precipitation
coming into the CWA Monday night and then being out of the area by
Tuesday afternoon. System is not very strong and looks like a simple
front/mid level wave coming through, so most of the precipitation
will be showers. However, very warm temps and an increase in
moisture means that some isolated thunderstorms will not be out of
the question. By Tuesday morning, most of the precip will have moved
off to the east with only the eastern part of the CWA left with come
lingering showers. By Tue afternoon, all the precip will be out of
the area and well east of the state.
Dry and warm weather will return for Tue night through Wed night as
the CWA sits in a some-what zonal flow. This flow will keep the area
in a very warm airmass for middle of the week and into the latter
part of the week.
Then another system will be developing in the southwest US and move
out into the plains Thur into Thur night. Models are in agreement
that this will be occurring but differ on timing and location of the
weather and surface features, including a warm front. The Canadian
has the warm front further south than the GFS and ECMWF and with
such warm air we have been having the last week, believe Canadian
too far south and am more inclined to side with the other two
models. This system will also be deepening some as it moves out of
the southern plains. There should be plenty of moisture and with
dynamics increasing, showers and thunderstorms appear likely,
especially in the warm sector and probably along the developing warm
front. Current forecast models indicate the timing of the front
through the CWA could be late enough that the best instability and
dynamics would be in eastern IL Fri afternoon, then pushing east
into Indiana for Friday evening. This is 5-6 days out and lots could
change between now and then. However, believe showers and storms
warranted in the forecast for Thur night and Fri across the CWA. As
the system lifts northeast into the Great Lakes region Fri night,
showers will linger in the east with any wrap around precip being
north of the CWA.
Dry weather then returns for a brief period for Sat and Sat night
and temps will drop to slightly below normal for Sat during the day
and also that night. However, this cool down will be very short
lived as warm temps will quickly return for next Sunday. A weak wave
will lift northeast across northwest IL and some precip is possible
in northwest part of the CWA during the day.
Temps will remain above normal through most of the week, but then
cool briefly for Sat and Sat night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 505 PM CST Sun Feb 19 2017
Fog with LIFR/VLIFR conditions expected to overspread the area
from south to north this evening roughly in the 03z-06z time
frame. Low clouds and fog/hz late this afternoon were confined to
areas south of our TAF sites. However, after sunset we should see
the fog start to develop and then expand across the forecast area.
The fog will slowly lift after 15z on Monday as increasing
southerly winds ahead of our next storm system develop across the
area. The stratus deck looks to improve only to MVFR category by
afternoon. The winds tonight will be southeast at 5 to 10 kts and
then southeast winds will increase on Monday to between 12 and 17
kts with a few gusts up to 23 kts possible in the afternoon.
&&
.CLIMATE...
Issued at 312 PM CST Sun Feb 19 2017
Record Highs / Record Warm Lows - Sunday Feb 19th...
Peoria........ 71 / 50
Lincoln....... 71 / 46
Springfield... 70 / 54
Champaign..... 68 / 46
Bloomington... 70 / 47
Decatur....... 66 / 48
Danville...... 70 / 54
Galesburg..... 63 / 52
Charleston.... 72 / 53
Effingham..... 70 / 45
Record Highs / Record Warm Lows - Monday Feb 20th...
Peoria........ 68 / 46
Lincoln....... 70 / 46
Springfield... 74 / 46
Champaign..... 71 / 45
Bloomington... 67 / 45
Decatur....... 70 / 47
Danville...... 70 / 48
Galesburg..... 64 / 41
Charleston.... 73 / 48
Effingham..... 68 / 54
Record Highs / Record Warm Lows - Tuesday Feb 21st...
Peoria........ 69 / 46
Lincoln....... 69 / 45
Springfield... 69 / 48
Champaign..... 67 / 47
Bloomington... 69 / 46
Decatur....... 68 / 48
Danville...... 67 / 50
Galesburg..... 68 / 40
Charleston.... 71 / 52
Effingham..... 73 / 52
Record Highs / Record Warm Lows - Wednesday Feb 22nd...
Peoria........ 71 / 51
Lincoln....... 71 / 52
Springfield... 71 / 53
Champaign..... 69 / 49
Bloomington... 70 / 53
Decatur....... 72 / 51
Danville...... 71 / 54
Galesburg..... 61 / 45
Charleston.... 71 / 52
Effingham..... 74 / 55
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...HJS
LONG TERM...Auten
AVIATION...Smith
CLIMATE...Auten
Area Forecast Discussion
National Weather Service Northern Indiana
629 PM EST Sun Feb 19 2017
.SYNOPSIS...
Issued at 100 PM EST Sun Feb 19 2017
Unseasonably mild conditions will continue through much of the
upcoming week. Weak winds associated with a departing ridge of
high pressure will likely lead to fog formation once again
tonight, with a potential of some dense fog late tonight into
early Monday morning. Dry conditions will continue through Monday
afternoon, but rain will become likely Monday night into early
Tuesday. There is another chance of rain Wednesday night as a
system tracks north of the area, but the greater chance of showers
and a few thunderstorms is expected by Thursday night and Friday
as a stronger storm system takes shape across the middle of the
country. Wednesday is expected to be the warmest day of the week,
with highs reaching into the 65 to 70 degree range. Low
temperatures tonight will range from the mid 30s to lower 40s.
High temperatures on Monday will range from the mid to upper 60s
across northwest Indiana, to the mid to upper 50s across south
central lower Michigan.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 254 PM EST Sun Feb 19 2017
Areas of fog were able to form in a shallow cold layer with
overnight radiation last night. There should be a similar situation
tonight with fog reforming over at least the southwest half of the
forecast area in light return flow. The HRRR appears to have a good
handle on this scenario. Otherwise, the mild pattern will continue
with lows tonight staying above freezing. Highs Monday should be in
the 60s, except possibly of over far northeast areas. Highs Monday
should be well above normal in the 60s again and approach the
records of 67 at Ft Wayne and 65 at South Bend.
&&
.LONG TERM...(Monday Night through Sunday)
Issued at 254 PM EST Sun Feb 19 2017
The unseasonably mild pattern will persist through most of the
upcoming week with highs well above normal as the long wave upper
trof persists over western North America. A leading short wave was
near the Four Corners area this afternoon and has moved out of the
main long wave trof. This system will move east and should reach the
forecast area Monday night and spread showers over the area into
Tuesday. The GFS and ECMWF are still in good agreement with the
timing of this system along with the Canadian GEM suggesting the
best chance for rain Monday night and early Tuesday. Otherwise,
there will be a little break in the rain Tuesday night and Wednesday
before a stronger system reaches the area Thursday and Friday. The
Storm Prediction Center has already placed part of the forecast area
in the Day 6 severe weather outlook. Several factors were coming
together for the chance for severe storms including the advection of
an elevated mixed layer. Kept thunder in Thursday night and Friday.
Temperatures should still be mild into Friday, but then turn much
colder Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 623 PM EST Sun Feb 19 2017
Stayed with previous TAF idea of fog/stratus development overnight
with some minor adjustments to timing per latest hires guidance.
HRRR handled fog/stratus well last night and appears to have
handle on residual stratus over OH valley late this afternoon.
Followed this model rather closely which is in line with previous
TAFs. Latest guidance is a bit slower to bring in lower VIS and
CIGs from the south and trended a little later. Latest Consensus
Short model has trended a bit further south with northern extent
and keeps the lowest Cigs and VIS just south of terminals but
still very close. Expect mixing by late morning to help dissipate
morning clouds and fog with VFR by afternoon.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Marsili
SHORT TERM...Skipper
LONG TERM...Skipper
AVIATION...Lashley
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AREA FORECAST DISCUSSION
National Weather Service Jackson KY
653 PM EST Sun Feb 19 2017
.UPDATE...
Issued at 653 PM EST SUN FEB 19 2017
Narrow band of clouds continue to hold on just north of the I-64
corridor. While the erosion of the clouds has slowed some with
sunset, the subsidence building into the region should help to
gradually erode the remainder of the clouds as the night goes on.
Something to note is that we have a nice boundary showing up on
JKL radar this evening associated with the differential
temperature boundary from the cooler/cloudy areas in the north
today to the areas that cleared out to the south. This boundary
appears to be sagging southward towards our office. Behind the
boundary, valley locations have already reached the upper 40s. We
should see a sharp fall continue with temperatures in the valleys
this evening. MOS guidance is supporting some mid 30s and based
on current conditions, this doesn`t seem that unrealistic. Thus,
will drop the valley locations a bit colder tonight. Regardless,
temperatures will fall well under cross over temperatures, setting
up a good night of radiational fog. Current forecast has this
covered well. Also tweaked sky cover down overnight. Outside of
the clouds in the north early on, probably only dealing with some
high clouds moving in late tonight.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 335 PM EST SUN FEB 19 2017
19z sfc analysis shows high pressure moving over Kentucky. While
rather weak it has mustered enough strength to start the clearing
process through the southern two thirds of the CWA. With the
returning sunshine temperatures have rebounded into the lower 60s
in the south but still are in the low 50s under the clouds for
locations north of Interstate 64. Dewpoints, meanwhile, have held
rather steady in the mid and upper 40s along with light and
variable winds. Look for the ceilings continue to erode into the
early evening with most places seeing clear skies through sunset.
The models are in good agreement aloft through the short term
portion of the forecast. They all depict a strong ridge passing
over Kentucky and the Deep South tonight through Monday in advance
of a full latitude trough crossing thr Rockies. This trough starts
to split apart later Monday night with the southern portion
closing off as it exits into the western Gulf. Meanwhile, the
northern portion pushes quickly into the Great Lakes stretching
the energy with this trough. Some of that energy will look to ride
over eastern Kentucky early Tuesday ahead of the main trough axis.
Given the decent agreement among the models have favored a
general blend with a significant lean toward the higher
resolution HRRR and NAM12 in the near term.
Sensible weather will feature mostly clear skies to start the
night leading to good radiational cooling. With the fairly high
low level moisture in place we will likely see fog develop rather
early in the night in the valleys and spread through much of the
CWA - becoming dense late - particularly in the valleys. Have hit
this in the grids (and TAFs) and will highlight it in the
forthcoming HWO. Later shifts will need to monitor cloud cover and
vsby changes tonight for a possible SPS or Dense Fog NPW. The fog
will burn off quickly Monday morning with a very warm day on tap
ahead of the slowly approaching cold front. For Monday night, the
front starts to move into the state, but likely remain too far
west through dawn for any significant rain chances. Will also
apply some patchy fog to the valleys early Tuesday under
increasing and thickening high clouds.
Used the CONSShort and ShortBlend as the starting point for the
grids through the short term portion of the forecast. Did make
some adjustments to temperatures each night to account for a small
ridge to valley difference tonight and a bit larger one tomorrow
night. As for PoPs, kept them as initialized with no impact
expected before 12z Tuesday.
.LONG TERM...(Tuesday through Sunday)
Issued at 330 PM EST SUN FEB 19 2017
The extended portion of the forecast will begin on Tuesday with an
active and progressive pattern setting up. At this time, the main
features of concern will be a wave tracking across the northern
CONUS as well as another low tracking over the lower MS Valley
undercutting the upper level ridge along the Front Range. During this
time, eastern Kentucky falls in between the bulk of the forcing of
these two features leading to a bit less QPF over the area,
especially as it seems this boundary passing through the area begins
to shear out by Wednesday morning. The super blend seems to hint at
some lingering moisture behind this feature but with the new 12z
Euro showing no indication, will leave pops out on Wednesday.
By Thursday, a vigorous low ejects from the Front Range and into the
central Plains as strong southerly flow develops just east of the MS
River. Model profile indicate some good instability developing with
the formation of the warm front on Thursday and into Thursday night.
Therefore have introduced some thunder into the forecast during this
period. By Friday morning, the warm front has lifted north of the
area putting eastern Kentucky firmly in the warm sector. In fact,
expect highs to reach into the lower 70s across the area. For this
period, some of the best baroclinicity develops that has not been
seen for a few weeks. Model profiles indicate a renewal of some good
instability with the developed cold front. Have indicated some
thunder for late Friday and into Friday night as well. While severe
convection is still a low chance for eastern Kentucky, it is worth
noting that SPC has highlighted a slight severe chance in central
Kentucky for the Friday period.
After passage of the most significant cold front not seen in a few
weeks, temps on Saturday morning and into the day on Saturday will
either be slowly rising or steady through the day. At this point,
the bulk of the CAA is slow to enter the area with much of the
moisture exited by the time the colder air filters into the area.
While now apparent at this time, a post front would chance this
chance but it seems the profile dries and clears out after passage,
which also means for some of the coldest low temps of the
extended.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 653 PM EST SUN FEB 19 2017
Some MVFR cigs will hold on north near I-64 over the next hour or
two, before slowly eroding. Attention will then turn to fog
formation as we have fairly high cross over temperatures. This
will allow for an earlier onset of fog than normal late this
evening. This will allow the fog to become dense in the valleys
overnight. The fog may try to creep onto some of the ridges around
daybreak Monday, but confidence is somewhat low on this
potential. Fog will burn off Monday morning with VFR conditions
returning by 14z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...KAS
Area Forecast Discussion
National Weather Service Topeka KS
533 PM CST Sun Feb 19 2017
...AVIATION UPDATE...
.SHORT TERM...(This evening through Monday)
Issued at 121 PM CST Sun Feb 19 2017
The primary issue in the very short term is the impact of an area
of low cloud cover on near term temperatures. This stratus deck
has been advancing northeast while also eroding from the sides. It
has not been particularly deep but has been deep enough to limit
sunshine and keep temperatures cooler. On the other hand, as it
continues to advance it will keep temperatures warmer overnight.
Precipitation chances become the focus after 9 PM as an elongated
neutral-tilt upper trough is moving across the plains. Upper flow
overhead is quite meridional with ample deep moisture advection
into the region. Several short wave troughs were moving toward the
NNE out of the main longer wave trough. One of particular interest
was evident over the Big Bend region of TX in WV imagery. This
appears that it may be the first piece of lead energy to provide
focused ascent for precipitation locally. Model guidance has
generally increased the expectation for precipitation late this
evening into early Monday largely tied to the trajectory of this
energy. Hi-Res guidance such as recent runs of the HRRR and RAP
support the larger-scale model theme, and seem to focus the
optimal timing for precip in the local forecast area between
midnight and 8 AM with a gradual SW to NE precip transition. There
is some potential to linger a bit longer in the far east as the
upper trough slowly moves east and another slight chance for
precip mainly in far northern KS late in the day as the surface
front eventually moves into the area.
PWAT values are forecast to flirt with record values for this time
of year with some forecast values approaching 1.3-1.5". There
should also be some modest elevated instability, and the
combination of the two features may allow for a few areas of
decent rainfall to materialize. Duration will not be very long
with the progressive waves of energy, but wouldn`t be surprised to
see precip amounts range from very light in north central KS to
potentially a half inch or more where better convection develops.
.LONG TERM...(Monday night through Sunday)
Issued at 121 PM CST Sun Feb 19 2017
Conditions will dry out for Monday night through Thursday morning.
Expect quite a bit of sunshine through Tues/Wed with dry air just
above the boundary layer likely to mix to the surface. Similar
conditions in recent days have led to warmer and drier than
expected conditions so at this time have been forecasting a bit
warmer and a bit drier but will want to monitor for any potential
to go warmer and drier yet. Luckily wind speeds are unlikely to
exceed 20 mph either day so explosive fire conditions are
unlikely although MinRH could fall below 20% each day.
On Thursday, model agreement is still strong in a strong jet
streak crossing into KS with surface cyclogenesis in southeast
Colorado. Expect a strengthening frontal zone to extend across
northern KS by late Thursday with cold air being pulled into north
central KS by Thursday evening. Guidance remains split on how soon
and how impressive the intensification of the upper low will be
but the overall message remains generally the same. Expect windy
conditions with the strengthening surface low, and continue to
see decent potential for snow over mainly northern KS northwest
of a Minneapolis to Clay Center to Marysville line but this could
obviously change substantially between now and the end of next
week. If snow develops, some accumulation is possible but expect a
sharp gradient in accumulation and could very well end up nearly
snowless especially with the warm ground temperatures.
Colder air overtakes the entire region for the weekend, but even
while it is much colder than the current airmass it will still be
fairly close to normal values. Another very weak system will bring
precip chances for Sunday with rain or snow possible, and the
active weather pattern looks to continue into the following week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday)
Issued at 533 PM CST Sun Feb 19 2017
Models are in good agreement with the good surge of moisture
moving across eastern KS along with some PVA. Forecast soundings
even show around 500 J/kg of elevated instability overnight. With
the moisture advecting northeast, MVFR CIGS are expected to return
along with some 3SM to 5SM BR. Timing of this is a blend of
available guidance and the timing of the precip is based largely
off the HRRR. By Monday afternoon, models push the deep moisture
axis east of the area and shift winds more to the southwest. This
should allow for the low level moisture to scour out and conditions
to improve to VFR.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Barjenbruch
AVIATION...Wolters